Re: Chain idler efficiency - roller vs. toothed

Tom Sherman wrote:
> 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 re***bent with a complicated

> chain-line.

Why not avoid idlers and re***bents with complicated chain-lines?

It might not (yet) be possible with a tandem, but for a single
rider bike, cruzbike offers a short normal chain-line.


JonB