Constant Crank Swapping, Should I or Shouldn't I?

Alrighty, so here’s some background:

Bought my 36er with 114’s originally, and ran it with those for a few months. I ended up buying some 150’s because and putting them on, because I’ve been doing some of the bigger climbs in my area. They’re absolutely fantastic when it comes to climbing, and I’ve had some awesome rides on them.

Now, though, I’ve got a route mapped out to my work, and want to begin commuting within the month. The commute isn’t long, 8 miles per day, and flat. I can average 10 mph on my 150’s, but the ride would still be faster on 114’s. However, since most of my ‘regular’ rides on the 36er involve climbs, I’d be switching cranks every time that want to go on a ‘regular’ ride. It’s not that time consuming, but I’ve heard that on square tapers, this can be bad since you’re constantly shearing off bits of metal from the taper.

So, should I switch between my cranks all the time? Or should I keep running my 150’s (which I’m not in any way opposed to, I’d just have to plan some more time for my commute)? Or should I bite the bullet and get some 125’s :roll_eyes: (when I already need to buy some lights and watter bottle/cage)?

Thanks guys.

Get your favorite double-hole cranks and save yourself some hassle.

If you have old-style moments, you could probably drill them at 114 mm without weakening them enough to matter. I have done this operation with a drill press and the appropriate taps. It would be best to find someone with a milling machine to make a clean job of it.


They’re square tapers. I’d love double hole cranks, but there seem to be none available except for the ‘dialed’ ones…

You might be able to drill out some Nimbus 2 150 mm square taper cranks. It will weaken them, but they should still be OK for 36" road riding.

Square taper cranks are supposed to wear if you change them a lot (rumor), but my guess is that you could swap them every day without much wear if you were careful to use appropriate torque. It would get old.

I like 137 mm on my 36 for moderate hills. I find it much more comfortable to spin than 150 mm cranks. (What I actually have on it is 110/137, but I leave it in the 137 hole most of the time.)


I used to swap cranks regularly on several of my unis. As long as you do it carefully and check for tightness before every ride it shouldn’t do any harm.

However, think about the speed thing. Every time you accelerate, decelerate, make a tight manoeuvre, cope with crowds or traffic, you need to leave more “margin for error” with short cranks. The short cranks give you a higher cruising speed and a higher top speed but I am not convinced that they necessarily give you a higher average speed over a mixed journey.

I used to ride a 28 on cranks as short as about 80mm and I used to ride a cheap 24 on easy off road on 102mm cranks but as I have become more experienced I have found more and more that I prefer longer cranks. They are more versatile. If you can spin medium-long cranks, you retain the torque for when you really need it.

I now ride my 36 on 150s. These are good for virtually everything including cross country, ascents and descents, and cruising on the flat.

Last November I did a non stop 27 mile ride on this set up and I not only averaged more than 10 mph for the ride, but I averaged more than 10 mph for each individual mile of the route. If I can do that, I’m sure you can. I’m 50 and far less fit than I used to be, A few years ago I was regularly averaging 12+ mph on 150s for an hour at a time.


I’d suggest doing your 8 miles commute a few times, alternating between 114’s and 150’s, trying to do it at similiar times of day and similar road conditions.

Time how long it takes, then you’ll have an idea of whether the 114’s actually do lead to a quicker journey.

As Mike and others have pointed out, longer cranks aren’t necessarily slower- I found when comparing 150’s and 125’s over proper timed journeys, that the 150’s were actually a little faster: the greater control they afford can enable you to idle, rather than dismount, to go over rough ground that you’d otherwise ride round, etc.

Obviously, if you find the 114’s to be appreciably faster, then you can continue looking for a solution, but, if they’re not, then there’s no actual problem to solve.

Get a new hub and stop mucking around with square taper, then you can get dual hole cranks!

On a big wheel, short cranks are great for going straight and flat, but hit the hills and it could be a struggle.

I find anything shorter than a 150 on a big wheel is too short for muni.

I rode my 32" last night, big road climb, some rolling gravel, smoothish single track, then back to rolling gravel. The 150’s were a tad short at times, a tad long at times, but for the majority of the ride they were just fine.

Don’t give up just yet Killian. Aspenmike is riding a 36er with a square taper hub and still have triple-holes cranks on !

He even gives the reference later in the thread: Kooka 3 hole cranks.

You can try to search for them and ask him for advice if you don’t find them :slight_smile:

Kookas are no longer made, and when they were made, a three or two hole crank was a custom order that cost $200 in 1990 dollars. Good luck finding a set already drilled.

If you insist on running square taper, you either need to swap cranks or have a set of cranks drilled and tapped.

You could buy a set of Nimbus Venture 150mm and have a second set of holes drilled and tapped at 125mm.

Someone on this forum had luck drilling his Spirit cranks for a second hole, then buying taps and tapping them, not sure who they are, maybe do a search. I also remember reading about someone paying for a set of Spirits to be drilled for a second hole and the shop messed them up :astonished:

A new ISIS 36h hub is $55, you could probably find a used one if you looked around or just asked me :roll_eyes:

I also have a ton of ISIS cranks, 150/125, 165/137, 137, 145, 140.

I’ve asked Mike about his cranks, and the Kooka’s are a rare beast.

I’m liking Daves suggestion to try both a couple times and see what I like. If 114’s aren’t noticeably faster, than there’s no reason to use them.

Ben, I’m sticking with square taper for now. If I went to ISIS I’d also need to get a new frame, and then build the wheel. I haven’t had a problem with square tapers other than lack of dual hole cranks.

But then, my 36er is a road only machine. :stuck_out_tongue:

I’m not saying I wouldn’t go ISIS, just not now.

Where are new ISIS hubs $55?

Square taper cranks do form to the spindle, and they do get pushed further onto the taper each time you install. With that in mind it isn’t the best thing to change them frequently.

Square taper cranks aren’t all that bad. Especially for a Coker. I have dialed cranks (140/120) on one of my uni’s and can’t be happier. They are heavy steel, but that doesn’t seem to be of too much consequence. As far as steel cranks go they seem to be more robust than many, and so I’m not worried about bending them. I would like them better if they had less offset, but at least I’m not hitting my ankles on them. FWIW the offset is about the same as Moments.

Jtrops, where did you get your dialed cranks?

My 48" has 3 hole steel cranks. RBR (ridable bicycle replicas) sells them for $35. The holes are on 1 inch centers. They are cottered style but it would be easy enough to cut and weld a square taper end on. Something to think about maybe.

Who really wants to change cranks or pedal hole positions all the time? I’d go with the 125mm cranks and never look back. 36er with 125s is a happy medium and best of both worlds as they’re long enough for most climbs and still “feel” fast on the flats and downs. I’ve got 125s on my 36er that I use to ride vanilla XC as well as the occasional road ride; have made it up some reasonably steep climbs as well. But a lot of what you can do given a specific unicycle setup comes with experience so your mileage may vary!

Good luck!

I have 150mm/127mm dual hole cranks and don’t change all the time but I do change based on the majority of the riding I plan on doing. FWIW, if I were going to pick one crank length for everything I do on my 36" it would be around 140.

Yeah I was gonna suggest finding a pair of Kookas and drilling them.

Prowheel cranks can be drilled for at least one hole.