Author Topic: V brake pads and rim wear  (Read 9640 times)

Offline wayne3109

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V brake pads and rim wear
« on: August 01, 2009, 06:21:56 AM »
Hi there.  Just wondering if anyone can recommend a type of brake pad to use with V brakes for the GM wheels?  The rim doesn't have a smooth surface for braking so not sure what type of brake pads to use...

Also wondering what happens when the rim wears excessively and how it can be replaced?  Buy a whole new motor with wheel or replace rim and keep motor?  Would be keen to try the Magic Pie if it comes on the market...

Cheers.

Wayne  :)

Offline Perbear

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Re: V brake pads and rim wear
« Reply #1 on: August 01, 2009, 09:31:19 PM »
I do not have problems with excess wear but my latest motor was bought without a rim. I delivered it a local wheel builder who installed a MAVIC A719 using double butted spokes to get strength up and weight down.

For my next ebike I plan on using hydraulic disc brakes  :P 

Offline Bikemad

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Re: V brake pads and rim wear
« Reply #2 on: August 01, 2009, 10:42:07 PM »
Also wondering what happens when the rim wears excessively and how it can be replaced?

Wayne,

If you are using regenerative braking the rim is most unlikely to wear excessively, as most of the braking is done without any friction at all.

If the rim was damaged due to an accident etc. any decent cycle repair/service center should be able to fit a suitable replacement rim.

Alan
 
« Last Edit: August 01, 2009, 10:43:50 PM by Bikemad »

Offline wayne3109

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Re: V brake pads and rim wear
« Reply #3 on: August 03, 2009, 12:07:51 AM »
Cheers for that..  Pardon my ignorance but is the regen braking in effect when I use the GM supplied brake levers with the switch?  I was planning on not using those as they look a bit ugly on my bike, but if braking performance is improved then maybe it's the way to go...   :)

Offline Bikemad

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Re: V brake pads and rim wear
« Reply #4 on: August 03, 2009, 10:18:25 AM »
Cheers for that..  Pardon my ignorance but is the regen braking in effect when I use the GM supplied brake levers with the switch?  I was planning on not using those as they look a bit ugly on my bike, but if braking performance is improved then maybe it's the way to go...   :)

Wayne,

On the magic controller, regen should work when the brake lever switch is activated.
(But it does not work with all batteries)

If you are not using brake levers with switches, you have no power cutoff.

Braking must cut the power to the motor for motor protection, safety and legal reasons!

Imagine the following scenario:

You're using full throttle to get to the top of a steep hill. As you go over the top and start to descend the other side of the hill you release the throttle. The bike continues to accelerate down the steep hill until you suddenly realise the throttle is stuck on full. So you apply the brakes, but because the motor is still giving full power, you have to pull really hard on the levers to try and slow down. Unfortunately you have to apply so much braking pressure that the front brake cable (the frayed one you've been meaning to look at for a while, but never found the time to replace) finally snaps!
So now we have a heavy bike going very fast down a steep hill with the motor on full power and only a rear brake to try and stop with. Are you really going to be able to stop the bike with only the rear brake trying to overcome all those other forces?
If you then add poor visibility, wet/uneven road surface, a tight bend and oncoming traffic into this scenario, then the outcome does not look good.

The power breaking levers are supplied for a reason, so fit them and make sure they work correctly to ensure your bike is both safe and legal!
(And make sure you always replace worn or faulty brake components immediately.)

Unless your ambition is to become another accident statistic!

Alan
 

 
« Last Edit: August 03, 2009, 11:30:26 PM by Bikemad »

Offline muzza.au

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Re: V brake pads and rim wear
« Reply #5 on: August 03, 2009, 11:07:24 PM »
An alternative if you don't want to use the brake cutoff levers and don't have or need regen but still want the cutoff in an emergency is to have the break cutoff wired into a switch that you can get to quickly. You could use the following throttle that has the switches built in.

I'll probably consider using this because I'm slowly converting a bike that has hydraulic disc brakes and cant use the levers for cable v-brakes.

Muzza.

Offline e-lmer

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Re: V brake pads and rim wear
« Reply #6 on: August 04, 2009, 12:30:51 AM »
I just posted in a different topic about a magnetic reed switch
for the brakes.

I am going to make mine actuated by the brake cable instead
of the levers, but the hydraulic brakes could be triggered by
the reed switch instead.