So, new SLX trail brakes fitted to my Scott Spark, great on ‘normal’ xc trails, but on the local downhill trails they just don’t perform, quickly getting extremely hot, and then squealing like pigs for the rest of the trail and feeling like they are not working very well.

I admit I’m a bit cautious on the steep and rocky stuff, and could probably do with a bigger travel bike, but would bigger brakes solve these issues? I currently run 180mm front, 160mm rear on the pads that came with the brakes.

If the levers are spongy then give them a bleed. I’d stick some new pads in because that’s the complete opposite of my, and many others experiences with the 2012 Shimano brakes.

could probably do with a bigger travel bike,

Yep that’ll cure your lack of any kind of skillz. 😆

Sounds like you need to brake less.

Yeah I have those and I’m no DH champ but I can’t get them to fade on the longest downhills. Maybe the Scottish weather helps keep them cool..

The others have got fair points too…

I ran the xtrs out at mega this year, and didnt suffer any problems for the whole week. If anything they felt better at the end of the week then they did at the start.

Personally your over braking maybe be down to you being under biked. Sparks are out and out race bikes, that can be used as trail bikes. But they are seriously out there depth on dh runs.

Dont know what to suggest in all honesty

The Scott Spark is not a DH bike! Shimano brakes should be plenty powerful enough for xc.

What DH runs are you trying?

After watching some riders last 6hrs of Fort Bill DH Enduro, on 180/160 rotors, and XC brakes – I looked at my Hope 6Ti’s (225/205 rotors) and concluded I needed to grow a larger set of balls!

mate has them on a nomad and rates them very highly, have you shortened the hoses? sounds like they need a bleed or are contaminated…

In all seriousness, instead of spending money on brakes or a new bike, why not go on a skills course instead?

Sorry if that sounds patronising, but after looking at some of the stuff the olympic riders were getting over on 100mm hardtails, I think it’s more about the man than the bike.

In all seriousness, instead of spending money on brakes or a new bike, why not go on a skills course instead?

Yes, but for the price of a set of new pads and a re-bleed, I’d give that a go first to see if it restores some power and control to the brakes first before spending money elsewhere… Shimano brakes are fantastically reliable in general, but if they need a bleed and/or the pads are contaminated or just not bedded in properly yet, they’ll be no more effective than a canti brake.

The slx brakes should be fine for pretty much anything you want to ride down. Spongy levers means its time for a bleed, squealing could mean contaminated pads, which could also be the reason for the fact they don’t feel powerful and you’re having to use them so much they are getting hot. What pads are in them, and have you been a little libral with the (spray?) chain lube?

Bigger balls, obviously.

Don’t forget that the rides you do with discs have all been done before with rim brakes, in the rain, by people who are fatter than you.

Ah yes, mboy +1! Crossed posts.

Don’t forget that the rides you do with discs have all been done before with rim brakes, in the rain, by people who are fatter than you.

Have you been spying on me again?

I’ve just fitted SLX brakes and they seem fine so far, loads of power but I’m worried about pad life as they’re quite small. I haven’t ridden any long DH runs with yet though but I’ve never had problems with brake fade anyway regardless of brake type!

Have you been spying on me again?

I’ve got shirts that would shelter you and all your family…. 😆

8)

There was no shortage of power on the 2012 SLX brakes I had. Must be contaminated pads or a bleed needed?

Definitely as powerful if not more powerful than Formula RX, Avid Elixirs, Avid Juicy’s, basic Shimano, old SLX, old XT….

You wouldn’t want to put proper DH brakes on a Spark, so I’d try a bleed and fit some fresh pads once bled. And then perhaps size up to a 200mm rotor at the front?

Eh I like big **** off brakes (in my case I’ve just bought Tech Evo V2s) in the Alps, simply because you don’t have to pull on the levers so hard when late braking.

On long epic rides bigger brakes make all the difference when it comes to fatigue. On a DH race bike I’d actually go with smaller brakes (race X2’s or M4’s) though as the runs are only usually 3 to 10 minutes long.

I have M4’s on one bike and SLX on the other, the Slx feel much more powerful.

I run 203-160 rotors.

Thanks for all of the advice.

Levers don’t feel spongy, hoses were shortened and bled afterwards, but a bleed might be worth trying.

Pads are standard shimano that came with the brakes (with the cooling fins), not contaminated as far as I can tell, certainly not had any lube near them. I might try a new set of pads if I can find some out here. Might have to be mail order.

I’ve been doing the red and black runs at Luchon and Le Mourtis, quite steep and rocky (for me), up to 12k long runs. I’m fully aware that the Spark isn’t a DH bike, but it’s what I’ve got right now and apart from the brake issue has coped very well, and my skills have improved too. The Spark is also quite handy on the 11k average 9% gradient ride up to Le Mourtis when the navette isn’t running . . .

you might have ridden though a puddle with some oil in/the nipper might have been ‘helping ‘ with bike maintenance/you might have used gt85 in the garage. etc etc if thy are squealing it likely they have come form of contamination. dont forget you`ll need to clean the rotor too as well as pads.

my fave solution is ,when the missis is out, lob the pads and rotors in the oven on gas mark 9 for 30 mins.

then refit and try again.

make sure not to touch the braking surface with anything including fingers etc. that should sort any contamination issues and saves buying new pads/rotors. i`m doing mine later when the missus is doon the pub as my brakes feel crap too.

Levers don’t feel spongy, hoses were shortened and bled afterwards, but a bleed might be worth trying.

A bleed is not “worth a try” if there’s no evidence that there is air in the system.

Get some mud in your hand and slather it on the brakes. Do this a few times and it will sort any problem with contamination.

Trust me – my mate shimano deores were literally dripping brake fluid off the pads/discs. Put mud on and bang more powerful than before he decided to drain all the fluid out.

I’ve got the XT’s on my Pitch with 203/180 rotors, but there’s not many 12k downhill tracks in the UK, bust having said that they shoul dreach a steady state quite quickly and not get any hotter on a 12k course than a 2k course at the same gradient.

My money would be on needing bigger balls, it’s probably pretty hard to waste moeny on a skills coaching session as unlike brake pads, rotors or any other upgrade they get better with time rather than wearing out!

i’m so crap at riding bikes that i get put in my own category at races – i’m not even kidding.

i brake far too much, all the time all, over the place.

i have no problem with shimano brakes, even the deore brakes are ace.

I run the SLXs on my 29er, can’t comment how it cope with DH runs as it’s never on them but have found them very good XC brakes. A mate runs the XT ones on a Mega and had no issues with overheating in the Alps.

Do find they are seriously sensitive to contamination and if I’ve not used them in a while they need cooked before coming to life. That’s ok if there’s a long fire road descent at the start of the trails but not so much if it’s straight into a technical section!

Braking less isn’t necessarily going to result in less heat, because you will need to slow down at some points on the trail from your awesome speed and you’ll be braking harder for less time, which might well result in a lot more head.

The mud idea is a good one, for when you’re out on the trail. The best thing when you aren’t is clutch cleaner, NOT brake cleaner. There’s an awful lot of brake contamination about, people don’t realise it and just blame their brakes.

I reckon those brakes should be fine unless you are really heavy (are you?).
Try using them less often and brake hard and late when you need to.

boriselbrus – Member

In all seriousness, instead of spending money on brakes or a new bike, why not go on a skills course instead?

It’s 87% impossible to teach yourself how to brake properly. You really should be paying someone to show you how it’s done.

It’s 87% impossible to teach yourself how to brake properly. You really should be paying someone to show you how it’s done.

You’d be amazed. I’ve lost count of the number of clients I’ve had who book a session on the basis that “I’m a competent rider and just want to learn how to do jumps/corners/steps etc better”. The first thing I do with them is speed control. Ride down a grassy slope at running speed and stop as quickly as you can when you get to the line. The average is 10-15 bike lengths. Ten minutes later they are doing it in less than two bike lengths. Effective speed control is a cornerstone of smooth and effective riding, and in these days of mega powerful disc brakes it’s a skill which is often ignored. The result is often more crashes, brake pads wearing quickly, more braking bumps and lower cornering speed.

Most riders (maybe 87% of them? 😀 ) brake like they do in a car – just sat on the seat and hitting the brakes. There are better ways…

😀

Don’t think anyone’s mentioned tyres. If you’re running skinny little tyres with not much tread it doesn’t matter how sharp your brakes are on the sort of runs you’re talking about.

Tyres are 2.25 Cinders, 75% tread. My weight is 95kg, so no lightweight.

I like the comment about braking less. Really, this stuff is dusty, rocky and steep, at the limit of my abilities, so I need to brake.

I’ll look into local skills sessions though.

At the top of the lift at Luchon a couple of local kids asked if I was riding back down the road to Luchon and looked pretty surprised when I told them I was taking the 8k red run.

No, braking less is stil good advice. I had a week in the Alps and the first thing you find out is that braking less often but more powerfully, saves brakes and makes you quicker.

SLX are fine for DH. end of.

I looked at my Hope 6Ti’s (225/205 rotors) and concluded I needed to grow a larger set of balls!

Bigger balls would make you heavier – and you wouldn’t be able to fit bigger rotors…

I like the comment about braking less. Really, this stuff is dusty, rocky and steep, at the limit of my abilities, so I need to brake.

Yeah but when you are at the limit of your abilities you tend to be a bit tense/nervous, and you brake too much. I’m not saying this like I’m some riding god that never brakes – I often have to remind myself to lay off them a bit. Harder once you get tired as well IME as again you tense up more.

Rather than dragging the brakes near-constantly, look ahead for good braking points, and try and lay off until you get there. The bike will roll over rocks better, you’ll have more grip, and the suspension works better. Often easier said than done though once the fear takes over.

Yep, as said brakes are plenty capable. Could be contaminated or such. And learn to brake. It’s all about the rider, a spark is capable of dh tracks, I regularly ride the tracks at inners on mine.