Upgrading brakes

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Snoozeboy

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Hello all, I'm thinking of upgrading the brakes on my Cube Stereo Hybrid Pro (2018).

There are a lot of big hills around here (Lausanne area), I'm quite heavy at 100kg and I'm finding that my brakes make a lot of noise and then begin to fade quite badly. I'm guessing that my low-end brakes (Shimano M315 caliper, 180mm rotors, Shimano no-name levers) aren't up to it.

It's not so much that the brakes aren't powerful enough, they're fine when they're cool. It's more that they heat up far too quickly.

I think I'll need:
- bigger rotors - 203mm
- caliper upgrade as the M315s are not compatible with 203mm rotors
- adaptors for the fork and rear
- Shimano bleed kit
- Shimano mineral oil

I was thinking of leaving the levers as they are, as I'm not unhappy with the lever travel etc.

I was also thinking of just changing the front one to see how much hassle and effect it has.

Anything I'm missing? Do I have to change the hoses and levers too? Maybe if I bought a whole front brake system I wouldn't need to bleed it.
 
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The usual questions:
Did you bed in the brake pads properly before riding?
Do the brakes need bleeding? If so buy the kit and do them. You will have the kit for ever.
Have you tried different pads? Some last better than others, some fade less.

The above costs significantly less than a whole new braking system. And if you haven't addressed the above three questions, they will still need addressing on your new system, sooner or later.
 
Thanks for your reply.

Did you bed in the brake pads properly before riding?
>I thought I did, but it's possible I didn't on the two sets of pads I've gone through so far. I'm due another change of pads shortly, so I'll make sure I bed them properly before making the decision to upgrade.

Do the brakes need bleeding? If so buy the kit and do them. You will have the kit for ever.
>I doubt it. The brakes don't feel spongy and the problem has been with the bike since new. I'm happy with how the brakes feel when they're cold. It's halfway down a long hill they start to scream and then feel they're about to disappear completely needing two fingers of heavy pulling.

Have you tried different pads? Some last better than others, some fade less.
>No, I've always stuck with Shimano resin, because the discs are marked resin only, another reason why I think they may be worth upgrading.
 
Seems unusual the callipers are not compatible with larger rotors.
If you are happy with the feel, bigger rotors and adapters would be the sensible first step, and go from there.
 
Snoozeboy said:
Hello all, I'm thinking of upgrading the brakes on my Cube Stereo Hybrid Pro (2018).

There are a lot of big hills around here (Lausanne area), I'm quite heavy at 100kg and I'm finding that my brakes make a lot of noise and then begin to fade quite badly. I'm guessing that my low-end brakes (Shimano M315 caliper, 180mm rotors, Shimano no-name levers) aren't up to it.

It's not so much that the brakes aren't powerful enough, they're fine when they're cool. It's more that they heat up far too quickly.

I think I'll need:
- bigger rotors - 203mm
- caliper upgrade as the M315s are not compatible with 203mm rotors
- adaptors for the fork and rear
- Shimano bleed kit
- Shimano mineral oil

I was thinking of leaving the levers as they are, as I'm not unhappy with the lever travel etc.

I was also thinking of just changing the front one to see how much hassle and effect it has.

Anything I'm missing? Do I have to change the hoses and levers too? Maybe if I bought a whole front brake system I wouldn't need to bleed it.
Click to expand...

bigger rotors!!! 203 mm and other pads ...bleeding Kit and new oil...?
 
The 315’s are of the lower Shimano Altus range and the rotors will be similar spec and therefore not compatible with sintered metal pads. Will find they have resin only printed on them.
You need a better braking system period, as currently yours is not keeping up.

As a minimum I would be looking at the Shimano m7000 series SLX fitted with some finned pads and matched up to some 203mm floating rotors.

There are better out there and a 4 pot caliper system would be better than 2 pots system given your weight and elevation you ride.
 
Update - I upgraded the front brake with an XT M8000 and a 203mm RT64 Shimano rotor . It feels a little sharper than the previous unit, especially having taken the time to bed it in properly and I'm hoping it won't heat up so much, which was the main problem.

I also have the back brake version of the above as I bought the two as a bundle, but it's a bit more complicated to fit in that:
- it comes pre-connected with a cable to the lever, but I have to run the cable through the frame
- or I could just use the old cable but it's a lower quality cable and a straight to straight connection, whereas the new cable is straight to banjo.

Do I...?
a) cut and re-use the previous cable, which isn't quite as high pressure, but is already run through the frame.
b) bite-the-bullet and take it to the LBS for the to install it? Running a replacement cable through the frame looks too fiddly for me.
 
I upgraded to Shimano zee brakes and they are good and cheap if you're not doing mental stuff.
 
I looked it up and it looks like (b) as the banjo fitting is factory sealed to the hose, so I have to run the new hose through the frame.
 
snoozeboy.

Firstly I'm glad you bought a whole new higher spec brake instead of wasting time trying some of the suggestions here to make your M315 brake work better.
M315s are budget Altus level brakes and were never intended for heavy off road use in the first place and IMO won't ever feel all that great no matter how much money you throw at them..

Your new issue in fitting the rear brake can be solved fairly easily.
Firstly. No. You can't use the hose from your M315 on the M8000. The fitting at the caliper is different.
With a bit of time and patience internally routing a new brake hose is not an especially difficult job.
You have three options to DIY all 3 involve removing the hose from your new brake and re-fitting (you probably got new olives and inserts with the brake to shorten the hose anyway?) and will involve at least a lever bleed once re-fitted. (easy job but you'll need a funnel/syringe and mineral oil)

first option:
fix the new hose to the old one using a reverb threaded hose guide connector. the tiny red anodised part that comes with new reverbs. and carefully push the new hose through while carefully pulling the old one out.
Second option:
remove the old hose and just route the new hose through manually "fishing" it through the entry/exit holes in your frame (may require dropping the motor and can be far more time consuming/fiddly) and almost certainly will require some ingenuity and perhaps zipties to make a noose or a pick to hook the hose.
third option:
Buy a dedicated internal routing tool kit and use this to tow the new cable through each section of frame. (this may still require the motor to be dropped)

If none of these appeal take it to any decent LBS and have them do it and the lever bleed/hose shortening caliper alignment required.
 
Nothing nicer than upgrading to a decent set of Shimano 4 pot brakes and big rotors when riding a heavy bike.
 
Firstly, thanks for all the advice, whether it's Gary's advice that my brakes weren't up to it, which perfectly answered my question, or Steve's slightly tangential advice, which still is the benefit of that I now take extra care to bed in each set of new pads.

I tried the new brakes today and the result wasn't good. They too suffer badly from brake fade and are in some ways even worse than the originals. The originals went from ok to noisy-but-ok and then faded slowly. The new ones go from very sharp to completely faded with no warning.

It's possible that my braking technique is to blame - the brake fade happens on fast, long descents on steep tarmac, when I'm dragging the brakes over a long period, overheating them. It's less of an issue on trails because I'm going slower and braking in a more staccato manner.

It's also possible that I chose the wrong upgrade - I bought two pot XTs, thinking that power was never really an issue, it was the heat dissipation that was lacking and I couldn't really see how 4 pots would dissipate much better than two pots. Despite the fanned edges of the 2-pot XT pads and the bigger rotor, there really doesn't seem to be much difference in heat dissipation. In fact the bigger rotor has a shallower profile, so whilst there is more leverage, there's less area to dissipate heat.

I don't know where it goes from here. Sintered pads or maybe when I "upgrade" the back brake I'll get a Shimano ICE rotor to put on the front and move the current one to the back.

Maybe I'll just have to be more careful when riding tarmac.
 
Dragging your brakes is the worst thing you can do, no chance for your pads and discs to cool.

It's much better to scrub some speed and then come off the brakes. I'm a big guy and it's the only way I can get down without blowing up my brakes.

Good rotors make a difference. Also I find the Shimano finned pads stay much cooler and ice tech rotors are superior.

Before I upgraded i was getting brake fade after two hairpins. Now I can do alpine descents and fade free.
 
Snoozeboy said:
Firstly, thanks for all the advice, whether it's Gary's advice that my brakes weren't up to it, which perfectly answered my question, or Steve's slightly tangential advice, which still is the benefit of that I now take extra care to bed in each set of new pads.

I tried the new brakes today and the result wasn't good. They too suffer badly from brake fade and are in some ways even worse than the originals. The originals went from ok to noisy-but-ok and then faded slowly. The new ones go from very sharp to completely faded with no warning.

It's possible that my braking technique is to blame - the brake fade happens on fast, long descents on steep tarmac, when I'm dragging the brakes over a long period, overheating them. It's less of an issue on trails because I'm going slower and braking in a more staccato manner.
Click to expand...
Dragging brakes kills pads - rapidly.

It's also possible that I chose the wrong upgrade - I bought two pot XTs, thinking that power was never really an issue, it was the heat dissipation that was lacking and I couldn't really see how 4 pots would dissipate much better than two pots. Despite the fanned edges of the 2-pot XT pads and the bigger rotor, there really doesn't seem to be much difference in heat dissipation. In fact the bigger rotor has a shallower profile, so whilst there is more leverage, there's less area to dissipate heat.
Click to expand...
Definitely. 4 pot brakes are much better for an ebike for many reasons.
Firstly, they are more powerful due to a wider braking area. That wide braking area also aids in cooling - plus you can get pads with added cooling fins.
 
Larger brake rotors provide better braking but they will also heat up more than smaller rotors, there are more metres per second passing through the brake pads on a larger rotor. I have Shimano Saints with ice-tech rotors and finned pads which I find brilliant but I still avoid dragging my brakes on long descents. As stated above, I scrub off speed then give them a rest. I usually never apply just one brake too, it's usually both at the same time.
 
On my DH bike I used to boil my brake fluid to begin with! I was dragging the rear brake all the time as I didn't have the confidence to use the front brake, after I learnt to use both, the problem went away!
 
HORSPWR said:
Larger brake rotors provide better braking but they will also heat up more than smaller rotors, there are more metres per second passing through the brake pads on a larger rotor.
Click to expand...

Half right, bigger rotors means more friction as you have more rotor passing through the caliper, however......

Larger rotors don't need as much clamping force to generate the same braking force.
Larger rotors have more surface area therefore they dump heat much better than smaller rotors.

Which is why bigger rotors run cooler assuming all other variables are the same.
 
hello all, I bought a new cube reaction hybrid set 625.

now after 3 months the lbs told me I need to change my rotors, already? I thought..
but in all honesty, I am 94kg, ride 4/5 times a week, and basically only climb mountains, I usually ascent around 11/1200m (no other options in Lebanon Beirut) only to ride back down on tarmac so yeah heavy breaking there.
these are 50km rides give or take.

so my question is are there special pads or rotors that will last longer?
right now it has 203mm rotors in front and 180mm rear, Shimano sm-rt64.

the cube has the Shimano XT BR-M8120 break system, which is excellent I think.
perhaps I should change the rotors to ice-tech (not sure if I say it correct), would that help a little besides losing weight? ;)
oh and should I go for metal pads instead of resin?

thanks in advance & blessings

B76C2A7C-349E-47E3-B1C9-6B3F8EAEC39E.jpeg
 
Last edited:
Rotor braking surface life will be much of a muchness between brands. They're just 1.8mm thick sheets of shaped steel and so their lifespan will vary more from braking surface size and pad contact size/shape than what particular brand of rotor you use. and with the same calipers fitted this is not going to change hugely anyway.
Pad life however varies considerably from compound to compound.
your dilemma is if you buy the hardest wearing pad material you'll wear your rotors out quicker.

Icetech rotors aren't any more durable or lighter - they simply cool down a little quicker due to the shape and the construction (alloy sandwiched betwen steel)
Icetech finned pads are also designed to reduce heat.
Less heat may well lead to slightly better lifespans... BUT at TWICE the cost. so no real saving for you overall. infact it'll cost you more.
 
Floyd Pepper said:
losing weight? ;)
Click to expand...
The other way to increase your rotor/pad life is to learn how to brake efficiently.
ie. Stop dragging them. and only brake when you actually need to. to scrub off just enough speed before a corner/feature etc. most folk brake far too much TBF.
 
Gary said:
Rotor braking surface life will be much of a muchness between brands. They're just 1.8mm thick sheets of shaped steel and so their lifespan will vary more from braking surface size and pad contact size/shape than what particular brand of rotor you use. and with the same calipers fitted this is not going to change hugely anyway.
Pad life however varies considerably from compound to compound.
your dilemma is if you buy the hardest wearing pad material you'll wear your rotors out quicker.

Icetech rotors aren't any more durable or lighter - they simply cool down a little quicker due to the shape and the construction (alloy sandwiched betwen steel)
Icetech finned pads are also designed to reduce heat.
Less heat may well lead to slightly better lifespans... BUT at TWICE the cost. so no real saving for you overall. infact it'll cost you more.
Click to expand...

Magura use thicker rotors . 2.0 mm
 
it all makes so much sense, thank you Gary for your responds.

i will keep changing to the original rotors and pads for now.
guess i have to start seeing pad and rotor cost as fuel money.

indeed no dragging of the breaks here, short light or heavy squeezes to keep them breathing.

thanks again!
 
Actually. No. Rosemount has a valid point. You could fit 2.0mm thick rotors. it would just mean your pads/pistons will just have a little less retraction when pads are brand new but shouldn't cause an issue in use. shimano pistons need advanced outwards from new anyway.
I've no idea what a 203mm magura rotor costs (£25?) but other brands (Clarks/Tektro) 203mm 1.8mm 6 bolt rotors can cost as little as £5 a piece (with bolts)
 
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