When to expect the disc KH cranks

[MuniAddict]

Originally Posted by unishark

ben, my understanding/expectation is also that the new kh disc brake cranks can also be used in conjunction with the d'brake

fify

[Fatlazypig]

In expectation of these new cranks I have been looking at disc brakes and the d'brake bearing cap

My understanding is the d'brake is IS spacing.
Most brakes seem to be post mount spacing and I need an adaptor

Should I expect said adaptor to be included when buying a disc?

Secondly how is this adaptor revered to. Is it a 'IS to post' adaptor. Or conversely a 'post to IS' adaptor
I was planning on buying from my LBS and have the guy there sort it out but he has refused to sell a single brake and only sells in pairs. So will be using
Chain reaction cycles

[MuniAddict]

The frame mount would be necessary for use with the schlumpf hub. The Dbrake bearing mount would not work because of the specialized schlumpf bearings.

[saskatchewanian]

The D'Brake mount would work just fine with a schlumpf after a quick date with a belt sander. Or if you don't like modifying things you can use a MountainUni UCM which has a thinner profile and should bolt right up.


I believe you want a standard rear adaptor for whatever size disk you are using with the D'brake or UCM. I can't remember for sure though as I just brought the unicycle in to a shop and asked for a adaptor that would fit.

Adaptors are often included with disk brakes but not always.

[MuniAddict]

Originally Posted by saskatchewanian

The D'Brake mount would work just fine with a schlumpf after a quick date with a belt sander. Or if you don't like modifying things you can use a MountainUni UCM which has a thinner profile and should bolt right up.


I believe you want a standard rear adaptor for whatever size disk you are using with the D'brake or UCM. I can't remember for sure though as I just brought the unicycle in to a shop and asked for a adaptor that would fit.

Adaptors are often included with disk brakes but not always.

Yeah Kris had told me about the sanding of the dbrake. And I hope he won't mind me quoting a short excerpt with regards to using the dbrake with the Schlumpf hub:

"One caveat though, about using the disk brake on a Guni: as you know, the knurled housing is braced against turning by being clamped in the bearing housing. Because a crank-mount disk brake runs the braking through the gearing system, it may place additional rotational force on this interface, depending on the rider and the riding style."


So I would definitely NOT want to use the dbrake for my G26er, and would only consider the frame mount.

[saskatchewanian]

Terry:

Either way if you are using a crank mounted disk with a schlumpf the braking forces are going through the gears. From the hubs perspective you are just adding back pressure to your cranks. It doesn't matter where the calliper is mounted.

[MuniAddict]

Originally Posted by saskatchewanian

Terry:

Either way if you are using a crank mounted disk with a schlumpf the braking forces are going through the gears. From the hubs perspective you are just adding back pressure to your cranks. It doesn't matter where the calliper is mounted.

It's primarily the fact that there would be uneven pressure on the specialized schlumpf bearings, especially the knurled bearing, given the fact that the dbrake cap must be tightened all the way down on the leading side, leaving a big gap on the other side. And either bearing be damaged by over-tightening the bearing caps. This is one of the main reasons why the frame mount would be much better. So in this case, I defer to Kris.

[bouin-bouin]

Originally Posted by Fatlazypig

Should I expect said adaptor to be included when buying a disc?

I received my brakes with adaptator but if yours is delivred without, you can use this one http://www.chainreactioncycles.com/M...?ModelID=69495

[Nurse Ben]

Terry, this is a non issue. If the brake torque is so significant, then the frame will twist under braking anyhow, causing uneven pressure on the bearing cap, which will cause the same non problem that is worrying you.

For a counter perspective, Josh at UDC said that one of the reasons they went away from frame mounted disc brakes is because it was twisting the frame. He added that by placing the brake caliper on the the bearing holder, the torque was more controlled and LESS of an issue because the wheel/bearing moves with the bearing holder unlike the frame which would be twisting above the bearing holder.

Now back to your scheduled program...it's June already, when are the cranks coming in??

[uniShark]

Originally Posted by MuniAddict

It's primarily the fact that there would be uneven pressure on the specialized schlumpf bearings, especially the knurled bearing, given the fact that the dbrake cap must be tightened all the way down on the leading side, leaving a big gap on the other side. And either bearing be damaged by over-tightening the bearing caps. This is one of the main reasons why the frame mount would be much better. So in this case, I defer to Kris.

Your quote from Kris does not at all address the issue of frame vs bearing cap mount, so I'm not clear on what you're deferring to?
Speculation aside, I hope and expect we'll get some guidance and instructions on use of the disk-mount cranks when they are released.

[Nurse Ben]

It's primarily the fact that there would be uneven pressure on the specialized schlumpf bearings, especially the knurled bearing, given the fact that the dbrake cap must be tightened all the way down on the leading side, leaving a big gap on the other side. And either bearing be damaged by over-tightening the bearing caps. This is one of the main reasons why the frame mount would be much better. So in this case, I defer to Kris.

Not to mention, you can put the knurled bearing on the side opposite the D Brake if this is such a concern.

The D Brake adjusts diffently than a normal bearing cap, but it is designed to do so by having one side "set" while the other side is used to establish bearing pressure.

In all liklihood, it is a BETTER way to manage bearing pressure since with a typical bearing cap, both sides of the bearing cap "gap", whereas the D Brake has one side set with the upper and lower caps flush, thus it reduces bearing movement and is MORE secure.

I think UDC should design all of their bearing caps so that one side is adjusted flush and the other side is used for tensioning, it makes more sense to adjust tension from one side vs two.

[Nurse Ben]

In expectation of these new cranks I have been looking at disc brakes and the d'brake bearing cap

My understanding is the d'brake is IS spacing.
Most brakes seem to be post mount spacing and I need an adaptor

Should I expect said adaptor to be included when buying a disc?

Secondly how is this adaptor revered to. Is it a 'IS to post' adaptor. Or conversely a 'post to IS' adaptor
I was planning on buying from my LBS and have the guy there sort it out but he has refused to sell a single brake and only sells in pairs. So will be using
Chain reaction cycles

You need a front brake IS adaptor, most brakes come with one specific to your disc size (160, 185, 200).

A "front" brake will have a shorter hose, so that's your best bet for a muni, though it could still be little long. A "rear" brake might be a better choice for a 36er where you have the brake mounted on a touring bar out in front of the seat.

The brake description will often list the hydraulic line length, so measure what you use for your Magura. If measuring with no brake at present, be "generous" in your estimate and add in a frame wrap or two if you think you'll be using it for more than one mounting style in the future.

There are lots of opinions on what disc size is best. I have a 185 on my 36er and 160's on my 26-29, I don't have problems stopping with the smaller disc, but some brakes/pads are better than others, so keep in mind that a bad pad will make a good brake work poorly. Organic pads tend to be the best choice, but most disc brakes come with semi metallics, which work fine most of the time.

At this time, there is not a mechanical brake caliper that will fit with a unicycle disc brake, so hydraulic is your only choice. The are some reviews posted under the disc brake thread ini reviews.

[Feisty]

Originally Posted by saskatchewanian

The D'Brake mount would work just fine with a schlumpf after a quick date with a belt sander. Or if you don't like modifying things you can use a MountainUni UCM which has a thinner profile and should bolt right up.


I believe you want a standard rear adaptor for whatever size disk you are using with the D'brake or UCM. I can't remember for sure though as I just brought the unicycle in to a shop and asked for a adaptor that would fit.

Adaptors are often included with disk brakes but not always.

Front front front!!!! Rear has a 10mm different position to the front requiring a 20 mm larger disc for the same sized adapter (a 160mm rear adapter is the same as a 180mm front adapter).

Most brakes that come with a disc rotor come with an adapter but remember to buy a front setup as that is what the Dbrake mount is built for

Read this thread for all the info in this thread

[MuniAddict]

Again, I am only talking about the dbrake application for a schlumpf hub, and that *both* bearings have to be tightened to a specific torque, which may be exceeded by use of the dbrake. I will wait for someone else to use the dbrake mount on their schlumpf, and wait for their ride report. No hurry here. I've been very happy with my magura, but it would still be nice to finally have a disc brake option for the schlumpf, while still being able to use the [new version] moment cranks.

[OutdoorJunkie]

Originally Posted by Nurse Ben

The brake description will often list the hydraulic line length, so measure what you use for your Magura. If measuring with no brake at present, be "generous" in your estimate and add in a frame wrap or two if you think you'll be using it for more than one mounting style in the future.

Huh? Are you talking about measuring how long your magura brake line is and then getting that length for a disc brake? Or have I misunderstood what you said? Cause if you order a brake line for a disk brake the same length as your magura line then chances are it will be too short.