Upgrading brakes on converted bike

EmSeeDee

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Oct 13, 2015
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HI, All,

I have a Raleigh Pioneer utility bike with 7 speed shimano hub gears, to which I've added a GSM motor and HL battery from Whoosh. I've found that the combination of my weight (a bit on the wrong side of 16st), the increase in weight from the motor and the battery, and the increase in speed is causing my brakes to work less well and wear out faster. The bike is currently fitted with V-brakes, but since it has a disc brake mount on the front fork, I was thinking about converting the front to disc brake.

I'm a bit concerned that only doing the front might unbalance the bike's dynamics (there isn't a mount for a rear disc, so that's not an option)

Another concern is whether a disc brake mechanism going to be compatible with the brake levers supplied as part of the GSM kit.

Has anyone done this, or got any comments on the idea?

Thanks for your time

Mike
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Go for it a front HDB will transform your ride, the handling and extra braking assurance will a big improvement. Your front wheel will have to be rebuilt though as you will need a front disc hub to allow the disc to bolt on, with HDB you buy the whole set up already prebled all you do is bolt it on. Re the GSM brake levers no not compatible unless you use a cable disc brake. On my defunct GSM bike I dismantled the levers to use the sensor/wire and a magnet.
Alternatively you could up grade both brakes with better HVB's.
 
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D

Deleted member 4366

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There will be no problem with balance. nearly all the braking is done by the front wheel, so that's where you need a decent brake. You can fit any hydraulic brake you want, but you need the right adapter between the fork and the caliper. The adapter also depends on what size disk you have. 180mm disc is probably about right. If you're lucky, you might find a brake, disc, and adapter as one lot. You then only need to choose side mount or post mount to suit your fork.
 
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EmSeeDee

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Oct 13, 2015
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Coventry, UK
I'm planning on rebuilding the front wheel. At the moment it's got a Shimano hub dynamo; I plan to get a new dynamo with rotor mounting holes.

It's interesting that you seem to be suggesting hydraulic. Is it significantly better than cable?

Mike

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Alan Quay

Esteemed Pedelecer
Dec 4, 2012
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I'm planning on rebuilding the front wheel. At the moment it's got a Shimano hub dynamo; I plan to get a new dynamo with rotor mounting holes.

It's interesting that you seem to be suggesting hydraulic. Is it significantly better than cable?

Mike

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Yes, hydraulics are much better. Because they are self adjusting they need virtually no maintenance, where as mech disks need a lot of fiddling.

You can get a pair of Shimano ones for £40, so expect about £20 for a single.

Make sure you get a long enough hose and a spare olive so you can cut it to the right length.

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Nealh

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Hydraulic is the way to go, braking performance is superior. No adjusting or cable stretch. All that is needed once or twice throughout the pads life is a small allen screw adjustment on the lever to take up lever movement.
Use a front HDB and the rear you can use your exisiting with the GSM lever just means you will have odd levers. Shimano M395/445/446 are very good HDB's with out spending too much money, front brake length will need to be about 90cm but you should be able to take a measurement starting from you existing lever down to the disc mounts. Caliper/pad fitting is easy bolt on then loosen bolts apply brakes tighten said bolts before releasing lever wheel should spin freely with out rub, if you get rub repeat over again.
 
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Deleted member 4366

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Once you've had a hydraulic disc brake, you'll never go back to anything else if you can avoid it.

I don't get the bit about the dynamo. Surely, if you're going to get a the wheel rebuilt, you'd chuck the dynamo. Where's the sense in using a battery to power a motor to turn a wheel with a dynamo to make electricity to power a light when you can use the battery to power the light directly.

You have to remember that any power that comes out of a dynamo has to be put in and more. It doesn't give energy for nothing. Say you had a 5w light set: when the lights are on, there would be a drag on your bike of about 7w, which is about 10% of your normal pedal effort. With battery lights, there's no drag.
 
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trex

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EmSeeDee

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Oct 13, 2015
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Coventry, UK
Once you've had a hydraulic disc brake, you'll never go back to anything else if you can avoid it.

I don't get the bit about the dynamo. Surely, if you're going to get a the wheel rebuilt, you'd chuck the dynamo. Where's the sense in using a battery to power a motor to turn a wheel with a dynamo to make electricity to power a light when you can use the battery to power the light directly.

You have to remember that any power that comes out of a dynamo has to be put in and more. It doesn't give energy for nothing. Say you had a 5w light set: when the lights are on, there would be a drag on your bike of about 7w, which is about 10% of your normal pedal effort. With battery lights, there's no drag.
d8veh, I realise that it's a bit daft fitting a hub dynamo to a bike with a big battery, but the battery's 36V, the lights are 6V, and I can't find an easy way of getting a feed from the battery to the lights. The controller on the GSM kit doesn't have a light output feed and I don't fancy designing and building a switch-mode down-converter. Of course, if you have a better idea...
 
D

Deleted member 4366

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Chuck the lights too, and get some decent battery ones on Ebay. There's also the ones from Banggood.com that run directly from the 36v battery.

I quite like these beause you can use them for anything. They're zoomable, so you can set one near and the other further out. You can get extra batteries and chargers for a few quid:

http://www.ebay.co.uk/itm/UK-2-x-Cree-XML-T6-Q5-Mountain-Bike-Torch-Lights-Head-Light-Set-Battery-Charger-/141839287477?var=&hash=item210647c4b5:m:mUrnT8jXWMF-Y5zvRvnj0ng
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
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d8veh, I realise that it's a bit daft fitting a hub dynamo to a bike with a big battery, but the battery's 36V, the lights are 6V, and I can't find an easy way of getting a feed from the battery to the lights. The controller on the GSM kit doesn't have a light output feed and I don't fancy designing and building a switch-mode down-converter. Of course, if you have a better idea...
Or one of these:

URL: http://pages.ebay.com/link/?nav=item.view&id=381431572007&alt=web

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