Hub motor hydraulic caliper clearance

Hyena

10 GW
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Aug 13, 2008
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6,222
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Sydney, Australia
Hey guys,
I thought I'd start this thread as a reference for everyone to post up what sort of hydro calipers they're using on their hub motors and what mods were necessary to get them to fit. People often ask me "will the [insert brand and model] brakes that came on my bike fit the motor" etc so I thought it's be good for everyone to state what they've found what what's involved to make them fit - be it a straight bolt up fit, with a washer or 2 or a half inch thick bar of steel jammed in there :lol:

Tell us what the motor you're using and the make and model of your calipers. I guess the 2 most popular ones will be the new style 9C and the new Hx35 crystalytes. The new crystalytes do have a little more clearance than the 9Cs so should be able to accept wider calipers but not by much.
From memory the clearance on the 9C is around 14mm and around 18mm on the crystalyte (from center of the disc to the the side cover of the motor)
I'll edit this first post with everyones findings to make an easy to find list.

I'll kick it off with the new crystalyte Hx35 motors. I've dummy fitted a juicy 3 caliper and it JUST contacts the motor side case. With a 2mm spacer under the disc and the fat washer that comes on the motor on the inside of the frame to push the caliper back out a similar amount it should work fine.

My Clarks S2 that are on on the front miss out by a fair margin though. Not so much the side of the caliper but the 'knuckle' where the hydro hose leaves the caliper sticks out another few mm.
 
I had fitted many hydro brakes to the X5, all with 203mm disc.

Hayes 9 too tight and need to space the disc, but if you omit the washer inside the dropout you only need to remove the lockwashers off the motor cover screws and it will clear.

Then replaced with Avid code, had to shim the disc

Magura Gustav perfect fit, plenty of clearance, best so far
 
MadRhino said:
I had fitted many hydro brakes to the X5, all with 203mm disc.

Hayes 9 too tight and need to space the disc, but if you omit the washer inside the dropout you only need to remove the lockwashers off the motor cover screws and it will clear.

Then replaced with Avid code, had to shim the disc

Magura Gustav perfect fit, plenty of clearance, best so far

I just had a look at those Magura Gustav's- they are bloody expensive!!! :(
 
I tried the cheap, but effective, Shimano mechanical brake disc caliper, its just a bit too wide.

There is a cheapo Promax caliper, it came on the front of my old Raleigh Chinhook, and it seems to be slightly narrower and looks like she might be a runner.

I desperately want front and rear disc brakes. I understand that a stiff fork with a big front disc is most important, but a rear disc is also nice, for two reasons: First, the motor is drilled for brake rotors so its a pity not to use them and secondly, its a pain in the ass seeing my rear rim covered in a fine film of rubber particles from the shoddy rear side-pulls.
 
Good Hydro brakes are expansive, that is a fact. The magura Gustav M had been in production for so many years, and they are not used for racing anymore, so it is relatively easy to find them used. I bought one recently on Ebay for 137$, and one locally for 150$, still looking for a 3rd

The Gustav M is a very low maintenance, very robust and powerfull brake caliper. It uses plain mineral oil, easy to bleed, the big pads last a whole season and can be found locally for 10$. The feeling is precise, it is a floating self adjusting caliper made of magnesium, should last a lifetime.
 
shimano-br-m535.jpg


that Shimano caliper will not come close to fitting on a Magic Pie.

my Hayes mechanical disk brake caliper that came with the bike does fit. so i run mechanical in the back and hydro in the front with a 180mm disk. plenty of stopping power.
 
Looks like still no joy for getting reasonably priced hydros on most hub motors.
Avid BB5 and BB7 supposedly fit clyte and I believe 9C motors as well. I'm not sure what model hayes but likely it was the MX-4s
I have cheap tektro iox mechanicals on my clyte and they have about 2mm clearance.
 
The Mighty Volt said:
Hi there, whats the full name of the Hayes brake that does fit? Cheers.
I've had Hayes 9 on one of my bikes, with an X5. The fit is very tight, needs disc spacers about half a mm.
The Hayes caliper worked well for a while, then seized during the winter, due to corrosion from the melting salt.
 
I don't know about hydro either, but my Hayes MX-4 mechanical fit tight but close. You can also grind off part of the holder for the pad fairly easily if it doesn't clear. This is on a new style nine continent.
 
I'm going to go over to mechanical on the rear for my HS3540 motor as my hydro breaks are a pain in the arse to align up. Also I will be able to use the mechanical lever to trigger the regen which I couldn't do on my hydro's.

Mechanical and regen should be enough stopping power on the rear with a big hydro on the front.
 
Demosthenes said:
I don't know about hydro either, but my Hayes MX-4 mechanical fit tight but close. You can also grind off part of the holder for the pad fairly easily if it doesn't clear. This is on a new style nine continent.

Never thought of that myself. Cheers. :D
 
This is a bump. The Gustav's are discontinued as of 2011 for new buys as most shops are now only bringing in 2012 models of brakes. So its used if you want to go that route unless your LBS has old stock.

Anyone have access to some Hayes Stroker Aces or Hopetech M4s that they'd be willing to post measurements of? Supposedly 4 cylinder brakes are a little lower profile. I know I've seen build threads with these mentioned but couldn't find any measurements... (liveforphysics? you had a set of aces, no?)

- Ben
 
Ben_S said:
This is a bump. The Gustav's are discontinued as of 2011 for new buys as most shops are now only bringing in 2012 models of brakes. So its used if you want to go that route unless your LBS has old stock
They've been announcing that Gustav M would be discontinued next year, for the last 8 years :lol:
Still, you can buy Gustav M brakes online on Magura website, and my guess is that you still will in 5 years from now. The reason why is that Magura never succeeded to make another brake caliper that is as reliable and painless as the Gustav.
 
MadRhino said:
The Mighty Volt said:
Hi there, whats the full name of the Hayes brake that does fit? Cheers.
I've had Hayes 9 on one of my bikes, with an X5. The fit is very tight, needs disc spacers about half a mm.
The Hayes caliper worked well for a while, then seized during the winter, due to corrosion from the melting salt.

I have Hayes 9 on a BMC V2s. Fits fine even with a small 6" disc. (As a backup plan I had an 8" that would have moved the caliper upward, where the hub is less wide, but this was not necessary.) Clears with a mm or so.

So far I have had good luck with my three Hayes 9. Got them used or on used bikes from $20 on local swaps etc. Among the cheaper brakes I prefer them over say Shimano Lx. And I think any working hydro is better than a mechanical.
 
MadRhino: The Magura website says they are discontinued and sales from factory stopped at Dec 2010. http://www.magura.com/en/products/disc-brakes-2011/prod/gustav-m-40.html
If I've missed a page where they are available for purchase, please do post it up!

I also checked chainreactioncycles, universal cycles and few others. All discontinued/unavailable.
- Ben
 
No idea the size, tho looks small, and maybe worth the gamble, at only $104!!
Magura MT 2 Hydraulic Disc Brake

As with the MT4, the brake lever supplied on the basic model in the MT range is made from CARBOTECTURE®. The lever and clamp are manufactured from aluminium. The two-piece brake calliper provides for a more economic production process, and MAGURA passes on this price advantage directly to the end customer. As a basic model, the MT2 is only behind its bigger sisters in tipping the scales, as it delivers the same braking power and optimum lever geometry as the models toward the top end of the range. Value-for-money even for the thrifty - and for all those who aspire to thrift. Comes in rear length, can be bled for front application.


Features:
* High Performance!
* Best price/performance ratio
* CARBOTECTURE body
* ANTI-Features
* FEEL SAFETY-Ergonomics
* EBT (Easy Bleed Technology) Can Be Used For Front Or Rear
* Weight 345g (including 160 mm Storm Rotor)

Item Shown: 100067031
Item Color: BLACK

CBO Price: $103.95

They just showed up here: MT2 Affordable Disc Brakes, scroll down
 
Here's the Nine Continent Caliper Clearance for the Magura Gustav in case anyone is wondering. No shimming or anything. It just fits out of the box. So the inside measurement must be like 10mm or less. (I don't have the tools to measure this accurately, but the nine continent front has about 14.5mm total clearance.)

ninecontinentwithmaguragustavcloseup.jpg

ninecontinentwithmaguragustavclearanceback.jpg

ninecontinentwithmaguragustavclearancefront.jpg


- Ben
 
The Gustav M will clear with any hub motor, cause the pistons are on the outside only and the inside is very thin.
 
Good information , thanks people!
I found a Hope M4, internal measurement (rotor/calliper internal edge) is 17.3. Not enough (14clearance +3spacer=17mm)
Hope X2 on rear hub anyone?
 
Hello guys... I'm also in trouble with brakes. I bought a pre-built bike and its brake is poor, i hate it. I once bought a shimano hydraulic one, used, but it didn't fit. I noticed that the space between the rotor and the motor cover on my bike is 14,3mm probably. I'd like to know if someone knows a cheap brake that can fit there, i prefer hydraulic ones, but mechanicals will be accepted since they'r easty to adjust. If you have the brake, please measure the size of that part that goes behind the rotor and tell me, so i can decide which one will fit better. Thanks !
 
You can adapt to 9" rotors, that will solve most motors clearance problems so you can fit any caliper you want. Hayes sells them with the adapter included, 44$ at Chain Reaction Cycles
 
MadRhino said:
You can adapt to 9" rotors, that will solve most motors clearance problems so you can fit any caliper you want. Hayes sells them with the adapter included, 44$ at Chain Reaction Cycles
It would need much adapters to make it fit, i'd win only 1.1cm radius, might not be enough for all calipers. Also, i'm looking for a caliper that fits in, maybe with some spacers between the rotor and the hub. Thanks anyway =D
 
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