Front and Rear 4 Piston Brakes

Thanks team. Braking fade could be part of my problem as my rides often include 800m elevation gain and then loss on my ride home, meaning I am spending a lot of time on the brakes. Some really good suggestions above which I will look into.
If you are looking to make a rotor change on a Magura system, and your pads are a little worn, consider the Tektro Type 17 as replacements.
Magura rotors are 2.1mm thick, which is of course thicker than the usual industry standard rotor. Tektro Type 17s were originally marketed as a niche product for downhill bikes. Tektro has remarketed them as ebike rotors and they are much more widely available today than when DIY ebike builders started using them a few years back.

They are 2.3mm thick. You can fit them pretty easily if your Magura pads are worn a bit. Once your pads wear down and need replacement, the thicker rotors will have worn down so they will fit with fresh pads. They don't take much wear to fit in nicely. Spanking new there is only 1mm extra on each side.

More rotor material means you are working with a bigger heat sink. A secondary benefit is they take forever to wear out. Being thicker they are also more difficult to warp. Oh, and they are also cheap! I bought two from this seller just a couple of weeks ago.


Pad to rotor alignment and contact is perfect if you use the matching Magura front and rear caliper adapters, with no spacers. The rotors are also available in smaller diameters if you just want the extra meat without going bigger.

img_20191011_133705-2-e1571241209971[1].jpg
 
Last edited:
If you are going to go with Magura rotors, I suggest you consider the MDR-C instead. Its 1-piece instead of floating/2 pc like the MDR-S, which I prefer for heat dispersion from the rotor face. 1-piece construction and more of it makes for a bigger heat sink which helps with fade. Its also cheaper although still much more than the Tektros.


I tried them on my Bullitt front wheel in a 180mm size (its a 20" wheel) although I eventually went to a 203mm. Before the MDR-C's came onstage and I figured out the Tektro thing I used Magura Storm HC's, whichwork fine and are still available.

pxl_20210202_012309248-e1616020086290[1].jpg
 
If you have an older ebike, upgrading the front brake is one of the best improvements you can make. I have a 2019 Homage and went from a 180mm to a 203mm front rotor and upped the number of pistons to four. The stopping power improvement is notable. The rear brake you can leave as is. This is what R&M has done to their new models.
 

Attachments

  • IMG_0212.JPG
    IMG_0212.JPG
    277.5 KB · Views: 214
If you have an older ebike, upgrading the front brake is one of the best improvements you can make. I have a 2019 Homage and went from a 180mm to a 203mm front rotor and upped the number of pistons to four. The stopping power improvement is notable. The rear brake you can leave as is. This is what R&M has done to their new models.
Is that a 220mm rotor, and if so what did you do for adapters to get it to fit? I assume the base fork has 160mm posts.
 
How far can you squish down the lever? I take it you never, ever get close to the hand grip when engaging?
Correct. I can lock everything up with plenty of room left and the lever is firm on full application. I think the increased rotor and trying different pads sounds like solutions I should explore first. Brake fade due to heat is most like the culprit.
 
Is that a 220mm rotor, and if so what did you do for adapters to get it to fit? I assume the base fork has 160mm posts.
The new rotor is 203mm. I needed to replace the caliper adapter (from Magura) to go from 180->203 since the new caliper would not mount on the existing posts. I considered using the 220mm rotor but my fork is limited to a max 203mm. I did some research beforehand and the manufacturer (Suntour) implied I might damage my fork by using the 220mm rotor. It seems too much braking force is not a good thing.
 
The new rotor is 203mm. I needed to replace the caliper adapter (from Magura) to go from 180->203 since the new caliper would not mount on the existing posts. I considered using the 220mm rotor but my fork is limited to a max 203mm. I did some research beforehand and the manufacturer (Suntour) implied I might damage my fork by using the 220mm rotor. It seems too much braking force is not a good thing.
yes dont go larger then the fork is set for. my rockshock commuter fork will only do 180 but thats plenty for fast commuting.
 
Certainly a 203mm with a good 4-piston caliper should stop anything that calls itself a bike. The 220 is gold for real downhill biking where your braking is hard on and very frequent. ;-)
 
The new rotor is 203mm. I needed to replace the caliper adapter (from Magura) to go from 180->203 since the new caliper would not mount on the existing posts. I considered using the 220mm rotor but my fork is limited to a max 203mm. I did some research beforehand and the manufacturer (Suntour) implied I might damage my fork by using the 220mm rotor. It seems too much braking force is not a good thing.
I was wondering if it was 220 as I saw you used a single adapter. From what I understand, to get the 220mm to fit anything resembling a standard brake mount, you either need to use a Hope adapter, or stack two adapters to bring the caliper out. If you have 180mm post mounts, a single QM45 adapter will do the job.

The concept of stacking adapters is to my mind one more nail in the coffin for that rotor.
 
Correct. I can lock everything up with plenty of room left and the lever is firm on full application. I think the increased rotor and trying different pads sounds like solutions I should explore first. Brake fade due to heat is most like the culprit.
If you can lock everything up =all= of the time then i don't think changing pads, rotors or pistons will help you at all. The only things that would help in that scenario would be Bosch ABS, Tyre's & less weight.
If however you do have fade towards the bottom of hills and that's what you're talking about then yes, larger rotor, different pads, etc.
 
If you can lock everything up =all= of the time then i don't think changing pads, rotors or pistons will help you at all. The only things that would help in that scenario would be Bosch ABS, Tyre's & less weight.
If however you do have fade towards the bottom of hills and that's what you're talking about then yes, larger rotor, different pads, etc.
I'm going push back on this as there's another step in between - getting better tires.
 
203mm rotors and dual piston front brakes on the SD Mountain so changing pads, changing tyres (currently fitted with off road oriented Nobby Nics) or loose some weight look like my best options. I agree tyres are important and it may in fact be my issue causing less than expected braking power on steep roads (and fade on long descents), but as I ride 80% off road I am hesitant to move to a more road oriented tyre. Next step is shedding 5kg of body weight.
 
On the topic of fade - are those of you who are having issues holding the brake to maintain a certain speed (dragging?)

We just did a ride up to Mount St. Helens this past monday, which ended in a 15mi descent of about 30min of uninterrupted downhill riding at a sustained 26-35mph. We were on a stock 2021 Supercharger2 and 2021 Homage respectively and neither of us experienced any fade with the stock comfort pads on either bike...
 
Last edited:
On the topic of fade - are those of you who are having issues holding the brake to maintain a certain speed (dragging?)

We just did a ride up to Mount St. Helens this past monday, which ended in a 15mi descent of about 30min of uninterrupted downhill riding at a sustained 26-35mph. We were on a stock 2021 Supercharger2 and 2021 Homage respectively and neither of us experienced any fade with the stock comfort pads on either bike...
Nice ride! I tend to 'pump' my brakes on long descents to try and allow some cooling to occur. My steepest descents are always at the end of my rides when my brakes are under the most use - so I'm not sure if it is actually fade or force impacting on equipment (pads, tyres) which is the culprit, in my instance.
 
Back