Touring - Another crank question

I'm going to build up a MTB as a touring rig. I have always used 175 MTB cranks and wanted some input on
building this bike. On my road bike/commuter I use 170 length cranks. I have found them to be comfortable and have no issue with them at all. I have a 32" inseam, and according to the "Inseam x 5.48 = " rule I should use a 175. Thing is, is this something I should concern myself with, or should I just build it and go? I already have a set of older LX cranks set aside for the project. Thanks

I have gather from past questions / responses of this nature, that one barely notices the difference. After reading about this previously, I checked out my two MTBS, and noted that one was 170, the other was 175. I could not tell the difference.

Regards, Mark.

I have gather from past questions / responses of this nature, that one barely notices the difference. After reading about this previously, I checked out my two MTBS, and noted that one was 170, the other was 175. I could not tell the difference.

Regards, Mark.

Sheldon Brown seems to have reached the same conclusion:


My latest experiment is taking place on plastic Trek frame I picked up in a barter deal. I had a pair of TA 150 cranks that used to be on my kids' Cinelli BMX bike, so I've put these on the Trek. I'm running a 45/17, which gives a gain ratio of 5.9, just a bit higher.

When I first get on the bike after riding with longer cranks, it feels a bit funny at first, but within a very short distance it's just fine. I go just as fast, climb just as well. For a given speed, my pedal rpm is higher (though my pedal speed is the same) but the short cranks make it easy to spin much faster than I normally would.

After riding this bike for a few miles, when I get back on "normal" cranks, they feel a bit weird and long at first, then I get used to them after riding a couple of minutes.

I think people really obsess too much about crank length. After all, we all use the same staircases, whether we have long or short legs. Short legged people acclimate their knees to a greater angle of flex to climb stairways, and can also handle proportionally longer cranks than taller people normally use.

http://www.sheldonbrown.com/cranks.html

Thanks. Mounted those LX cranks regardless.

After re-reading my post, I thought to myself, "the internet caused me to ask this question. because
I never cared before, why should I care now?"

I do notice a difference, though I don't think about it past about 1-day. Ask me to and I'll still feel the difference.

I prefer longer cranks, honestly, though I spin better with shorter ones. Thing is, terrain undulates, and I'm constantly having to up my input to stay at speed...long cranks give me the leverage and allow me to power-through those undulations.

However, I don't ever buy cranks based on length unless I'm trying to use the length to help with bike-fit. For instance, a bike with a shorter headtube means I either have to spacer up the steer tube or get longer cranks to lower my carcass...or both. It can be the make or break for a bike with a good TT but an otherwise funky fit.