Further divergence but perhaps helpful. I was recently at John Hollands' frame shop north of Baltimore in Maryland. He is very knowledgeable and happily shares that information. He also builds beautiful appearing frames although I have never ridden one of them. To the point-he advised that he receives approximately one e-bay frame weekly with problems. Most problems are the wrinkled top and down tube; the fracture in front of the bottom bracket shell; and one I was ignorant of-the hairline fracture in the right Campagnolo dropout. He had a 2 lb. coffee can full of fractured Campagnolo dropouts. His theory is that the normal freewheel style set up allowed for an extended spacer or spacers between the right side lock nut end of the bearing. This extended axle would continually flex while riding constantly massaging the dropout and eventually and apparently, inexorably, leading to failure. The theory seems reasonable to me. More importantly, when purchasing a used bicycle, that is an area that bears scrutiny especially with a magnifying glass.
TomWitkop Rockville, MD
(Who reduced his bicycle menagerie by two in the last two days by giving
away a mountain and BMX bike-I can trip over a classic bicycle just as
easily as a BMX bike.)
On Mon, 15 Jan 2001 16:52:19 -0500 Sheldon Brown
<CaptBike@sheldonbrown.com> writes:
> Brandon"monkeyman"Ives wrote:
>
> > >Sprinting and Keirins bring out the conservative in any rider.
> 200 lb
> >>riders who can squat lift 400 lbs and more do strange things to
> bikes.
> >>Every bit of rigidity obtainable can make a difference in how
> squirrely the
> >>bike is in the final turn. How the bike tracks through this turn
> makes all
> >>the difference in determining possible lines, effect of rules and
> finishing
> >>strategy. There is also a psychological component in having
> complete
> >>confidence in the bike.
> > >Joe
> >
> >Sorry Sheldon but Joe is 100% right-on about the need for really
> strong
> >bikes on the track.
>
> I never said anything to the contrary.
>
> >I've watched just about every part on a track bike
> >break just on the stresses exerted by the rider. Stems and forks
> snap,
> >wheels and chainrings fold, seatposts and frame tubes twist. I
> know people
> >who have replaced their bolt-on axles with QR axles (without the
> QR) to
> >save weight but have always bent or broken the axles.
>
> A QR axle _without_the_QR_ is certainly weaker. I'm not convinced,
> however that a QR axle _with_ a good QR tightened properly is any
> weaker in practice.
>
> >If you use a QR on
> >the track it WILL slip. If you watch someone like Marty Nothstein,
> Ken
> >Carpenter, or my young friend Jason Vance pull on a pair of bars
> you will
> >understand the use of overbuilt parts.
>
> Again, I never said anything to imply that they don't need strong
> parts--but, the drive train stress is inversely proportional to the
> chainring size, and directly proportional to crank length. Thus
> even
> behemouth sprinters who snap stems and bars like toothpicks aren't
> pulling as hard on the chain with their 165 cranks and 48 tooth
> rings
> as a mountain biker grinding a 24 tooth granny gear with 175 cranks.
>
> >If all you do is cruse around town
> >on a track/fixed bike lightweight parts are fine, but on a 48
> degree bank
> >at 30+mph they just won't cut the mustard.
>
> Neither the top speed nor steepness of the banking have anything to
> do with the need for strength. Indeed, the greatest stresses on a
> sprint bike occur at the lowest speeds, at the beginning of a jump.
>
> Sheldon "Campagnolo 1010 Dropouts Are Strong Enough For Anybody"
> Brown
> Newtonville, Massachusetts
> Harris Cyclery, West Newton, Massachusetts
> Phone 617-244-9772, 617-244-1040, FAX 617-244-1041
> http://harriscyclery.com
> Hard-to-find parts shipped Worldwide
> http://captainbike.com
> Useful articles about bicycles and cycling
> http://sheldonbrown.com
>
> _______________________________________________
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