Thomas, PM sent about 46t middle chainrings I have. To answer your question - it depends on the chainring. Some have a chamfered edge that help with up shifts. To be in the correct orientation with the chainring bolt recesses, chainrings are marked as middle or outer. In practice you can swap middle and outer, but chainring bolts won't sit flush if you keep the chamfer edge correctly facing the inside. David Chicago
On Wednesday, June 17, 2015 at 3:27:38 PM UTC-5, Thomas Lynn Skean wrote: > > Hi! > > Has anyone used the 46T Origin-8 chainring sold by RBW (or one like it) in > the middle position on the RBW-sold Sugino crank (or one like it)? Any > comments on how well it works or worked? If you got it to work "well > enough" for you, was there anything non-obvious that you had to do to make > that happen? > > So here's the deal: I have three bikes, two Hillbornes and a Bike Friday > (406BSD wheels). The Hillbornes have the triple Sugino cranks sold by RBW. > The Bike Friday came with a 130BCD triple crank, 52T/42T/30T. I got rid of > the 52T chainring because I never used it; higher than I want in general. > Replacing the 42T middle chainring with a 44T was an improvement in the > overall gearing on the Bike Friday and leads me to want to try a 46T. > > However, as another goal I'd like to have the same Sugino 110BCD crank on > all three bikes. My question above arises because I don't see any > 46T-or-greater 110BCD chainring on the web sold as a "middle" ring. Some, > including the 46T 110BCD Origin-8 chainring sold by RBW, are not described > as being either explicitly inner, middle, or outer. I note that RBW's > web-site says that its 44T chainring can be used as either a middle or an > outer; it does *not* say that for the 46T. > > With respect to a given 110BCD chainring that is sold as a middle vs outer > ring for a triple crank, what about the chainring makes it that way > (instead of being position-agnostic)? > > In case it matters to potential respondents... the Hillbornes have 7-speed > clusters in the back and the Bike Friday has an 8-speed cluster. Also, I'm > uninterested in 9-speed unless I'm forced by product availability to go > that way. Fortunately I have predicted the demise of less-than-9-speed > drivetrains, thus making it very likely that they'll stay around. I wonder > if that principle works when predicting one's own demise? > > Yours, > Thomas Lynn Skean > P.S. > Just so you know I've considered it... the shifting between the 30T inner > and the 44T middle chainring on the current Bike Friday setup works "well > enough" for me. I've literally had zero problems, but I've done it rarely > enough that it's a very limited sample size. I suspect the 30T-46T would be > good enough for me also, though I do have a 32T 74BCD chainring waiting in > the wings, which I presume would have a decent chance of shifting much like > the 30T-44T combination. With the overall gearing on the Bike Friday, > goodness knows I'd be happy enough with a 36T inner ring if they are > available. > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
