Improve bicycle braking performance?

Energize · 22 Apr 2013 at 00:08

I've noticed that my bicycles braking performance is not the best, especially going downhill; even with the brakes on full I nearly rear ended a bus the other day and I wasn't going that fast to begin with.

The front wheel has disc brakes and the rear wheel v brakes, the tyres are 2.1" MTB type.

What can I do to improve my braking performance? Would road tyres make a big difference, or better brakes?

This is the bike I have, minus mudguards and front light.

[DOD]Asprilla · 22 Apr 2013 at 08:25

The only things I can suggest are that you check and, if necessary, replace the pads on the front disc brake and also adjust the callipers to make sure they are close to the disc.

If the disc is warped the brakes may rub so that might need replacing as well.

For the rear brake just ensure the pads are 2-3mm from the rim.

Tyres will only make a difference if you are skidding rather than failing to lock the wheels. I don't think you've got a rear disc mount and you'd need to change the rear wheel to go down that route (I assume this is motorised so that's probably out). I also assume your front disc is cable operated so there might be an improvement by moving to hydraulic disc brakes but I've never used them so I don't know I'm afraid.

Sorry, but of a ramble but hope it helps.

divuk83 · 22 Apr 2013 at 08:32

I would guess that the front discs are cable discs rather than hydraulic ones? I had some cable ones on an old mtb and I though they were crap when I first got it. Spend a little time setting them up right and they will work much better. Depending on their age it might be worth getting some new front pads too? Rear brake is less important, as long at it works OK I wouldn't do anything to it as you don't really wanting to be locking the rear wheel to stop.

Dave

grudas · 22 Apr 2013 at 08:39

go to your local LBS and get them to replace the pads, adjust the brakes etc etc and it'll work fine.. depends how much you ride but i wear my pads in a month(400-500miles)

so they need replacing every month..

Begbie · 22 Apr 2013 at 08:48

I spend a while replacing my pads, setting my brakes up. (moving the 'triggers' to the right location for one finger braking etc) and WOW the difference is night and day!

Few videos etc on youtube, on how to set up your brakes.

Energize · 22 Apr 2013 at 12:57

[DOD]Asprilla;24159412 said:
The only things I can suggest are that you check and, if necessary, replace the pads on the front disc brake and also adjust the callipers to make sure they are close to the disc.

If the disc is warped the brakes may rub so that might need replacing as well.

For the rear brake just ensure the pads are 2-3mm from the rim.

Tyres will only make a difference if you are skidding rather than failing to lock the wheels. I don't think you've got a rear disc mount and you'd need to change the rear wheel to go down that route (I assume this is motorised so that's probably out). I also assume your front disc is cable operated so there might be an improvement by moving to hydraulic disc brakes but I've never used them so I don't know I'm afraid.

Sorry, but of a ramble but hope it helps.

Thanks I'll check the pads and look into hydraulics, the reason I mentioned the tyres is because in the past the bike has skidded on the road.

The wheel itself isn't motorised it's a chain drive motor so it can be replaced.

[DOD]Asprilla · 22 Apr 2013 at 13:15

If you can lock up the tyres then there isn't anything wrong with your brakes, other than modulating them. You should try to avoid it when braking.

Most bikes rotate around the centre of mavity when you brake and so the rear wheel lifts. The battery location will moderate that to some extent, but it's still going to happen, hence your front brake is more powerful than the rear. If you don't have the necessary mounting points on your rear stays then you won't be able to easily fit a rear disc. There are workarounds but I've not used any of them so can't comment on them.

I don't think hydraulics give you much more stopping power, they are just more adjustable and more consistent.

Energize · 24 Apr 2013 at 01:49

After looking at the rear brakes there is definitely a problem with them, the rear wheel now has hardly any stopping power, furthermore the right pad doesn't release properly without manual intervention and as a result rubs on the rim, so I've got two problems. The pads themselves are ok though, I've only done ~150 miles on it so I'd hope so.

[DOD]Asprilla · 24 Apr 2013 at 07:05

Energize said:
After looking at the rear brakes there is definitely a problem with them, the rear wheel now has hardly any stopping power, furthermore the right pad doesn't release properly without manual intervention and as a result rubs on the rim, so I've got two problems. The pads themselves are ok though, I've only done ~150 miles on it so I'd hope so.

Run though this to see if you can set the up better;

http://m.parktool.com/blog/repair-help/linear-pull-brake-service-v-brake-type

Rear brake is mainly for moderating speed rather than stopping because heavy braking actually lifts the rear wheel from the ground. V brakes don't have brilliant stopping power but its not bad.

grudas · 24 Apr 2013 at 08:15

[DOD]Asprilla;24171245 said:
Run though this to see if you can set the up better;

http://m.parktool.com/blog/repair-help/linear-pull-brake-service-v-brake-type

Rear brake is mainly for moderating speed rather than stopping because heavy braking actually lifts the rear wheel from the ground. V brakes don't have brilliant stopping power but its not bad.

lifts the rear of the ground? the front does that if you're off your seat

but rear never lifts on its own..

using both at once is the best idea when you need a lot of breaking.. or front alone

rear on its own is just for fun..

[DOD]Asprilla · 24 Apr 2013 at 08:22

grudas said:
lifts the rear of the ground? the front does that if you're off your seat but rear never lifts on its own..

using both at once is the best idea when you need a lot of breaking.. or front alone

rear on its own is just for fun..

If you are moving forwards and then brake the braking friction is where tyre meets road acting as a force in the opposite direction. As a result the bike rotates around the centre of mavity and the back wheel lifts.

That's why folks go over their handlebars when emergency braking. Even when braking hard the back wheel skids before the front because there is less downward pressure on it.

When emergency braking on a bike you should try to get off the back of the saddle to move the centre of mavity backwards and down.

Course in this case the massive battery on the back helps with rear braking performance.

Supercow · 24 Apr 2013 at 08:24

You can also always opt for bigger rotors.

Energize · 24 Apr 2013 at 23:56

[DOD]Asprilla;24171245 said:
Run though this to see if you can set the up better;

http://m.parktool.com/blog/repair-help/linear-pull-brake-service-v-brake-type

Rear brake is mainly for moderating speed rather than stopping because heavy braking actually lifts the rear wheel from the ground. V brakes don't have brilliant stopping power but its not bad.

That link doesn't appear to work, but using another website I refitted the brakes and adjusted the tension using the screws and now the brakes work perfectly again and my breaking performance has massively improved.

My other problem is that the chain always seems to come off on the front sprocket when I go down a certain hill on my way home, my speed down it is around 35mph, 7th gear (max) and it has a few bumps which I suspect cause the problem.

Is there any way to remedy this? Bike has ~160 miles on it.

Caseh · 25 Apr 2013 at 07:14

Supercow said:
You can also always opt for bigger rotors.

This way is the most fun.

[DOD]Asprilla · 25 Apr 2013 at 09:12

Energize said:
That link doesn't appear to work, but using another website I refitted the brakes and adjusted the tension using the screws and now the brakes work perfectly again and my breaking performance has massively improved.

My other problem is that the chain always seems to come off on the front sprocket when I go down a certain hill on my way home, my speed down it is around 35mph, 7th gear (max) and it has a few bumps which I suspect cause the problem.

Is there any way to remedy this? Bike has ~160 miles on it.

Sorry, that was the link to the mobile version and for some reason it doesnt work on full browsers.

Here's the link to the full site: http://www.parktool.com/blog/repair-help

Their walk though's a very good indeed if you need to do any maintenance.

Do you have multiple chain rings at the front? If so I assume you are on the largest ring when the chain is coming off?

Energize · 25 Apr 2013 at 16:07

No there is only one ring.

grudas · 25 Apr 2013 at 16:18

get some lube too while you're at it