How do you tell if your cranks are too long?

[bigreen505]

Simple question and I want to talk in generalities rather than specific crank length/leg length ratios. Last year I moved from a pretty standard crank to one slightly longer and overall it felt great. This year I moved to a more upright riding position both to improve the handling of the bike and gain some power.

The bike definitely handles better than before and I do feel more powerful on flats or very slight inclines. However, on any decent hill, I feel like it takes more effort to turn the cranks. On the first couple rides after the new fit, it seemed difficult to push the cranks over the top of the pedal stroke.

So the question really boils down to do I stick with the new fit and see if muscles adapt or do I try going back to the shorter crank?

[Nelson99]

Crank length advantages start to diminish as you have begin to have trouble at the top and bottom of your stroke. You can invest some time to see of you comfortably adapt and get back to smooth circles, but if that doesn't work out, moving down incrementally until the circles are back would seem warranted.

[Charles M]

you're you.

That's pretty much the only accurate "generalization" anyone can make.


when you answer your own question, Let us know.

[bigreen505]

Ok Pez, perhaps a better question is how long does it take to adapt to something different? Or perhaps, how long do you give something new before deciding whether it works or not?

[bigreen505]

Another question might be phrased: aside from knee pain, how can I tell if cranks are too long?

[RPS]

Another question might be phrased: aside from knee pain, how can I tell if cranks are too long?
Lower power due to lower pedaling efficiency. Rocking due to lack of relative flexibility. Etc...

IMO anything that doesn't work right or as right as before may be a good sign that they are too long. However, that assumes crank length was your only change (variable) and in this case it doesn't appear to be. That's a much bigger problem to analyze IMO.

[David Kirk]

As much as this is a non-answer..............whatever works for you is what you should use. And......the only sure fire way to know what works best for you is to try different stuff.

Any of us can tell you that you should go longer/shorter but only your body can tell you for sure.

dave

[Charles M]

Ok Pez, perhaps a better question is how long does it take to adapt to something different? Or perhaps, how long do you give something new before deciding whether it works or not?

How long / how many miles will be helped by how you ride a little...

When you change positions and the changes are substantial enough, you'll benefit by going out and doing shorter rides at lower force / higher cadence to adapt. Especially when you're doing something with your fit that changes the ass to feet range...

How long it should take is pretty personal, but if you give it time and ease in to it (but ride regularly, 3+ times a week) you should know if it's going to work for you some place inside 6 weeks.

[Louis]

Given that you don't want to consider the leg length to crank length relationship (which IMO is like saying you don't want to consider leg and torso length when deciding what size frame is best for you) then the simplest option is to try several different crank lengths and see what works best for you.

Good Luck
Louis

[jtakeda]

I have some 175 cranks and some 170s I ride. They both feel great but I have to keep in mind to change my pedal stroke.

As long as you are comfortable and remember the timing of your pedal stroke it should work.

[slowgoing]

If you switch back again on the same bike you should have a better idea. It may turn out that either size has its own advantages/disadvantages, but at least you'll know.

[Peter P.]

If the new cranks leave you with a nagging dislike you can't get over such as that over the top of the stroke you refer to, then it's safe to say that length is not for you.

I ride 170's on the road. When I bought my first mountain bike it came with 175's (don't they all? ;-) ) . It didn't take more than a few weeks to conclude the longer cranks weren't for me; now I run 170's on my ATB and I'm happy.

[avalonracing]

If the back wheel pogos off the ground at the bottom of each pedal stroke I would say your cranks are too long.

[eddief]

doesn't he know when our things are too long?

[bigreen505]

Thanks all, good info.

Given that you don't want to consider the leg length to crank length relationship (which IMO is like saying you don't want to consider leg and torso length when deciding what size frame is best for you)

I didn't say that I didn't want to consider it, I just didn't want to bring it into this discussion. FWIW, I'm using 180 cranks with an 88.5 cm inseam (I'm 5'9" and all legs). Initially when I moved to that length from a 175 crank I couldn't tell much of a difference beyond that the pedal circle felt more natural on the longer cranks. After I changed my position to something that had worked well in the past on other bikes, the cranks suddenly felt a bit big when pushing over the top of the stroke.

[Louis]

FWIW, I'm using 180 cranks with an 88.5 cm inseam (I'm 5'9" and all legs). Initially when I moved to that length from a 175 crank I couldn't tell much of a difference beyond that the pedal circle felt more natural on the longer cranks. After I changed my position to something that had worked well in the past on other bikes, the cranks suddenly felt a bit big when pushing over the top of the stroke.

Wow, you really are all legs.

I'm 6' and my inseam is ~87.2 cm. and I consider my leg-torso ratio higher than average. Yours is even higher. You must really require a custom frame to get a good fit.

I went up to 175 (from 172.5) about 6 or 7 years ago and noticed an improvement, especially to help maintain rprm on small rolling hills without shifting. I bought some 177.5's a while back but haven't had a chance to try them.

IMO use a) what works best for your knees, and b) what gives you the most efficient stroke for the type of riding you do.

[RFC]

You have to tuck it in your socks.