MXUS 3000 caliper clearance

eAdrian

100 mW
Joined
Apr 8, 2016
Messages
38
Hi

I have tried to find information about getting hydro brakes working with MXUS 3000 v3 on using regular 135 mm dropout frame and 160mm brake disc.
I am very curious how you guys have solved the caliper clearance issue for this motor?

My setup.

Fork <--2 mm spacer--> Disc <--3mm spacer-->Motor giving me 15.3 mm clearance between the disc and the motor.

What will not work:

  • Another extra spacer between motor and disc. Disc touches the cables during rotation
    203 mm brake disk will not fix clearance, 60mm ontop 160mm is required.
    Buying Magura Gustav. It is just too expensive
    Shave of 1-2mm. Walls became to thin and did not hold for the pressure.

I read that Clarke Exo Skeletal http://www.bikester.se/clarks-skeletal-hydraulic-disc-brake-skivbroms-set-rear-vit-337827.html might work. But I am not sure.

So please share how you managed to get hydro brakes work on this motor?


Thanks
 
There's a few different tricks depending on the frame. Where are you based?
 
I am located in Sweden.

Adding more washers bending the fork more creates vertical misalignment of the mounting and the disc.
 
I had this problem with Mxus 3k 135mm and avid bb7 160mm. It just scratched the motor plate even with the adjustable bolt sanded and washers. I gave up and just used the brake regen and front caliper brake :)
 
Two spacers with m5x 16mm bolts is one solution.

There are some mechanical brakes with good clearance. Use a 203mm rotor.


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waz

Have you considered this?
http://www.bikester.se/clarks-skeletal-hydraulic-disc-brake-skivbroms-set-rear-vit-337827.html

I ordered today and see if it fits and I will let you know.
 
Yes. I tried mechanical brakes and it has 2 mm clearance.

203mm rotor will not help. I measured at least 220mm.
 
I'm following this thread with interest. I have an old MXUS3000 lying around and recently bought Andersons, spokes + dh rim at my local grin. I'm sure solutions are highly situation dependent. My caliper is a pig, and the only way to buy a couple mm clearance would be to grind down my 8" rear IS adapter mount or have another IS mount fabricated to specs, then build out the disc with spacers. I may go this route, as I have an inexpensive metal fab place in the neighbourhood and any old block of metal with threaded holes in the right place should do - it doesn't have to be pretty.

eAdrian said:
waz

Have you considered this?
http://www.bikester.se/clarks-skeletal-hydraulic-disc-brake-skivbroms-set-rear-vit-337827.html

I ordered today and see if it fits and I will let you know.

Reading reviews on the skeletals, some users have complained they (in particular the front brake) can warp under heavy load, and that the pistons can seize after extended disuse or storage. Let us know how it goes.
 
I got the Clarks Exo Skeletal brakes today.

Executive summary:

  • For 50$ kit from bikester.se, not bad deal getting both rotor and extra pads. (Not tested braking function yet)
  • Clearance is not as good as I was hoping for. With some measurements caliper is 15.3 mm and it about 2 mm less than the shimano BR M447.
  • Caliper slighly shaving off color on thickest part of the motor, which is where the text is.
 

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There are thin shim spacers that you can build up to the right thickness, then also use a zip tie or other collar to prevent the phase wires from being rubbed by the rotor/screws.

http://www.niagaracycle.com/categories/syntace-disc-shim-8-piece-set?gclid=Cj0KEQjwyum6BRDQ-9jU4PSVxf8BEiQAu1AHqh3VsFbiRx-1KN9H59i1_D7Iwr9g2bpMzPJzFoUp2agaAnfA8P8HAQ
 
Thanks for the detailed tests; the skeletals look like they have potential; let us know how they rate in comparison to the Shimanos for braking power etc.

I can also see from this that 15.2 mm seems to be the magic number.

Did you end up using the 160mm rotor?
 
molybdenum said:
Thanks for the detailed tests; the skeletals look like they have potential; let us know how they rate in comparison to the Shimanos for braking power etc.
Yes will do that when bike is done.
molybdenum said:
Did you end up using the 160mm rotor?
Yes
 
cal3thousand said:
There are thin shim spacers that you can build up to the right thickness, then also use a zip tie or other collar to prevent the phase wires from being rubbed by the rotor/screws.
Yes. I think I will go for such set of 8.

My next steps would be
  • Turning motor 180 degree and putting cable to the back
  • Adding additional shims 4*0.2 mm between motor and disc
  • Getting longer rotor screws since to get through total shims of 2.3+0.8mm
  • Extra 1-2mm spacer towards the fork
 
I have now implemented my next 4 steps and achieved the clearance of 0.5 mm at the thickest part of the motor.
I have also put the cable backward and it is much better not fearing cable will touch the rotor. (see pic).

Final implementation details:
Instead of extra 0.8mm shim , I went with 1.0 mm. That in turn lead to spacers to get brake mounting clearance to the left of the rotor. And that in turn lead to spacers on the right side to get motor centered. :)

So I am posting a picture visualizing what worked for me with a 135 mm drop out setup. (See mxus-spacers.jpg)
 

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molybdenum

I have now tested the skeleton brakes.

They perform "OK" I would say.
I was expecting to squeeze less to lock the wheel.
I had to press rather hard on asfalt since I have 2.35" rear. But also in general, the squeeze feeling is like mechanic brakes, but just better braking.

I don't have anything to compare with for this motor. I had shimano before on this bike and it was smooth to press.
But I think having 12 kg motor makes huge difference stopping that wheel on 160mm magura rotor.

I was riding in the forest and I could have rather good control pumping the handle controlling the locking of the wheel.
 
Thanks for the detailed tests.

I'm not surprised it's difficult to lock up these brakes; my shimanos on 203 rotors barely locked up with a clyte hub and a 85lb bike + 170lb me.

These are on sale from chain reaction cycles for $47.49 CAD for the rear, so I've placed the order and will definitely post my experiences here. - too many people running with no rear brake due to lack of options for the wider MXUS hubs imo.
 
Are there any mechanical disc brakes which have enough clearance even without spacers?
 
Use a rotor of a diameter large enough that the caliper is beyond the motor's cover diameter, and it should work with whichever caliper you like. if the caliper is particularly large you might need to clear the spoke flange too.

The larger rotor can give you better braking / control with the same caliper than a smaller rotor, too.
 
In this case it is not possible because a bigger rotor would have contact with the frame.
And I don't want to add washers because I don't want to spread it further.

I think the only hydraulic brake that has enough clearance is the Magura Gustav M.
Are there any mechanical brakes that have enough clearance?
 
The Magura Gustav is the only one of its kind. It was easy to find when I started building, but now I guess most of them are on ebikes. Any other caliper will require some mod to your frame. I usually make extended torque plates that have the brake mount integrated. The motor axle is set back a few inches and this is solving many problems, including frame clearance for wider tire and choice of brakes. It is also giving the bike some extra stability by stretching the wheelbase, and let it accelerate higher power with proper wheelie control.
 
Earlier in this thread was written that mechanical brakes have 2mm clearance. But I am not aware of any mechanical brakes with such a clearance.
 
I think Everyone has 203mm discs for much better for clearance and im using a 3mm and the standard plastic one that comes on it. my Shimino XTR 9020 fit fine, I had to smimmy the bracket but that depends on your frame i guess.

Countersink works good too with Cable,
 
Today I have modified a mechanical disc brake rotor with the angle grinder. Now it fits also without the disc spacers. I have enough clearance for any disc size, but I plan to go for a 203mm disc.

Where the adapter would sit, I have about 12mm space between the frame and the disc and dont want do add a washer to spread the frame more.
My Shimano adapters are about 12.5mm thick.

Are there any IS2000 to Post Mount adapters which are slightly thinner? Maybe around 10mm thick?
 
The IS2000 to PM 8‘‘ adapter made by Formula is 10.7mm thick and fits.
The same adapter made by Shimano is slightly thicker (10.9mm) and also fits.
 
I had a Machinest shave/mill off some of the thickness of my rear 203 mm adapter .




hias9 said:
Are there any IS2000 to Post Mount adapters which are slightly thinner? Maybe around 10mm thick?
 

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