Surly Custom Conundrum Trifecta with MountainUni rotors

Here are pics of my 29" cruiser wheel, 26" LM wheel with the Larry tire (3.8) and my 24" LM wheel with a DH 3.0 tire on it. All fit and after some tweaking, I got them all to work with my Formula Oro K24 disc caliper. I chose this caliper because it’s reliable and after it’s set-up, you really never have to touch it. It’s a bit o a pain to bleed but if you take care of it, you really never have to. My only grips is the banjo bolt is on the inside of the set-up and I have to air down my Larry tire to fit it in the frame :smiley:
The other two are of the disk caliper, MountainUni rotor and MountainUni frame tab welded onto the frame (it’s been powdercoated), the caliper is actually silver, not white; and the last one is of the 29" wheel with the Big Apple tire at the crown showing the clearance (it’s tight but beautiful)
I thought quick release bearing holders would be awesome but the same allen wrench needed to take the wheel off is also needed to quickly adjust the caliper for the new wheel/rotor so it’s going to take me a few minutes to change the wheel anyway :slight_smile:

Nice collection! :slight_smile: How would you change crank lengths on the fly, like the dual hole moments? And would these cranks, esp. the “spider” side, hold up under extreme MUni conditions with big drops? I can see how the disc brake could be a nice setup for my 36er, since I never change crank lengths.


Looks like a slightly downsized version of my plan for my triton.

Love that green colour!

EDIT: Terry: A few people have drilled second holes in the SINZ cranks. As far as I can tell they are BMX cranks and meant to take a beating.

I’d drill them if I thought I’d need it. I had 150/125 and 137/165 KH moments and I NEVER changed them on the fly. I’d bet the majority of uni riders on this forum probably don’t use single hole cranks over dual hole KH moments. The bigger problem is probably going to be that 135mm is the smallest Sinz crank you can get right now. I would bring a pair of 145’s to a machinist and have them drill and chop the cranks down if I needed a smaller set. Right now, 135mm is small enough. When I tinker around with the MountainUni bearing holder mount on my 36-er and some of my other frames, I may decide to bring a set of Sinz cranks to a machinist The smallest I use are 125mm anyway though.

They ARE BMX cranks… BMX riders actually ride with slightly longer cranks comparably and arguably get MUCH more air than most uni riders so I think my 155mm, 145mm and 135mm cranks are going to be just fine :wink:

Thanks :slight_smile:
I am really happy with the color (colour) too, it only cost me $20 to get it powdercoated. I am thinking of having the 36-er frame done too, it’ll probably cost me $40-$50; totally worth it.

I still think its funny looking to see a uni with disc brakes…mainly because of how strong those brakes are.

kb1jki has made dual hole quick change ones for his 36

That’s why they’re awesome to have on a uni… And needed. There have been plenty of times where my maggies just didn’t cut it. Add to that the smoothness of disk brakes and it’s a win!

Hmmmm, I suppose one day I’ll be good enough to shred on a muni. :smiley:

I don’t drop on the 36, and I haven’t ridden it that much yet this season so I have not discovered any issues with the QR collars that stick out 20mm… it’s a test. Jogi broke a pair of dual hole sinz after some drops and stair sets. We are working on durable multi pedal positions for the next generation of the ISIS system.

Turtle has done some 8’ drops on single hole Sinz cranks, and Jogi has not had any issue with single hole Sinz either. I think the shorter the crank, the harder to bend. I doubt custom 110mm Sinz would bend. It would cost extra to customize the cranks but it’s possible.


cranks: after doing the drop below about 10 times (to get the best pic with the timer) my right 155 crank (not at the spider side) was bent a little bit…

now i’m running 135, and i’ve no problems and i’m getting really fast :slight_smile:

What you must think about also is that the impact of bmx is much different than uni. Bmx is jumps and ramped landings, uni can have some very very hard, and sometimes flat landings. But that’s very cool that they seem to be up to the task.

Turtle, are you landing that SIF? I would… I’m all for big air but for me, it has to be functional. That way, the landing probably won’t be completely flat. SIF would take some stress from the cranks and distribute it through your muscles.

sorry for beeing OT:
in muni i don’t land SIF i land rolling, usually (also here) not in a float spot, more downhill, so i can roll out…

if you do drill and bob Sinz cranks, it would be cooler to just hack up some 175’s, since anything under 155 is rare and would be a shame to cut down. We are working on a solution for crank sizes in ISIS… and multiple pedal positions.

I’m not going to do it but if I was, it would cost me like $20-$30 and I would do it with something over 155. :smiley:

I haven’t had ANY trouble buying 135 and 145 crank sets; they might be existing stock, but there seems to be a bunch.

where are you finding them?

Dans comp, ediscountbike, eBay, Goridebmx… I have just searched “sinz expert Isis” and have found 2 sets of 135, 2 sets of 145 and no indication that there were not any more than what I was buying.