Ever lost your brakes !

[JohnW]

I once lost my brakes completely.

If anyone knows the place, they'll know how it felt. On my way to work - always in a hurry because always at the last minute. Coming down Halifax Road into Brighouse - a steep drop down to a large roundabout where two busy A-class roads meet at a 'cross-roads' - at morning rush hour. I'd put new inner cables into my brakes - as I braked for the roundabout, both nipples pinged off at once (obviously defective, but what a time to discover it!). Busy dual carriageways to my right, left and a humped roundabout in front of me, with a busy dual carriageway leading on from it, and downhill. The first car coming from my right must have actually seen my situation - how that driver had registered it I don't know, because he stopped almost dead, and the traffic behind him did the same. I bounced over the kerb onto the planted roundabout, got between the direction chevrons some how, and down onto the dual carriageway away from the roundabout, causing all sorts of screeching of brakes and sounding of horns. I stopped by scraping on the kerb of the central reservation.

I had tested and adjusted my brakes before I left home

This was 35+ years ago, and I still shudder and sweat to think of it.

Very hairy!!
Someone was looking out for you that day!

Did you do anything different afterwards when fitting/ fettling?
Always buy top quality cables? Test them hard?
It's difficult to know how you could have avoided such a dire predicament?

Yes PDQ - someone was looking out for me that day - including the motorist on my right! I had tested the brakes on the way down there (I had five miles of almost continuous downhill before Brighouse) and the cables were quality ones - never had trouble with them before, nor since. The bike shop changed them without question, but I didn't make a fuss...............maybe I should have. When it happens like that, I find that one is grateful to be alive. But you're right - test them hard.

[NATURAL ANKLING]

Hi,
Probably about 45 years ago.
Did not maintain bike that well, always left outside, and the habit of only using front brake.
The cable was sticking on front brake so every time I used it, it did not return, so after braking a tweak of front calliper with fingers to return lever
The back brake was seized because I never used it.
Eventually the lever came further back with wear, and then one day a short cut round the back of shops, a car came round corner on wrong side of road and stopped, I grabbed brake and nothing, the nipple had dropped out of lever

This was the first time hitting a car, (second on the way to work head down parked car and planted on boot still in toe clips, bent frame), bent forks.
Luckily a few hundred yards from home.

Don't think I ever neglected brakes ever again.

[profpointy]

Well we await your design for fail-safe bike brakes..

Maybe we should have a weight limit as a constraint - under 1kg maybe. Best of luck

[Username]

You may have seen it on tv this week and it was DIY SOS. This episode was about altering a house for a very brave lady who had ridden down a steep hill and lost her brakes. Sadly it resulted in her being paralysed from the waist down and she is now in a wheel chair.
Its remarkable how she has come to terms with it and I in no way want to pass criticism on her whatsoever but it left me wondering how she managed to lose her brakes.
If this has ever happened to you I would be interested to learn what happened and by telling us it may prevent it happening to anyone else.

That makes 2 of us. The brakes on my bike are found on my handlebars, and being physically attached, that is where they always are. However if they were not there one day, I would notice this before I ride off even without actually checking them specifically. So to actually lose a brake, or a calliper sounds completely weird to me. I've never lost my brakes and if I did, I would have the sense not to ride a bike that has.

[Brucey]

John's report is not an entirely unique incident; about 35 years ago a chum of mine (who regularly braked hard enough to lift the rear wheel) fitted two new brake cables and promptly ran into the side of a car which pulled out on him when the nipples pulled off the ends of the cables. The cable manufacturers (well suppliers probably) were Aztec and they paid for a new frameset and other bits and pieces. He wasn't badly injured, fortunately.

I have not personally heard of any other cable failures of this sort since then. I have seen plenty of brakes that have not worked well enough since, almost invariably through lack of maintenance, although tampering is a possibility that should not be ignored either. Obviously some brake designs tolerate lack of maintenance differently to others, and similarly some work in an 'obvious' way and others don't, so folk who are not good bike mechanics may or may not spot a fault, either.

Most recently a chap I know reported that he tore the canti bosses off his Surly cross-check fork. It isn't clear exactly what happened, but it is possible that his brake blocks (which were 'road cartridge' type ones) were worn enough that the brake blocks dived beneath the rim and ended up in the spokes. He hadn't been aware of that possibility, and he did report that the brake blocks were 'about half-worn', which could be enough. [Modern canti-boss spacing is typically about 3-1/4", which is way wider than it needs to be unless you intend to use ~50mm tyres; the result is that the brake blocks move on a spectacularly bad path, especially when the rim is fairly narrow... I much prefer the 'old' canti boss spacing from that point of view.]

If you are concerned about brakes and cables I'd suggest that you get into the habit of

1) being attentive about brake maintenance; it really doesn't take long to do a visual check of most rim brakes and their associated cables, for example.

2) checking that you have brakes before you start off; pull the levers back and see that there is something there

3) not replacing both cables at the same time, not with identical inners from the same source. This pretty much eliminates the possibility of a John W/my wheel lifting chum type incident; even if you get a bad cable batch only one cable should be affected.

4) testing the brakes thoroughly after working on them; it is easy to (say) leave a cable clamp not tight enough or on the verge of stripping its thread. Only pulling as hard as you can on the levers will simulate what you might do in an emergency.

cheers

[rmurphy195]

A good reason for using a back-pedal brake and having several different types of brake

OTT - just pull the brake levers before you get on the bike, that's a quick check. If you earn to fly checking the brakes (along with everything else) is part of the pre-flight checks, and something I do in the car at the start of every journey (apply when still moving very slowly)

[The utility cyclist]

@ Cyril Haearn
How many incidents out of billions of journeys? You said they have to be fail safe and yet even flawed they produce so few serious incidents as to be not newsworthy.
people check their brakes and even when brakes fail which is extremely rare the vast majority can deal with it or are not seriously hurt, I'm sure there are incidents involving serious injury even death but the numbers are infinitesimal or we'd be hearing about it. I was curious as to why you reckoned brakes needed to be absolutely safe 100% of the time (fail safe) and/or in the style of train brakes based on what we know about how little brake failure is having a detrimental affect on cycling safety.

[Samuel D]

Bowden cables are quite fragile, likewise the cable clamps can easily loosen

How do cable clamps loosen? Mine never have and I don’t see what would cause them to. I use well designed hardware to minimise this sort of risk.

I use a torque wrench when fitting new cables to ensure the clamp is neither too loose nor tight enough to crush the cable and damage strands or damage the M6 fixing bolt. And after setting the cable tension I pull the lever right back to the handlebar ten times per Shimano’s instructions. This test is violent but reassuring.

I’ve never heard of nipples being plucked from cables, although the possibility has exercised my imagination. JohnW’s terrifying story won’t help with that.

In contrast to my careful choice of brakes, set-up, and maintenance, almost every bicycle I see around Paris has brakes that wouldn’t make me happy. The problems are too many to list and range from minor to shocking, but suffice to say it is the norm for bicycle brakes to be badly fitted, maintained, and even used. I ride with people who don’t even know to twist the barrel adjuster as the pads wear. One was reluctant to let me make that adjustment for him, saying he was taking the bicycle into the shop next week anyway! A huge number of the roadies at Longchamp ride with their quick-release permanently open.

You said they have to be fail safe and yet even flawed they produce so few serious incidents as to be not newsworthy.

Given my observations above, I have no doubt that bad bicycle brakes have contributed to accidents where that hasn’t been recognised.

[Tangled Metal]

Well not completely failed but on a very steep hill with one hairpin bend and a junction at the bottom I applied the brakes and carried on accelerating. I gripped the brake levers as hard as I could but I only slowed when the slope eased just before the hairpin. Saved my life but I still had a few 90 degrees bend and a steeper section to come.

Let's just say I got to the bottom and up the hill the other side a bit. I had to wait for the rest of the party. When together I got asked why I shot off like that. I explained and then touched my brake blocks and accidentally touched my rims. Last me with a burn. The rims were very hot indeed!

Poor maintenence. It needed new blocks and I suspect rims too. Still another issue came up and I got to busy doing other stuff so didn't ride much after that. Not until I got a new bike. Hat bike is in my shed now waiting for repairs well over a decade by now.

[Brucey]

....I use a torque wrench when fitting new cables to ensure the clamp is neither too loose nor tight enough to crush the cable and damage strands or damage the M6 fixing bolt...

NB a lot of cable clamp bolts are M5 threaded, not M6 threaded, even though the fastener heads may look like they belong to an M6 bolt.

cheers

[Samuel D]

All the more reason to use a torque wrench!

On the point about testing the brakes by pulling the lever to the bars: given that calliper pivot friction increases with the bicycle’s retardation, it may be possible to pull the cable harder when the bicycle is rolling than when it is stationary. That is, the lever may not so readily approach the handlebar in actual braking, thereby allowing greater – untested! – cable tension if you pull it to the bar anyway.

I believe this effect is detectable on my bicycle as a spongier feel at the front brake lever when stationary than when braking reasonably hard.

[PT1029]

I have never lost my brakes.
Once we were on the top of the Long Mynd, approaching the steep descent into one of the villages at the bottom. As we approached the start of the descent, we ummed and ahhed about whether to stop or not to admire the view before descending. We (narrowly) decided to stop and admire the view, in stopping at the top to admire said view, someone's front brake cable snapped. Lucky escape....

[ferrit worrier]

Front brake on a steep hill going down into Bristol, the surface of the road was horrendous and the little lever that opens the calliper up for wheel removal vibrated to the open position. Managed to stop ok, initial thought was the cable had pulled through then spotted the lever out of position. I think even if I'd spotted it on the way down I wouldn't have been able to let go of the bars to re set it, the vibration was that bad.

[francovendee]

No, but borrowed a friends bike that had the levers hitting the grips and the bike just slowed a bit, this was on the flat. I often wonder about brakes on bikes that get used just cycle to the shops. No maintenance and little awareness of gradual wear is very dangerous in an emergency situation.

[Brucey]

All the more reason to use a torque wrench!....

provided you are not tightening an M5 threaded fastener as if it were an M6 threaded one....

The actual torque required to grip the cable securely varies with the state of the screw thread, what is happening beneath the fastener head (which often bears on the clamp plate at an angle), the finish on the cable and the clamps, and a few other things besides. A good pragmatic method is to tighten the clamp in stages until the cable doesn't slide through the clamp when proof tested. If the bolt is then further tightened through a small angle, the clamp is then secure.

The cable itself is quite squashy, and there is always potential for further settling within the clamp; because the bolt is short and the clamp plate is not flexible, the main elasticity in the joint is effectively in the cable that is gripped itself. The cable must arguably both yield and remain springy where clamped, in order to be properly secure.

On the point about testing the brakes by pulling the lever to the bars: given that calliper pivot friction increases with the bicycle’s retardation, it may be possible to pull the cable harder when the bicycle is rolling than when it is stationary. That is, the lever may not so readily approach the handlebar in actual braking, thereby allowing greater – untested! – cable tension if you pull it to the bar anyway.

I believe this effect is detectable on my bicycle as a spongier feel at the front brake lever when stationary than when braking reasonably hard.

It is not clear to me that this is the case. If anything (the effects of panic braking asides...) I think it is possible to generate the same cable tension, which does not mean that the caliper moves in the same way, or that the lever feels the same. When in motion on the one hand (because of the side/twisting load) the brake pivots have increased friction, but the brake block face is constrained differently where it is pressed against the rim depending on whether the rim is sliding past it or not.

Thus the brake will feel different when the bike is in motion, but this does not necessarily mean there is a different cable tension; the tension at the lever end basically only depends on how hard you are pulling on the lever. The tension at the caliper end of the cable may vary if the rim is uneven, but in order for this to be a significant effect, one would expect the brake to be pretty poor to start with.

cheers