Brake disc upgrade

[RedWhiteMonkey]

I am looking at upgrading the brake discs on my wife's cargo e-bike. It currently has Magura MT5 brakes using 203mm Magura Storm (I think) brake discs. Whilst the bike does stop it makes quite a lot of noise under hard braking and the discs seem to have a tendency to vibrate and make some noise at certain speeds. I have spent ages calibrating the calipers but I've come to the conclusion that the current discs are just not stiff enough.

The obvious step up in the Magura range would be the MDR-P but I was wondering whether there is any reason why brake discs from another brand couldn't be used (subject to matching diameter and thickness of course). I like the look of Hope's floating discs.

Are these things interchangable?

[witko999]

Yes. I have uberbike 203mm floating discs with Magura calipers. If you want more stopping power then going up in disc size will probably be the most effective way, along with a different brake pad.

[RedWhiteMonkey]

witko999 said:

Yes. I have uberbike 203mm floating discs with Magura calipers. If you want more stopping power then going up in disc size will probably be the most effective way, along with a different brake pad.

Thanks, going up a brake disc size with the existing calipers just means getting the appropriate standoff adapter thing for the caliper, correct?

[witko999]

Yes, ordinarily, although I have no idea what the setup on a cargo bike looks like. Forks are usually limited on maximum disc size. I think mine are 220 max, for example.

[RedWhiteMonkey]

It's almost like a "normal" bike (https://www.cube.eu/uk-en/cube-longtail-hybrid-family-725-grey-n-reflex/822200) with a standard front fork and wheel. Should be able to take a bigger disc, and although I can't find the post anymore I'm sure I saw someone on another forum that had fitted a 220mm disc.

I think I will only do the front disc for now. I'm sure I can do it but accessing the rear wheel by taking off the belt drive looks like a bit of a pain due to the frame stuff on the back.

[BOR]

RedWhiteMonkey said:

I like the look of Hope's floating discs.

Are these things interchangable?

Hope floating discs are an excellent way to cure squeal and vibration.

But, the floating top hat dowels can catch on some calipers.

There is a Hope disc that places the dowels lower on the disc to provide more clearance to more calipers.

Recommended.

[P-Jay]

RedWhiteMonkey said:

I am looking at upgrading the brake discs on my wife's cargo e-bike. It currently has Magura MT5 brakes using 203mm Magura Storm (I think) brake discs. Whilst the bike does stop it makes quite a lot of noise under hard braking and the discs seem to have a tendency to vibrate and make some noise at certain speeds. I have spent ages calibrating the calipers but I've come to the conclusion that the current discs are just not stiff enough.

The obvious step up in the Magura range would be the MDR-P but I was wondering whether there is any reason why brake discs from another brand couldn't be used (subject to matching diameter and thickness of course). I like the look of Hope's floating discs.

Are these things interchangable?

By and large yes, there are a few oddities like TRP who use a thicker disc, but otherwise no.

Sounds to me either your current discs are warper, or the pads have been contaminated or are the wrong compound.

Sintered pads are harder wearing but can squeal a lot, organic pads are quieter and have more power.

Discs warp for fun, but a decent bike shop should be able to straighten them for a few quid. Floating discs are great at avoiding warping through heat, but even with the weight of a cargo bike, I doubt it's caused by heat build up unless your Wife is hitting Alpine trails on it.

If you prefer DIY, disc straightening tools are cheap and YT is full of how-to videos.

[RedWhiteMonkey]

P-Jay said:

Sounds to me either your current discs are warper, or the pads have been contaminated or are the wrong compound.

The bike isn't that old and it has done it since we got it. I have checked them and they don't seem obviously warped, I really think it is just a case of the manufacturer went for a cheaper option when specing everything up. The brakes do work but they could be better and I'm happy enough to upgrade them.

[OutInTheShed]

My guess is, if you change the discs, the noise will be much the same.

But it's cheap to try.

[InitialDave]

BOR said:

RedWhiteMonkey said:

I like the look of Hope's floating discs.

Are these things interchangable?

Hope floating discs are an excellent way to cure squeal and vibration.

But, the floating top hat dowels can catch on some calipers.

There is a Hope disc that places the dowels lower on the disc to provide more clearance to more calipers.

Recommended.

Note that Hope also have a vented floating disc which is quite a bit thicker than most, and I think only really compatible with their V4 caliper, so probably avoid that one.

[RedWhiteMonkey]

InitialDave said:

Note that Hope also have a vented floating disc which is quite a bit thicker than most, and I think only really compatible with their V4 caliper, so probably avoid that one.

Yes, I saw those and then realised they're not for me as I don't want to change the calipers and levers as well. I assume you'd have to be into some extreme downhill to make those vented discs really necessary.