What Crank Lengths are you using?

Montana St Alum

Active member
Feb 13, 2023
255
204
Park City Utah
I've tried 175, 170 and 165 on my mountain bike. I tend toward Achilles tendonitis and pedal at slow cadence so the increased torque on the shorter crank arms on the mountain bike are a problem in that regard. On my E-mountain bike with reduced torque input on my part, 165 seems to work just fine with no tendon pain.
 
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I'm using the 160mm Raceface Aeffect R cranks. I played around with several lengths and 160mm is the shortest I will go to enjoy my rides.

From my experience, crank length should be determined by the rider's morphology, fitness level or health, bike size or geometry, and also riding style.

Shorter cranks improve ground clearance and can reduce pedal strikes. They can also give you more acceleration. Can reduce knee strains if you suffer from knee pain or injury.

But shorter cranks make it harder to propel the bike with the motor turned off. Shorter cranks also require readjusting the saddle and handlebars height.
 

Cell4soul

E*POWAH Master
Jul 11, 2022
518
1,324
Mesa, AZ
155 5Dev cranks and skinny blade runner pedals. Much less pedal strikes since I went to this set up. I like the higher cadence and so does my Fuel EXe.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,565
5,027
Coquitlam, BC
160mm. The bike came with 165mm alloy. I wanted to install 155mm cranks for less pedal strikes but I couldn’t find them in carbon.

I watched a video of some guys destroying carbon cranks. Failures were mainly at the inserts, which to me is a critical weak point. However the Era carbon cranks broke or failed in the middle under more pressure or torque. That made more sense to me.

After a serious peddle strike I don’t want the crank failing at the peddle insert or motor insert. A broken crank near the middle takes more effort. So I was convinced. These ERA cranks are only slightly shorter (5mm) and I never really noticed a difference in my cadence or additional torque required. But they were pricey, but not as pricey as Titanium cranks (holy sh**).

Thread 'Cane Creek Titanium "Electric Wings" ISIS Cranks'
Cane Creek Titanium "Electric Wings" ISIS Cranks

@Zimmerframe did a good review of the 3D printed Titanium cranks. I can’t attest to the strength comparison between these Titanium and Carbon cranks, but the Era carbon cranks seemed to be lighter.
IMG_6015.jpeg
I’ve been using these for several months now.
 

CliffP

New Member
Jan 24, 2023
59
60
San Antonio Texas
I've tried 175, 170 and 165 on my mountain bike. I tend toward Achilles tendonitis and pedal at slow cadence so the increased torque on the shorter crank arms on the mountain bike are a problem in that regard. On my E-mountain bike with reduced torque input on my part, 165 seems to work just fine with no tendon pain.
Yes on my Stump Jumper I have 170s and it works well. Regarding an EMTB I have been experimenting with shorter cranks and because of the motor the torque leverage is less important IMO. The benefits are numerous with the ability to have a lower bottom bracket and reduced rock strikes. Plus’s it it easier to keep slightly higher cadence and staying in the power band. . BTW Miranda aluminum cranks are inexpensive so you can experiment with low sink cost. They have great customer service.
 

Jurassic

Active member
Subscriber
Jul 22, 2022
236
243
Helensburgh, Scotland.
155s for me as well. I replaced the OEM 165s that came on my bike with Miranda 155s and I can't think of any reason to swap back. I'd like to experiment with going even shorter if cheap 145s were available but afaik 150 is as short as Miranda go and I'm not sure that another 5mm would be very noticeable. More expensive 145s are available but I don't really want to spend a lot in case I prefer 155.
 

EMTBSEAN

E*POWAH Elite
Subscriber
Feb 20, 2020
1,036
733
Sheffield
I’m running Hope 155mm cranks, even though I’ve only done around half a dozen rides since I bought them I’ve only had a couple of peddle strikes so already it’s been a great buy 😎
 

Mabman

E*POWAH Elite World Champion
Feb 28, 2018
1,124
1,853
Oregon USA
After digging my outside 170mm crank arm into the dirt on a corner that was totally unexpected and dropped me like a hot rock I have gone to 155mm Miranda's and never had it happen again. Doesn't do much for unassisted pedaling but works fine as long as the power is on and you can keep a high cadence easily if that is what your bike performs well at.
 
Hearing about y'all short cranks, like 155mm, I've been wondering how tall you guys are? Wouldn't tall riders with longer legs be negatively effected by short cranks?

At 6'1 using Large frame bike and 160mm cranks, I needed to adjust my saddle fairly high, then raise my stem/handlebars to align with saddle height. Not sure how short I can go before the bike becomes unadjustable or even unridable!
 
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Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,565
5,027
Coquitlam, BC
Hearing about y'all short cranks, like 155mm, I've been wondering how tall you guys are? Wouldn't tall riders with longer legs be negatively effected by short cranks?

At 6'1 using Large frame bike and 160mm cranks, I needed to adjust my saddle fairly high, then raise my stem/handlebars to align with saddle height. Not sure how short I can go before the bike becomes unadjustabe or even unridable!
5’9” here. My 5mm change in pedal length (165 to160) was barely noticeable. I didn’t need to change the seat hight and I only hope I have less pedal strikes.

Stem hight remained the same. I’m probably not a very good test-monkey for crank-length. But installing a longer dropper (170mm) made a huge difference for me without changing any geometry on the bike. My inseam is 32” I think 🤔 and a medium sized Trek fits.

I imagine after a few rides we could get use to the new geometry if that came with improvements.
 

CliffP

New Member
Jan 24, 2023
59
60
San Antonio Texas
Hearing about y'all short cranks, like 155mm, I've been wondering how tall you guys are? Wouldn't tall riders with longer legs be negatively effected by short cranks?

At 6'1 using Large frame bike and 160mm cranks, I needed to adjust my saddle fairly high, then raise my stem/handlebars to align with saddle height. Not sure how short I can go before the bike becomes unadjustabe or even unridable!
I am 6’ and with E-bikes the perfect efficiency ( perfect saddle height) is way less important because of the motor help. This was one thing that took me the longest to get use to. Run seat lower and it helps in many areas.
I have no Issa with saddle height going to 150/155 cranks
 

EMTBSEAN

E*POWAH Elite
Subscriber
Feb 20, 2020
1,036
733
Sheffield
I’m 5’10” and the change in crank arms length has changed my gear ratio a little bit, it wasn’t that noticeable before my forced absence from MTB’ing, what it’ll feel like when I make a return remains to be seen or felt 😁
 

mustclime

Active member
Apr 19, 2023
438
354
New Jerzy
The biggest issue with going to shorter cranks is the change in saddle/ cockpit height.You knock 10mm off your crank arms, you end up moving your saddle and bars up 10mm. If you just add spacer under your stem you are reducing your reach so the best option is higher rise bars or a longer stem. When people ask me about shorter cranks I recommend they get new bars or a stem with the cranks so bike fit stays the same.
 

Jurassic

Active member
Subscriber
Jul 22, 2022
236
243
Helensburgh, Scotland.
The biggest issue with going to shorter cranks is the change in saddle/ cockpit height.You knock 10mm off your crank arms, you end up moving your saddle and bars up 10mm. If you just add spacer under your stem you are reducing your reach so the best option is higher rise bars or a longer stem. When people ask me about shorter cranks I recommend they get new bars or a stem with the cranks so bike fit stays the same.
In theory I know that you're right but in practice it's not been an issue for me. I lifted the saddle the corresponding amount but my bars stayed the same. When I'm descending my saddle/dropper is slammed anyway so it's irrelevant. I suppose it depends on where you are on the bike sizing scale as well, if you're in the middle of the height range for the size of bike you bought then it's not going to be an issue. If you're on the upper limit (i.e. you like to ride a small frame) then it's potentially more of an issue.
 

Haveland

Active member
Apr 21, 2022
218
152
New Brunswick, Canada
I'd love to find small cranks for my Norco Bigfoot VLT but I tried a different set and it didn't come clear to having the clearance needed for being a fat bike.

It comes with "Samox Alloy, 32T, 165mm" and EP8. I haven't tried contacting Samox yet but should.
Would love to go 155mm

Currently, run 160mm on my Turbo Levo but would go to 155mm if I could on my Bigfoot as well. Even so they are very different bikes I like keeping some similarities across them.
 

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