i like cunning stunts Posted March 2, 2011 Report Share Posted March 2, 2011 As the title need some opinions which sprocket is going to feel like 18-15 on 175 cranks? I have less leverage so am thinking the 16t but somethings telling me i might need a 14t am confuzzled and need an answer. Quote Link to comment Share on other sites More sharing options...
Mark W Posted March 2, 2011 Report Share Posted March 2, 2011 18:16 would be the prime choice. Quote Link to comment Share on other sites More sharing options...
i like cunning stunts Posted March 2, 2011 Author Report Share Posted March 2, 2011 Ta mark knew i was right just had a bit of a blank. Quote Link to comment Share on other sites More sharing options...
ogre Posted March 2, 2011 Report Share Posted March 2, 2011 18-16 is to soft in my experience, 18-14 would be the one to go for, 170mm isn't that different to 175, if you had 160 maybe go for 18-16 then... 1 Quote Link to comment Share on other sites More sharing options...
i like cunning stunts Posted March 2, 2011 Author Report Share Posted March 2, 2011 18-16 is to soft in my experience, 18-14 would be the one to go for, 170mm isn't that different to 175, if you had 160 maybe go for 18-16 then... To be honest from what i have tried so far on 170 cranks at 18 -15 its a big difference, i just cant seem to gap / sidehop with it, its frustrating. So your saying 16t would be too light.. hmmmmmm Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted March 3, 2011 Report Share Posted March 3, 2011 I had this f**k about the 5mm does make a difference. I ended up with 16/13. Quote Link to comment Share on other sites More sharing options...
forteh Posted March 3, 2011 Report Share Posted March 3, 2011 I had this f**k about the 5mm does make a difference. I ended up with 16/13. Ive got 165 burns... 18:15 felt too heavy 18:16 felt too light 16:13 felt too heavy 16:14 felt spot on That said, Ive just switched back to 18:16 because my 16t middleburn ti bash is quite badly worn and the teeth are sharky. I guess it will just be a bit of technique adjustment, iirc inur ran 18:17 on 158 cranks for years and preferred it. Quote Link to comment Share on other sites More sharing options...
i like cunning stunts Posted March 3, 2011 Author Report Share Posted March 3, 2011 Am confused again now maybe 14t is the answer.. Quote Link to comment Share on other sites More sharing options...
forteh Posted March 3, 2011 Report Share Posted March 3, 2011 Am confused again now maybe 14t is the answer.. You need to lighten the gearing, you have shortened the crank so cannot put the same amount of torque through the pedals, lightening the gearing will regain some of that mechanical advantage at the expense of forward motion. For the same force applied to the pedals: - 170 cranks will give you approximately 3% less power into the drive than 175s 165 cranks will give you approximately 6% less power into the drive than 175s 18:15 gives a gear ratio of 1:1.2 - 360° revolution of the cranks results in 432° or rotation at the rear wheel. 18:16 gives a gear ratio of 1:1.125 - 360° revolution of the cranks results in 405° or rotation at the rear wheel. 18:14 gives a gear ratio of 1:1.285 - 360° revolution of the cranks results in 462° or rotation at the rear wheel. Longer cranks allows you to put more force into the drive, shorter cranks will theoretically spin up faster. After all that imho you want 18:16 Quote Link to comment Share on other sites More sharing options...
Greetings Posted March 3, 2011 Report Share Posted March 3, 2011 I'll make things more complicated for you. Ran 18:17 on 158mm cranks for 4 years. Absolutely loved it. Very responsive, short run up distnances etc. It lacked the speed though. Quote Link to comment Share on other sites More sharing options...
forteh Posted March 3, 2011 Report Share Posted March 3, 2011 ...iirc inur ran 18:17 on 158 cranks for years and preferred it. I'll make things more complicated for you. Ran 18:17 on 158mm cranks for 4 years. Absolutely loved it. Very responsive, short run up distnances etc. It lacked the speed though. What did I tell you Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted March 3, 2011 Report Share Posted March 3, 2011 I dont know what I like best to be honest, running 16/13 170mm cranks seems to work for I. Quote Link to comment Share on other sites More sharing options...
i like cunning stunts Posted March 3, 2011 Author Report Share Posted March 3, 2011 You need to lighten the gearing, you have shortened the crank so cannot put the same amount of torque through the pedals, lightening the gearing will regain some of that mechanical advantage at the expense of forward motion. For the same force applied to the pedals: - 170 cranks will give you approximately 3% less power into the drive than 175s 165 cranks will give you approximately 6% less power into the drive than 175s 18:15 gives a gear ratio of 1:1.2 - 360° revolution of the cranks results in 432° or rotation at the rear wheel. 18:16 gives a gear ratio of 1:1.125 - 360° revolution of the cranks results in 405° or rotation at the rear wheel. 18:14 gives a gear ratio of 1:1.285 - 360° revolution of the cranks results in 462° or rotation at the rear wheel. Longer cranks allows you to put more force into the drive, shorter cranks will theoretically spin up faster. After all that imho you want 18:16 Right after playing about on 170 cranks with 18 -15 i think that the gear is too light. Contrary to what you just explained it feels like i need to go the other way and wack a 14t on. There seems to be no "kick" at the moment Quote Link to comment Share on other sites More sharing options...
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