This may not be the best forum given the type of questions I see but I'm giving them all a shot at this.
I recently swapped out a DA 7610 and crank for a DA 7710 setup on a track bike. This is one of our team bikes from years back at Subaru, a custom made Ti GT but it has a non-standard ~66.5 mm BB. I know it was GT's first foray into making track bikes so who knows what the other guys’ bikes had for BB widths.
The driveline has been perfect with the 7610 for many years, who knows why. For some CRAZY reason with new the 7710, the chainline is out of wack now by 3+mm to the right and noisy as hell. Nothing else has changed. Basically same length spindles and they should provide identical chainlines anyway. So I added a 3mm spacer on the drive side cup and everything lines up great and is super smooth and quiet now and not in danger of jumping a chain. I’m running an HKK Vertex chain.
BUT, now both crank arms are 3mm off center towards the driveside. This is "only" my fixed gear road bike now but I get more miles on this than my track bike by a long shot. I really don’t want to cause any physiological issues once I start using this new setup. I thought of insetting my right cleat 3mm to make my feet symmetrical on the bike centerline but I use the road shoes on another couple bikes as well. My rear wheel for this bike is a set of DA duplex hubs so I can’t redish it without loosing a useable side.
So on to my question weary readers! Has anyone experienced any negative effects from 3mm of asymmetry? I cannot feel this when testing the bike briefly but not sure about knees after 40 or 50 miles.
Thanks for your help.
Scott
I recently swapped out a DA 7610 and crank for a DA 7710 setup on a track bike. This is one of our team bikes from years back at Subaru, a custom made Ti GT but it has a non-standard ~66.5 mm BB. I know it was GT's first foray into making track bikes so who knows what the other guys’ bikes had for BB widths.
The driveline has been perfect with the 7610 for many years, who knows why. For some CRAZY reason with new the 7710, the chainline is out of wack now by 3+mm to the right and noisy as hell. Nothing else has changed. Basically same length spindles and they should provide identical chainlines anyway. So I added a 3mm spacer on the drive side cup and everything lines up great and is super smooth and quiet now and not in danger of jumping a chain. I’m running an HKK Vertex chain.
BUT, now both crank arms are 3mm off center towards the driveside. This is "only" my fixed gear road bike now but I get more miles on this than my track bike by a long shot. I really don’t want to cause any physiological issues once I start using this new setup. I thought of insetting my right cleat 3mm to make my feet symmetrical on the bike centerline but I use the road shoes on another couple bikes as well. My rear wheel for this bike is a set of DA duplex hubs so I can’t redish it without loosing a useable side.
So on to my question weary readers! Has anyone experienced any negative effects from 3mm of asymmetry? I cannot feel this when testing the bike briefly but not sure about knees after 40 or 50 miles.
Thanks for your help.
Scott
