Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.sers
02-26-06, 08:17 PM
Today, I finally had a chance to put the finishing touches on my Mark V's new drivetrain ( Pictures and details here (http://www.bikeforums.net/showthread.php?t=172725) ) After removing the 1mm bb spacer, my chainline was as close to perfect as I can tell and quiet to boot.
After 10 odd miles of riding, I was thoroughly impressed with the setup. My new 49/18 gear ratio makes spinning, hills and starts a lot easier, although moving a little less per revolution is going to take some getting used to. It's smooth, responsive and stiff, and for not a terrible amount of money.
I'm sort of glad that I opted to go with the sealed cartridge bb, instead of the sugino 75, since there was a decent amount of brown grimey water that came out after the original bb was removed. I also would estimate that my chainline is off by less than a mm, so a 109 wouldn't make a world of difference.
I'd also like to note that the threading on the IRO BB might be a little odd. I make absolutely sure that I wasn't stripping the bb, but there's varying amount of resistance when instaling. Perhaps it's the UN-73 bb.
The stock drivetrain on the IRO is the weakest link, especially if you ride it a lot. While a new chainring might do the trick, money spent on an upgraded drivetrain is mone well spent.
After 10 odd miles of riding, I was thoroughly impressed with the setup. My new 49/18 gear ratio makes spinning, hills and starts a lot easier, although moving a little less per revolution is going to take some getting used to. It's smooth, responsive and stiff, and for not a terrible amount of money.
I'm sort of glad that I opted to go with the sealed cartridge bb, instead of the sugino 75, since there was a decent amount of brown grimey water that came out after the original bb was removed. I also would estimate that my chainline is off by less than a mm, so a 109 wouldn't make a world of difference.
I'd also like to note that the threading on the IRO BB might be a little odd. I make absolutely sure that I wasn't stripping the bb, but there's varying amount of resistance when instaling. Perhaps it's the UN-73 bb.
The stock drivetrain on the IRO is the weakest link, especially if you ride it a lot. While a new chainring might do the trick, money spent on an upgraded drivetrain is mone well spent.