Of course, it's nice to have a choice of BB spindle to use ! To further that..... think about the effect on the chainline between the 107mm and the 113/115 "recommended" by Sugino and most retailers. The common road triple is about 45mm(measured center seat tube to center of middle ring). Mtb triples are spec'd 47.5 and up. So, Riv is giving you a pretty tight chainline(for a triple), I don't know what it is w/107 BB, but I bet it's 45mm or less. This works best if you ride mostly in the two big rings, which most road riders do. If you wanted to use the 2 smaller rings mostly.... to get the most usable gears in the small ring you would be better off using a longer spindle. A 113/115 would add 3/4mm to the chainline. That puts it in the Mtb small ring rider category.
That's the beauty of a cartridge style BB too..... you can adjust the chainline with different spindles or use spacers to get it wherever you wish. Even if say.... a 107 BB was a bit too tight on a frame, you may be able to just add a 1mm spacer inside the drive side cup so the small ring clears the frame adequately. Stay with me here........ I've searching my (few) options for a 185mm crank length that I use, and one choice is a Surly Mr. Whirly. I asked Surly what the Q factor was, and they told me it was 171mm with the middle length axle they offer(They offer 3 axle lengths). The shortest axle, for a 68mm BB shell, would knock that down to 161mm, which is quite good for a Mtb crank. But, the chainline is designed to be at 47.5mm even with that, their shortest axle. You can change that to 45mm by removing the drive side spacer of the Outboard Bearing Cup, but of course that adds 2.5mm to the other side. Thats the only problem I have with the OBB desings, you have limited choice, if any, of axles. Surly offers 3, which is rare, but the shortest isn't really short enough for proper road use. Bummer. That's why tapered cranks and cartridge BB's are so sweet. Versatility. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en -~----------~----~----~----~------~----~------~--~---
