BMX wheels for recumbent tandem use?



J

Jim

Guest
We have a RANS Screamer tandem and the front 20" wheel was damaged by
the local bad roads. (Both sidewalls bent outward when hitting a
hole.) We are looking for a replacement. The original is made by
Velocity. The original wheel held up well until this.

The options are to get another rim (perhaps Velocity) and graft it on
to the old hub.

Or find another wheel. Many of the 20" wheels are made for BMX use.
Most have 36 spokes, 32 and 40 are also available.

Any idea if these are any good? Given the abuse a BMX bike takes the
wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
popular and there are a bunch of others, too.

Opinions? Personal experience?

Thanks,
Jim
 
N

Nate Knutson

Guest
On Aug 26, 8:39 am, Jim <[email protected]> wrote:
> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> the local bad roads. (Both sidewalls bent outward when hitting a
> hole.) We are looking for a replacement. The original is made by
> Velocity. The original wheel held up well until this.
>
> The options are to get another rim (perhaps Velocity) and graft it on
> to the old hub.
>
> Or find another wheel. Many of the 20" wheels are made for BMX use.
> Most have 36 spokes, 32 and 40 are also available.
>
> Any idea if these are any good? Given the abuse a BMX bike takes the
> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> popular and there are a bunch of others, too.
>
> Opinions? Personal experience?
>
> Thanks,
> Jim


Some friends toured loaded cross country on their Screamer using a
Velocity Aeroheat up front. Well built, it stayed perfectly true the
entire time, but near the end of the trip it literally started falling
apart; numerous fatigue cracks in many places. It seemingly wasn't up
to the purpose. If you use a Velocity, probably the Taipan is a
reasonable choice, especially if you'll be unloaded, but you couldn't
be faulted for using a Psycho. As you know, recumbent tandem front
wheels take BIG loads.

A Rhynolite or Alex DM24 would be a good choice too. Largely it
depends on what kind of riding you do and what size tires you want to
use.

Many current BMX rims from BMX-only companies are really expensive for
what they are, usually because of a combination of pretty colors,
weight-saving drillings, and probably smaller production, and in most
cases you'll be on your own in terms of seeing how well they actually
manage fatigue-wise on your Screamer.

If the hub is still in good shape, there's no reason to trash it. You
want a handbuilt wheel anyway.
 
N

Nate Knutson

Guest
On Aug 26, 8:39 am, Jim <[email protected]> wrote:
> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> the local bad roads. (Both sidewalls bent outward when hitting a
> hole.) We are looking for a replacement. The original is made by
> Velocity. The original wheel held up well until this.
>
> The options are to get another rim (perhaps Velocity) and graft it on
> to the old hub.
>
> Or find another wheel. Many of the 20" wheels are made for BMX use.
> Most have 36 spokes, 32 and 40 are also available.
>
> Any idea if these are any good? Given the abuse a BMX bike takes the
> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> popular and there are a bunch of others, too.
>
> Opinions? Personal experience?
>
> Thanks,
> Jim


Also, thought I'd add this: BMX rims do need to be really strong, but
the use that a typical one sees is pretty different from that which a
recumbent tandem will be putting it through, so you can't really make
assumptions about how well they'll hold up. The peak loads (badly
landing from high in the air versus accidentally slamming into a
pothole at 40mph) are probably pretty similar, but BMX rims just
aren't used for the same kind of mileage, and may have it easier in
terms of the amount of fatigue resistance they need in order to last a
reasonably long time. BMX rims die by sudden violence. So in other
words, many BMX rims may be perfectly good at never cracking if put on
a recumbent tandem, but you really don't know until you try.
 
J

jim beam

Guest
Nate Knutson wrote:
> On Aug 26, 8:39 am, Jim <[email protected]> wrote:
>> We have a RANS Screamer tandem and the front 20" wheel was damaged by
>> the local bad roads. (Both sidewalls bent outward when hitting a
>> hole.) We are looking for a replacement. The original is made by
>> Velocity. The original wheel held up well until this.
>>
>> The options are to get another rim (perhaps Velocity) and graft it on
>> to the old hub.
>>
>> Or find another wheel. Many of the 20" wheels are made for BMX use.
>> Most have 36 spokes, 32 and 40 are also available.
>>
>> Any idea if these are any good? Given the abuse a BMX bike takes the
>> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
>> popular and there are a bunch of others, too.
>>
>> Opinions? Personal experience?
>>
>> Thanks,
>> Jim

>
> Some friends toured loaded cross country on their Screamer using a
> Velocity Aeroheat up front. Well built, it stayed perfectly true the
> entire time, but near the end of the trip it literally started falling
> apart; numerous fatigue cracks in many places.


what was the spoke tension? seems like it was too high.


> It seemingly wasn't up
> to the purpose. If you use a Velocity, probably the Taipan is a
> reasonable choice, especially if you'll be unloaded, but you couldn't
> be faulted for using a Psycho. As you know, recumbent tandem front
> wheels take BIG loads.
>
> A Rhynolite or Alex DM24 would be a good choice too. Largely it
> depends on what kind of riding you do and what size tires you want to
> use.
>
> Many current BMX rims from BMX-only companies are really expensive for
> what they are, usually because of a combination of pretty colors,
> weight-saving drillings, and probably smaller production, and in most
> cases you'll be on your own in terms of seeing how well they actually
> manage fatigue-wise on your Screamer.
>
> If the hub is still in good shape, there's no reason to trash it. You
> want a handbuilt wheel anyway.
>
 
J

JeffWills

Guest
On Aug 26, 7:39 am, Jim <[email protected]> wrote:
> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> the local bad roads. (Both sidewalls bent outward when hitting a
> hole.) We are looking for a replacement. The original is made by
> Velocity. The original wheel held up well until this.
>
> The options are to get another rim (perhaps Velocity) and graft it on
> to the old hub.
>
> Or find another wheel. Many of the 20" wheels are made for BMX use.
> Most have 36 spokes, 32 and 40 are also available.
>
> Any idea if these are any good? Given the abuse a BMX bike takes the
> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> popular and there are a bunch of others, too.
>
> Opinions? Personal experience?
>
> Thanks,
> Jim


IMO (and that's all it is) a Sun Rhyno Lite rim is a good choice. It's
a moderate width double-wall rim with single eyelets. Double eyelets
would be better, but I haven't seen those on any rims for a while.

Given that the old rim's sidewalls bent outwards, I'd guess one or
both of these things happened:
1: the rim had a fair number of miles on it and the sidewalls were
worn by the brake shoes
2: you were using a wide-ish, high pressure 20" tire

The Rhyno Lite would be well-matched with a 1.3" to 1.5" wide tire. If
you were going wider (say, 1.75" to 2.1"), a Sun Big City rim might be
a better match. I've ridden with Screamer teams that rode on 28mm wide
Continental front tires, which I thought was sketchy, and 2" Schwalbe
Big Apples, which seem to be more popular. A local couple have an
extensive website devoted to their Screamer : http://www.tandemride.com/

Jeff (another Jeff)
 
J

Jim

Guest
On Sun, 26 Aug 2007 11:08:10 -0700, Nate Knutson <[email protected]>
wrote:

>On Aug 26, 8:39 am, Jim <[email protected]> wrote:
>> We have a RANS Screamer tandem and the front 20" wheel was damaged by
>> the local bad roads. (Both sidewalls bent outward when hitting a
>> hole.) We are looking for a replacement. The original is made by
>> Velocity. The original wheel held up well until this.
>>
>> The options are to get another rim (perhaps Velocity) and graft it on
>> to the old hub.
>>
>> Or find another wheel. Many of the 20" wheels are made for BMX use.
>> Most have 36 spokes, 32 and 40 are also available.
>>
>> Any idea if these are any good? Given the abuse a BMX bike takes the
>> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
>> popular and there are a bunch of others, too.
>>
>> Opinions? Personal experience?
>>
>> Thanks,
>> Jim

>
>Also, thought I'd add this: BMX rims do need to be really strong, but
>the use that a typical one sees is pretty different from that which a
>recumbent tandem will be putting it through, so you can't really make
>assumptions about how well they'll hold up. The peak loads (badly
>landing from high in the air versus accidentally slamming into a
>pothole at 40mph) are probably pretty similar, but BMX rims just
>aren't used for the same kind of mileage, and may have it easier in
>terms of the amount of fatigue resistance they need in order to last a
>reasonably long time. BMX rims die by sudden violence. So in other
>words, many BMX rims may be perfectly good at never cracking if put on
>a recumbent tandem, but you really don't know until you try.


I was thinking the same thing and it would be good to find out from
people who went through the same thing.

On the other hand, this is the fourth wheel on a 3 year old bike. With
the previous velocity rims, heating from braking caused some kind of
oily stuff to leak onto the adhesive rim strip. That caused the
adhesive to lose its grip, the rim tape slid to one side, and the tube
punctured after the tube went into a spoke hole.

Oh, and it always happened after a long downhill run, the initial
cause of the rim heating. The dealer and the Velocity people were
pretty good. They finally built a wheel with a Velocity Taipan and
that one was great until it took a too-big hit.

Thanks again,
Jim
 
J

Jim

Guest
On Sun, 26 Aug 2007 14:56:40 -0700, JeffWills <[email protected]>
wrote:

>On Aug 26, 7:39 am, Jim <[email protected]> wrote:
>> We have a RANS Screamer tandem and the front 20" wheel was damaged by
>> the local bad roads. (Both sidewalls bent outward when hitting a
>> hole.) We are looking for a replacement. The original is made by
>> Velocity. The original wheel held up well until this.
>>
>> The options are to get another rim (perhaps Velocity) and graft it on
>> to the old hub.
>>
>> Or find another wheel. Many of the 20" wheels are made for BMX use.
>> Most have 36 spokes, 32 and 40 are also available.
>>
>> Any idea if these are any good? Given the abuse a BMX bike takes the
>> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
>> popular and there are a bunch of others, too.
>>
>> Opinions? Personal experience?
>>
>> Thanks,
>> Jim

>
>IMO (and that's all it is) a Sun Rhyno Lite rim is a good choice. It's
>a moderate width double-wall rim with single eyelets. Double eyelets
>would be better, but I haven't seen those on any rims for a while.
>
>Given that the old rim's sidewalls bent outwards, I'd guess one or
>both of these things happened:
>1: the rim had a fair number of miles on it and the sidewalls were
>worn by the brake shoes
>2: you were using a wide-ish, high pressure 20" tire
>
>The Rhyno Lite would be well-matched with a 1.3" to 1.5" wide tire. If
>you were going wider (say, 1.75" to 2.1"), a Sun Big City rim might be
>a better match. I've ridden with Screamer teams that rode on 28mm wide
>Continental front tires, which I thought was sketchy, and 2" Schwalbe
>Big Apples, which seem to be more popular. A local couple have an
>extensive website devoted to their Screamer : http://www.tandemride.com/
>
>Jeff (another Jeff)


Last question on BMX wheels: What about the axle widths? Do they
match up with "normal" wheels? Many of the ads do not list the width.

Same for axle diameter. Do they use the same size as regular bikes?

Thanks,
Jim
 
A

A Muzi

Guest
>> Jim <[email protected]> wrote:
>>> We have a RANS Screamer tandem and the front 20" wheel was damaged by
>>> the local bad roads. (Both sidewalls bent outward when hitting a
>>> hole.) We are looking for a replacement. The original is made by
>>> Velocity. The original wheel held up well until this.
>>> The options are to get another rim (perhaps Velocity) and graft it on
>>> to the old hub.
>>> Or find another wheel. Many of the 20" wheels are made for BMX use.
>>> Most have 36 spokes, 32 and 40 are also available.
>>> Any idea if these are any good? Given the abuse a BMX bike takes the
>>> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
>>> popular and there are a bunch of others, too.
>>> Opinions? Personal experience?


> Nate Knutson <[email protected]> wrote:
>> Also, thought I'd add this: BMX rims do need to be really strong, but
>> the use that a typical one sees is pretty different from that which a
>> recumbent tandem will be putting it through, so you can't really make
>> assumptions about how well they'll hold up. The peak loads (badly
>> landing from high in the air versus accidentally slamming into a
>> pothole at 40mph) are probably pretty similar, but BMX rims just
>> aren't used for the same kind of mileage, and may have it easier in
>> terms of the amount of fatigue resistance they need in order to last a
>> reasonably long time. BMX rims die by sudden violence. So in other
>> words, many BMX rims may be perfectly good at never cracking if put on
>> a recumbent tandem, but you really don't know until you try.


Jim wrote:
> I was thinking the same thing and it would be good to find out from
> people who went through the same thing.
>
> On the other hand, this is the fourth wheel on a 3 year old bike. With
> the previous velocity rims, heating from braking caused some kind of
> oily stuff to leak onto the adhesive rim strip. That caused the
> adhesive to lose its grip, the rim tape slid to one side, and the tube
> punctured after the tube went into a spoke hole.
>
> Oh, and it always happened after a long downhill run, the initial
> cause of the rim heating. The dealer and the Velocity people were
> pretty good. They finally built a wheel with a Velocity Taipan and
> that one was great until it took a too-big hit.


I believe that you are honestly reporting what you believe you saw. I do
not believe a rim liner can creep to one side with a pressured tube/tire
installed.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
J

Jim

Guest
On Sun, 26 Aug 2007 19:36:23 -0500, A Muzi <[email protected]>
wrote:

....
>Jim wrote:
>> I was thinking the same thing and it would be good to find out from
>> people who went through the same thing.
>>
>> On the other hand, this is the fourth wheel on a 3 year old bike. With
>> the previous velocity rims, heating from braking caused some kind of
>> oily stuff to leak onto the adhesive rim strip. That caused the
>> adhesive to lose its grip, the rim tape slid to one side, and the tube
>> punctured after the tube went into a spoke hole.
>>
>> Oh, and it always happened after a long downhill run, the initial
>> cause of the rim heating. The dealer and the Velocity people were
>> pretty good. They finally built a wheel with a Velocity Taipan and
>> that one was great until it took a too-big hit.

>
>I believe that you are honestly reporting what you believe you saw. I do
>not believe a rim liner can creep to one side with a pressured tube/tire
> installed.


I never expected something like that, either. Thanks to the digital
camera:

Here's our first wheel. Notice the discolored area in the rim tape
right over the rim joint. The rm tape moved very freely and the area
was oily.
http://home.rochester.rr.com/n2vx/wheel1b.JPG

And that's where the inner tube got cut. Not a puncture, a cut:
http://home.rochester.rr.com/n2vx/wheel2c.JPG

I replaced the stock rim tape with Pedro's after wiping the area clean
with rubbing alcohol. After a long downhill the oily stuff made the
Pedro's "unstick" too with the same results.

The dealer thought it was a freak thing and sent another wheel. The
second wheel didn't do any better:
http://home.rochester.rr.com/n2vx/wheel2a.JPG
http://home.rochester.rr.com/n2vx/wheel2b.JPG

The third wheel was made by the dealer using a Rhyno Lite. Spoke
tension was uneven. It was poorly trued, had windup, and got worse on
the first ride. We made arrangements to send it back.

Wheel number 4 was the other Velocity and it worked OK for 3 years
until hitting a hole when we coud not swerve. Never had to retrue it.
A pretty good wheel considering the load on it.

Perhaps rims 1 and 2 had something left on them from when they were
run through the dies used to form the shape. All flats came after
downhill runs where we had to brake and heat up the rims. There were
no problems with rim 4, a different Velocity model.

Any and all ideas are welcome. It is something I haven't seen before
or since.

Jim
 
J

jim beam

Guest
Jim wrote:
> On Sun, 26 Aug 2007 19:36:23 -0500, A Muzi <[email protected]>
> wrote:
>
> ...
>> Jim wrote:
>>> I was thinking the same thing and it would be good to find out from
>>> people who went through the same thing.
>>>
>>> On the other hand, this is the fourth wheel on a 3 year old bike. With
>>> the previous velocity rims, heating from braking caused some kind of
>>> oily stuff to leak onto the adhesive rim strip. That caused the
>>> adhesive to lose its grip, the rim tape slid to one side, and the tube
>>> punctured after the tube went into a spoke hole.
>>>
>>> Oh, and it always happened after a long downhill run, the initial
>>> cause of the rim heating. The dealer and the Velocity people were
>>> pretty good. They finally built a wheel with a Velocity Taipan and
>>> that one was great until it took a too-big hit.

>> I believe that you are honestly reporting what you believe you saw. I do
>> not believe a rim liner can creep to one side with a pressured tube/tire
>> installed.

>
> I never expected something like that, either. Thanks to the digital
> camera:
>
> Here's our first wheel. Notice the discolored area in the rim tape
> right over the rim joint. The rm tape moved very freely and the area
> was oily.
> http://home.rochester.rr.com/n2vx/wheel1b.JPG
>
> And that's where the inner tube got cut. Not a puncture, a cut:
> http://home.rochester.rr.com/n2vx/wheel2c.JPG
>
> I replaced the stock rim tape with Pedro's after wiping the area clean
> with rubbing alcohol. After a long downhill the oily stuff made the
> Pedro's "unstick" too with the same results.
>
> The dealer thought it was a freak thing and sent another wheel. The
> second wheel didn't do any better:
> http://home.rochester.rr.com/n2vx/wheel2a.JPG
> http://home.rochester.rr.com/n2vx/wheel2b.JPG


strange. maybe the rim joint peg is glued into position and heat is
affecting it?


>
> The third wheel was made by the dealer using a Rhyno Lite. Spoke
> tension was uneven. It was poorly trued, had windup, and got worse on
> the first ride. We made arrangements to send it back.
>
> Wheel number 4 was the other Velocity and it worked OK for 3 years
> until hitting a hole when we coud not swerve. Never had to retrue it.
> A pretty good wheel considering the load on it.
>
> Perhaps rims 1 and 2 had something left on them from when they were
> run through the dies used to form the shape. All flats came after
> downhill runs where we had to brake and heat up the rims. There were
> no problems with rim 4, a different Velocity model.
>
> Any and all ideas are welcome. It is something I haven't seen before
> or since.
>
> Jim
 
N

Nate Knutson

Guest
On Aug 26, 11:11 am, jim beam <[email protected]> wrote:
> Nate Knutson wrote:
> > On Aug 26, 8:39 am, Jim <[email protected]> wrote:
> >> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> >> the local bad roads. (Both sidewalls bent outward when hitting a
> >> hole.) We are looking for a replacement. The original is made by
> >> Velocity. The original wheel held up well until this.

>
> >> The options are to get another rim (perhaps Velocity) and graft it on
> >> to the old hub.

>
> >> Or find another wheel. Many of the 20" wheels are made for BMX use.
> >> Most have 36 spokes, 32 and 40 are also available.

>
> >> Any idea if these are any good? Given the abuse a BMX bike takes the
> >> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> >> popular and there are a bunch of others, too.

>
> >> Opinions? Personal experience?

>
> >> Thanks,
> >> Jim

>
> > Some friends toured loaded cross country on their Screamer using a
> > Velocity Aeroheat up front. Well built, it stayed perfectly true the
> > entire time, but near the end of the trip it literally started falling
> > apart; numerous fatigue cracks in many places.

>
> what was the spoke tension? seems like it was too high.


not my wheel, but i believe it was in velocity's recommended 100-110
range. the failure was so extreme that i doubt there was a lower
tension that would have prevented fatigue cracking but would still
allow the wheel to be strong enough. loaded recumbent tandem front
wheels in messy conditions get hit *hard*.
 
J

JeffWills

Guest
On Aug 26, 4:08 pm, Jim <[email protected]> wrote:
>
> Last question on BMX wheels: What about the axle widths? Do they
> match up with "normal" wheels? Many of the ads do not list the width.
>
> Same for axle diameter. Do they use the same size as regular bikes?
>


BMX front hubs are the same width as most other front hubs: 100mm.

Axle diameters are not. "Normal" BMX hubs use a 3/8" diameter axle,
while "freestyle" axles are 14mm in diameter. Both are larger than the
typical road hub's 9mm axle. *Some* 3/8" axles have flats machined
into them, which allow them to be slipped into a "road" fork's
dropouts. Those are pretty rare, I think.

Another problem with using a typical BMX hub: they are universally
bolt-on. You'll lose the quick-release, with no easy way to install
one. I'd say you're better off having the old hub rebuilt with a new
rim. This should be an easy job for a competent bike shop.

Jeff
 
N

Nate Knutson

Guest
On Aug 26, 5:08 pm, Jim <[email protected]> wrote:
> On Sun, 26 Aug 2007 14:56:40 -0700, JeffWills <[email protected]>
> wrote:
>
>
>
> >On Aug 26, 7:39 am, Jim <[email protected]> wrote:
> >> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> >> the local bad roads. (Both sidewalls bent outward when hitting a
> >> hole.) We are looking for a replacement. The original is made by
> >> Velocity. The original wheel held up well until this.

>
> >> The options are to get another rim (perhaps Velocity) and graft it on
> >> to the old hub.

>
> >> Or find another wheel. Many of the 20" wheels are made for BMX use.
> >> Most have 36 spokes, 32 and 40 are also available.

>
> >> Any idea if these are any good? Given the abuse a BMX bike takes the
> >> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> >> popular and there are a bunch of others, too.

>
> >> Opinions? Personal experience?

>
> >> Thanks,
> >> Jim

>
> >IMO (and that's all it is) a Sun Rhyno Lite rim is a good choice. It's
> >a moderate width double-wall rim with single eyelets. Double eyelets
> >would be better, but I haven't seen those on any rims for a while.

>
> >Given that the old rim's sidewalls bent outwards, I'd guess one or
> >both of these things happened:
> >1: the rim had a fair number of miles on it and the sidewalls were
> >worn by the brake shoes
> >2: you were using a wide-ish, high pressure 20" tire

>
> >The Rhyno Lite would be well-matched with a 1.3" to 1.5" wide tire. If
> >you were going wider (say, 1.75" to 2.1"), a Sun Big City rim might be
> >a better match. I've ridden with Screamer teams that rode on 28mm wide
> >Continental front tires, which I thought was sketchy, and 2" Schwalbe
> >Big Apples, which seem to be more popular. A local couple have an
> >extensive website devoted to their Screamer :http://www.tandemride.com/

>
> >Jeff (another Jeff)

>
> Last question on BMX wheels: What about the axle widths? Do they
> match up with "normal" wheels? Many of the ads do not list the width.
>
> Same for axle diameter. Do they use the same size as regular bikes?


BMX front wheels can use either oversize 14mm axles, or 3/8", which is
cross-compatible with 9mm. The backstory is that originally all
branches of BMX used 3/8", but then 14mm axles came out for freestyle
bikes, leaving 3/8" as the domain of race bikes and low end BMX-style
bikes, but now many riders and companies are using 3/8" front hubs to
save weight, because 14mm really isn't needed up front for most
riding. Spacing in either case is the same 100mm as most bikes.
They're mostly nutted, although some higher end ones use allen bolts.
If it happened to use a standard axle you could convert it to QR, but
most BMX hubs that you'd actually want to buy won't use a standard
axle, because that implies cup 'n cone and all such hubs used in BMX
right now are pretty janky, with the exception of the high end Shimano
DXR race hubs, which don't use standard axles anyway.

The other thing about using an actual stock BMX wheel is that you'll
have to be careful about which front hub you use. Especially prevalent
are crudely designed and made no-name cartridge hubs, which you can
find on some fairly expensive "non-prefab" BMX wheels. Those aren't
gonna handle the miles very well. I've also seen some higher end
brands using hubs that are basically of this caliber and just look
pretty. Outside of the true high end, expensive stuff (Profile, Phil,
King, Crupi), the only brand I can think of whose hubs have production/
design values that should be high enough for what you're talking about
is Odyssey. And being a nicer bike and a tandem, just using a high-end
hub might be a good idea.
 
N

Nate Knutson

Guest
On Aug 26, 8:44 pm, JeffWills <[email protected]> wrote:
> On Aug 26, 4:08 pm, Jim <[email protected]> wrote:
>
>
>
> > Last question on BMX wheels: What about the axle widths? Do they
> > match up with "normal" wheels? Many of the ads do not list the width.

>
> > Same for axle diameter. Do they use the same size as regular bikes?

>
> BMX front hubs are the same width as most other front hubs: 100mm.
>
> Axle diameters are not. "Normal" BMX hubs use a 3/8" diameter axle,
> while "freestyle" axles are 14mm in diameter. Both are larger than the
> typical road hub's 9mm axle.


IME, there's not really a fork compatibility issue between 3/8 and
9mm, at least with the forkends used on most bikes. There are probably
exceptions, I'm sure. Remember that 3/8 is extremely common on many
types of lower-end adult bikes.
 
D

DougC

Guest
Jim wrote:
> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> the local bad roads. (Both sidewalls bent outward when hitting a
> hole.) We are looking for a replacement. The original is made by
> Velocity. The original wheel held up well until this.
>
> The options are to get another rim (perhaps Velocity) and graft it on
> to the old hub.
>
> Or find another wheel. Many of the 20" wheels are made for BMX use.
> Most have 36 spokes, 32 and 40 are also available.
>
> Any idea if these are any good? Given the abuse a BMX bike takes the
> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> popular and there are a bunch of others, too.
>
> Opinions? Personal experience?
>
> Thanks,
> Jim


I haven't looked real closely--but most BMX rims I seem to have seen
were fairly wide, ~35mm+, where most bents come with rims that are
fairly narrow, around 25mm.

The wider rim might be a good idea, if you planned on running a fatter
tire (than you were before).
~
 

daveornee

New Member
Sep 18, 2003
2,763
0
0
Jim said:
We have a RANS Screamer tandem and the front 20" wheel was damaged by
the local bad roads. (Both sidewalls bent outward when hitting a
hole.) We are looking for a replacement. The original is made by
Velocity. The original wheel held up well until this.

The options are to get another rim (perhaps Velocity) and graft it on
to the old hub.

Or find another wheel. Many of the 20" wheels are made for BMX use.
Most have 36 spokes, 32 and 40 are also available.

Any idea if these are any good? Given the abuse a BMX bike takes the
wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
popular and there are a bunch of others, too.

Opinions? Personal experience?

Thanks,
Jim
48H Psycho with a good hub and use DB spokes with a quality build.
Wash the rim when done building to remove any lubicants used on threads, heads, and rim sockets.
If the drilling will hold them, use Veloplugs and a strong rim tape that covers the entire width of the inside.
 
C

clare at snyder.on.ca

Guest
On Sun, 26 Aug 2007 21:44:06 -0400, Jim <[email protected]> wrote:

>On Sun, 26 Aug 2007 19:36:23 -0500, A Muzi <[email protected]>
>wrote:
>
>...
>>Jim wrote:
>>> I was thinking the same thing and it would be good to find out from
>>> people who went through the same thing.
>>>
>>> On the other hand, this is the fourth wheel on a 3 year old bike. With
>>> the previous velocity rims, heating from braking caused some kind of
>>> oily stuff to leak onto the adhesive rim strip. That caused the
>>> adhesive to lose its grip, the rim tape slid to one side, and the tube
>>> punctured after the tube went into a spoke hole.
>>>
>>> Oh, and it always happened after a long downhill run, the initial
>>> cause of the rim heating. The dealer and the Velocity people were
>>> pretty good. They finally built a wheel with a Velocity Taipan and
>>> that one was great until it took a too-big hit.

>>
>>I believe that you are honestly reporting what you believe you saw. I do
>>not believe a rim liner can creep to one side with a pressured tube/tire
>> installed.

>
>I never expected something like that, either. Thanks to the digital
>camera:
>
>Here's our first wheel. Notice the discolored area in the rim tape
>right over the rim joint. The rm tape moved very freely and the area
>was oily.
>http://home.rochester.rr.com/n2vx/wheel1b.JPG
>
>And that's where the inner tube got cut. Not a puncture, a cut:
>http://home.rochester.rr.com/n2vx/wheel2c.JPG
>
>I replaced the stock rim tape with Pedro's after wiping the area clean
>with rubbing alcohol. After a long downhill the oily stuff made the
>Pedro's "unstick" too with the same results.
>
>The dealer thought it was a freak thing and sent another wheel. The
>second wheel didn't do any better:
>http://home.rochester.rr.com/n2vx/wheel2a.JPG
>http://home.rochester.rr.com/n2vx/wheel2b.JPG
>
>The third wheel was made by the dealer using a Rhyno Lite. Spoke
>tension was uneven. It was poorly trued, had windup, and got worse on
>the first ride. We made arrangements to send it back.
>
>Wheel number 4 was the other Velocity and it worked OK for 3 years
>until hitting a hole when we coud not swerve. Never had to retrue it.
>A pretty good wheel considering the load on it.
>
>Perhaps rims 1 and 2 had something left on them from when they were
>run through the dies used to form the shape. All flats came after
>downhill runs where we had to brake and heat up the rims. There were
>no problems with rim 4, a different Velocity model.
>
>Any and all ideas are welcome. It is something I haven't seen before
>or since.
>
>Jim

Put an atom hub brake on to use as a "drag brake" to take the heat
load off the rim. Or better yet, possibly, a DISK BRAKE wheel. Keep
the rim brakes as well - but use the hub or disk brake for long
downhills. Better yet - put 'em on both ends.

--
Posted via a free Usenet account from http://www.teranews.com
 
M

Michael Press

Guest
In article
<[email protected]>,
Jim <[email protected]> wrote:

> On Sun, 26 Aug 2007 19:36:23 -0500, A Muzi <[email protected]>
> wrote:
>
> ...
> >Jim wrote:
> >> I was thinking the same thing and it would be good to find out from
> >> people who went through the same thing.
> >>
> >> On the other hand, this is the fourth wheel on a 3 year old bike. With
> >> the previous velocity rims, heating from braking caused some kind of
> >> oily stuff to leak onto the adhesive rim strip. That caused the
> >> adhesive to lose its grip, the rim tape slid to one side, and the tube
> >> punctured after the tube went into a spoke hole.
> >>
> >> Oh, and it always happened after a long downhill run, the initial
> >> cause of the rim heating. The dealer and the Velocity people were
> >> pretty good. They finally built a wheel with a Velocity Taipan and
> >> that one was great until it took a too-big hit.

> >
> >I believe that you are honestly reporting what you believe you saw. I do
> >not believe a rim liner can creep to one side with a pressured tube/tire
> > installed.

>
> I never expected something like that, either. Thanks to the digital
> camera:
>
> Here's our first wheel. Notice the discolored area in the rim tape
> right over the rim joint. The rm tape moved very freely and the area
> was oily.
> http://home.rochester.rr.com/n2vx/wheel1b.JPG
>
> And that's where the inner tube got cut. Not a puncture, a cut:
> http://home.rochester.rr.com/n2vx/wheel2c.JPG


Those are some huge pictures with very little information.
I stopped downloading here.

--
Michael Press
 
N

NickP

Guest
First you'd better check that it's the same 20" size rim. The two most
common sizes that call themselves 20" are the 451mm BSD rim used by Bike
Friday and some recumbents, and the 406mm BSD rim used for BMX. If your
tandem uses 451 rims then the brakes will most likely not accomodate a BMX
wheel.

Nick

"Jim" <[email protected]> wrote in message
news:[email protected]
> We have a RANS Screamer tandem and the front 20" wheel was damaged by
> the local bad roads. (Both sidewalls bent outward when hitting a
> hole.) We are looking for a replacement. The original is made by
> Velocity. The original wheel held up well until this.
>
> The options are to get another rim (perhaps Velocity) and graft it on
> to the old hub.
>
> Or find another wheel. Many of the 20" wheels are made for BMX use.
> Most have 36 spokes, 32 and 40 are also available.
>
> Any idea if these are any good? Given the abuse a BMX bike takes the
> wheels may be sturdy enough for tandem use. The Sun Rhyno Lite seems
> popular and there are a bunch of others, too.
 
J

Jim

Guest
On Sun, 26 Aug 2007 19:25:12 -0700, jim beam
<[email protected]> wrote:

>Jim wrote:
>> On Sun, 26 Aug 2007 19:36:23 -0500, A Muzi <[email protected]>
>> wrote:
>>
>> ...
>>> Jim wrote:
>>>> I was thinking the same thing and it would be good to find out from
>>>> people who went through the same thing.
>>>>
>>>> On the other hand, this is the fourth wheel on a 3 year old bike. With
>>>> the previous velocity rims, heating from braking caused some kind of
>>>> oily stuff to leak onto the adhesive rim strip. That caused the
>>>> adhesive to lose its grip, the rim tape slid to one side, and the tube
>>>> punctured after the tube went into a spoke hole.
>>>>
>>>> Oh, and it always happened after a long downhill run, the initial
>>>> cause of the rim heating. The dealer and the Velocity people were
>>>> pretty good. They finally built a wheel with a Velocity Taipan and
>>>> that one was great until it took a too-big hit.
>>> I believe that you are honestly reporting what you believe you saw. I do
>>> not believe a rim liner can creep to one side with a pressured tube/tire
>>> installed.

>>
>> I never expected something like that, either. Thanks to the digital
>> camera:
>>
>> Here's our first wheel. Notice the discolored area in the rim tape
>> right over the rim joint. The rm tape moved very freely and the area
>> was oily.
>> http://home.rochester.rr.com/n2vx/wheel1b.JPG
>>
>> And that's where the inner tube got cut. Not a puncture, a cut:
>> http://home.rochester.rr.com/n2vx/wheel2c.JPG
>>
>> I replaced the stock rim tape with Pedro's after wiping the area clean
>> with rubbing alcohol. After a long downhill the oily stuff made the
>> Pedro's "unstick" too with the same results.
>>
>> The dealer thought it was a freak thing and sent another wheel. The
>> second wheel didn't do any better:
>> http://home.rochester.rr.com/n2vx/wheel2a.JPG
>> http://home.rochester.rr.com/n2vx/wheel2b.JPG

>
>strange. maybe the rim joint peg is glued into position and heat is
>affecting it?


Good question. The rim was greasy and slippery at that spot. It also
made the rim tape unstick. It also happened on both rims of that
type. The third Velocity wheel did the trick, at least up until now.

And I can't complain about getting 3 years out of it, either. Total
weight must be around 370 lbs of rider + say 40+ lbs of bike. That's
quite a load and we have bad roads.

I'm going to head down to the LBS and see about the Rhyno Lite XL. It
has a welded seam and looks a bit wider than what we got now.

From the other comments BMX hubs sound like a non-starter; there may
be quality problems and we're not looking for a solid-axle no-quick
release hub.

And I'd like to thank all the people who took the time to reply. You
have been a big help.

Jim
 

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