Join Date: Jul 2005
Location: Los Angeles
Bikes: Dahon Jetstream XP, Merlin Road Ti, Fisher Mt. Tam
Originally Posted by LittlePixel
The other way - perhaps more work but possibly more elegant, is to retrofit some sliding Rohloff-compatible dropouts that apparently hold tightly enough to the hub so as not to need the torque arm. Since both make use of non-vertical dropouts I can't quite see where you'd need the tensioner. Is this purely for bikes with double or triple chainrings up front maybe? Anyone?
Yes, true, if you have horizontal dropouts you could theoretically get away without the torque arm and the chain tensioner, which would definitely save on some weight. The caveat here would be for bikes with rear suspension, or whose rear triangle pivots under the bike, in which case the change in distance between the BB and rear hub might create or increase the tendency for the chain fall off. In those cases, even with horizontal dropouts, the tensioner would be necessary. (I know those don't apply to your R20.)
As far as fitting OEM style dropouts, that would mean engaging the services of a competent frame builder to modify the frame, so add that to the cost of the Rohloff. It would also mean that you are stuck with the Rohloff, as the frame has been rendered useless without it (except for SS/Fixies
). Perhaps someone has designed dropouts which are compatible with both standard derailleurs and
the Rohloff, but I haven't seen it.
When I put a Rohloff on my Jetstream XP, I went through these mental gyrations as well. I elected to go with the torque arm and chain tensioner in spite of the added weight, not because I was worried about the retrofitting of a standard derailleur back onto the Jetstream, but because I expect the Rohloff will outlast my Dahon, and I want to be able to easily migrate it to another frame in the future.
Rohloff provides lots of information, including technical drawings for dropouts, here
. They even provide the dropout specs in .dxf format for your friendly neighborhood CNC machine shop. (!)
Good luck and keep us up to date on your progress.
Originally Posted by 14R
Never heard of the Millenium Falcon? She made the Kessel Run in "less than twelve parsecs".
FWIW: That line has long been a source of some consternation among my fellow co-workers and me. (I have been doing special effects for movies and TV since 1983. We're all geeks, and recite these movies in toto
in our sleep.) A parsec is a unit of length/distance, but Han is using it as though it were a measure of time. The debate has raged for decades.
I came to say I must be folding . . .
Dahon Jetstream XP
Dahon Helios SL
— or not . . .
Fisher Mt. Tam (c.1988)
Merlin Road flat bar project
Schwinn Twinn Deluxe
Last edited by CaptainSpalding; 08-02-07 at 04:01 PM.
Reason: Added a smart-ass comment.