I've got a question about the chainwrap capacity of a sram X.7 short cage rear derailleur. Can it handle the difference between a 12-21 cassette and a 22/38 double crank? I would like to change my 1x8 setup (38x11-32) to make it more efficient for long distance rides. BTW, my bike is a Giant Iguana, not the Mongoose on my profile. I am planning to replace my worn cassette and put slick tires on it to make to bike more of a commuter bike
I've got a question about the chainwrap capacity of a sram X.7 short cage rear derailleur. Can it handle the difference between a 12-21 cassette and a 22/38 double crank? I would like to change my 1x8 setup (38x11-32) to make it more efficient for long distance rides. BTW, my bike is a Giant Iguana, not the Mongoose on my profile. I am planning to replace my worn cassette and put slick tires on it to make to bike more of a commuter bike
I fail to see how changing from an 11-32 to a 12-21 is going to make the bike more efficient? As for X7, my X7 short cage is currently running 11-34 on a 34t ring and handles it fine, don't know how much difference those extra 4 teeth would make.
Yeah thats pointless, a 21 - 22 easiest gear is harder than 34 - 34. Youd be better spending the money on 10spd kit with an 11 - 36 cassette, and run a 34t or 36t ring.
Edit: cam, ring diameter on single rings just changes chain length, its incidental to cage length, its the difference between hardest and easiest gears that matters.
The reason why I was interested in changing to a road cassette is that for some reason, I only have access to 6 gears on the cassette before the chain rubs on the lower part of the cage. That brings the cassette to only 21t and I need to get more range and solve the odd clearance issue. I figured if I put a 22/38 crankset, the difference in the front is 16 teeth and there would be a 9 tooth difference in the back, making a 25 tooth chainwrap. Then I could "in theory" keep the derailleur and shifter and only have to buy a new cassette, chain, and eventually the granny gear. I only need the granny gear for really long hills I would end up facing.
That's just a set up issue, try fixing it instead of throwing money at the problem? And if you are gonna spend money get something current and reasonably priced (deore stuff is brilliant) instead of prolonging the ultimate death of your outdated 8spd system.
I don't think I was being clear about what my build plan was. I need to replace the cassette and chain and I was pondering about getting a road cassette for a challenge. Then, I would only put on a granny gear and front derailleur when I go for the great FANY ride next year, which is a 500 mile ride from Niagra Falls to Saratoga Springs. In reality, I don't need a granny gear for my ordinary rides.
No you weren't clear at all. You should be fine with the short cage as youll only really be in the easiest 2 gears. Still think a fully working system would be better and probably no different in cost if not cheaper, even if you stay 8spd