20 speed - 10 speed casette question ???

twedspeed

Am thinking about giving one of those 10 spd casette and 2 chainrings up front a try = 20 speeder ,
But what will I have to change ???
Obviously a new 10 speed casette will be required and probably diferent sized chainrings , But will my rear deraileur have the range to move across 10 rear cogs or will I have to change that as well ????

supersonic

Need new rear derailer for sure. We have an article in the FAQ on compatibility.

stu8975

And a 10spd shifter and chain

MountainMonster

All the drivetrain stuff will need to be changed.

Derailleur, casette, chain, chainrings, shifters.

uphillbothways

A 10 speed shifter, cassette and chain should be all you need. 8, 9 and 10 speed chains are all the same width internally - the 9 and 10 speed chains are made narrower externally by using thinner chain plates, which is one very good reason not to go 10 speed unless you really need the extra gears. You absolutely don't need new derailleurs to upgrade - a 10 speed front triple might shift marginally better, but a double will shift no differently. 10 speed chainrings are spaced slightly differently to eliminate the risk of the thinner chain falling between the inner and outer rings, but unless you do really silly things with your shifters it's a negligible risk.

Unless you're racing, think hard about whether you really want to upgrade. If you want a wider range of gears, you'll be far better off going for a wider cassette or switching to a compact or triple. 10 speed is significantly less durable, more fiddly to set up and more prone to indexing issues because of the tighter spacing of the sprockets.

http://www.sheldonbrown.com/speeds.html

stu8975

uphillbothways wrote:

A 10 speed shifter, cassette and chain should be all you need. 8, 9 and 10 speed chains are all the same width internally - the 9 and 10 speed chains are made narrower externally by using thinner chain plates, which is one very good reason not to go 10 speed unless you really need the extra gears. You absolutely don't need new derailleurs to upgrade - a 10 speed front triple might shift marginally better, but a double will shift no differently. 10 speed chainrings are spaced slightly differently to eliminate the risk of the thinner chain falling between the inner and outer rings, but unless you do really silly things with your shifters it's a negligible risk.

Unless you're racing, think hard about whether you really want to upgrade. If you want a wider range of gears, you'll be far better off going for a wider cassette or switching to a compact or triple. 10 speed is significantly less durable, more fiddly to set up and more prone to indexing issues because of the tighter spacing of the sprockets.

http://www.sheldonbrown.com/speeds.html

Sheldon is not fully up to date

Think you will find the new shimano dyna sys 10spd stuff uses different pull ratios to the 9spd stuff (just for future ref. )..ie..10spd dyna sys shifter w/9spd mech will pull it twice as far as a dyn sys 10spd mech per shift, therefore shifting 2 sprockets rather than one. Therefore you cannot use a 9spd mech on the new dyna sys 10spd stuff.

supersonic

Yeah, poor old Sheldon never lived to see 10 spd mtb stuff. New rear mech is required.

uphillbothways

Sorry lads, had a senior moment myself and thought I was in the Road forum for some reason, hence the blather about compact cranksets and racing. What stu895 said, Dyna-Sys uses a different pull ratio.

My remarks about durability stand - you gain an extra sprocket, but you lose a fair bit of metal between you and your rear wheel. You're trading up to a fiddlier mechanism that demands more precision, which is even more critical on a mountain bike. The technical improvements in Dyna-Sys ameliorate the situation somewhat, but you're still cramming more sprocket teeth into the same size of cassette, which will inevitably compromise reliability.

pastey_boy

what about a 9spd shimano rear mech and the ultegra flat bar sti units ?

pastey_boy

or even a pair of dura ace 10spd bar end shifters converted to thumbshifters using the mounts from pauls or sjs cycles running on a sram apex 11/32 cassette and any 10 spd road chain. the friction front would sort any indexing problems out and the whole conversion would cost approx £100ish with best online prices

njee20

That's rather pointless though, you can have wider ratios with 9 speed and an 11-34 cassette.

Why use the road drivertrain bits, you could use a 9 speed Shadow MTB mech with the DA shifters (or the flat bar road shifters), a 10 speed MTB 11-36 cassette (giving the range advantages), and your choice of chain.