[Yak] A speedier slug (was: PL a slug? Does a chicken have hard lips?)

[John S. Allen]

At 04:58 PM 10/1/2008, Galfromdownunder wrote:

> From the desk of none other than Rob English, http:// 
> www.bikefriday.com/gallery/robenglish, due to race a recumbent in
>RAAM, so he should know...
>
>Three things I think:
>
>1. Gearing. Greg doesn't say if he is spinning out or not, but with
>only a 89" gear (the 406 wheel is about 18.5" diameter), compared to
>120" on a typical 700C bike, he needs a bigger chainring.
>
>(or that Capreo! Some people use both, like BF Club of Austin, TX's
>Ron Neher and his 62 tooth chainring+Capreo  http:// 
>www.bikefriday.com/gallery?imageId=2262 - LC)
>
>
>2. Tyres. The smaller wheels seem to amplifly the difference in tyre
>rolling resistance. The fastest tyres I know of in the 406 size are
>the Schwalbe Stelvios (get them quick before they stop making them
>for '09).
>
>(or switch to a 451mm bike like the Pro - LC)

Or just switch wheels. My NWT has 451 wheels. I call it my Rocket 
Tourist. Apparently this was the original owner's preference -- te 
bike was factory-refurbished.

There is relatively little difference in performance depending on the 
frame -- really, the Llama frame probably only weighs a pound or two 
more than the PL frame, if that. But gearing and tires make a *big* 
difference. My Raleigh Twenty has 406 wheels with 47 mm wide tires, 
and it is noticeably slower than the Friday. You will need to adjsut 
the brakes and may have to change them, to match the different rim size.

>3. Aerodynamics. I don't know what handlebars are being used, but
>assuming the typical mtb bars on a PL, the upright position and width
>makes a huge speed difference compared to drops, even when drafting.

Also, lower bars make for more efficient power production. The 
gluteus muscles can't go to work unless they are extended, and they 
are extended only if the trunk is leaning forward.

>( I will stop butting in - LC)

Task passed on to me -- JSA!

John S. Allen

jsallen *at* bikexprt.com

http://bikexprt.com