Originally Posted by jcwitte
I'm probably not describing all of this very good, but here goes.....
When I tried the 26T, I could not shift onto the smallest 5 or 6 rings on the rear cog without the chain rubbing on the 42's shifting ramps. The actual ring I bought is a generic one from Nashbar. The chainring was flat. The 30 that it replaced had a ridge near the outer edge of the ring allowing the teeth to be further away from the 42 chainring. In other words, the actual teeth sat on a sort of ridge that acted as a spacer. I'm guessing that if I could find a 26T chainring that had a similar ridge, then my problem would be solved. Does anyone know where I can get one like that? Are the TA rings sold by Peterwhite cycles like that?
http://www.peterwhitecycles.com/chainrings.asp
I'll try to illustrate what I mean by flat versus a rdige....
(30T chainring with a ridge near the teeth) Note the extra spacing between the teeth of the 30 and 42
52__________
42________
30-----__
(flat 26T chainring)
52__________
42_______
26-----
I need to go for now (go Bears) but I'll check back later for any replies and try to answer any questions to clarify any of this.
I know what you mean – I had the same issue when replacing the 30 with a flat 26 on my Fuji, and had to shell out $10 for one that was offset.
Having said that, I would not do another long tour involving mountains with this setup. The jump between 26 and 42 is too big – not only in ratio but also when shifting down the chain kept wanting to jump off onto the BB unless careful and shifting up I had to overshift (I had sti shifters though). I would replace the whole crank with 48-36-26.
Around home unloaded I never use the 26, even on steep hills, but would not tour without it...