bolt the rotor to the inside side of the spider so the caliper clears the crank. I bet those cranks will work! With square taper, the cranks may creep so space the rotor from the crank with the spacers when you weld on the mount. There will be welding instructions on the web.
We are working on a bolt on mount because aluminum frames may have to be stripped of paint and heat treated after welding, and titanium welders are very specialty.
A disk brake is also cool, because you could have a 29er frame with mount welded on, and build up a 29, and 24 inch isis wheels with the cranks and rotors and just swap wheels.
Part of the reason I want one, but you missed my favorite size 
My Hunter 24 getting Disc Applied
My Steel 24 Hunter 3.0 has just left for the fabricator to install the rotor onto a Legacy MUniac Lightfoot Hub. I believe we’re going to use the Avid mechanical to ensure 24, 29 & 36" wheels all have proven concept and worthy of application.
We’ll be sure to re-post the pictures of 24 square taper option and 29 ISIS together once completed. Thank you for the compliments on the idea. I agree
This is sounding really great to me. I will be interested in purchasing as soon as it is made available.
Did I miss something, or will the crank be offered in a 110mm or 115mm range? I feel as if these are the most common crank lengths for long distance road 36ers.
The square taper is offered in 115 from Sinz, but the smallest available in Isis from Sinz is 135. So, to get those sizes, we have been thinking of selling dual hole 150/125, 135/110. That may be left to the customer until we can justify the investment with the manufacturer. (So buy a bigger size and have a machinist drill and tap the smaller size you prefer for about $30-$40.) We need to establish the market before we spend the $ on dual hole, so we can see a return. You may also purchase the rotor, spacers, and chainring bolts to work with your own 110mm bcd bicycle cranks that you bring to a machinist for custom lengths.
I think the next thing we will make available will be a production rotor, and steel mounts for conventional uni’s, Hunter frames, and the nightrider nimbus.
Many folks don’t want to deal with finding a welder, and with aluminum the heat treated frames may anneil during welding and compromise strength and fatigue quickly… so a bolt on mount is in the works!
We intend this system to work with Muni and Commuters, but not street or flatland.
you could send a pair of cranks to these guys to get them shortened.
They shorten cranks for recumbents for $50.
I am really excited about this, I like swapping wheels but generally can’t be bothered to move my brake.
If you used these for flat you could invent the new “rotor roll” assuming you got rid of the brake caliper 
I don’t believe the rotor or rider will survive consistent use of this system for street and flat. You’re more likely to bash the rotor or yourself on the rotor for those genres. Even Muni will be less likely to bash the rotor, because you’re not smashing the cranks against obstacles purposefully.
I think 150/125 would be popular, would 135/110 be a sensible option for 36ers?
It might be, but I would probably go for 140/120.
I’d get the 110/135s, but I’d only ever use the 110s.
I think that it would be perfect for a 36er but then we all have different ideas when it comes to crank length.
I would use both lengths, 135 for commuting and as a “bail out gear” and 110 for road rides.
until we make cranks, the smallest for ISIS seems to be 135, and only Sinz offers the 115 square tapers. So the only way to sell those sizes will likely be a dual hole offering or something that you can have the hole drilled in. you could also bob the cranks if you never use the longer position. We may not offer the dual hole initially.
If the rotor was offered a la carte, would you use your own cranks if you had to drill a hole in a set of Sinz or AC cranks that we may offer if the smallest size were 135? both cranks are made for chain lines of 113mm, and though you aren’t running chains, that seems to put the rotor at the right distance for the caliper. cranks that support 117 mm chain line, or larger may place the disk too close to the frame, we have not experimented with those either.
One of our testers has had our standard mount welded on and uses an Avid Juicy 5 working well on square taper Sinz so far. Another tester hasn’t received our kit due to ash, and we’re waiting to find out how the third tester’s luck went with the welding. We are working on Hunter and nightrider weld on mounts, as well as a universal bolt on mount.
If you need a tester for the bolt-on universal mount, I have a Surly conundrum and Nimbus nightrider that I could try it on.
INteresting on the 120-140 position
Interesting?!, the 36 er we have built up currently has 120-140 holes and I really like it too. Less knee throw than the 150 , and a great position at 120 for a good fast spin
Are those the Trek “Dialed” cranks? I actually emailed them a while ago to see if I could get a pair to use on my Nightrider. If they ever reply my plan is to take a hacksaw to the spider, and cut the chainwheels off. I know they have the cranks in two lengths, but the 140/120’s are the ones I asked about.
That was our proof of concept. However, square taper cranks creep, so our pat pend is on the chain ring style rotor that uses spacers to dictate rotor displacement. You can make one if you can source a crank, but with standardized bolt patterns, we can fit and sell many. ours will be precise, adjustable, and standardized, (easy to replace once your cranks wear out). Don’t pay too much for the dialed cranks, because what we have to offer will be superior.
I wasn’t actually thinking of making them disc ready. This was before I considered the disc conversion. I wanted dual hole cranks because I don’t like switching my cranks very often, and I liked that they had some with square taper to fit my coker wheel.
If they ever get back to me I’ll think about what I want to do, but for now I’m waiting to see what you end up offering.
Mountainuni disc brake!
Last week I had the brake mount from Mountainuni.com welded onto my Nimbus Titan frame. I have a Coker wheelset with a square taper axle, and the Sinz 125/150 cranks are working great! The custom rotor is a lot more solid than the rotor that came with the Avid Juicy 5 brake. It is a little thicker (but not too thick), and it has more surface area also.
The installation went very smoothly, and so far the brake lever is working great on my T7 handlebar (right in between the handlebar grips).
The modulation is perfect, a light pull and it starts to engage, and a full pull completely stops the wheel. I just did a 14 mile ride yesterday, and I was able to fly down the hills with confidence knowing I could slow down or stop with no problem. I really love this brake set-up. I got the Avid Juicy 5 from Cambria, and because the first two brakes I ordered were out of stock they gave me the Juicy 5 for $70 bucks.
I have put about 40 miles on this set-up so far, and I’m liking it better all the time.
