>When the chain is in the small ring up front and the small ring in the back...the chain is making contact with the inside of the big ring.
Dear RDS, The Wide/low is a triple crank with the outer chainring replaced with a chainguard. I'd be deeply surprised if the inner ring reached the small cogs without fouling the chain on the middle ring. With a super-compact gear setup (like the one you're using), it is usually done such that the outer ring is set at the chainline (centered around 43.5mm from the centerline of the bike in your case), and the inner is checked that it clears the chainstay. In practice, many will set the bike up such that the inner just clears the chainstay. The outer ring should work with the full cassette range. The inner ring is a bailout gear, and need only work with the half or so of the cassette closest to the centerline of the bike. By the way, almost all of the bikes (double or triple) I've owned have scrubbed the outer ring in the inner front /small rear combination. It is, as Steve pointed out, your bicycle's way of encouraging good shifting practices, like avoiding the big/big and small/small combinations. Best Regards, Will William M. deRosset Fort Collins, CO On Sunday, August 2, 2015 at 9:25:05 PM UTC-6, RDS wrote: > > Rear spacing is 130 on the Soma San Marcos. I have tried a 110 BB and > currently a 118 BB. Same issue using both BB's. Again, this is just in > the workstand setting things up. Meaning, I have not rode the bike yet. > Installed the crank on a VO Campeur and the Soma San Marcos and same issue > on both. So, asking the question from ignorance as I am a novice mechanic > at best. Thanks for the feedback. > > On Saturday, August 1, 2015 at 8:43:14 PM UTC-4, Dave Johnston wrote: >> >> That is the cross-chain audible warning mode. It is a feature. >> >> What size BB are you using and is the rear spacing 130mm or 135mm. I have >> not experienced this on the 3 double setups I'm using. 43/29, 40/26, an >> 42/28 >> >> -Dave >> >> On Friday, July 31, 2015 at 2:53:00 AM UTC-4, RDS wrote: >>> >>> Installed the Sugino Wide/Low double Crank (40/26). Still in repair >>> stand. 9 Speed. Cassette is 11/34. When the chain is in the small ring >>> up front and the small ring in the back (yes, I realize that this might not >>> be a good gear combination to ride in), the chain is making contact with >>> the inside of the big ring. To clarify, the chain is NOT coming in contact >>> with the FD, but the inside portion of the big chain ring. >>> >>> Does this mean that I need a BB that is more wide? Or does this mean >>> that I should never have the chain in that combination? Or ??? Any help >>> appreciated. >>> >>> Bike is a 59 Soma San Marcos. >>> >> -- 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.
