Disc Brake Reviews: Post what you got!

Three month update:

Still running Magura MT 2 on all my unis, upgraded to 200mm rotors which seems to keep them cool longer, one set of rotors are Magura wave, the others are Shimano standard drilled. Not sure if one rotor is better than the other, though the Shimanos seems to have more power.

No real issues with the brakes, though I have an off and on squeal with the brake on my 26/29, not sure if it’s bad pads or what, but it does it with either wheel set, wet and dry weather, and I’ve cleaned up the pads a few times.

It did get better recently, so maybe I finally got things seated well.

Overall the Maguras have been trouble free, pads are easilly removed for cleaning; don’t need to remove the wheel or caliper. Pads are lasting well, no leaks, holding pressure, no fade issues when hot.

A great brake for a great price.

When lookin for a set, be sure and order the calipers with the adjustable hose angle, there are some that don’t have the adjustment and you’ll want it if you use a D’ Brake.

Disc brakes… LOVE THEM.

Kay now that i got that out of the way quick question to the people running disc brakes with the D’brake adapter that UDC sells. If I dont tighten up my bearing clamps up pretty tight after a short time the D’brake adapter will loosen up causing some lovely vibration with braking. Right now I have them pretty tight so I can ride without having to tighten them up mid ride.

Anyone else have this same issue???

@Ben

Have you noticed any increase in stopping power by using a larger rotor?? I talked to another rider and he said he hated how “sticky” the brakes were so I told him to go down a rotor size and he said it made a big difference.

My MT2’s had some squeak for a bit but lately there isnt any. I hope it stays that way as well :roll_eyes:

Vibrations

Jacob, your vibration is likely a result of the caliper mount actually touching the upper bearing caps that are welded to the frame. That’s the primary reason why we machined the Mountainuni UCM to have a 1mm gap between the flats faces. Those vibrations won’t transfer to the frame if the two don’t touch. I have many in stock, and there’s 1 easy was to proof that’s the issue, buy one and try for yourself. :slight_smile:

@Mountainuni1

I checked my caps today and went for a ride… well results showed no vibrations and one side of the cap was touching the other cap. I can see there being a problem if both ends were touching but with only one I think that is realistically how many bearing caps will always be.

Best solution overall, mounts welded to the frame. Then you can easily change out parts.

I did a video review of the D Brake.
Im using an Avid Juicy 5 with a 160mm rotor. I originally fitted a 203mm rotor and it had so much bite it was unusable. It would just lock and throw you off no matter how gently you pulled the lever.

Moral of the story, bigger isn’t always better. It’s how you use it :stuck_out_tongue:

I haven’t felt vibration with Roger method msg#35

Once, I put the D-Brake in contact on the frame in the opposite side and I had some crack noise in the hub; it disappeared when I tightened the D-Brake correctly as on the drawing. Tightening the 2nd bolt of the D-Brake is not very easy, you need to pay attention not to tighten too much and I always use Loctite because tightening torque on this 2nd bolt is lower than with standard bearing cap. No issue when correctly fitted.

The bigger rotor does not have more power, it’s neither stronger nor stickier, it is still the same surface area under the pads, but it does seem to stay cooler when I use it hard, which was the purpose in increasing rotor size.

I think the brake you choose shoudl be one that modulates well, ie does come on too strong, can be varied by pressure, so one finger vs two fingers, etc…

All brakes are grabby at times, I don’t really notice the Maguras being grabby, if anything they are on the mushy side, but the work fine and slow me down when I need to be slowed down.

I could get a more powerful brake, but I’d worry that it would lock up the wheel and pitch me, so for me the Maguras are pretty much perfect.

I use the UDC method for tightening the D Brake and it works fine, haven’t had any probelms with the tensioning bolt loosening and it is not overtightened, keep threads greased lightly.

Whilst the the friction area is the same the larger rotor has greater leverage so is more “powerful” with the same force on the lever, the flip side is you lose modulation over a smaller disc as the point of lock up on the travel of the lever will be sooner than on a smaller rotor so you would have less lever movement to modulate between off and lock up.

This is why you will always see smaller rear discs on a bike / car as there is less traction on the rear wheels under braking so a less force is required to lock the wheel, using smaller rear disc rotors helps balance the brakes (although a brake bias valve does most of the work on a heavy car)

So on a Uni where we don’t want to be locking up our wheel the smallest disc we can get away with with the least amount of finger/hand pressure is optimum, but in reality sticking on the biggest rotor you can makes sense as the loss of modulation won’t be noticed by many.

There are lots of factors

Brake design/function
Pad friction material
Hand strength
crank size
body weight
Steepness of terrain
Wheel size
Traction (road/snow/mud)

On a 26" Uni with 145mm cranks a 160mm was fine with only mild hand cramps on long descents

When I switched to a 29" with 137mm my leg force with my lightish 11 stone body weight meant I was being lifted out of my seat so had to pull the saddle handle more when on the Uni above I would have just controlled my speed with my legs. I therefore changed my rotor to a 180mm which due to the large wheel didn’t change the modulation feel but brought the effort I had to exert on the lever back to around where I was on the 26".

I could have got a 203mm rotor to be honest and saved my hand some work on the big hills but I thought the rotor almost being as long as my cranks would look a bit odd

I always recommend getting a Shimano brake with the “servowave” feature (STX/XT/XTR) as this has a cam in the lever that keeps the rotor further away from the disc then when the pads hit the rotor the cam slides down giving more power. This more importantly means no annoying disc / pad rubbing. The SHimano’s are very good quality, cheap and use nice mineral oil. There are lighter or more powerful brakes but we are not riding 35# bikes down hols at 30 mph+

The real benefit with discs is they are not as effected by mud so are more consistent, are not impacted by a buckled wheel and are self adjusting so virtually maintenance free

As for fitting as NurseBen has said the UDC fitting of the D-Brake works fine, clamp the brake side down nice and tight and tighten the other enough so the wheel spins freely

Some pictures of my 180mm 2 piece Shimano rotor with an STX brake on my KH29

braided_hose.JPG

29er_brake_small.JPG

Tightened up the D’brake mount according to the picture so now ill see how long it stays tight! So far it has been lovely feeling with zero vibrations :slight_smile:

You guys get hand cramps when you brake?? I have never had to hold onto the brake that hard. It honestly feels a lot easier than the maggies and almost to easy at times! Im using an MT2 and 180mm disc with 145s on a 24inch (maybe thats why i dont get cramps :p)

The only different thing about disc that I have noticed with riding is that when Im riding fast down a hill and appling the brake is that the unicycle wants to pull out in front of me. So ill be riding and stand up and the seat will be out in front of me while im braking. It is actaully pretty odd to see

Heres a question for you guys

Is there a way that I can bring the lever closer to my fingers?? I got short fat buggars and I have to move my hand down to get it to the lever. Ive moved everything as close as I can but the lever still sticks out about a half inch away from my finger when it is extended out.

Have you already adjusted the lever inward using the star nut which is accessed through the front of the handle?

If that’s still not close enough, you could add spooner or starfighter to make the lever thicker.

After that, I guess you could bend you brake mount or use spacers to lift the rearmost attachment points

I suppose that changes things to a degree, giving more braking “distance” on the rotor per revolution, but the amount is really insignificant, 10%??, not enough for me to notice at least. Local bikers in Tennessee tend to favor smaller rotors because the mountains are “short”, whereas the big DH folks out west who ride long downhills favor the bigger rotors, but it’s really about maintaining a cool rotor to avoid burning your pads. I had some pad “cooking” on my 29er with a 160/180mm rotor, but it is since resolved with a big 200mm rotor

I have looked at that rotor before and it looks pretty good- although could it be a bit too wide to work the the KH Spirit mount system?

I’d love to upgrade to discs and I will eventually but it is a big cost to upgrade from maguras. I’d prefer to get a new KH frame with the welded disc mount because it looks better and so you don’t have to take the bearing holder with the brake off everytime you take your wheel out of the frame! Also the D mount would require a lot of machining which could be costly.

So heres what I’m thinking I’ll do when I upgrade to discs for the 26 all mountain + downhill rig.

New KH frame with welded frame mount -$240 (sell my current kh26’’ frame)

Spirit cranks 150/127 - $170 does any one know why it says 160 mm or 180 mm disc here http://www.krisholm.com/khu/spirit I get why you can’t have a 160mm disc but why not a 203mm disc?)

Then for a brake I was thinking

http://www.chainreactioncycles.com/Models.aspx?ModelID=82434 Shimano Zee Disc Brake M640 $224

http://www.chainreactioncycles.com/Models.aspx?ModelID=54868 $220 Shimano XTR Race M985 Disc Brake

http://www.chainreactioncycles.com/Models.aspx?ModelID=83173 Shimano SLX M675 Disc Brake looks like a great cheaper option @ $146

http://www.chainreactioncycles.com/Models.aspx?ModelID=73474 Hope Tech X2 Evo Front Brake cheaper than I though hope brake would be, I really like how you can get it fitted with braided hose at $210 love the hope machining too.

All those brakes have good reviews and pretty good weights. I want to get a reliable brake and one that can take a bit of a beating.

For a rotor I’m not sure weither to get 160/180 or 203- I’d prefer to have a smaller rotor thats more out of the way with more modulation just as long as it have enough heat distribution and power. Shimano XT/Saint RT86 Ice-Tech 6-Bolt Disc Rotor looks good but seems kinda pricey for $50 a rotor

Or maybe a hope floating rotor.

Or this one is even cheaper just looks like an older model for about $40 http://www.chainreactioncycles.com/Models.aspx?ModelID=39007

Or Avid HS1 Heat-Shedding 140/160/180/200mm Rotor for $50

And finally a KH Starfighter Brake Lever Extension for $40

Far out so with new frame + new spirit cranks + hope brake + rotor+ starfighter it comes to a wooping $700! - say minus $160 for selling my current KH frame, so about $540 Eeeeek thats an expensive upgrade haha- might not happen for a while :astonished:

Any thoughts on my plan and what brake do you think looks best?

Smooooth…

Thanks for this, it’s fixed my vibration problem, which I’d been assuming was something to do with the brake adjustment, or the pads.

I’d followed the instruction per tightening the brake side fully and first, but I’d overlooked or forgotten the specific 3mm detail for the other side; I had it closer than that, and the high-speed vibration on braking was both LOUD and painful as it transmitted through my hand and arm! Loosened the caliper on that side back to c. 3mm, and braking is smooth and quiet.

I was nearly on the point of replacing parts to fix it, so that’s saved me some money, time, and disappointment.

Remember, kids, rtfm.

Used this method and I still feel vibration. I tightened up the D’brake mount the opposite way and there was no vibration :thinking:

I honestly dont mind it as long as my bearing holder doesnt come loose. That is when i experience most vibration.

Also to note:
This method I get A LOT more squealing. The pads are in a different position than before so maybe this could be a cause of sqeaking??? (i dont know)

OK! so i got bit by the disk bug and i am doing a spirits and was wondering what is a really good break that wont brake the bank.

I like the older radial master cylinder Shimano SLX Chain reaction have them for £60 then add a cheap rotor and your laughing. The slx and xt shimano brakes have a servo wave feature that keeps the pads clear of the rotor to stop rubbing then the initial lever pull moves the pads quickly then as they hit the rotor a cam in the lever drops to increase the force.

Just a quick question - when choosing a disk brake… Do you go for a front and rear one? Is there a mechnical difference or just the mount/adapter - I am referring to Hope or Magura brands as these two on my debating list for a future uni :slight_smile: -

Cheers
M.B

Doesn’t matter, just be careful as some rear adapter can be used for a front brake but with a different disc diameter !

140 IS (international standard) rear = 160 IS (international standard) front

This ^

The only other thing is hose length and sometimes the levers are sided but us unicyclists care not for such things.

Another thing to consider is the angle of the reservoir some set ups while fine on bikes let air into the system due to the angle of the lever under the seat. Ideally you want a radial mounted master cylinder (runs from the lever hinge to the clamp rather than one that runs straight forward).