UKC

I'm not in any way a serious biker - I'm the fat lad you usually see puffing away up a relatively easy hill. I have very little mechanical knowledge about bikes - I can repair a puncture and I've only just worked out how to change spokes and get the rear cassette off.

I had an incident today. Went out with a few mates up to Mam Tor and went down Winnatts Pass. Didn't feel like I was going too fast...got behind a line of three cars so put the brakes on and kept a bit of distance...then the car in the front of the line slowed down (for no apparent reason that I could see), so I hit the brakes...car kept slowing, so I had to keep brakes on...and then the brakes just seemed to slowly stop working, as if I was releasing the pressure on the brake levers. Panic kicked in a bit, so tried to hit the brakes harder, but nothing happened.

No room to undertake the car in front, no room to overtake (there was a motorbike coming up the pass, which is the only reason I can think the car in the front of the line slowed down - maybe thought it was a tighter squeeze than it actually was). Bit of a panic, ended up squeezing both brakes as tight as I could and slamming my feet against the road to try and get any sort of stopping power. Thought I would either have to run off into the verge on the inside or hit the back of the car and hope for the best.

Luckily the line of cars in front picked up enough speed (and my foot on the road slowed me down enough) to give enough space to avoid any mishap.

Really strong smell of burning...mate behind noticed it as well. Brake discs were too hot to touch at the bottom. Slight discolouration of the discs now as well.

So have I knackered the brakes? Is this a common problem? I've not really had to use the brakes to that extent before.

I appreciate that the problem was caused by me and I totally appreciate I was at fault for not leaving enough distance between me and the cars in front...just before anyone piles in with a kicking about knobhead cyclists. The small brown stain on my underpants is testament to my lesson.

In reply to ThunderCat:

sounds like you overheated them, they should work fine once cooled down tho, surprised they got cooked so fast tho unless you were dragging them down the whole pass i guess. Its more of a problem you would expect in the alps or at races when youve been given it some beans

In reply to admackie:


It wasn't that fast...but I'm a big lad (20 stone)...I'm wondering if the mass had a play in it.? (Lot of momentum to lose!!!) Bloody scary though, to feel them just gradually fail like that and have no way out.

We had another 25 miles to get home on some fairly steady descents (down Long Hill into Wlay Bridge), and they felt fine then. Mate says to try and feather them on and off as a matter of course in that situation.

In reply to ThunderCat:

Lordy Lordy . I was waiting for you to say that before I posted. I'm sure your mass had some effect on those brakes.
Glad you're safe have you thought of upgrading to cables and rim brakes. None of this disc faff

In reply to ThunderCat:

Probably fine - you've just cooked the brakes, take it out for a spin tomorrow to see. The two problems you might have is if you have glassed the pads (never heard of this happening on bikes though) which you could just file off or more likely if you have boiled the hydraulic fluid then when it cools down you can end up with air bubbles in your brakes in which case you will need to bleed your brakes. You'll know this if your brakes have lost their snappiness when you pull them and fell a bit spongy (in effect what you are doing is compressing the air bubble not moving fluid when you pull the levers). Bleeding brakes isn't a hard job but you do need to buy the kit and its worth checking out how to do it with a google search for your brake model. Otherwise a bike shop will do it for you pretty cheap.

Realistically once they've cooled down (don't touch the disk trust me from painful personal experience its f*cking hot) they'll probably be good as new - it also helps to straighten your disk if you've got a bit of a ding.

In reply to ThunderCat:
What sort of brakes? I had this problem with Avid BB5 mechanicals on 160mm rotors, organic pads.
I burnt the pads out.

I've upgraded to Shimano hydraulic m615s. These will take a sintered pad (more hard wearing), pads with cooling fins, and uprated aluminium core rotors.

Next upgrade for me will probably be to fit a 180mm rotor and a spacer to the mount to accommodate it. You can get fancy ice tech sandwich rotors, so I plan to whack one the front.

Or chain reaction have cheapie Shimano hydraulics for £30 on your existing rotor. They just bolt on.

In reply to Dave the Rave:



I really thought that discs were the way forward mate (see, didn't call you Dave this time) - I thought they were an improvement on rim / brake blocks

I can appreciate the physics of the brakes having to work a lot harder for a chunky monkey like me though...I just thought I'd have a lot more slow-down time before they quit on me. I think next time, I'll wear my brown cycling shorts to hide the embarassment. hahaha...

In reply to team fat belly:



Gave the discs a few tentative flicks with a glob of spit on my finger...no hiss, but could feel the heat. As I say, they seemed to be fine for the rest of the journey home....just the slight discolouration on the discs is a bit worrying. Got a bit of a jaunt planned tomorrow so will give them a workout.

Got a few good shops within easy distance of the house so will give them a visit if it seems any less responsive though - cheers.

In reply to ThunderCat:
I answer to Dave now. Even the mrs calls me by it
Yeah, the discs are probably the way forward, I'm just jealous.
Used to know someone with discs who spent more time fecking about than peddling.
I bet the driver of that car was shitting his sen

In reply to Dave the Rave:

If my mate had his GoPro working, there may be footage of my screaming like a banshee on the way down...I'll forward you the link if it's recorded...

In reply to ThunderCat:
Hahhahahh ! It's shite when you know you're going to crash. Butty van at Mam tor any good?

In reply to Dave the Rave:


A bit of wee came out.. hahaha..

Van at Blue John Cavern (base of Mam Tor) is ok...not a patch on the glen ogle one though....

In reply to ThunderCat:

That's what chammy is for


Did you cycle up Winnats?

In reply to Dave the Rave:


Pfft. No. Cam up from Chapel En Le Frithe, went down Winnats, and then back up around the old disused / collapsed road. Not ready for coming up Winnats yet...

In reply to ThunderCat:


Nice . I've never cycled that either. Used to cycle up from Stoke to Edale pretty regular. Nice run down into Edale. You know you've made it when you get to the Mam tor summit.

In reply to ThunderCat:
Surprised no one has mentioned this, but it sounds very like you were dragging your brakes (on the brakes behind car then further slow down of cars)

Disc brakes are vastly superior to rim brakes in most applications, but you do need to treat them differently. A far better thing that putting a little bit of brake on for a long time is to brake hard then release, then brake hard again as required. Dragging brakes will heat them up in a surprisingly short amount of time especially if you are quite heavy. If you find yourself in this situation again, alternate between front and rear so you give the brakes a rest, and even coming of the brakes for just a second can help get a bit of bite back.

What kind of bike? A new fangled roady with discs or an MTB?

What size rotor are you using? If you are running 180 or less go up a size (or2) (203/200 being largest easily available) you will also need an adaptor for the called all in you should be able to do not for £15-20 each end.

Remember your back brake does very little compared to the front brake, so don't be surprised if yourmrear is smaller, and you can keep it that way. So if you have 160front, 140rear, buy a 180 and move the 160 disc from the front to the back

If you are already are running 203s then you need to look at floating rotors (better heat distribution) bit more (£40) but he careful to make sure you don't have clearance issues as they are wider than one piece discs. You may be able to get pads with heat sink fins attached which helps massively.

If this still causes problems then you may need to look at changing make/model perhaps some more downhill orientated brakes if its an MTB, or multi piston systems if not.

Let me know what size you are, and I'll have a dig through the tool box I've got a few different size one piece discs I've replaced over the years

Other minor things to think about are when did you last clean your rotors? Use isoproyl alcohol or specific disc cleaner, and be very careful not to contaminate the pads with oil over spray etc.

In reply to balmybaldwin:
Discs! My rim! As I said before, it sounds like a load of faff. Theres nowt sweeter than the sound of leather on steel, pulled by solid cables/)

In reply to ThunderCat:

MTB or road ?
What sort of tyres ?
Hydraulic or cable ?
Rotor size ?
When did you last clean your pads/rotor ?
Have you checked the wear on your pads - metal on metal isn't a good idea !

Have to admit I've only ridden up Winnats, coming down seems like a waste of gravity but also the fatality there last year, and a horror story from a mate a few years earlier, has put me off. But on my road bike I know it's not the discs nor my weight that are the main factor in the braking, it's the contact patch on the tyres.

In reply to Chris the Tall:

Are you saying road tyres have too small a profile to grip?

In reply to balmybaldwin:

Hi, I pretty much bought the bike 'off the peg' at halfords, but this is it:

http://www.halfords.com/cycling/bikes/mountain-bikes/voodoo-bizango-29er-mo...

To be honest, the winnats pass descent isn't the typical type riding I'd do. We just wanted a long, slow rise up from Stockport to Mam Tor, and then a quick way to get down again.

It's pretty much brand new though. Apart from approximately 4-5 weeks of commuting to work along flat urban roads (18 miles a day), this is the first real run out I've done.

In reply to Dave the Rave:


Being from the North East, I always thought that was where I want my ashes scattered...but I'm tempted by the some of the High Peak at moment. Lovely area. I really like it.

In reply to ThunderCat:

A 203 rotor on the front and adapter would be a good idea on a 29r but just being aware of the issue and not dragging the brake will probably keep you out of trouble especially if you don't do this kind of sustained descent normally. You can feel it beginning to go soft normally ,and stopping for a minute or 2 will allow it to cool (when stopped don't pull the brakes) also beware of the heat if you ever come off you don't want it on your leg.

In reply to Dave the Rave:


I hate the thought of riders going out on the new tiny rotored road bikes that suddenly seem to be appearing. I don't think the power is necessary, but the likeyhood of new riders wanting/needing to drag the brakes with out being properly warned and running into this problem is quite high and not worth the risk IMO.

On a mountain bike I wouldn't think about using rim brakes now.

In reply to ThunderCat:

Surely with a 29" wheel you ought to have correspondingly bigger brake discs as a bigger wheel must have consderably more "leverage"?

At 20 stone I'd say the brakes definitely overheated, especially as that road is one of the steepest in Britain.

In reply to ThunderCat:

Looking at the link to your bike - my bike came with an earlier version of these brakes, and I managed to boil them so that they no longer worked (and I am not 20 stone ). They and the discs they normally come with are only meant to be used with resin/organic pads, and if you put sintered pads on they boil really easily. Bleeding the brakes didn't solve the problem.

I upgraded to Shimano Deore M625s with some matching rotors (all on special offer at Chain Reaction at the time) and haven't looked back - they're excellent.

In reply to cat22:

Nice bike. No point putting on the cheapie £30 hydraulics I mentioned. Worth googling to check 200mm discs will fit with your fork

Also worth taking to back to Halfirds for their checkup as if a brake is dragging it could cause overheating.

In reply to Dave the Rave:


No, but the extra power of discs is superfluous on skinny road tyres. There are other advantages to discs though, particularly if you're a big bloke riding the potholed streets of Sheffield and aren't very good at straightening your own wheels.

In reply to ThunderCat:


Yeah. There's a good feel to the place. I don't go as often now I've moved though.
Used to be great going over Mam summit and the view to kinder opening up. Very exciting are the Pennines. No matter how busy it is on the edges, a 50 m walk into the plateau and you see no one. Used to do the Hayfield circuit a lot on bike. Good route.

In reply to ThunderCat:

I had the same problem a couple of weeks ago on the road. Did the London to Brighton charity ride and a fair few downhill sections so managed a fair old speed as the roads were mostly closed. Noticed at the bottom when I started to pedal again the same burning smell.

Stopped for a drink and there was a free bike clininc, asked them and they said just overheating, should be fine but if I were going to be doing a lot more downhills and using the brakes a lot more then get them upgraded or get a better bike...... 6ft 3 and 15.5 stone for the record :0)

In reply to Denni:

Skinny sod...

In reply to ThunderCat:


Only because I have lost 1.5 stone by getting out on the bike!!