Re: Chain idler efficiency - roller vs. toothed

TandemFan wrote:

[cross-posted to ARBR for Perry Butler's amusement]

> We have a R[ANS] Screamer tandem and there are a few idler rollers for
> the chain.  An outfit sells toothed idlers for about $250:
>
http://www.terracycle.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=T&Product_Code=IdlRansScr&Category_Code=IdlersALL
> 
> They have a long blurb on why they are better:
> 
>
http://www.terracycle.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=T&Category_Code=IdlersALL
> 
> What's the scoop?  Does it make any difference at all, or are we going
> to go faster?
> 
Someone needs to tell Pat Franz that it is "RANS" and not "Rans".

While the manufacturers in question are trying to meet a price point for 
their bicycles, they are not going to be putting junk chain idlers on 
their bicycles [1]. Therefore, while there is room for improvement, the 
gains will likely be small as drive-train friction is a small component 
of total non-conservative losses, even on a recumbent with a complicated 
chain-line.

If you want to make a RANS Screamer a lot faster than stock, put a front 
fairing (Zzipper or Mueller) and a bodysock on the bike.

[1] Unlike some defunct manufacturers of the past.

-- 
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful