[Closed] 6ft 3inch, shortish legs - should I go for shorter cranks?

Personally think 165mm will be spot on for 32" inside leg, Ive got long legs for my height so about 34" and love 165mm.

Thanks

With today's geometry, 165mm cranks are da bomb.

6ft nowt

Get them.

This  https://highpath.co.uk/crank-length-calculation/   is what I looked at many years ago when choosing crank length. I went for 165mm based on it and they work well for me. I'm also happy with 170 and have used 175 oiff road with no problem but definitely don't get on with them for long periods of sat down peddling.  I'm a lot shorter than you at 5'6" with an inside leg of 30"

I have bikes with 175 and 170.  I cannot tell any difference.  My inside leg is similar to yours

I'm 6'2" 33" inside leg, I use 165mm cranks.

Probably easier to spin a cadence, aggravates my osteoarthritis less, and gives a little more clearance when I put a crank turn in the wrong place. it's not an obvious instant noticeable effect where you realise that the cranks are shorter or longer but rather effects on pedalling dynamics.

I am tall but blessed with short ( 32 inch) inside leg.

I'm 6'3", with the 35" leg. I reckon though 165mm is ideal for yourself. I think I'd be better off with 170mm, but 165mm suits pretty well.

So lucky you. Never though I'd be jealous of another mans legs 😕

6'2 with a 34" inside leg. I've one bike with 165mm, several with 175mm and one with 180mm. All feel fine, I can sorta feel 180 to 165, but the difference is gone within seconds

Hardtail Party did a video where he tested lots of different crank lengths back to back. Might be worth a look on YouTube.

I have a 32” inside leg and think 150-165mm is ideal.

I’m 6’2” and also have short legs. I’m currently on 170mm cranks on all bikes, even the single speed.

Keen to try 165mm on the full sus

Except for pedal strikes on a particularly low bb bike, I can’t tell the difference even on long rides. I’m 5’9 with a 30” inside leg and I’ve had a singlespeed with 180s down to 155 at present on the ebike. Ebike obviously masks any potential difference in power delivery but still can’t say I notice anything weird when I do pedal with the motor off.

Looking at different pedal and shoe combos I have, I’d say there is as much of a size difference swapping between those.

Probably easier to spin a cadence, aggravates my osteoarthritis less, and gives a little more clearance when I put a crank turn in the wrong place. it’s not an obvious instant noticeable effect where you realise that the cranks are shorter or longer but rather effects on pedalling dynamics.

Yeah, I'm 6'3" and 175 mm cranks made it harder to "sit and spin" on my roadbike and plus aggravated knee pain more. Happy at 170 mm.

It depends what kind of riding you do however, if you're mostly doing steep technical MTBing crank arm length may not matter much and longer arms could offer a slight leverage advantage going from standstill and up across some roots or whatnot (at the cost of lowered clearance). That said I'd still go shorter.

You won’t notice the difference. My fixed bikes are all 165, geared road bikes 170 and mtb are 175. There is little in it. The shorter cranks are to avoid pedal strikes because you can’t coast.

Some people have ridden odd length cranks and still not noticed 😂

I'm 6"4 with 36" legs

One mtb has 180mm cranks

Two MTBs have 175mm

One road bike has 170mm

Gravel bike and second road bike have 175mm

It makes..... No difference.

I'm about your height but have far longer legs and always 'understood' that I needed long cranks, but, my Cotic is a bit low so recently I put on 165's for more clearance.

Work fine, the only thing to note is the reduction in leverage, so I dropped from a 32t to a 30t.

My HT and gravel bike are both on 175's.

I dunno TBH.

I'm a stumpy 28in inside leg and have 165mm cranks on all my MTBs.

The only thing I'd warn about it that it effectively raises your gearing, as you have a bit less leverage.

If you have one of those big 12speed cassettes you should be fine, but if your gearing is tighter and you can't drop a chainring size then it could be an issue.

Edit: I was typing that while intheborders was making a similar comment 🙂

All MTBs should come with 165mm cranks. It's arguably a freak of (road) history that we ended up with 175/170 as the norm.

6ft 1in here on 165mm cranks. Would actually be keen to try shorter!

I’m 6”1’ ish and tried 165s on my ECR for touring/bikepacking. I was hoping I’d like them but after a few trips I went back to another bike with 170s and felt much better so I now have 170 on the ECR and much prefer it.

I wanted to like 165 because the ECR has a low bb and I hoped it would be nice to my knees but for some reason I much prefer the bike with 170. I may give them a go again to check.

I can’t help thinking that we must have bottomed out on the low bb thing if we have to get round the problem it causes by using shorter and shorter cranks… unless of course that shorter cranks are better all round.

I can’t help thinking that we must have bottomed out on the low bb thing if we have to get round the problem it causes by using shorter and shorter cranks… unless of course that shorter cranks are better all round.

No, it's the low BB that's better so consequently needs shorter cranks.

Shorter cranks also enable a longer dropper.

No, it’s the low BB that’s better so consequently needs shorter cranks.

Shorter cranks also enable a longer dropper.

That’s what I’m trying to work out… so you lower the BB to gain an advantage derived from sitting lower, then you shorten the cranks which means you end up sitting higher. Does that not cancel it out?

Low bb is about lowering centre of gravity, crank length doesn't really change where the weight is.

Low bb is about lowering centre of gravity, crank length doesn’t really change where the weight is.

But… if you drop the BB by 5mm you lower the CofG (of your body) by 5mm. Then if you shorten your cranks by 5mm you have to raise the seat by 5mm so placing your body back where it was. Or am I being thick?

Cranks level it's the same, when cornering your outside pedal will be higher/clearer and your inside will be lower with shorter cranks so err, balls, you got me thinking now, never thought about saddle height in the equation, low bb is more about out of the saddle handling.

I'm 5ft5 with short legs (28 inch leg) and fine on 175mm and 170mm cranks.

Center of gravity will only change if measured while the cranks are vertical.

Shorter cranks also means less leverage. So less power.

Less leverage so less power, but the higher cadence makes up for the lack of leverage/torque, plus if you're struggling to turn the crank you're in the wrong gear or on a singlespeed. For acceleration off the line or a sprint to the finish line, 165mm gives you the advantage.

I'm 187cm with 33" inside leg and keen to try 165 cranks, but struggling (along with most of STW I think) to find any in stock. My preference is Deore or SLX or RF Aeffect - something along those lines.

I had 170 on a bike in the past and no complaints.

Center of gravity will only change if measured while the cranks are vertical.

Yes, but the saddle will be a few mm higher so technically you can't get quite as low. In reality, I doubt it's going to make any difference.

crank length *does* matter.

but the difference between 165 and 175 is about 5% - it should not come as a surprise that people can't feel much difference. it's sort of the same difference as between 19" and 20" frames

i'm 6'2", 36" leg, i use 165's : (a bit) easier to spin, (a bit) less knee pain, fewer strikes.

MsWife is 5'1", she's got 140mm cranks - now they feel weird!

(i'd need 230mm cranks to get an idea of how inappropriate 165's would be for her)

Shorter cranks also means less leverage. So less power

https://www.pinkbike.com/news/why-shorter-cranks-are-better-according-to-science.html

for the roadies, shorter cranks are more aero.

it's true!

1) smaller frontal area

2) your foot is going faster than you when it's going over top-dead-centre. 165's are 6% shorter than 175's, so your feet are going 6% slower. drag is proportional to the square of the speed, so 165's mean your feet have ... 12% less drag. And that's big enough to laugh in the face of marginal gains. that's a straight-up real difference.

5'7" and 29" I/L here and run 165s on everything barring the road bike but that's just because it came like that & I never ride it anyway. Would run shorter than 165 if they were readily available. (I'm sure they are but I tend to buy all my stuff 2nd hand and it's not something that often comes up)

Cannot fathom how the industry has settled on a blanket 175mm fits all policy when it comes to cranks when 165mm would suit so many more people/bikes.

On a related note also can't understand why BMX racers tend to favour long cranks given the speeds they have to spin at - maybe that's one usage case where the pros (gate start & huge benefit to getting out front early) outweigh the cons.