Brake locks front wheel resulting in flying over the handlebars

[YahudaMoon]

Reading the OP post it looks like he / she is looking at every avenue possible to find blame on the mechanic other than the daughters miss judged calibration on the new brake set up ....

Or is it just me ?

 

[Sheffield_Tiger]

Reading the OP's post it sounds like he is doing the exact same as the rest of us. Trying to work out what MAY have happened without actually being able to see the bike.

 

[YahudaMoon]

Reading the OP's post it sounds like he is doing the exact same as the rest of us. Trying to work out what MAY have happened without actually being able to see the bike.

That being the old brakes were poor so got replaced with brakes that do work.

 

[lulubel]

Reading the OP post it looks like he / she is looking at every avenue possible to find blame on the mechanic other than the daughters miss judged calibration on the new brake set up ....

Even if that is what he's doing, it seems perfectly natural to me. He's a dad, she's his daughter. Isn't that what dads do?

Or maybe it's just my Dad who's overprotective.

 

[fossyant]

That being the old brakes were poor so got replaced with brakes that do work.

Like it.

My son, on getting a decent first 20" MTB commented, oh brakes that work - he was about 6 at the time ! Having gone from a basic toddler bike.

V brakes and non specific levers will certainly be good. Hmm might have to try that with my MTB - just replace the Canti's with V's. Stop on a sixpence.

TBH If you pull the brakes hard enough you can easily endo any bike - I can even do it on my fixed with fully loaded panniers if I brake hard.

 

[fossyant]

Even if that is what he's doing, it seems perfectly natural to me. He's a dad, she's his daughter. Isn't that what dads do?

Or maybe it's just my Dad who's overprotective.

Probably.

Bike riding is not for ninnies ! Fall off, get up and check the bike, and ride. Worry later on if your leg falls off !

 

[mcshroom]

There is definitely a canti hanger on the front of the bike which suggests that the bike used to have cantis at some point.

To be honest under emergency braking in the wrong conditions any brake setup could lock the front wheel up, but I would check that the levers on the bike are appropriate for the brakes that are on there if the shop has just changed from cantilever to v-brakes.

 

[Linford]

I would want to see the brakes being efficient enough to lock the wheels at speeds of up to 20mph. It is then up to the rider to use that wisely.

 

[MontyVeda]

i know two people who've done the same thing with the front V brake, one had a broken arm and collar bone, the other just had a broken arm. IMO, they are too efficient.

 

[YahudaMoon]

Even if that is what he's doing, it seems perfectly natural to me. He's a dad, she's his daughter. Isn't that what dads do?

Or maybe it's just my Dad who's overprotective.

Nothing wrong with that I just glad Im not the mechanic that fixed the bike lol

 

[albion]

Is this a vote to make anti-lock brakes compulsory?

 

[simon.r]

Any news from the OP? I'm intrigued as to what the outcome of this is going to be.

 

[Freddy92]

Fair point Simon - about time I re-entered the fray and maybe summed it all up.

I don't know why I have to apologise for being an engineer but there you go. At least one contributor seems to think this is necessary. I put this in because I think you need to know I have a good technical background but other than looking after my own bikes am not a bike specialist and people who specialise always know more than those who don't. On the other hand non specialists can have a view from the outside. I would like to thank the numerous people who have responded in a very positive way and I think this thread is one of the most fruitful I have ever initiated. Oh - for those who find my initial posting controversial - it was intended to be. We wouldn't have 3 pages of discussion if it hadn't been :-)

I want to get this out of the way first - I think that in all probability the brake was not fitted badly, or that if one of the brake shoes was a little high this was not the cause of locking the front wheel in the first place. It is pretty clear that the combination of a V-brake with a cantilever brake lever is perfectly capable of locking the front wheel at a pull that would nowhere near lock the wheel with a cantilever brake. Therefore having a cantilever brake replaced with a V-brake is potentially dangerous for a non technical rider.

My working life is made something of a pain by our company having to produce risk assessments for just about every activity. I have always thought these a waste of time until this incident with my daughter. If the bike shop or maybe better - the brake manufacturers - had done a risk assessment on replacing cantilever brakes with V-brakes then these problems would have surfaced and every V brake sold separately would come with warnings about checking the brake lever can be adjusted for lower leverage and replace if necessary. Also to warn the user about the greater braking effect. Now it is a fact that if my daughter had been injured or worse, then she or I would have come after the bike shop that fitted the brake. There are those that have contributed here that won't like this but I can assure them that under current health and safety legislation the bike shop would be liable and so would the brake supplier if they had not included instructions as I have suggested.

For my daughter I want to thank mickdrippin60 for leading me to the device that limits the cable tension and thereby reduces the efficiency of the V-brake. I note this device is made by a brake manufacturer so they obviously know the problem. I would say this whole thing comes down to what type of rider you are. If you are an experienced downhill enthusiast who understands exactly how your brakes work and can think fast enough in all situations to never pull too hard for the conditions then you should be able to install whatever you like. On the other hand if you are a bicycle commuter who does not understand the mechanics and hardly ever has to pull up fast then some sort of tension limiter on a front V-brake is essential. It is very like the argument for abs on cars.

 

[albion]

The fact is that one gradually adjusts to ageing brake blocks so new blocks always give that initial surge.
Its seems like it was just unfortunate timing of use.

 

[TheDoctor]

The manufacturers have done a risk assessment - that's why you get V-brake levers and 'other' levers. I'm not certain I can do a stoppie on my road bike, but I certainly can on my MTB. With all respect, I think it's simply that the brakes were improved out of all recognition and the rider didn't know, or didn't take that into account.