3x7 to 2x10

Drzoidberg

Hello
I currently have a crappy 3x7 set up which took off my hardrock and stuck onto a santacruz superlight frame, my question is this can i just chuck a 2x10 Sramx9 crank on there?

In my head it will be fine as a crank is a crank and ill somehow muddle my way through and get the front gears shifting

Can it be done?

Cheers

craker

Yeah but you'll want a new bottom bracket for the new crankset, a new chain a new rear mech a new 10 speed cassette and probably a new back wheel for it to go on. And a new rear shifter but you'll get away with the old front shifter.

been there, done that. With all the leftover parts I put together a nice spare bike

Drzoidberg

Rightio

Hows about this then, leave the 3x7 set up alone

But fit a shimano SLX 3x10 crankset on there? Is that a nice easy take off the old crankset and put on a new

Chunkers1980

Plan a should work ok though.

Drzoidberg

plan a being put the 2x10 cranks on all will be well? I dont really want to go buying new derailleur, shifter ect ect for now

craker

Ah... I see what you're getting at. You _just_ what to change the crankset? If your chain is worn then it wont work very nicely. On the roadie side you can get away with 7/8 speed on a 9 speed crank and 9 speed on a 10 speed crank - you're making the jump from 7/8 straight to 10. You might find the chain doesn't shift to cleanly (thick chain on narrow rings).

Personally I'd be tempted to leave it be and save up for a whole new groupset, you're likely to make things worse otherwise with no obvious benefit.

The Rookie

The pitch between the gears gets less with the higher number of gears, 7 and 8 are the same, 9 and 10 each narrower in turn, you may get away with using a 10 speed crankset with a 9 speed chain which will still work with you 7 speed rear, but I suspect the wider chain 7/8 speed chain make cause shifting issues.