Square hub vs. ISIS on a 36" uni

OK, I recently built up an old Coker Rim with a super wide UDC square hub and a Nimbus Nightrider frame just to see if I like riding a 36" uni. I love it… I’m not 100% sold on the frame, the rear posts don’t seem to be centered, it won’t affect brakes or clearance… I just don’t like the look :slight_smile:

I’m also suspect about the stiffness of the frame.

I want a lighter wheelset and was almost completely sold on getting an ISIS set-up although Coker’s new wheelsets are fairly light (1170g) and decently priced (much less than an ISIS set-up). I know they’re not as hearty as ISIS hubs but I don’t plan on abusing it too much. At 205lbs. I don’t want the thing falling apart by going off a curb or down a few stairs (that’s about as extreme as I will get).

What do you all think? Any ideas on a light, durable wheelset for a 36" uni?

I am 195# and put over 500 miles this summer on my Coker square hub. I have NO problems riding on road and the occasional trail. Have ridden off a 3 step a few times and still no problems.

I rode a square tapered 36 for a while. I had a cranks come loose a couple times but I also swapped cranks 2-3 times a week according to the conditions and what I was planning on riding. I did not always seat the crank properly before going for a ride so that was probably the issue.

My next 36er is going to have an ISIS hub as I believe that ISIS is better if you plan on swapping cranks often. I am also going ISIS for compatibility reasons letting me mix and match pieces from various unicycles.

Square taper hubs/cranks should be no problem with what the vast majority of people do with 36ers. I would say that at least 80% of the unicycles raced at RTL (biggest/longest unicycle road race ever) were square taper.

I haven’t had any trouble with ISIS, and was willing to spend the extra for peace of mind. Then again, the coker hub is 48 spokes. . . I wouldn’t ever need more than a 36 spoke wheel, being in the featherweight category, but I would suspect it is fine for most.

Either way I think would be OK to be honest. I do love my moment cranks though <3

as for the nightrider frame, no those little supports are not even. OCD riders may find this extremely disturbing. . . I didn’t even notice until 2 weeks after I had bought it. I find the frame to be perfectly ok unless you’re running hydraulic brakes, which I don’t. It’s the T7 flexing that I don’t particularly like, but it works well, and I like the position of it.

to add a bit about the discussion of the Coker wheel and Nimbus frame

My nimbus frame was symmetrical but it was an older frame from the airfoil era. Yup they are flexy side to side but one thing they do well is resist twisting. They handle very well unless you are running brakes in which case you will probably have rubbing issues especially with maggies.

The Coker wheel is a great deal but the 48 spokes is a big turnoff for a lot of people. I would be willing to bet the advertised 1170g is the rim only and the whole wheel is considerably more. When I finally get the extra dough to get one myself i will take it all apart and weight the individual components.

My plan is to get one, re-lace it to a Nimbus ISIS hub and put it in a KH frame. It will be one bomber 36er.

The Tour de France riders power up Alps putting more torque through their cranks than any unicyclist who is not doing vertical drops. At one time they did this with old fashioned cottered cranks, and then square tapered bottom brackets became the next big thing. Have no doubt that a square tapered hub will cope with any torque you can put through it merely by riding.

a few stairs can be rough on your uni, but the latest rims are pretty good. Square taper is stronger than lots of people give it credit for, especially if you’re running short cranks.

If you want a light coker wheelset you will have to do some customization. right now, tubes are 500g, rims are 1100-1200g, tires are 2000+, then you have the stuff that matters somewhat less like hubs, cranks etc.

If you really want light you’ll have to get your hands a bit dirty. swapping to a 29’er tube (there is lots of advice around here on this) makes a noticeable difference. Also some people are trimming rubber off their tires, saving another 200 grams or more. You will notice a reduction of 200 grams at the outside edge of the wheel as a rule, but we’re still rolling around with four kilogram wheelsets until someone gets a true road unicycle on the go…

The sort of riding where the extra strength of ISIS will be any benefit isn’t the sort of thing you’d be doing on a 36er anyway. Like people have said, square taper isn’t exactly weak.

Over the last couple of years I’ve swapped my muni and 36er over to ISIS, partly for the strength (on the muni - although I never had crank problems on my old sq-taper muni), partly for looks (moments look nice on the muni), but I mostly did the 36er for compatibility of cranks between the two.

So I’d say the biggest decision-maker is if you’ve got other unicycles you want to be able to share cranks with.

(those Coker wheels do look like a good deal though)


I don’t like square tapered cranks on coker’s. I’ve ridden thousands of miles with them, and I have bent/broken many crank arms at my heavy weight of 135 pounds.

I strongly recommend ISIS, mainly for the crank strength.


PS: Eric, at RTL, I would say 95% of people had square tapered cranks – there wasn’t a option (from unicycle.com) for ISIS until after (KH36 / Nimbus 36), unless you built your own wheel.


It isn’t the taper that is weak, it is the crank selection available for the square taper.


If you are interested in dropping off anything I think it’ll be worth going with the ISIS hub/cranks. The more comfortable you get riding the 36er the easier it will seem to do the things you did on any other unicycle.

Square taper will likely be strong enough, but you’ll have to check it often for tightness. I’m 190lbs and a few sloppy 10"-12" drops have slightly damaged my 150mm coker cranks.

I know it’s not actually a 36" wheel, but my Schlumpf 29er (29" or 43")is square taper. I’ve covered a few thousand miles, dropped down many kerbs, and done mild muni without any problem at all*. (I don’t ride down stairs with it though).

As has been mentioned, the strength of square taper is a lot higher than a lot of people give it credit for. There is still a large range of cranks out there too, and if you already have these ones then that’s a good reason to stick with it.

I would have said that if you’re the kind of person to change your cranks often that you’d be better off with ISIS. However, Steve Colligan done his Mount Everest ride on a square taper 36" wheel and was swapping cranks at least once a day without issue - and that’s the kind of place where you can’t afford mechanical breakdowns!


  • One of the cranks broke once. But this wasn’t anywhere near the square taper part, and was down to a manufacturing defect.

I’ve bent several pairs of cranks doing drops–I know the 36ers aren’t really made for that, haha–but the hub has never failed. For regular road/distance riding, and even light XC, the square taper is perfectly fine. I would definitely go with the double walled alum rim, over the old style, heavier and much weaker steel rim.

If you don’t mind fiddling about with a crank puller every now and then i would say go the square taper. The one advantage with the ISIS hubs is that there is a on the market, dual hole crank (KH Moment) which can be advantageous if you are riding on varied terrain. If that is not so important a square taper with 125mm or 114mm cranks will get you through most terrain quickly and easily.


Good point. My older Coker (from 2002) is on its original square taper with no problems. No bent cranks either. And my 27 year old 45" big wheel is still running on its original cottered hub. The wheel was rebuilt in '94 but I kept the original hub. I have bent cranks with that one, but have only ever used the original pair of 6.5" steel ones that came with it. When they get bent I take them off and beat them with a sledge hammer. :slight_smile:

Best reason to use ISIS on a 36"? Schlumpf hub. Second best reason is if you’re going to do a lot of drops & stairs, etc. If you’re just thinking about curbs and not-super-technical MUni, a square taper is probably fine. My newer Coker is only used for MUni. But not very technical. Technical MUni is just not fun on a 36". Unless you have the perfect trail for 36" I guess… That would have a lot to do with it. But the perfect 36" trails for me are fast and less-technical ones.

The Schlumpf hub is square taper!

The best reason to use ISIS on a 36" is KH Schlumpf hub :smiley:


Some of the smaller wheel square hubs are terrible

Not so, so far, as far as I know, in 36. The UDC square hub is the square deal, and the buzz is the Coker hub is good as well. Are there any other 36 square hubs?

The ISIS splined set up is the only way to go for trials unis, and I would not settle for less than a new KH 36, if I was rich. Yet I don’t feel bad riding around on my old rusty Radial 36 with a square UDC hub. I have 140 Sugino cranks on it, my impression is it will outlive me. The 36 hubs don’t get the poundings, and are also better made than the cheap square hubs that are found on cheap small wheeled unis.

So yeah, you can trust the UDC and Coker 36 square hubs. They are well suited to their task, and not just made to be cheap.