170mm to 165mm Crank - would I notice the difference?

[bernieUK]

Good morning

I am in the market for a new crank as my present one is showing it's age! I am currently specced at 170mm X 48t. I ride a single speed commuter bike covering only about 12 miles a day. I have seen a rather tasty 165mm Sugino 75 crank selling at about 40 quid lower than the 170mm equivelent. Would I really notice the difference if I went to 165mm?

Any advice would be appreciated.

 

[PpPete]

How tall are you? Inside leg (crotch to floor)?
There are various formulae that give a supposedly "ideal" length of crank according to what size you are. Unless you are a real "short-arse" 165mm cranks are not usually recommended.

However - 5 mm difference (less than 1/4", and more importantly less than 3% difference in the crank length) is probaby small enough that you may not notice the difference.

 

[bernieUK]

I am 5'9'' (175cm) with an inside leg of 29'' (74cm) - so pretty much average height. As I said I am a strictly a commuter through London streets and, at the age of 51, I do not exactly "go at it" with too much vigour (try my best though)

 

[Kestevan]

I've just replaced my 175 cranks with 170s.

I noticed the difference initially - the pedalling action didn't feel right somehow.
Messed around with the saddle height, and soon got it adjusted so now it feels perfect again.

 

[Banjo]

I think you will notice but doubt it will matter once you get used to it.

When i jumped on the bike recently I new my seat had moved down a bit ,when I checked it had slipped less than 6 mm.

 

[ASC1951]

I usually ride 170mm cranks (172.50s off road) and tried 165s on my fixie. Hopeless - I span along happily on the flat but couldn't generate the grunt to get up hills.

Of course leverage isn't as important with gears.

 

[piedwagtail91]

i don't think you'll notice after a few miles. I did our clubs 150 mile ride with odd length cranks on ( found a crack in one of the original pair the night before) poss. 170 one side and 175 the other. No ill effects. I've different length cranks on two bikes and hardly notice the difference. don't forget to set your saddle height though.

 

[4F]

I would say you would see more benefit with 165's if you were riding fixed as there would then be less chance of pedal strike when cornering.

 

[Deleted member 1258]

I am 5'9'' (175cm) with an inside leg of 29'' (74cm) - so pretty much average height. As I said I am a strictly a commuter through London streets and, at the age of 51, I do not exactly "go at it" with too much vigour (try my best though)

I would say you would see more benefit with 165's if you were riding fixed as there would then be less chance of pedal strike when cornering.

Inside leg seems a bit short for 5'9"? My inside leg is 29 and I am only 5'6". I ride fixed and have often wondered if I would get a benefit from using the shorter crank, not in the corners, but from a bit better leverage from not getting the hips and knees folded up as much at the top of the pedal stroke. I have done some reading on this, but it seems the more I read the more complicated it gets.

 

[4F]

Inside leg seems a bit short for 5'9"? My inside leg is 29 and I am only 5'6". I ride fixed and have often wondered if I would get a benefit from using the shorter crank, not in the corners, but from a bit better leverage from not getting the hips and knees folded up as much at the top of the pedal stroke. I have done some reading on this, but it seems the more I read the more complicated it gets.

I am 5'7" with the same inside leg and got 165's on my fixed. I have 170's on my geared bike and to be honest I don't really notice a difference in the pedal stroke. I went down the 165 route because of the pedal strike possibility.

 

[Deleted member 1258]

I am 5'7" with the same inside leg and got 165's on my fixed. I have 170's on my geared bike and to be honest I don't really notice a difference in the pedal stroke. I went down the 165 route because of the pedal strike possibility.

This one of those things where I think I will have to try shorter cranks on my Pearson at some stage and make my mind up from there.

 

[ASC1951]

I went down the 165 route because of the pedal strike possibility.

I would be surprised if you can get anywhere near pedal strike out on the road. I ride a small, low frame and I've never come close, even with 170s.

 

[Deleted member 1258]

I would be surprised if you can get anywhere near pedal strike out on the road. I ride a small, low frame and I've never come close, even with 170s.

The only time I have struck a pedal was very many years ago on a geared bike when I threw a very sharp right avoiding a pedestrian who ran into the road. Didn't have time to think, just chucked it right as he appeared in front of me, and didn't stop pedalling hence the pedal strike. I have never had a pedal strike on a fixed bike.

 

[Steve Austin]

I used to ride 180 cranks and rarely got pedalstrike, and that was on a MTB!!

I've ridden all sizes from 170 to 180. For me, 170 feels to small and hurt my legs as i was spinning too much. 180 felt too big, unable to spin very fast. I think a lot of it is down to perception, but if it feels wrong, you'll notice it, every time you ride.
For me, I want to be as comfortable as possible when riding and be able to turn the gear i want to. so its 175 on every bike i own hth