The length of spindle you use should be driven entirely by chain line. Velo Orange says that the Gran Cru will be 'about 139mm' in Q- factor. That means that when you pick the right spindle length for chainline, the Q-factor will be about 139mm. They also throw in that is 'the narrowest ever'. So, anybody who wants to run that crankset should make sure their frameset is among the narrowest ever, so they can choose the right spindle for chainline. If you put the narrowest ever crankset on a wide chainstay frame, like the Bombadil, your crankarms will hit the chainstays. You'll probably have to use a spindle that is 8mm longer on both ends to clear the stays. Doing that will foul up your chainline, probably badly. You might not even be able to use the largest cog or two in the small ring. You are correct to point out that if people choose to use whatever spindle with whatever crankset, that the Q-factor is not an intrinsic property of the crankset at all. It is a property of the combination of spindle and crankset. When crank manufacturers or retailers state Q- factor, they are assuming you are going to use the right spindle length for chainline, which is what you should do if you can.
On Apr 29, 10:23 am, happyriding <happyrid...@yahoo.com> wrote: > On Apr 22, 11:25 am, William <tapebu...@gmail.com> wrote: > > > Another thing to keep in mind if you have your eye on that crank. Pay > > very close attention to how the Q-factor of the crankset goes with the > > chainstay width of the frame you are setting up. > > How is Q a property of the crank? Wouldn't the bottom bracket that is > necessary to allow the crank to clear the chain stays determine the > Q? Or do some cranks only fit on certain narrower bottom brackets? > > Also, has anyone had a problem adjusting to the huge Q of a Rivendell > bike? That is something I hadn't really considered. > > > I don't know what > > bike you are building, but I will report that my 155mm Q-factor > > Ritchey (113mm spindle) barely fit on a Bombadil. There is no hope > > that a 130-something crankset would fit without a massively long > > spindle, which would change it into a 155mm Q-factor crankset and > > would foul up your chainline and front shifting. That 46/30 Gran Cru > > would be sweet on an old school Rando/Brevet bike (basically a road > > bike). No chance would that crankset work on a Bomba/Hunqa. Even a > > Hillborne/Hilsen would be questionable. Roadeo should work. > > Ok, thanks. Good to know. > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To post to this group, send email to rbw-owners-bu...@googlegroups.com. > To unsubscribe from this group, send email to > rbw-owners-bunch+unsubscr...@googlegroups.com. > For more options, visit this group > athttp://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
