Jonesy Posted September 21, 2015 Author Posted September 21, 2015 Just swop the cassette out for a road one with smaller gears. Best solution for going faster ask the downhill guys. Doesn't a road cassette also 11t on the tallest gear?
raptor-22 Posted September 21, 2015 Posted September 21, 2015 you don't have any other alternative other than going SRAM or get a different bike. 42 is the biggest outer ring you can fit on modern MTB's thanks to the wheel revolution
Jonesy Posted September 21, 2015 Author Posted September 21, 2015 Surely if you want to change the gearing to that extent a mountain bike was not the right choice for your new bike? Do you use it mostly for that .....New bike is carbon with rigid carbon fork. It will be used almost exclusively on road, but I'll also be able to take detours off tar when the need arises, with total confidence
Rocket-Boy Posted September 21, 2015 Posted September 21, 2015 New bike is carbon with rigid carbon fork. It will be used almost exclusively on road, but I'll also be able to take detours off tar when the need arises, with total confidenceSuddenly it all makes more sense, should have built a cyclocross bike then!
Eddy Gordo Posted September 21, 2015 Posted September 21, 2015 to go from 42 to 50 is huge, i would not do that. i can reach around 40km/h on downhill (dirt roads) not sure if i would attempt that speed any other place. what speed do u wanna reach and what speed are you getting to now?That kind of speed is reserved for trails
JXV Posted September 21, 2015 Posted September 21, 2015 I had 44-32-22 with 3x9 on my old 26" bike. Now on a 29er with 2x10 and 38-26 front chainrings - it feels almost the same in top gear due to the larger wheel size... so remember to account for this if wheel sizes are different between your new and old bikes. Going with SRAM Cassette and freehub you can go from 11t at the rear down to 10t. This gives 10% longer gearing in top but quite costly. Some modern mtb frames have wider chainstays just behind the BB. This can limit chainring size and even crank choice. Some modern frames can only fit 1x cranksets due to this issue. So check specs and measure before you commit funds to new cranks or chainrings. Also dont forget to lengthen your chain if you fit bigger rings
Chro Mo Posted September 21, 2015 Posted September 21, 2015 I was told that I could simply fit a road crank, with some mods and this should sort things out. Do you agree?I do. Make sure the BB shell is 68mm, or the crank-axle will be a tad short ( if the Mtb BB is 73mm standard). Perhaps there are road cranks that are made to fit larger width BBs?
Jonesy Posted September 21, 2015 Author Posted September 21, 2015 I had 44-32-22 with 3x9 on my old 26" bike. Now on a 29er with 2x10 and 38-26 front chainrings - it feels almost the same in top gear due to the larger wheel size... so remember to account for this if wheel sizes are different between your new and old bikes.Going with SRAM Cassette and freehub you can go from 11t at the rear down to 10t. This gives 10% longer gearing in top but quite costly.Some modern mtb frames have wider chainstays just behind the BB. This can limit chainring size and even crank choice. Some modern frames can only fit 1x cranksets due to this issue. So check specs and measure before you commit funds to new cranks or chainrings. Also dont forget to lengthen your chain if you fit bigger ringsInteresting.....Thanks for the useful pointers!
Jonesy Posted September 21, 2015 Author Posted September 21, 2015 I do. Make sure the BB shell is 68mm, or the crank-axle will be a tad short ( if the Mtb BB is 73mm standard). Perhaps there are road cranks that are made to fit larger width BBs? Thanks for your input. Appreciate it!
Jonesy Posted September 21, 2015 Author Posted September 21, 2015 Suddenly it all makes more sense, should have built a cyclocross bike then!Then I lose the comfort 2.2 tyres offer..... Also, the way I see it, a good Mtb frame would actually be over-engineered for my application, which I simply love the idea of. Also cyclocross bikes seem to have smaller rotors than the 180/160mm rotors on my Mtb, which will be more powerful and less prone to fade on longer downhills.....
Jonesy Posted September 21, 2015 Author Posted September 21, 2015 Thanks to all for your comments and advise.
Baaisikilist Posted September 21, 2015 Posted September 21, 2015 I had 44-32-22 with 3x9 on my old 26" bike. Now on a 29er with 2x10 and 38-26 front chainrings - it feels almost the same in top gear due to the larger wheel size... so remember to account for this if wheel sizes are different between your new and old bikes. Going with SRAM Cassette and freehub you can go from 11t at the rear down to 10t. This gives 10% longer gearing in top but quite costly. Some modern mtb frames have wider chainstays just behind the BB. This can limit chainring size and even crank choice. Some modern frames can only fit 1x cranksets due to this issue. So check specs and measure before you commit funds to new cranks or chainrings. Also dont forget to lengthen your chain if you fit bigger ringsHe said his Groupset is XT 2x10. You cant just slap a SRAM cassette and XD Driver on there and be done with it...That's an 11 speed cassette.
JXV Posted September 21, 2015 Posted September 21, 2015 He said his Groupset is XT 2x10. You cant just slap a SRAM cassette and XD Driver on there and be done with it...That's an 11 speed cassette.Fair enough....so then it would be a shifter and RD too.....I'm not too clued up on the SRAM stuff... Not really a practical option... even more pricey than I thought.
Spoke101 Posted September 21, 2015 Posted September 21, 2015 He said his Groupset is XT 2x10. You cant just slap a SRAM cassette and XD Driver on there and be done with it...That's an 11 speed cassette. Technically you could , you would just have to choose whether you wanted the 10T or the 42T when setting your gears.
Jonesy Posted September 22, 2015 Author Posted September 22, 2015 Found two cranks with 44t and 46t. I think these are off 3x9 setups though. Can somebody tell me if either will work with 10 speed cassette? Thanks.
Goodbadugly Posted September 23, 2015 Posted September 23, 2015 As you have figured out for yourself the only way is a 3 speed crank. If it fits on your frame.Try to get a 3x10 crank. I have seen a 10 speed chain getting caught between the 32 and the 44 chainring on a 3x9 crank before. Try to get a 3x10 crank like this one: https://www.bikehub.co.za/classifieds/149850-xt-crank-3x10-fair-to-good-condition/Remember that you will also need a 3x fd and a 3x front shifter for this conversion.
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