Crankset length?

[mattsurf]

Originally Posted by velofinds

I've found this to be a useful/reasonable bottom-line recommendation for me:



If you are a taller individual (say, 6' and up) 172.5 or 175 are probably ok and, unless you are highly sensitive and attuned to your bike, you will probably not be able to tell the difference. I'm 5'8" and am happy on both 170 and 165 (and can't tell the difference switching between those two despite putting lots of miles on both). I can tell the difference between 170 and 175, however, and am happier on the former.

YMMV.

Exactly the same, 5'8'' tall, I cant tell difference between 165 and 170, however, 175 feel horrible.

I use 170 on all my bikes now

[93KgBike]

I bought a CL bike that had a 172.5/175 l/r setup that I thought would be terrible, intolerable, unrideable. It wasn't any of those things. It was more like, hmm, non-optimal. Still I changed it like the next morning and then sage smoked the whole frame, rinsed it in holy water and got a tarot reading.

I like 165s for track and technical single track. And for sitting up high.

[Mark McM]

When I switched from 170mm to 172.5mm cranks on my road bike, I noticed right away, and found I preferred the shorter crank. But I didn't notice the difference in my legs (not exactly anyway); I ride with a fairly acute hip angle, and the longer cranks caused my legs to come up higher, and squeeze my abdomen a bit (making it a little harder to breathe).

On my MTB, where I have more upright riding position, switching between 170mm and 175mm cranks is barely noticeable.

[timenoway]

The take home message seems to be that because we can get more aero these days on our bikes, shorter cranks are the way to go without sacraficing too much of the leverage onto the pedals?

[bironi]

It all depends on your choice of saddle and the color of your bike.

[oldpotatoe]

Originally Posted by timenoway

The take home message seems to be that because we can get more aero these days on our bikes, shorter cranks are the way to go without sacraficing too much of the leverage onto the pedals?

2.5 or 5mm in crank length makes no difference in aero-ness or not.
Put 3 people in a room and ask about crank length, get 4 opinions. Overall feel and injury prevention is what is important but again..a 6 foot person using 170/172.5/175 really makes little difference in leverage, aeroness, 'power'..

l..l<-that's about 2.5mm

Had a lady customer, really pretty pink DeRosa..doin' an overhaul..cranks come off(SuperRecord..old stuff)..right crank was 172.5, left crank 170..she didn't even know it..

[zmalwo]

the truth is if the UCI frame geometry regulation was based on a 190mm crank, we would be now arguing how 185mm, 190mm, 192.5mm, 195mm, etc...... fits 5'2, 6'4 etc...... I personally think it makes no difference whatsoever.

[Ralph]

Originally Posted by LouDeeter

I've experimented for 35 years between 170-175. I'm 5'7". I found that the longer cranks tended to cause more knee and hip pain when riding hard. Sheldon Brown and I had a conversation about the "leverage" of crank length and he convinced me that while seated, the chainring teeth number are the leverage, not the crank length, which comes into play more when riding out of the saddle. Since I live in Florida now, I rarely encounter a hill that requires me to rise out of the saddle so I have gravitated toward 170 more so to protect my aging knee and hip joints. I would tend to use the crank length more to get my knee over pedal position correct than anything else. This is just my unscientific opinion of course, but it makes sense to me.

For my 5' 10" height....above is how I look at it also. If I wanted more mechanical advantage from longer crank, instead of going longer, just use a ring with fewer teeth. 53 on 172's like 52 on 170's, about same percentage difference etc. (or 50, 51) And it's directly proportional. This is basic stuff we learned in high school physics studying pulleys and levers. On my Dad's old farm....he had a well......with a bucket attached to a rope, that went up over a pulley, then back down to a large piece of round wood, with a handle stuck/driven in the side to wrap up the rope when you turned the crank. There was always a lot of discussion about whether to use two pulleys at top or one....sacrifice distance for advantage, and how big the piece of wood need to be, and the length of the crank, where the rope wrapped up. We could make it easy or hard, slow or fast...depending on those factors. Same principles.