john
Just as important( if not more) (to prevent pedal strike) is the Tread or
q-factor of your crank/pedals/shoes. If you have wide or poor "cornering"
pedal this should be as much of a concern (meaning don't go too slow) as a
longer crank. The reason is the riding surface to bike angle is at nearly
45 deg. at that angle, whether you go up or in, same effect....
For example I ride with 170mm length cranks that were made for 113mm bb
spindle but installed on a 103mm.(my chnrng is outside of "big" chnrng
position). Pedal axle to crank interface is chamfered for at least another
5mm each side.
So I would have the same cornering clearance as a bike set up "normally"
with 160mm cranks. Or, If I rode with 180 cranks, i would have same
cornering clearance as a "typical" bb/crank/pedal setup with crank length of
170mm.
It is also easier on my knees and better aerodynamics (albeit slight).
However if you have duck feet, ie your heels tend to hit the chainstays,
you are out of luck and Short cranks or custom high bottom bracket, or when
on the track, just ride fast will be required.
As long as I am sending out an email, Wrote some articles on securing
wheels to frame... Although slipping a wheel is not as likely on a track
bike since the chain force is lower then other types of cycling (cause the
gearing is high, well ok unless your running microdrive, like a 34x11,
etc]., it is still important, since micro adjustment of the chain is often
required.
There are some inexpensive track hubs (and some expensive ones too) whose
main upgrade should be an increase in the surface area clamping onto the
frame (bigger dia locknuts and washers, and loose the serrations! ). Also
if you have threaded cone and locknut, use threadlock, the axle nut clamping
force can easily overcome the adjustment "preload" and if no thread lock
they will go loose and bearing adjusment will be lost.
http://bikeeng.blogspot.com/2008/05/bolting-bicycle-wheel.html
http://bikeeng.blogspot.com/2009/02/quick-release-force.html
On Sat, Apr 4, 2009 at 3:57 PM, Garcia wrote:
> 1) I prefer and use 165 crank arms, but agree not to go over 170 for
> general track racing.
>
> 2) The rental GT bikes have the 14/15t cogs with a 46t ring, i.e. 88.71and 82.8 gear inches, which is the most common bike use for the Track
> Development Classes and racing, but we also have some Fuji bikes with only a
> 16t cog and with 48t ring, i.e. 81 gear inch. For guys the have been riding
> quit a bit but not road racing, I would recommend around an 86 gear inch.
> I've been known to an 86 to start the season when it's cold.
>
> Garcia
>
> ------------------------------
> *From:* Mike Murray
> *To:* Chip Slöan ; obra@list.obra.org
> *Sent:* Friday, April 3, 2009 10:23:05 PM
> *Subject:* Re: [OBRA Chat] Track bike advice
>
> 1) Depends on the event. You could run 180 or more for pursuit. I would
> not run longer than 170 for general track racing at Alpenrose.
>
> 2) The rental bikes have 46T rings and 14 and 15t cogs, i.e. 88.7 and 82.8
> gear inches. Generally for guys somewhere between those 2 gears is a good
> gear to start track racing.
>
>
>
> Mike Murray
>
> -----Original Message-----
> *From:* obra-bounces@list.obra.org [mailto:obra-bounces@list.obra.org] *On
> Behalf Of *Chip Slöan
> *Sent:* Friday, April 03, 2009 19:53 PM
> *To:* Obra
> *Subject:* [OBRA Chat] Track bike advice
>
> So I'm building up my very first track bike to hit some Wednesdays and get
> going on the track. 2 Questions:
>
> 1) Crank length. How long can I go? I run 175s on the road bike, but it
> seems most run shorter cranks.
>
> 2) What gear ratios are good to start with? Like what are on the rental
> bikes?
>
> Thanks,
>
> Chip
>
>
>
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--
jms, pe pdx, or
http://bikeeng.blogspot.com/