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Missy Giove's QR pops open - Page 17  

post #241 of 255

Re: Missy Giove's QR pops open (long)

In news:timmcn-8EE116.15004204062003@gemini.visi.com, Tim McNamara <timmcn@bitstream.net> typed:
>
> James Annan, Jobst Brandt and Chris Juden- to name three- are not "clueless and inexperienced
> morons."

Jobst AFAIK doesn't ride mountain bikes, Chris does but I've found some of his comments in the CTC
magazine "curious", James I don't know about.

> When it's muddy, I don't ride on the trails because it's destructive and leads to trail erosion
> and closures. Riding in the mud may be fun, but it's selfish.
>

If I followed that advice I would rarely get out off-road ;-(

> Disk brakes *do* exert an ejection force on the axle because the design necessarily makes it so.
> Simple as that. If you want to experiment, turn your bike upside down, loosen the QR, spin your
> wheel in the appropriate direction, and hit the brake. The axle will pop out of the dropout either
> partially or completely. That *is* the design flaw and it's not a hypothesis, unless you think
> that Newtonian laws of physics and pi are also hypotheses.
>

I guess you could say, take out all the wheel bolts on a car and drive down the road. The wheels
fall off. Is that a design flaw? No because the wheel bolts prevent them from falling off. It is not
uncommon that things would come apart in use without the fasteners. So whether its a design flaw or
not depends on the design of the fastening system.

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer
post #242 of 255
Thread Starter 

Re: Missy Giove's QR pops open (long)

Jasper Janssen wrote:

>
> I don't intend to accuse anyone, but it is the only way I can
possibly see
> for either of them to make any money from the whole debacle.

So in that case it is clear that I'm not going to make any money from it, despite your and
superslinky's mud slinging.

James
post #243 of 255
Thread Starter 

Re: Missy Giove's QR pops open (long)

Tony Raven wrote:

>
> It seems though that you are now arguing that any caliper configuration will lead to the QR
> loosening so are you advocating QRs should not be used with disc brake period? Because if you are
> we can all forget repositioning the caliper as every disc brake will need a bolt through axle.

I don't know for sure. As you said earlier, a poor 'solution' that does not address the problem
properly, may be worse than no solution at all. If skewers have to still be over-tight to prevent
unscrewing then that is not IMO a satisfactory solution. But I'm not trying to say what must be
done, rather pointing out some possible flaws in attempted solutions.

If any sort of full axle clamp is considered unreasonable, then a changed dropout angle combined
with a properly threadlocked skewer seems like it should be fine. However changing skewer design may
be a slow process as their manufacturers have no real need to change, roadies don't need it and
might object, but two forms of skewer on the market would be a recipe for disaster etc...

However a fully-surrounded clamped axle need not be that complex, Jobst's idea of a conical
interface might be fine, and there are already designs for end clamps from the bolt-through market
that could easily be adapted to clamp on teh stubs of a standard axle. I've seen some that just flip
off by hand, wheel removal would not be tedious and if lawyer lips were simultaneously dropped, it
might even be better than the current arrangement.

James
post #244 of 255
Thread Starter 

Re: Missy Giove's QR pops open (long)

Tony Raven wrote:

> Perhaps another way to put this in perspective. The sorts of accidents you are postulating will
> tend to be high speed aggressive braking probably on a steep downhill. Such accidents will tend to
> be serious - wheel loss leading to sudden pitch forward onto fork ends and head into ground. Yet I
> believe Russ has the dubious honour of being only the first or second mountain biker in Stoke
> Mandeville which is where all serious spinal injuries in the UK tend to be transferred for
> specialist treatment. If there is a big iceberg there the tip is mighty small.

I agree with that, most of the injuries are facial and head, a few concussions but (apart from Russ)
I know of no long term serious harm. You might have seen there was a narrow escape mentioned on STW
last year where someone was in intensive care (coma?) for a couple of days, but AFAIK they recovered
fine. I really don't know how these figures might translate to world-wide numbers. It does seem
quite possible that the UK is particularly susceptible, due to (any combination of) early adoption
of disks, a fashion for feeble skewers, and a habit of going on long day rides with lengthy descents
rather than round purpose-built courses for an hour or two at a time.

James
post #245 of 255
Thread Starter 

Re: Missy Giove's QR pops open (long)

Tony Raven wrote:
> In news:timmcn-8EE116.15004204062003@gemini.visi.com, Tim McNamara <timmcn@bitstream.net> typed:
>
>>James Annan, Jobst Brandt and Chris Juden- to name three- are not "clueless and inexperienced
>>morons."
>
> Jobst AFAIK doesn't ride mountain bikes, Chris does but I've found some of his comments in the CTC
> magazine "curious", James I don't know about.

James and jules were UK Trailquest champions and won the Manx End-to-End (both in the tandem
category only!), raced in the Transrockies Challenge last year (including a stage win and a 2nd
place in the mixed category) but most of our MTBing is just our commute to work these days. We've
also designed several of our bikes, partially built two of the frames and assembled and
maintained the rest.

James
post #246 of 255

Re: Missy Giove's QR pops open (long)

Tim McNamara <timmcn@bitstream.net> wrote in message
news:timmcn-8EE116.15004204062003@gemini.visi.com...

<snip>

> Modern bicycle disk brakes are a real improvement in one situation only: mud.

What total, utter and complete 'codswallop' (as my gran would have said). Modern hydraulic disk
brakes (not talking about the nasty stuff here) out-perform modern cable rim brakes (again,
referring to good quality pieces of engineering) in every desirable way _period_.

I live in the UK, have ridden in wet, dry, clean and muddy using both rim brakes (centre pull and
side pull road callipers, MTB canti's, MTB V's) and hydraulic disc (Hope Mini) at different times.
The hydraulic disk out-performs any of the rim brakes in any and all conditions.

Overall stopping power is greater and requires less physical effort, controlling the delivery of
that stopping power is easier than with (especially) the V's - there's just no question about their
superior performance.

Wake up and smell the bacon.

Shaun aRe
post #247 of 255

Re: Missy Giove's QR pops open (long)

"David Damerell" <damerell@chiark.greenend.org.uk> wrote in message
news:xUw*k6cUp@news.chiark.greenend.org.uk...
>
> How _exactly_ can you have more stopping power than enough to lift the back wheel?
>

Modulation. V-brakes are too grabby so you can't go confidently as close to the limit as you can
with discs. Personally I think the hydraulics are the key factor though as in the dry my Magura rim
brakes are everybit as good as my Hope discs

>
> Yes, hauling away on brake levers is pretty hard work - not like that pedalling stuff, that
> anyone can do.
> --

You have clearly never ridden a long technical downhill on a bike or you would not be saying that

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer
post #248 of 255

Re: Missy Giove's QR pops open (long)

In newsravdvoespbe2ijkfuo6jfna565l87fdfr@4ax.com, Jasper Janssen <jasper@jjanssen.org> typed:
> On Wed, 4 Jun 2003 18:32:22 +0100, "Tony Raven" <junk@raven-family.com> wrote:
>
>> There are very few circumstances that would push a front wheel forward out of a dropout
>
> How about braking on the rear wheel?
>

The ejection forces in such circumstances are less than you would get from gravity if you lifted the
front of your vertical dropout bike. If you are that concerned about the ability of your QR to
retain your wheel under those conditions stop riding now!

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer
post #249 of 255

Re: Missy Giove's QR pops open (long)

In news:req*e3dUp@news.chiark.greenend.org.uk, David Damerell
<damerell@chiark.greenend.org.uk> typed:
>
> Sure I haven't. Or maybe I have? Who knows? It's still got to be a damn sight less work for the
> fingers to work the brakes than for the legs to push you _up_ the hill in the first place.

You are just demonstrating further that my first response was right. Just for fun, sit on the couch
and squeeze a tennis ball hard for five minutes. See that's so much easier than doing something real
like pedalling uphill. Perhaps if you had ridden mountain bikes downhill with different braking
system your "theoretical" views on their performance would have more credibility

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer
post #250 of 255

Re: Missy Giove's QR pops open (long)

In news:timmcn-264DF6.17584806062003@gemini.visi.com, Tim McNamara <timmcn@bitstream.net> typed:
>
> Or you could consider the reality of physics. It's harder to pedal a bike uphill than to squeeze
> the brake levers coming down hill. Or does sitting on the couch squeezing your tennis ball elevate
> your heart rate and make you short of breath? ;-)
>

Bet I can ride a bike up hill for longer than you can keep a tennis ball squeezed.

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer
post #251 of 255

Re: Missy Giove's QR pops open (long)

"Tony Raven" <junk@raven-family.com> wrote:

>In news:timmcn-264DF6.17584806062003@gemini.visi.com, Tim McNamara <timmcn@bitstream.net> typed:
>>
>> Or you could consider the reality of physics. It's harder to pedal a bike uphill than to squeeze
>> the brake levers coming down hill. Or does sitting on the couch squeezing your tennis ball
>> elevate your heart rate and make you short of breath? ;-)
>
>Bet I can ride a bike up hill for longer than you can keep a tennis ball squeezed.

If you're talking about sqeezing the ball just hard enough to simulate the force needed to slow down
a MTB, my money's on Tim. I haven't ever finished a ride thinking "wow, my arms are wasted", but
plenty of 'em thinking "wow, my legs are wasted". In fact, the closest I've ever come to pumping out
my arms was on a road bike!

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
post #252 of 255

Re: Missy Giove's QR pops open (long)

> Are you talking about the bead slipping on the rim or the bead actually tearing?

Tearing. The bead was made up of two steel wires and the rubber pulled off of them.

--
Phil, Squid-in-Training
post #253 of 255

Re: Missy Giove's QR pops open (long)

David Damerell <damerell@chiark.greenend.org.uk> wrote in message
news:xUw*k6cUp@news.chiark.greenend.org.uk...
> Shaun Rimmer <shaun@newtronic.co.uk> wrote:
> >Tim McNamara <timmcn@bitstream.net> wrote in message
> >>Modern bicycle disk brakes are a real improvement in one situation only: mud.
> >Overall stopping power is greater
>
> How _exactly_ can you have more stopping power than enough to lift the back wheel?

Oh dear, you are rather confused aren't you?

> >and requires less physical effort,
>
> Yes, hauling away on brake levers is pretty hard work - not like that pedalling stuff, that
> anyone can do.

Your sarcasm here merely serves to highlight your ignorance.

I'm really sorry that the facts are not to your liking - maybe you better fabricate some new ones
that please you.

Shaun aRe
post #254 of 255

Re: Missy Giove's QR pops open (long)

Ryan Cousineau <rcousine@sfu.ca> wrote in message
news:rcousine-C80D8A.08190307062003@morgoth.sfu.ca...
> In article <07v3ev8qgi6h4jjj1v5lbj2fpj9rr6jq50@4ax.com>, Mark Hickey <mark@habcycles.com> wrote:
>
> > "Tony Raven" <junk@raven-family.com> wrote:
> >
> > >In news:timmcn-264DF6.17584806062003@gemini.visi.com, Tim McNamara <timmcn@bitstream.net>
> > >typed:
> > >>
> > >> Or you could consider the reality of physics. It's harder to pedal a bike uphill than to
> > >> squeeze the brake levers coming down hill. Or does sitting on the couch squeezing your tennis
> > >> ball elevate your heart rate and make you short of breath? ;-)
> > >
> > >Bet I can ride a bike up hill for longer than you can keep a tennis
ball
> > >squeezed.
> >
> > If you're talking about sqeezing the ball just hard enough to simulate the force needed to slow
> > down a MTB, my money's on Tim. I haven't ever finished a ride thinking "wow, my arms are
> > wasted", but plenty of 'em thinking "wow, my legs are wasted". In fact, the closest I've ever
> > come to pumping out my arms was on a road bike!
>
> I actually did finish a descent in a race a few weeks ago where I did so much braking my arms
> hurt, and it was a relief to start pedalling and stop braking. My arms were wasted .

I'd had frequent aching hands and forearms from braking on long/multiple descents before I fitted
the Hope brake, and for my size, I have quite large forearms, and I do have a good strong grip
(that'll be from the rock climbing I guess).

Even trying to keep a small constant/slightly modulated pressure applied with the fingers, at the
angles applicable to braking causes hands to stiffen and ache.

Shaun aRe - 'everyone knows that'...
post #255 of 255

Re: Missy Giove's QR pops open (long)

Tim McNamara <timmcn@bitstream.net> wrote in message
news:timmcn-0D6E71.15190706062003@gemini.visi.com...
> In article <bbq1h6$cdogt$1@ID-170198.news.dfncis.de>, "Shaun Rimmer"
> <shaun@newtronic.co.uk> wrote:
>
> > Tim McNamara <timmcn@bitstream.net> wrote in message
> > news:timmcn-8EE116.15004204062003@gemini.visi.com...
> >
> > <snip>
> >
> > > Modern bicycle disk brakes are a real improvement in one situation only: mud.
> >
> > What total, utter and complete 'codswallop' (as my gran would have
said).
> > Modern hydraulic disk brakes (not talking about the nasty stuff here) out-perform modern cable
> > rim brakes (again, referring to good quality
pieces
> > of engineering) in every desirable way _period_.
>
> In what way do they perform better?

I told you in the last paragraph, but I will add to that, 'they take a lot less maintenance to keep
at their peak performance than rim brakes'.

> > I live in the UK, have ridden in wet, dry, clean and muddy using both
rim
> > brakes (centre pull and side pull road callipers, MTB canti's, MTB V's)
and
> > hydraulic disc (Hope Mini) at different times. The hydraulic disk out-performs any of the rim
> > brakes in any and all conditions.
>
> In what way do they outperform?

Are you blind man?

> > Overall stopping power is greater and requires less physical effort, controlling the delivery of
> > that stopping power is easier than with (especially) the V's - there's just no question about
> > their superior performance.
>
> Utter tripe (the US version of codswallop, perhaps). Your stopping power is limited by traction
> and has nothing to do with what type of brakes you're using, as long as the brake can lock up
> the wheel.

Locking a wheel when the bike is static or moving slowly is easy. Get that speed up some, then
achieving the same becomes more difficult, as well as obviously less desireable. Good hydro discs
can achieve the same braking force with less lever pressure, and deliver it ina more consistant
(rather than condition dependant) and manageable manner that with rim brakes.

> > Wake up and smell the bacon.
>
> Wake up and stop hallucinating.

I believe you are projecting.

> Or go back to the Dwarf.

Oh dear, that cut me deeply - see you when I get back from victim therapy, heheheheheh....

Shaun aRe
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