[Closed] Overheating M4's - options

Maybe you just need new fluid. Older stuff will misbehave when it gets hot.

V2 vented will solve the problem [i]totally[/i], though a 203 on your M4 will be 50% of the way there.

And for the heroes who say "learn to ride better, then you'll not use the brakes"......that comes with time. If your brakes are fading badly it's kind of hard to not use them, and to go even faster, but trust that they'll be working when you try to brake hard from 30+mph

Fluid has already been changed a few times, and yep, done properly with the right stuff.

The v2 with vented is pretty much as far as it's possible to go, but at least there's no chance of brakes deciding to pack in just as you reach the bottom gate!

Yes, I could take a bigger brave pill or get better, but that doesn't happen instantly and for now, I'd like to stop.

Would the 203 on the m4 really make much of a difference? Don't want to buy it to discover that I'm still in the same boat!

Brake less?

God I'm being so helpful this morning.

use organic pads not sintered? I do find this odd tho as I only vary rarely overheated M4s on the tandem and that has 20+ stone on it

Already on organic pads, moved the sintered aside already as they really made it cook. Blue discs, smell of burning, a very odd sound and lack of any braking power might be an indication at they're a wee bit warm, oh, and watch the spit flash boil off them!

I run M4's with 203/180 discs on my hardtail and V2's with standard 203 discs on the full suss. The V2's are a definite step up in performance over the M4's. They are insanely powerful with standard discs so I doubt you'd need to go for the vented ones plus vented discs are crazy heavy. I'd also suggest fitting a +20mm adaptor at the back and upgrade to a 203 M4 disc (if the frame will accept it).

Have you got the phenolic plastic type pistons rather than teh metal ones?

Also, Stendec synthetic brake fluid works for me.

I am 100kg, 203mm front and 160mm rear and I have no problems in teh Alps,

HTH

If you want to use Hope and be [i]certain[/i] of stopping wherever/whenever you want, V2 vented is the best solution. Your brakes will never overhead and the pads seem to last ages as a result. They're neither cheap nor light, but they're the most confidence-inspiring brakes I've used.

bramblesummer - Member

I'm running hope tech m4's on 183/183 floating rotors on my bike at the moment. Annoyingly, I'm overheating the front fairly badly on longer descents, and I'm .... blah blah blah...

(sorry for cutting you short)

you say 'overheating' - what are the symptoms?

and what do you mean by 'long' descents?

overheating the front before the rear is a little weird, try braking more with the rear?

Yeah are they getting more and more solid like old c2s did when overheating

Or are they fading.

I did some fair long decents yesterday on x2 races 160 either end with no issue

Same decent had my xts fading like **** !

The back is also getting very hot, but not to the point of loosing power. The front disc will be a deep blue colour, the pad willnhave a nice burning smell and the power drops off a fair bit. I'm very familiar with brakes overheating and fading in my job. I'll have a play with the other fluid as that's much cheaper than swapping over callipers and rotors.

The m4s are the latest version with phenolic pistons and the rotors are the saw version.

Thanks for all the info, anyone want an m4 caliper?!

I've run M4s for years, I'm a fair bit lighter than you but I've noticed that there is a definite step up in performance if you opt for a 203mm rotor. Whether it'll solve the problem or not remains to be seen. It's well worth consulting Hope and asking their opinion I think, maybe a V2 is the way to go.

How very odd . V2s it is then !

Thanks for all the info, anyone want an m4 caliper?!

Do you drag the front brake? I overheat (but not cook) my rear brake cos i drag it sometimes, never had trouble with front tho. 180/180 m4s.

203s should help, more power so less braking, more metal to heat/cool too.

The front does get dragged a bit, if I don't then the dog gets left in my dust and the poor thing will do itself an injury trying to keep up! Think I'll go the v2 route as doing a bit of searching there seems to be a definite step up in performance that sounds like it'll stop the problems. Just have to hunt down some at the right price :o)

Annoyingly, I'm overheating the front fairly badly on longer descents

Seems strange. M4s should be capable of anything you would throw at them in the UK. Does the lever feel change? I can't imagine you'd exceed the capabilities of M4s whilst riding with your dog!

I'd call Hope if I were you.

Alternatively, brake in short bursts rather than leaving them on continuously.

I'm using Tech X2's (in hindsight should have gone M4's but that's another story). I found they were not the power upgrade from Mini's that I thought they would be.

The point is that I upgraded the X2's from 183/160 to 203/183 and have definitely noticed a difference in both outright braking performance and lack of fade. Did a 1000m descent off the Cairngorms yesterday with no problems. It's not an expensive upgrade either - 1 new rotor and 2 adaptors so definitely worth trying

Edit - if you do end up selling the M4 calipers give me a shout

If you are dragging the brakes to stop you running ahead of the dog try alternating the brakes or brake intermittently.

Or better still, get a length of bunjee cord and use the dog as an anchor.

I'm 15st + riding gear and I run m4's with a 203 floater ont front, never had any problems with over heating befor !

I found the best cure for overheating Hope brakes was called 'Shimano' or preferably 'Magura'

Both seem to be more than adequate remedies.

I moved up from 183 to 203... makes a big difference! Do it!

Drop Hope an e-mail via their website. I e-mailed them with a question about some V2s and the guy from the tech videos phoned me ten minutes later and spent quarter of an hour going through it with me on the phone.

First-class service. If they can't suggest a solution I would be very surprised.

Buy Shimano's. Sorted.

SLX with 160 rotors on the Inbred, M4 with 180 saw tooth on the 5. SLX far better will be buying some for 5 soon.

After cooking my hope mini's all the time I got some m4's, and after cooking them all the time I sorted the problem with Shimano. I wouldnt throw any more money at hope's offerings..

I have M4 front, X2 rear and have had fade up front (183/160). A friend has M4 front and rear and went from 183/183 to 203/183 and found them much better. Another friend has recently changed to XTR Trail and loves them. I might put mine on my wife's bike and get the XTRs or otherwise by a 203 and go 203/183.

enjoy your shitmanos when you cant get spares and the seals are toast ..... i have 3 that have gone that way

never again - used to swear by them now i swear at them !

magura ive never had cant comment

cantilevers.. never had brake fade yet..

No, you ALWAYS have brake fade, you just don't know it 🙂

when i cant get any spares i shall not worry,i'll buy some more.. running 2 pairs of shimano discs both over 5 years old, zero maintainence apart from pads. 1000s of miles on them..

Fair enought just dont go near big long decents - my piston seals melted after ben nevis north face Path after being good for 18 months

Taking my minis to alps in 2 weeks 🙂 - my old mono m4s never faded (200mm f +r) even on aonach mor !

Ultimate fade free braking - bb7 !

Used old Saints in Whistler and The Alps and SLX in The Alps. No problems, no issues, nowt. They were all perfect and fade free. Hope M4's, gave up on me in The Alps and a long rocky descent a couple of years ago and 3 riders in 9 having brake levers touching the bars at the bottom. All using Hopes. You like them, they go for it, I just don't trust them one bit.

M4 or mono m4 ? Old 2 piece m4s used to press them selves apart and leak - i hated them for that pre mono calipers hope were horrendous

They were the black and gold M4/Mini combo I had.