i just bought a new bike that came with 172.5mm dura ace cranks (private sale, not a shop, so i had no choice). i’m 6’ tall and have been on 175’s until now. before that i was riding way too short 170’s. so my question is, with only a 5mm overall difference in length and the fact that i’m not really tall, is it even worth the hassle to pursue swapping them out? thanks.
I definitely would. It takes like 10 minutes to swap the crankarms.
If you are six feet tall then you likely need longer than 175s, so if you are going to buy new cranks then don’t just buy some that are 2.5 mm different. That would be a waste of money. Try the Kirby/Zinn formula of .21 or .216 x inseam in mm (inches x 25.4) to determine if a longer crank might be a good idea. When I punched mine in I came up with a 190 and though that was crazy. Then I bought some and couldn’t believe how much better they were for me. Longer cranks to match your leg length won’t make a Superman out of you, but it will employ your longer leg better than proportionately shorter ones would.
If you don’t want to spend more money and have the 175s already that is better than nothing.
I can’t remember now the company that made my 190s, but they were about $200 which is not bad considering the cost of cranks these days. For the life of me I can’t remember the name of the company.
Chad
forgot to specify that my new bike has 9 speed octalink(sp?) cranks, but my old 175’s are square tapered (remember those?) so it would involve buying a new set of crankarms, not just a swap out.
Well then my suggestion is moot, since they only make square taper. Frankly, I like square taper better than Octalink. The longest crank you can get with octalink is a dura ace 180, which is still a big improvement over 172.5 if you need it. Check on ebay and they come up pretty regularly.
Chad
I dont think you will notice much change under a 5 mm change. I have a mountain bike with 172.5 crank , and 180s on the road bike . I think it helps in the climbing . But flat ground its not very noticeable.
I used to have 172.5 cranks on my tri bike and then swapped them out for 175s and rode them for about 5 seasons. I switched back to 172.5s 3 summers ago and I prefer them. I am 6ft tall and find that the shorter cranks seem to make it easier to spin out and improve my running off the bike. If you are a big gear masher then maybe the switch back would help you.
Well, then its a personal choice. If you’ve been riding 175’s up to now, and can’t tell much difference between the old and the new, then I wouldn’t bother.
Personally, I have tried the smaller cranks, and feel a big leverage difference between the two, and would definitely switch, even to a heavier/older design.