Adam Kadlubek wrote:
On 28 Kwi, 00:37, Jon Bendtsen wrote:
Tom Sherman wrote:
Jon Bendtsen wrote:
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/...=PROD&Store_Co...
They have a long blurb on why they are better:
http://www.terracycle.com/Merchant2/...=CTGY&Store_Co...
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.
Why not avoid idlers and recumbents 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.
And introduces a whole other set of compromises in seating position,
yeah, thats true.

weight distribution, traction on steep hills, etc. Long chain lines are
actually i dont find the traction too bad up hill. But
we dont really have hills in Denmark, it's just flat flat
flat compared to other places.

not necessarily a bad thing, as several issues with short chain lines go
away that make wide range gearing difficult.
Why would short chainlines make wide range gearing difficult?

Cross chain without guilt for instance.

Then combine a rohloff/nuvinci + a schlumpf drive == 0 cross chain.
If normal bikes can live with some cross chain, so can a recumbent.



JonB