Is there any huge difference between 175mm or 170mm crank length?  Wiggle has some 170mm on sale…

i have always had 175, am over 6ft ….

im clueless – advice appreciated

5mm

Not a massive difference, just under a quarter of an inch I believe..

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Of slightly more help, I ran a 172.5mm none-driveside and a 175mm driveside crank on the commuter for several months before I even noticed. I am 5’11.

Beaten to it

IME makes no difference to how it feels riding the bike

BUT

shorter ones you do seem to get less pedal strikes

I prefer short cranks. I went from 175  down to 165 and for me the closer foot spacing feels more stable when out of the saddle. I am 5′ 11″

And here I am wishing I had put in parenthesis – apart from 5mm!

Thanks all – helpful and appreciated

Haha.

Slightly more useful reply:

if it’s for a roadbike you ride a lot or you if have knee problems it’s worth thinking about but otherwise the benefits of going 5mm shorter are 5mm more pedal clearance and that shorter cranks do spin up faster and more easily in low gears. negatives are negligible

apart from 5mm!

10 mm if you add the two together.

Thought we were only doing subtraction? I change my mind

https://singletrackworld.com/forum/topic/crank-length-9/

My cycling inseam is only ~83cm, quite small for someone 178cm tall, my road bike has 172.5 cranks and the Wazoo has 175. I suspect I would benefit from shorter cranks, but I’ll be damned if I’m spending well north of £100 to experiment on both bikes.

IME makes no difference to how it feels riding the bike

BUT

shorter ones you do seem to get less pedal strikes

Yes.

Fashion right now: really low BB.

That’s fun going fast downhill. But sometimes a hassle as well…

If your bike has a low BB 170 mm might be an advantage in trails with lots of roots and rocks.

I’ve got 165, 170 and 175 on various bikes.  I notice the difference going between them, but forget about it after a few pedal strokes. Probably get fewer pedal strikes and less knee pain with the shorter cranks.  I’m 6′

<div class=”bbp-reply-author”>paton
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https://singletrackworld.com/forum/topic/crank-length-9/

If there’s a “crank length 9”, there’s also

https://singletrackworld.com/forum/topic/crank-length-8/

https://singletrackworld.com/forum/topic/crank-length-7/

https://singletrackworld.com/forum/topic/crank-length-6/

https://singletrackworld.com/forum/topic/crank-length-5/

https://singletrackworld.com/forum/topic/crank-length-4/

https://singletrackworld.com/forum/topic/crank-length-3/

https://singletrackworld.com/forum/topic/crank-length-2/

https://singletrackworld.com/forum/topic/crank-length-1/

https://singletrackworld.com/forum/topic/crank-length/

34″ leg here and I’ve found 170mm works best. However I prefer 165 to 175 on bikes with low BB heights.

With 175 I notice the extra leg movement required when swapping which foot is down with fast left-right-left-right corners whilst with 165 I notice the feet being a bit closer together and less stable. But I don’t notice anything with 170s, they just feel right.

Most don’t notice, some say it’s life-changing.

I’ve ridden 170-180 and not noticed.

Stupid but honest question: does it change the gearing?

Yes but not a lot. 175 to 165 you’d want to change from a 34 to 32 chainring.

Stupid but honest question: does it change the gearing?

Effectively, yes. Shorter cranks means your feet are moving more slowly, but you need to exert more force on the pedals for the same power output. In other words, you will need to shift down earlier on climbs to compensate. Whether it’s actually noticeable is another question.

For me it’s life changing… 2x5mm quite literally being the difference between joint pain for a week and not.

Out of the saddle not so much but a couple of hours pedalling on 175mm with my outside leg measurement and I’m in agony.

Quite honestly not something I’d ever considered prior to kiddy bikes and crane lengths but after looking into this I actually looked and I had 2 bikes, one with 170 and the other 175… I just swapped cranks and the bid that had been killing me swapped over….  I won’t even entertain 175mm now and quite tempted to go to 165mm purely for pedal strikes.

I have crap joints anyway (and I’m 50)… so this is amplified for me but anyone else it would be worth checking as you don’t want problems later in life.

Conversely I noticed no real performance hit using slightly shorter cranks or even really short ones except it changes your cadence.  I can use the 142mm cranks off Jnr’s bike quite happily..

short cranks are better for long distance rides in the saddle, its good for Aero, your breathing, blood pressure and your knees.  Thats what I just read.

I had demo on a Whyte a few years ago and found that it was fitted with170mm cranks. I felt something was different straight away and definitely prefer 175mm. I’m a shorty with a 30″ inside leg btw.

I had demo on a Whyte a few years ago and found that it was fitted with170mm cranks. I felt something was different straight away and definitely prefer 175mm. I’m a shorty with a 30″ inside leg btw.

Weird/curious what size frame …. I’m 5’10 (and a half) but 28-29 inside leg… (clothing wise) and the T-130’s I tried all had 175mm cranks and killed me.  (I don’t remember HT’s) Swinley are local and were hiring them at the time whilst I was getting a frame repaired but I tried from small through medium to large…. (Though I think I only sat on the large)

I ended up buying a T-130 anyway..(medium).. but changed the cranks immediately.

My only real criticism of the Whyte for me though is I really struggle for seat height… a 125mm dropper is absolutely slammed… (well perhaps 5mm on the Thomson and the reverb was slammed)

I’m sure frame geo and HT vs full squish vs long travel also make quite a difference though…

it was a 901(I think) HT and frame size was small, I’m 5’4″. The 170mm cranks to me felt akin to something you find on a child’s bike, like there’s a shortage of leverage and your legs barely move because the cranks are too short – but obviously not to that same degree. When I got home from the first ride I measured them and it was 170mm centre2centre. I then measured the BB height and knew why they’d made it like that.

On a similar subject I also find the 32t chain ring too small on 11sp and found the 170mm cranks compounded this. I’ve just bought a Giant Anthem and whilst it has 175mm cranks I’m going to change the chain ring to a 34 or 36 so I’m not down the bottom of the cassette most of the time.

@Keva….

I guess we are all different shapes…. I never quite got on with Giant Geo though .(not crane length and not BAD… I just found a bike that felt lie someone are it for me not someone a different proporiton – which is pretty much every Whyte I tried )… but I have short legs.  (5’10 and the important half when comparing to OH)  but I’m more 28-29 inside leg in trousers.

TBH until I was looking at bikes for Jnr I’d never given crank length a second thought….  I just had a bike I didn’t use… because it caused pain and the other I used instead…(both Giants)

When I then started to get interested due to Jnr I looked at the cranks…  ****-me… if the one I didn’t like riding had 175mm vs 170mm and swapped the cranks over… I couldn’t believe the difference the 2x5mm made to me.

Jnr has 142mm cranks and they don’t feel that bad… its a bit hard to judge on the small frame I guess but not the first awkwardness that comes to mind riding his bike… though to be fair its not killing his shock that is usually priority 1…. (Mostly when I ride his bike its because he won’t ride something and usually that means his 25kg would bottom out .. let alone my 74 kg and its too big or steep to push around)

Other than spinning out I’ve not noticed a great deal of difference on chainrings… and I’ve got/use 30 through 34

If you’re interested then somewhere this company got some figures/table… (scroll right to the bottom)

Crank Shortening

What’s interesting to me is it’s “outer leg” rather than inner leg … I don’t know where they got this from but it seems spot on….  it would be interesting to know where you fit…  (if you can be arsed)

My measurement worked out at 85cm so 170mm cranks , and that what I have on my four bikes (ht , fs , flat bar and drop bar road ) I used to run 175 as that’s what came on bikes I bought till a had an alfine geared bike that had 170 , it felt better (more comfort with a slightly less extreme circle) so as I changed my bikes over time I went for 170

Haven’t spotted anyone mention these upsides to LONGER cranks:
– longer crank means lower saddle, can be more comfortable / less fatiguing on the back muscles (alternatively you could lower bar height if preferred to increasing comfort)

– Longer cranks and lower saddle = more bum clearance when descending out of the saddle, good for those without droppers (the laggard halfwits without droppers…me included)

– I believe the greater range of motion is more complimentary to running as its a bit less different to running. No evidence for this just my hypothesis.

– slightly lower gearing on budget 1x conversions…if you are buying a middle ring for a given conversion then obviously this point is moot. Just get a 30t instead of 32t etc.

The above are why i run 180 cranks (34″ inseam) on two bikes. Have to admit that pedal strikes do annoy me on my t-129 with its 175 cranks so won’t be changing them.

You run 180mm cranks to give yourself 10mm more saddle clearance when your pedals are level?
Are you aware of how much clearance 10mm actually is?

It’ll only be 5mm more clearance, not 10mm

I should probably play about with 170mm cranks, I just happen to have always had 175mm’s
When I tried a bike with 165mm’s it felt like I couldn’t generate any power/torque, especially on climbs. It was a 1×8? spd freeride full susser though