Couple questions about bike tires

Dan Musicant said:

Every bike I remember owning had 27 x 1.25 inch tires. When my old Shwinn Continental frame broke
almost 5 years ago I bought another used

I thought those Continental frames were nuke proof.

Quoted message said:

I had a blowout a couple days ago. I was at elevation and noticed some bumping and saw a z-jag in
my back tire and took it REAL slow down the descent. I got to pretty flat elevation before the
tire unexpectedly blew out with what sounded like a gun shot. I just hopped off the bike, locked
it, and walked the rest of the way and came back and got it with my car later.

Was there a hole in the tire, or did it just blow off the rim? If it's the latter, it may not
have been seated properly on the rim. How much pressure did you have in it? Do your rims have a
hook bead? Also, your hard braking on the descent could have heated the rims, causing the
pressure to increase.

Quoted message said:

That tire was not on that bike more than about a month. It was one of several cheap tires I bought
a few years ago and they seem to have all gotten stiff, somewhat brittle and even crumbly just
sitting around. Does this always happen with bike tires? You can't buy them and store them without
them going bad? Is there something you can do to protect them, like an application of Armor All?

Keep the tires away from sunlight and ozone. Store them in a plastic bag in a cool dry place and
they'll last for years.

Quoted message said:

Another question I have is this: The place where I bought my used Miyata said they could convert
it to a 700cc bike to use the now common tire. I assume that there's a whole lot more available in
the 700 size, right?

There are plenty of good 27 x 1-1/4" tires. Try the IRC Road Winners at about $13.

Art Harris

On Fri, 18 Jul 2003 15:29:28 GMT, "Harris" <[email hidden]> wrote:

:
:"Dan Musicant" wrote:
:> Every bike I remember owning had 27 x 1.25 inch tires. When my old Shwinn Continental frame broke
:> almost 5 years ago I bought another used
:
:I thought those Continental frames were nuke proof.

One day I was commuting in the city and around 4 miles from home and I became aware that the down
tube had cracked and really all the way through right where it meets the bottom bracket. It was
tough getting home but I managed to do it, very slowly. It's almost 5 years so I don't remember it
well. I brought the frame to a local frame builder in the hopes that he could save it but he told me
to just get another bike, so I accepted the death of my old Continental. It was a heavy brute,
anyway, but I was so used to it that it felt like part of my body - like I had total control, like
it was part of my nervous system. I guess you get that way when you have one and only one bike for a
long period of time.
:
:> I had a blowout a couple days ago. I was at elevation and noticed some bumping and saw a z-jag in
:> my back tire and took it REAL slow down the descent. I got to pretty flat elevation before the
:> tire unexpectedly blew out with what sounded like a gun shot. I just hopped off the bike, locked
:> it, and walked the rest of the way and came back and got it with my car later.
:
:Was there a hole in the tire, or did it just blow off the rim? If it's the :latter, it may not
have been seated properly on the rim. How much pressure :did you have in it? Do your rims have a
hook bead? Also, your hard braking :on the descent could have heated the rims, causing the pressure
to increase.

It was really odd, actually. I saw an abrasion on the side of the tire before it blew. The abrasion
didn't go all the way through and I have no idea how it got there. After it blew I saw what looked
like a 2 inch gash in the center of the tire (where it meets the pavement), and longitudinal. There
was a tire liner just inside that gash and the liner looked fine - no hole or cut. The tube did not
protrude through the gash, as least not after the blowout. Inspecting the tube, I saw a hole it in
at least 1/4 inch in diameter and it was slightly town around that hole. It was about the weirdest
flat I've ever had because I couldn't figure out exactly what went on, what went wrong.

I had inflated the tire to 75 lb (the recommended inflation) a few days before, so it was probably
around 70 - 75 lb. when I noticed the bumps, and at that point I let a little air out to decrease
the possibility of a blowout, but probably not enough (that was my thought at the time, that I
should maybe let a little more out). I didn't have a guage with me, although I did have a pump. I
didn't want to have to pump more air into it and just let it be. It was probably around 65 - 68 lb.
when it blew.

It didn't blow off the rim. True, the braking on the descent probably increased the pressure. I
wouldn't have thought of that.
:
:> That tire was not on that bike more than about a month. It was one of several cheap tires I
:> bought a few years ago and they seem to have all gotten stiff, somewhat brittle and even crumbly
:> just sitting around. Does this always happen with bike tires? You can't buy them and store them
:> without them going bad? Is there something you can do to protect them, like an application of
:> Armor All?
:
:Keep the tires away from sunlight and ozone. Store them in a plastic bag in :a cool dry place and
they'll last for years.

I guess I'd need pretty big bags to store bike tires in or do you fold the tires?

I don't know why, but all my old tires seem to get stiff and crumbly after not too long.
:
:> Another question I have is this: The place where I bought my used Miyata said they could convert
:> it to a 700cc bike to use the now common tire. I assume that there's a whole lot more available
:> in the 700 size, right?
:
:There are plenty of good 27 x 1-1/4" tires. Try the IRC Road Winners at :about $13.
:
:Art Harris

Thanks for the suggestion. I'll see if I can find them. Can I get them online? There are a number of
bike shops around here and maybe I'll be able to find them there.

I'm way more concerned about having good tires now that I make that descent every day. Normally I'm
very secure on a bike even in the city since I have a whole lot of city biking experience and I've
learned to stay out of trouble. But I can't think of any way to go down that road without being
nervous unless I go 4 miles/hour. The more I do it, the more secure I feel going 20+ mph even in the
steepest parts (I've seen guys going 10-15 mph faster than me!), but I figure I could get messed up
royally if one of my tires blows, especially the front one.

Thanks for the ideas.

Dan

In article <[email hidden]>, [email hidden] says...

Quoted message said:

On Fri, 18 Jul 2003 15:29:28 GMT, "Harris" <[email hidden]> wrote:

:
:"Dan Musicant" wrote:
:> Every bike I remember owning had 27 x 1.25 inch tires. When my old Shwinn Continental frame
:> broke almost 5 years ago I bought another used
:
:I thought those Continental frames were nuke proof.

One day I was commuting in the city and around 4 miles from home and I became aware that the down
tube had cracked and really all the way through right where it meets the bottom bracket. It was
tough getting home but I managed to do it, very slowly. It's almost 5 years so I don't remember it
well. I brought the frame to a local frame builder in the hopes that he could save it but he told
me to just get another bike, so I accepted the death of my old Continental. It was a heavy brute,
anyway, but I was so used to it that it felt like part of my body - like I had total control, like
it was part of my nervous system. I guess you get that way when you have one and only one bike for
a long period of time.
:
:> I had a blowout a couple days ago. I was at elevation and noticed some bumping and saw a z-jag
:> in my back tire and took it REAL slow down the descent. I got to pretty flat elevation before
:> the tire unexpectedly blew out with what sounded like a gun shot. I just hopped off the bike,
:> locked it, and walked the rest of the way and came back and got it with my car later.
:
:Was there a hole in the tire, or did it just blow off the rim? If it's the :latter, it may not
have been seated properly on the rim. How much pressure :did you have in it? Do your rims have a
hook bead? Also, your hard braking :on the descent could have heated the rims, causing the
pressure to increase.

It was really odd, actually. I saw an abrasion on the side of the tire before it blew. The
abrasion didn't go all the way through and I have no idea how it got there. After it blew I saw
what looked like a 2 inch gash in the center of the tire (where it meets the pavement), and
longitudinal. There was a tire liner just inside that gash and the liner looked fine - no hole or
cut. The tube did not protrude through the gash, as least not after the blowout. Inspecting the
tube, I saw a hole it in at least 1/4 inch in diameter and it was slightly town around that hole.
It was about the weirdest flat I've ever had because I couldn't figure out exactly what went on,
what went wrong.

I had inflated the tire to 75 lb (the recommended inflation) a few days before, so it was probably
around 70 - 75 lb. when I noticed the bumps, and at that point I let a little air out to decrease
the possibility of a blowout, but probably not enough (that was my thought at the time, that I
should maybe let a little more out). I didn't have a guage with me, although I did have a pump. I
didn't want to have to pump more air into it and just let it be. It was probably around 65 - 68
lb. when it blew.

It didn't blow off the rim. True, the braking on the descent probably increased the pressure. I
wouldn't have thought of that.
:
:> That tire was not on that bike more than about a month. It was one of several cheap tires I
:> bought a few years ago and they seem to have all gotten stiff, somewhat brittle and even
:> crumbly just sitting around. Does this always happen with bike tires? You can't buy them and
:> store them without them going bad? Is there something you can do to protect them, like an
:> application of Armor All?
:
:Keep the tires away from sunlight and ozone. Store them in a plastic bag in :a cool dry place and
they'll last for years.

I guess I'd need pretty big bags to store bike tires in or do you fold the tires?

Tires with Kevlar beads can be folded, but not ones with wire beads. Just use a garbage bag and put
all your spares in one bag.

--
David Kerber An optimist says "Good morning, Lord." While a pessimist says "Good Lord,
it's morning".

Remove the ns_ from the address before e-mailing.

Fri, 18 Jul 2003 19:15:57 GMT, <[email hidden]>, Dan Musicant

Quoted message said:

:Keep the tires away from sunlight and ozone. Store them in a plastic bag in :a cool dry place and
they'll last for years.

I guess I'd need pretty big bags to store bike tires in or do you fold the tires?

Wrap them in plastic food wrap or that stretchy plastic film used in warehouses.

I stored two pairs of tires for 15 years. Temperature was never extreme and they were kept in the
dark. One pair was wrapped in the original packing cellophane. One pair was bare. The wrapped pair
survived in good condition. The other pair had deteriorated.
--
zk

Fri, 18 Jul 2003 15:37:56 -0400, <[email hidden]>, archer

ns_archer1960@ns_hotmail.com said:

Tires with Kevlar beads can be folded, but not ones with wire beads.

Sure they can. I do it all the time carrying home new tires.

rideyourbike.comtirefold.htmlOpen ↗
--
zk

I have similar concerns. I'm a little more reckless, and do go to 35 mph and beyond, but I notice
that my Hutchinson Carbon Comp 700c X 23 tires, from 2001, have some cracking where the sidewall
meets the tread. They hold 125psi (their rated max, and the pressure I run) fine, and the only issue
I've had is a flat from going up a sharp curb too hard (the presta valve stopped holding air). I've
been trusting that the belt will hold them together, as well as the interior rubber and anything
else that's not cracked (just that exterior layer of rubber).

Should I replace these tires? If so, how can I maintain their condition better? I suspect a standard
commercially available rubber treatment for automotive tires should suffice.

Dan Musicant said:

blow by me at probably 35 miles/hour on the steepest part ( !! ) but it makes me shudder to think
what would happen to them if they had a flat or a blowout. I read a story of a guy who's a
quadrapalegic now who had just such an accident in my vicinity.

That tire was not on that bike more than about a month. It was one of several cheap tires I bought
a few years ago and they seem to have all gotten stiff, somewhat brittle and even crumbly just
sitting around.

--
Rick Onanian

In article <[email hidden]>, Dan Musicant

Quoted message said:

them without them going bad? Is there something you can do to protect them, like an application of
Armor All? I also have many individual packets of Turtle Wax Clear Guard protectant that I could
try. I wonder if anyone uses this stuff with either stored tires or tires that they are riding in
an effort to prolong their life.

I wouldn't do that. Those "protectants" make rubber (or vinyl) very slick. Not good for traction!

If you store tires in a dark cool place and away from ozone
(i.e. electric motors) they last for a while.

Quoted message said:

I also have one not cheap new tire, a Michelin 27 x 1.38 inch tire, and it too seems to have lost
its suppleness and I'm afraid to try using it.

I would be too.

Quoted message said:

If I was just riding around the city I wouldn't be so afraid to just use these new but apparently
deteriorated tires and see what happens but since I'm doing descents at sometimes pretty high
speeds I don't want to take unnecessary chances.

Speaking of chances, do you have reasonably fresh brake pads?

Eric

On Fri, 18 Jul 2003 22:38:43 GMT, [email hidden] (Eric Murray) wrote:

:In article <[email hidden]>, 😄an Musicant
<[email hidden]> wrote:
:>them without them going bad? Is there something you can do to protect them, like an application of
:>Armor All? I also have many individual packets of Turtle Wax Clear Guard protectant that I could
:>try. I wonder if anyone uses this stuff with either stored tires or tires that they are riding in
:>an effort to prolong their life.
:
:I wouldn't do that. Those "protectants" make rubber
🙁or vinyl) very slick. Not good for traction!
:
:If you store tires in a dark cool place and away from ozone
🙁i.e. electric motors) they last for a while.
:
:>I also have one not cheap new tire, a Michelin 27 x 1.38 inch tire, and it too seems to have lost
:>its suppleness and I'm afraid to try using it.
:
:I would be too.
:
:>If I was just riding around the city I wouldn't be so afraid to just use these new but apparently
:>deteriorated tires and see what happens but since I'm doing descents at sometimes pretty high
:>speeds I don't want to take unnecessary chances.
:
:Speaking of chances, do you have reasonably fresh brake pads?

Probably not fresh enough, now that you mention it. There's one part of the descent where there's a
traffic signal. It's usually green, but when it's not I have trouble stopping in time. Cars have no
problem. I think I better switch out my brake pads. Thanks.

Dan
:
:Eric
:

Dan Musicant said:

I guess I'd need pretty big bags to store bike tires in or do you fold the tires?

Even wire bead tires can be coiled in a way that makes them easy to store.

See: draco.acs.uci.edu8b.23.htmlOpen ↗

Quoted message said:

:There are plenty of good 27 x 1-1/4" tires. Try the IRC Road Winners at :about $13.
:
:Art Harris

Thanks for the suggestion. I'll see if I can find them. Can I get them online?

Yes, Nashbar has them on sale. I just bought some today in 700 x 28, but they also have them in 27 x
1-1/8" and 27 x 1-1/4".

See: nashbar.comnashbar.comOpen ↗ The stock number is IR-RWD.

Art Harris

Quoted message said:

Probably not fresh enough, now that you mention it. There's one part of the descent where there's
a traffic signal. It's usually green, but when it's not I have trouble stopping in time. Cars have
no problem. I think I better switch out my brake pads. Thanks.

Oh come on! Have a little excitement in your life! Be a little dangerous... chicks dig that.

--
Phil, Squid-in-Training

Quoted message said:

Tires with Kevlar beads can be folded, but not ones with wire beads. Just use a garbage bag and
put all your spares in one bag.

Yes, they can. Well, not FOLDED so much as twisted. Set the tire vertical on a table. Grab it at 3
and 9 o clock. Twist the tire AROUND the y-axis while bringing your hands close together. Voilá,
it's now the square root the area it used to be.

If you order a 27" x 1" tire from Nashbar, they will be twisted in this manner when you receive it.

--
Phil, Squid-in-Training

Dan Musicant said:

I don't know why, but all my old tires seem to get stiff and crumbly after not too long.

Ozone.

On Sat, 19 Jul 2003 02:25:33 GMT, "Phil, Squid-in-Training" <[email hidden]> wrote:

:> Probably not fresh enough, now that you mention it. There's one part of the descent where there's
:> a traffic signal. It's usually green, but when it's not I have trouble stopping in time. Cars
:> have no problem. I think I better switch out my brake pads. Thanks.
:
:Oh come on! Have a little excitement in your life! Be a little :dangerous... chicks dig that.

No doubt about it. In fact I met one the other day by virtue of telling her about my blowout
adventure.

Dan Musicant <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Quoted message said:

Lately I've taken up daily 12 mile rides with about a 1000 foot mostly gradual climb. The descent,
however, is pretty steep. I've seen guys blow by me at probably 35 miles/hour on the steepest part
( !! ) but it

You may want to read the section on descending in the rec.bicycles faq. Tips on techniques etc.

The following clip discusses heating and clincher tires lifting off the rims. It doesn't sound
like that was your problem, but the implications of increased tire pressure are interesting.
Also, if you use tires intended for hooked rims on older smooth rims, they may be more prone to
lifting off.
========================================================================

This is a serious problem both for tubulars and clinchers because most clincher tires, given enough
time on a hot rim will blow off if inflated to recommended pressure. Pressure that gives good
rolling performance (hard) while tubulars roll off from lack of adhesion to the rim. The faster the
travel, the more descending power goes into wind drag and the better the rims are cooled. Going
slowly does not help, unless speed is reduced below walking pace.

On steep descents, where rims stay too hot to touch for more than a minute, reducing tire
inflation pressure is a sure remedy. However, tires should be re-inflated once the rims cool to
normal. The blow-off pressure is the same for small and large tires on the same rim, it being
dependent only on the opening of the rim width. Also, tires with a smaller air volume become hot
faster than larger ones.

There is no way of descending continuously and steeply without reducing inflation pressure, unless
there is an insulator between the tube and rim of a clincher. Insulating rim strips are no longer
offered because they were an artifact of dirt roads that often required riders to descend so slowly
that all potential energy went into the brakes and almost none into wind drag. These rim strips were
cloth tubes filled with kapok, their insulating purpose being unknown to most people when they were
last offered.
=======================================================================

Quoted message said:

makes me shudder to think what would happen to them if they had a flat

You need the new Voler par la Nuit airbag helmet. If an impact is severe enough to cause serious
injury, the airbags detonate and crush your skull so that some misguided paramedic won't have
anything to revive.

For some reason, we're having toruble getting it approved for sale.

Quoted message said:

Quoted message said:

Does this always happen with bike tires? You can't buy them and

store

Chemicals such as ozone, probably UV exposure would affect rubber. I believe storing in a
basement where furnace or water heater fumes are present would reduce the shelf life. Probably
discussed elsewhere.

Quoted message said:

Quoted message said:

said they could convert it to a 700cc bike to use the now common tire. I

Discussed at www.sheldonbrown.com as well as here (google groups search). Your brakes may not have
enough reach for the smaller rims. You may do this to upgrade from freewheel to freehub/cassette,
or just better quality wheels.

I recall some 27" tires at harris cyclery (sheldonbrown). Locally, I can buy a $5 tire rated at
90 psi, or a $30 kevlar-belted tire, or several in between. There are a lot of cheap / heavy 27"
tires as well, sold by Canadian Tire, Wal-Mart, aned other retailers of "top quality" cycling
products :-)

Quoted message said:

assume that there's a whole lot more available in the 700 size, right?

More choices. I don't consider the cost of upgrading justified only to have more choice in tires.
It is an opportunity to get better wheels and freehub/cassette, etc.

Quoted message said:

Quoted message said:

years and they seem to have reduced my flats by a factor of at

least 3.

Quoted message said:

I liked the Hutchinson Globetrotter 700*28's for ride and (relative) durability. Vredstein
Perfect 700*28's were more puncture resistant (special non-Kevlar belt). Vredstein Perfect
700*32's are "designed" in Holland, probably made in China, and are not as enjoyable a ride.
Fairly bulletproof, though. Some of the puncture resistance (glass, road debris) is due to the
tread, some due to the special belt.

I've considered Panaracer Pasela Tourguard with the Kevlart belt, but some people have posted
here that they had lots of flats when they tried them.

No idea about "high performance" tires, i.e. narrower, lighter, smoother or no tread.

ymmv

Dan Musicant said:

Lately I've taken up daily 12 mile rides with about a 1000 foot mostly gradual climb. The descent,
however, is pretty steep. I've seen guys blow by me at probably 35 miles/hour on the steepest part
( !! ) but it makes me shudder to think what would happen to them if they had a flat or a blowout.
I read a story of a guy who's a quadrapalegic now who had just such an accident in my vicinity.

35mph is not that fast. Anything can happen in any accident, of course, but usually a fall at that
speed will only scrape off a lot of skin, maybe break a collar bone. There may have been other
circumstances with the guy who is now a quadraplegic, or it may have been a tragically bad landing.

Quoted message said:

Well, that story stuck with me and I don't want it happening to me. Of course, there's just no
being really safe on a bike,

On balance, cycling is very safe. There is no being "really safe" driving, either, or walking across
the street. You have to decide what level of risk life is worth, and live your life accordingly.

Quoted message said:

I had a blowout a couple days ago. I was at elevation and noticed some bumping and saw a z-jag in
my back tire and took it REAL slow down the descent. I got to pretty flat elevation before the
tire unexpectedly

blew

unexpectedly? It's got this big bulge pushing it sideways and a blowout is unexpected? Next time,
when you see a seriously deformed tire, stop right away and fix it. It is stupid to try to downhill
with a tire like that.

There are things you can do to repair such a tire. The casing broke, for some reason. Could be a
cut, or maybe it was installed incorrectly, or perhaps it was defective. Carry with you some
material to "boot" the tire, which means to place a layer of strong material between the tire and
the tube, to shore up the damaged casing. A part of the casing of an old tire is best (with the
rubber tread removed), but there are some commercial boot material packages that are quite good. In
an emergency, paper money, power-bar wrappers, and all sorts of similar material can be used. Find a
soda bottle by the side of the road, or cut a square out of a water bottle. It will get you home.

Quoted message said:

Another question I have is this: The place where I bought my used Miyata said they could convert
it to a 700cc bike to use the now common tire. I assume that there's a whole lot more available in
the 700 size, right?

True

Quoted message said:

I've been finding it hard to find anything in a 27 x 1.25. I bought a couple at Orchard Supply
yesterday, made in China I guess. They are nothing special but at least the rubber seems fresh and
vibrant.

But they are junk, and will slow you down.

Quoted message said:

Additional note: I use urethane tire liners (oversized), which I glue into the tires with contact
cement. I've been doing that for a number of years and they seem to have reduced my flats by a
factor of at least 3.

All these miracle treatments to stop flats are compromises. That stuff, again, slows you down.
It makes it harder to ride. And, no matter what, you will still have flats. Some hazards can get
by anything.

There are a few simple riding techniques that cut down the flats without slowing you down.
Obviously, the first is to watch out carefully for hazards, potholes, glass, etc., and avoid them.
When a rough road is unavoidable, get out of the saddle to lessen the impact on the tires. Learn how
to jump over obstacles.

--

David L. Johnson

__o | We have a record of conquest, colonization and expansion _`\(,_ | unequalled by any people
in the Nineteenth Century. We are not (_)/ (_) | to be curbed now. --Henry Cabot Lodge, 1895

"Dan Musicant" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Every bike I remember owning had 27 x 1.25 inch tires. When my old Shwinn Continental frame broke
almost 5 years ago I bought another used road bike -- a Miyata, not a high end bike, but a pretty
good quality mass-production bike. It has a triple-butted frame of Chrome-Moly, fair components
but nothing special. The best thing is that it isn't particularly thief bait and I don't have to
be too nervous locking it up outside in my town (Berkeley, CA).

Lately I've taken up daily 12 mile rides with about a 1000 foot mostly gradual climb. The descent,
however, is pretty steep. I've seen guys blow by me at probably 35 miles/hour on the steepest part
( !! ) but it makes me shudder to think what would happen to them if they had a flat or a blowout.
I read a story of a guy who's a quadrapalegic now who had just such an accident in my vicinity.

Well, that story stuck with me and I don't want it happening to me. Of course, there's just no
being really safe on a bike, but I figure I can start here by paying attention to my tires and not
screaming down that hill.

I had a blowout a couple days ago. I was at elevation and noticed some bumping and saw a z-jag in
my back tire and took it REAL slow down the descent. I got to pretty flat elevation before the
tire unexpectedly blew out with what sounded like a gun shot. I just hopped off the bike, locked
it, and walked the rest of the way and came back and got it with my car later.

That tire was not on that bike more than about a month. It was one of several cheap tires I bought
a few years ago and they seem to have all gotten stiff, somewhat brittle and even crumbly just
sitting around. Does this always happen with bike tires? You can't buy them and store them without
them going bad? Is there something you can do to protect them, like an application of Armor All? I
also have many individual packets of Turtle Wax Clear Guard protectant that I could try. I wonder
if anyone uses this stuff with either stored tires or tires that they are riding in an effort to
prolong their life.

I also have one not cheap new tire, a Michelin 27 x 1.38 inch tire, and it too seems to have lost
its suppleness and I'm afraid to try using it. If I was just riding around the city I wouldn't be
so afraid to just use these new but apparently deteriorated tires and see what happens but since
I'm doing descents at sometimes pretty high speeds I don't want to take unnecessary chances.

Another question I have is this: The place where I bought my used Miyata said they could convert
it to a 700cc bike to use the now common tire. I assume that there's a whole lot more available in
the 700 size, right? I've been finding it hard to find anything in a 27 x 1.25. I bought a couple
at Orchard Supply yesterday, made in China I guess. They are nothing special but at least the
rubber seems fresh and vibrant.

Additional note: I use urethane tire liners (oversized), which I glue into the tires with contact
cement. I've been doing that for a number of years and they seem to have reduced my flats by a
factor of at least 3.

There are plenty of 27" tires available from Kenda gumwalls ( under $10) to the very nice Panaracer
and Inoue-IRC tires in 27x1, 27x1-1/8, 27x1-1/4 (both offer kevlar under the tread if you are so
inclined), the Michelin World Tour you noted that's quite an ample version of 27x1-1/4 and then all
the knobby 27x1-1/3 tires. There are several other brands available as well
. On an older bike the expense of new wheels is not always appropriate where the existing equipment
is in good condition.

(BTW fractions and decimals are used to denote different series of rims in our industry - you
shouldn't mix them)

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

On 19 Jul 2003 17:35:20 -0700, [email hidden] (mark freedman) wrote:

😄an Musicant <[email hidden]> wrote in message
news:<[email hidden]>...
:
:>>
:> Lately I've taken up daily 12 mile rides with about a 1000 foot mostly gradual climb. The
:> descent, however, is pretty steep. I've seen guys blow by me at probably 35 miles/hour on the
:> steepest part ( !! ) but it
:
: You may want to read the section on descending in the rec.bicycles
:faq. :Tips on techniques etc.
:
: The following clip discusses heating and clincher tires lifting off
:the rims. It doesn't sound like that was your problem, but the :implications of increased tire
pressure are interesting. Also, if you :use tires intended for hooked rims on older smooth rims,
they may be :more prone to lifting off.

It IS scary to realize the complexity of the problem. Maybe I can get by, though, without some of
these considerations. The descent itself, the one I'm concerned with, is probably about 650 - 800
feet, I'm not sure. The material below may be more directed to longer descents that last more than
mine, which is probably over in less than 3 minutes. The main portion, where major braking is
absolutely necessary probably lasts about a minute, and not much more. It does make me worry a lot
when I try to imagine what would happen if I had a blowout on either tire, particularly the front,
when on the steepest portion, which is not so steep that I and other riders can't ascend, but it's a
pretty steep
climb/descent. I think I'll try to have some conversations with the people who work in the local
bike shops. I'm bound to scare up some good advice and suggestions that way, too. How can I
tell if I have "older smooth rims" or "hooked rims"?

I've been inflating to recommended pressures, when I think of it, which for my tires has been 85 or
75 (lately), and now (as of the tires I bought a few days ago) 70 lb. pressure. Maybe I should only
have 60 lb. to allow for that descent.

Dan
:========================================================================
:
:This is a serious problem both for tubulars and clinchers because most :clincher tires, given
enough time on a hot rim will blow off if :inflated to recommended pressure. Pressure that gives
good rolling :performance (hard) while tubulars roll off from lack of adhesion to :the rim. The
faster the travel, the more descending power goes into :wind drag and the better the rims are
cooled. Going slowly does not :help, unless speed is reduced below walking pace.
:
:On steep descents, where rims stay too hot to touch for more than a :minute, reducing tire
inflation pressure is a sure remedy. However, :tires should be re-inflated once the rims cool to
normal. The :blow-off pressure is the same for small and large tires on the same :rim, it being
dependent only on the opening of the rim width. Also, :tires with a smaller air volume become hot
faster than larger ones.
:
:There is no way of descending continuously and steeply without :reducing inflation pressure, unless
there is an insulator between the :tube and rim of a clincher. Insulating rim strips are no longer
:offered because they were an artifact of dirt roads that often :required riders to descend so
slowly that all potential energy went :into the brakes and almost none into wind drag. These rim
strips were :cloth tubes filled with kapok, their insulating purpose being unknown :to most people
when they were last offered.
:=======================================================================
:
:> makes me shudder to think what would happen to them if they had a flat
:
: You need the new Voler par la Nuit airbag helmet. If an impact is
:severe enough to cause serious injury, the airbags detonate and crush :your skull so that some
misguided paramedic won't have anything to :revive.
:
: For some reason, we're having toruble getting it approved for sale.
:
:
:>>
:>> Does this always happen with bike tires? You can't buy them and
:store
:
: Chemicals such as ozone, probably UV exposure would affect rubber.
:I believe storing in a basement where furnace or water heater fumes :are present would reduce the
shelf life. Probably discussed elsewhere.
:
:
:
:> >
:> said they could convert it to a 700cc bike to use the now common tire. I
:
: Discussed at www.sheldonbrown.com as well as here (google groups
:search). :Your brakes may not have enough reach for the smaller rims. You may do :this to upgrade
from freewheel to freehub/cassette, or just better :quality wheels.
:
: I recall some 27" tires at harris cyclery (sheldonbrown). Locally,
:I can buy a $5 tire rated at 90 psi, or a $30 kevlar-belted tire, or :several in between. There are
a lot of cheap / heavy 27" tires as :well, sold by Canadian Tire, Wal-Mart, aned other retailers of
"top :quality" cycling products :-)
:
:> assume that there's a whole lot more available in the 700 size, right?
:
: More choices. I don't consider the cost of upgrading justified only
:to have more choice in tires. It is an opportunity to get better :wheels and freehub/cassette, etc.
:
:
:>> years and they seem to have reduced my flats by a factor of at
:least 3.
:>
: I liked the Hutchinson Globetrotter 700*28's for ride and (relative) durability. Vredstein
: Perfect 700*28's were more puncture
:resistant (special non-Kevlar belt). Vredstein Perfect 700*32's are
:"designed" in Holland, probably made in China, and are not as
:enjoyable a ride. Fairly bulletproof, though. Some of the puncture :resistance (glass, road debris)
is due to the tread, some due to the :special belt.
:
: I've considered Panaracer Pasela Tourguard with the Kevlart belt,
:but some people have posted here that they had lots of flats when they :tried them.
:
: No idea about "high performance" tires, i.e. narrower, lighter,
:smoother or no tread.
:
: ymmv

On Sat, 19 Jul 2003 22:19:22 -0400, "David L. Johnson" <[email hidden]> wrote:

:On Fri, 18 Jul 2003 15:05:38 +0000, Dan Musicant wrote:
:
:> Lately I've taken up daily 12 mile rides with about a 1000 foot mostly gradual climb. The
:> descent, however, is pretty steep. I've seen guys blow by me at probably 35 miles/hour on the
:> steepest part ( !! ) but it makes me shudder to think what would happen to them if they had a
:> flat or a blowout. I read a story of a guy who's a quadrapalegic now who had just such an
:> accident in my vicinity.
:
:35mph is not that fast. Anything can happen in any accident, of course,
:but usually a fall at that speed will only scrape off a lot of skin, maybe :break a collar bone.
There may have been other circumstances with the guy :who is now a quadraplegic, or it may have been
a tragically bad landing.

I do reach 35 mph on a lower portion of the descent, but at that point that's the maximum speed I
can achieve and it doesn't worry me as much. However I've seen guys achieve a similar speed earlier
in the descent where it's far steeper (probably twice as steep), where it's impossible to not use
the brakes, and with that steepness, a crash at 35 mph would be a worse matter since you would be
rolling and tumbling down a steep incline and have gravity to fight at a whole different level in
trying to come to a halt and stop the damage. It's hard for me to imagine escaping such an event
without catastrophic injuries, is what I'm saying. Maybe where it's not so steep, surviving a 35 mph
crash is not such a problem.

The guy who is a quadrapalegic now is Ralph Parker, and his wife Susie wrote the cover story in an
edition of the East Bay Express (and it must be about 2 - 3 years ago now) about the aftermath of
the crash. He was coming off Skyline Blvd. and made a left turn onto Claremont Ave., which abruptly
makes a descent there, and at that point he had his blowout. He was unable to control the bike and
ran onto the shoulder and the bike flipped and he landed on his head. He was wearing a helmet. He's
practically if not absolutely helpless without human aid.
:>
:> Well, that story stuck with me and I don't want it happening to me. Of course, there's just no
:> being really safe on a bike,
:
:On balance, cycling is very safe. There is no being "really safe" :driving, either, or walking
across the street. You have to decide what :level of risk life is worth, and live your life
accordingly.

I think what bothers me is that there doesn't seem to be anything I can do if that blowout happens
at the wrong time. I try to leave a safety zone when I drive or walk or rollerskate or bike in the
city, so that I can react if a dangerous situation arises. A steep bike descent doesn't seem to have
anything like that. No time to react and protect yourself, or practically none. I always wear full
leather gloves so that at least I wouldn't scrape the skin off my hands if I had to break fall, and
it's helped a couple times.
:
:> I had a blowout a couple days ago. I was at elevation and noticed some bumping and saw a z-jag in
:> my back tire and took it REAL slow down the descent. I got to pretty flat elevation before the
:> tire unexpectedly
:blew
:
:unexpectedly? It's got this big bulge pushing it sideways and a blowout :is unexpected? Next time,
when you see a seriously deformed tire, stop :right away and fix it. It is stupid to try to downhill
with a tire like :that.

The only way I could have fixed it was to leave the bike up there and hitch a ride down the hill.
Doable, but I figured I'd chance a VERY SLOW descent. On balance, considering what happened, I think
even that was probably foolhardy. I didn't go over around 4 or 5 mph on the steep part, though. I've
had similar deformed tires that didn't blow, so I figured I was probably OK to get home. I was
wrong, at least this time.
:
:There are things you can do to repair such a tire. The casing broke, for :some reason. Could be a
cut, or maybe it was installed incorrectly, or :perhaps it was defective. Carry with you some
material to "boot" the :tire, which means to place a layer of strong material between the tire and
:the tube, to shore up the damaged casing. A part of the casing of an old :tire is best (with the
rubber tread removed), but there are some :commercial boot material packages that are quite good.

I carry a kit with me, actually a couple these days. One is attached to the underside of me seat and
it has a piece of plastic, about 3/4 inch by 2 inches, to bridge a cut in the tire.

: In an emergency,
:paper money, power-bar wrappers, and all sorts of similar material can be :used. Find a soda bottle
by the side of the road, or cut a square out of :a water bottle. It will get you home.

Good ideas!
:
:> Another question I have is this: The place where I bought my used Miyata said they could convert
:> it to a 700cc bike to use the now common tire. I assume that there's a whole lot more available
:> in the 700 size, right?
:
:True
:
:> I've been finding it hard to find anything in a 27 x 1.25. I bought a couple at Orchard Supply
:> yesterday, made in China I guess. They are nothing special but at least the rubber seems fresh
:> and vibrant.
:
:But they are junk, and will slow you down.

Honestly, I don't care about the slow down. I only care about being safe. I've never raced a bike
and don't expect to. I race myself, use a bike computer to note how fast I'm doing, time elapsed at
different milestones in my ride, but it's all relative, and if a tire is slowing me down 5%, I don't
care. But an injurious accident does concern me. The only time I was hurt on a bike that I can
remember was when I was about 12 - 13 years old. I was going down a hill and somehow, unexpectedly
and without warning, the fork began to oscillate from side to side, The oscillation amplified until
the bike went down. I was unaware of having done anything dangerous or out of the ordinary. It
happened in a second and the next thing I knew I was on someone's couch. It was a block from my home
and I had a cut on my lip with a few stiches. Nobody at school would believe I wasn't in a fight!

:>
:> Additional note: I use urethane tire liners (oversized), which I glue into the tires with contact
:> cement. I've been doing that for a number of years and they seem to have reduced my flats by a
:> factor of at least 3.
:
:All these miracle treatments to stop flats are compromises. That stuff, :again, slows you down.
It makes it harder to ride. And, no matter what, :you will still have flats. Some hazards can get
by anything.

There's no way to objectively evaluate the advantages or disadvantages of my using urethane tire
liners glued into my tires but my sense of it is that I've been getting 30% or less flats than I was
getting before I started using them.

:
:There are a few simple riding techniques that cut down the flats without :slowing you down.
Obviously, the first is to watch out carefully for :hazards, potholes, glass, etc., and avoid them.
When a rough road is :unavoidable, get out of the saddle to lessen the impact on the tires. :Learn
how to jump over obstacles.

Sometimes, when I've found riding over glass shards unavoidable, I place my gloved hand on the tires
(while riding!) to dislodge shards that might not yet have worked into the tires. It's just such
shards, BTW, that the urethane liners are so good at protecting the tubes from. But even liners are
not 100% effective at protecting from glass.

I think the quality of the tube is important, too. I've been finding it hard to find quality 27 x
1.25 tubes - another reason to convert to 700's.

Dan Musicant said:

... I think what bothers me is that there doesn't seem to be anything I can do if that blowout
happens at the wrong time. I try to leave a safety zone when I drive or walk or rollerskate or
bike in the city, so that I can react if a dangerous situation arises. A steep bike descent
doesn't seem to have anything like that. No time to react and protect yourself, or practically
none. I always wear full leather gloves so that at least I wouldn't scrape the skin off my hands
if I had to break fall, and it's helped a couple times....

If you are really worried about falling due to tire failure, the solution is to add a third wheel.
Of course, there is a whole set of trade-offs that you may or may not find acceptable.

Tom Sherman - Quad Cities USA (Illinois side)