eddief
07-12-2010, 07:03 PM
A while back I asked how things might go if I tried to install a 26 tooth small ring on a Shimano road triple. Received a lot of encouragement with some of it being oriented around friction front shifting.
I purchased 26 and 28 tooth, 74 BCD rings from Salsa.
Went to install and re realized I was trying this on a DA road triple. Them cranks have the weird inner BCD and my new rings won't go there. So I took a 105 triple off of another bike. It has normal 74 BCD inner.
I install the new Salsa 26 to replace the Shimano 30. It installed fine, but on the test ride I heard chain noise. Upon examination, with the installed 26 inner, the route of chain manages to hit a bulge in the forging of the inner side of the middle ring. The diameter of the 26 being different than the 30 is not accounted for by Shimano's approach...which is anal as we all know.
It was only off by what looked like an mm or two. So off to the LBS for chainring spacers. They had been through this before and the first recommendation was to try 1.2 mm spacers to move the granny 1.2 further away from the middle.
Bought two sizes of spacers; 10 @ .80 each. You gotta pay the piper for inventory, parts, and good advice just in time. Love those guys...sometimes. Installed the 1.2 size and all seems to be working fine with 50,39,26 up front, 11-34 in the rear and STI shifters. I like working on Hollowtech...a good technology.
May have to take a link or two out of chain or watch out for small small combinations.
I purchased 26 and 28 tooth, 74 BCD rings from Salsa.
Went to install and re realized I was trying this on a DA road triple. Them cranks have the weird inner BCD and my new rings won't go there. So I took a 105 triple off of another bike. It has normal 74 BCD inner.
I install the new Salsa 26 to replace the Shimano 30. It installed fine, but on the test ride I heard chain noise. Upon examination, with the installed 26 inner, the route of chain manages to hit a bulge in the forging of the inner side of the middle ring. The diameter of the 26 being different than the 30 is not accounted for by Shimano's approach...which is anal as we all know.
It was only off by what looked like an mm or two. So off to the LBS for chainring spacers. They had been through this before and the first recommendation was to try 1.2 mm spacers to move the granny 1.2 further away from the middle.
Bought two sizes of spacers; 10 @ .80 each. You gotta pay the piper for inventory, parts, and good advice just in time. Love those guys...sometimes. Installed the 1.2 size and all seems to be working fine with 50,39,26 up front, 11-34 in the rear and STI shifters. I like working on Hollowtech...a good technology.
May have to take a link or two out of chain or watch out for small small combinations.