Sliding IS Brake Mount

I need a sliding IS brake mount for my hardtail build. I am planning on sending my design to Send Cut Send. I just found out their minimum price is $30. Each brake mount costs about $5. So for $30 I can get 1 brake mount for me, or if anyone wants to join in, I can get 6 for the same price. This image shows my design optimized for my hardtail build. If more people want one, I would make the design as universal as possible, but I’d like to make things easy on myself. Is there interest in this?


Sorry, it’s time for me to bail on the forum.


Unfortunately, I’ve already bought the modular dropouts. I’m a sucker for single speed but I don’t have the money to build up two bikes, so I plan to use the geared thru axle dropout for when the bike needs gears.

Is the concern that the rotor will not clear the brake when you have to slide it forward to de-tension the chain, or that it will not clear it when it slides rearward to remove completely? Based on my chosen brake, it will always clear the brake when moved rearward, but the rotor might contact the caliper when the axle slides forward.

picture of forward position and rearward position.

p.s. love your bikes walt. If you’re still in utah we should go for a ride if summer ever comes.

1 Like

Sorry, it’s time for me to bail on the forum.


I would go in on some with you, I’m planning to use the same dropouts for a couple single speed builds. Personally I prefer the design of tensioning the chain in a horizontal dropout than a sliding dropout adjustable dropout. 2005 technology doesn’t bother me one bit, this style is more economical for a lowly hobby builder like myself. I currently have a frame built with this style brake mount and I don’t have to take the brake off to remove the wheel, this depends on what angle the sliding tab is mounted at though. If designed appropriately it shouldn’t be an issue.

My only concern would be that this design is maybe specific to your seat stay angle which may not be a huge deal, we could maybe leave a little extra on the tab or I can adjust my design to be close to yours in terms of seat stay angle. Let’s talk!


Alright, I’ve put a little bit of time into making this more universal. This does a few things differently than the version I had previously posted.

  1. it sits further from my seatstay so hopefully that would make it a more universal option for different frames.
  2. Since it has been rotated slightly towards the rear of the bike, the brake caliper sits closer to top center on the rotor which should make putting the wheel on and taking it off easier.
  3. This has the negative effect of positioning the lower brake mount further away from the seatstay. personally I don’t love how much further back it will sit. Its about 5mm, but I have very strong personal opinions about aesthetics.

With some basic measurements, this should be able to clear a seatstay that has an angle of 50 degrees from horizontal.

Also, I learned some good things about Send Cut Send. The minimum order is $30 but that doesn’t have to be any single part. So if you want me to make your version of the brake mount more specific to your needs, I’m willing to do that since I can order the exact design I want at no extra cost.

If I were feeling really industrious, I could design several different versions based on what seat stay angle people want to use. @Daniel_Y I wonder if that would be a good candidate for the open source CAD parts library? It does seem like IS mount brakes are still something that people within the framebuilding world like to use.


Even though this style of SS dropout is not the fanciest design, I think it looks great. There is something elegant and punk rock about bolting a singlespeed wheel to a track dropout :fire:.

Another tip, in the notes, you can ask for steel parts to be media tumbled. It removes the slag, rounds off the corners, and leaves a nice finish.

I did some sensitivity analysis with the paragon 1.5 dropout. I could bin 5deg of CS-SS angles without it affecting the brake caliper position more than .5mm. I ended up making two custom tabs: for 40-45deg and 45-50deg CS-SS angles.

With your design, I don’t think this is as easy because the tab needs to be horizontal-ish

This is on my to-do list! Still need to find the best way to store files… But first I am working on getting people more comfortable with 3D and 2D CAD.

For now, I think the best way would be to post a dimensioned 2D drawing, or just a screenshot of your sketch, so people can re-create it for their designs. Honestly, it’s not too hard to generate custom DXF files either, but most people won’t know their CS SS angle till they have the dropouts physically on hand.

If it were me, I would use the compact design, then cut out a “trim to length” version for others.


Yo this is sick. I love this style of dropout even if it is a bit of a dated design. And despite what people say I never found the ones I have on my older model Karate Monkey all that difficult to use, especially once you make the shift to bolt on hubs.

Defo putting this one in the resources folder for when I get around to building my first frame. Cheers for sharing!


Update on this design.

So, What I’ve done here is set up a low, medium and high setting for this brake mount. For reference, the seatstays on this model attach to a 400mm seat tube. The low would probably fit best on seat tubes up to 400mm and the Medium would fit best on seat tubes up to 500mm with the High fitting best on seat tubes longer than 500mm. But this is entirely dependent on your seat tube lengths and how far down you attach your seatstays. The reason I designed several is for aesthetics. I think it looks better when it sits closer to the seatstay. Though the tabs can be left long and you can use a larger mount for any smaller bikes.

I’ll willingly share these files with anyone that wants them. In about a week or two, I’ll be placing a Send Cut Send order for a few for myself. If you want one for stupid cheap, they will cost about $5 before shipping. The more that are ordered, however, the better pricing. Since the quantity doesn’t matter which design is chosen, you can pick any of them and it’ll cost about the same.

Message me if interested in a group purchase from Send Cut Send, or if you just want the files.


I think you will find that you don’t need a sliding mount. Google the shimano spec for bmx caliper location. It blew my mind when Tony Periera told me about it. But once you imagine that the pads are located at 12 o’clock and +/- 10mm doesn’t move them off the rotor…


I know that if you plan on one rotor size and a single piston caliper there isn’t much change at all, but I wanted to make sure that multiple rotor sizes fit as well as different brakes. I found a significant difference in brake piston location between brakes like the Hayes Dominion vs the SRAM Code brakes. I had originally planned on using the horizontal slotted brake mount offered by Nova, but a test 3D print revealed that it would hit the calliper. So this route seemed the best and most universal.
Though, I’ve been wanting to build a BMX bike sometime so if you can find a link to that spec sheet, I’d love to have it.

scroll down a little




I just made a post on the education section on this topic… I’ll buy one if you want to have them cut