Upgrading to disc brakes. Buy disc brake compatible wheel, or entire bike to pull wheel from?

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Aug 28, 2016
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Hey folks, i've just have a question regarding an upgrade I want to do to my electric bike.

Background: I ride 16 miles to and from my university 5 days a week through rain, snow, puddles, you name it. Ever since getting into the e biking world, I love riding my bike every chance I get. I think the last time I used my car was about a month ago to drive 30 miles to a place that was too realistically far to go on my bike.

I live in Michigan, so riding in the road and darting through cars is a daily part of my commute. Welcome to the motor city I suppose.

Built the entire bike and all it's parts for $500. I did this with a small budget because this is just a commuter vehicle. I didn't need anything fancy like a BBSHD or anything. I bought a cheap ebay hub motor kit, and it has been running great for about 700 miles so far. In fact, cheaper stuff means it's more easily replaceable and when the goal is to save money over a car, this strategy can sometimes work better.

My riding style is 16 miles or nearly flat road, with occasional hills with a grade of <1%. I went with a DD hub motor for a simpler design and fewer parts to fail. Plus my commute is 80% perfectly flat ground so I just don't really need to climb anything.

Bike specs:

Bike: 2008? Gary fisher Wahoo mountain bike. Not entirely sure of the year. Got from craigslist.

"36v 500w" rear wheel conversion kit from ebay. I now run this hub motor at 1500w continuous:
https://www.ebay.com/itm/26-Rear-Wheel-36V-500W-Electric-Bicycle-Ebike-Conversion-Kit-Hub-Motor/321679232957?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Battery: 52v 16AH 14S8P custom battery made from old power tool 18650 cells from the scrap yard. Tested it at 40A continuous and performs great.

The controller is specced as a "36v 500w" controller except that when I opened it up, the controller had 63v input capacitors on the inside. I now run a 52v battery instead of a 36v battery like I did from the start.

I also performed a "shunt mod" on my controller and increased the current to 30 Amps. Acceleration is MUCH better than when I had my bike running at 20 amps only. Even after these mods, nothing even get's warn to the touch.

Now I can easily hit speeds from 30mph all day, so I am looking at installing disc brakes.

My rear wheel and fork already has mounts/eyelets for disc brakes, so i'll just have to REALLY widen the rear fork and add some washers, then I can fit disc brakes in the rear.

The front wheel is where i'm going to have problems. My front suspension fork does have eyelets to install disc brakes, but my current 26" front wheel isn't disc brake compatible.

I could either buy a cheap 26" disc compatible wheel for $75 online, or I could just buy an entire bike locally, pull off the 26" wheel, install the disc brakes on the front wheel then install the whole wheel to my 26" mountain bike.

Case and point. Found some random mountain bike locally that looks to have 26" wheels. My guess is these is a walmart bike, but i'm only buying it for the front wheel. The rest of the bike can be for spare parts as far as i'm concerned.

https://us.letgo.com/en/i/mountain-bike_24efab03-9fe9-413a-b533-0691693e1c51

I already have in my posession a set of Avid BB5 front and rear disc brake calipers and 160mm rotors I pulled from another very broken bike I found at my local junk yard + the bolts, so I trust these much better than whatever brakes come on the bike I found above. The brake pads on these calipers look barely worn.

One more question. I have been reading that these generic hub motors that you can find on ebay are actually generally 500w or 1000w golden motor hub motors, or they could be a 9 continent hub motor. Not sure which. I wish I knew wheat kind of hub motor my bike ran without actually going to the hassle of opening the hub motor since this is a commuter vehicle, and I need to got to school every day.

What should I do?
 
CUDAcores89 said:
Hey folks, i've just have a question regarding an upgrade I want to do to my electric bike.

Background: I ride 16 miles to and from my university 5 days a week through rain, snow, puddles, you name it. Ever since getting into the e biking world, I love riding my bike every chance I get. I think the last time I used my car was about a month ago to drive 30 miles to a place that was too realistically far to go on my bike.

I live in Michigan, so riding in the road and darting through cars is a daily part of my commute. Welcome to the motor city I suppose.

Built the entire bike and all it's parts for $500. I did this with a small budget because this is just a commuter vehicle. I didn't need anything fancy like a BBSHD or anything. I bought a cheap ebay hub motor kit, and it has been running great for about 700 miles so far. In fact, cheaper stuff means it's more easily replaceable and when the goal is to save money over a car, this strategy can sometimes work better.

My riding style is 16 miles or nearly flat road, with occasional hills with a grade of <1%. I went with a DD hub motor for a simpler design and fewer parts to fail. Plus my commute is 80% perfectly flat ground so I just don't really need to climb anything.

Bike specs:

Bike: 2008? Gary fisher Wahoo mountain bike. Not entirely sure of the year. Got from craigslist.

"36v 500w" rear wheel conversion kit from ebay. I now run this hub motor at 1500w continuous:
https://www.ebay.com/itm/26-Rear-Wheel-36V-500W-Electric-Bicycle-Ebike-Conversion-Kit-Hub-Motor/321679232957?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Battery: 52v 16AH 14S8P custom battery made from old power tool 18650 cells from the scrap yard. Tested it at 40A continuous and performs great.

The controller is specced as a "36v 500w" controller except that when I opened it up, the controller had 63v input capacitors on the inside. I now run a 52v battery instead of a 36v battery like I did from the start.

I also performed a "shunt mod" on my controller and increased the current to 30 Amps. Acceleration is MUCH better than when I had my bike running at 20 amps only. Even after these mods, nothing even get's warn to the touch.

Now I can easily hit speeds from 30mph all day, so I am looking at installing disc brakes.

My rear wheel and fork already has mounts/eyelets for disc brakes, so i'll just have to REALLY widen the rear fork and add some washers, then I can fit disc brakes in the rear.

The front wheel is where i'm going to have problems. My front suspension fork does have eyelets to install disc brakes, but my current 26" front wheel isn't disc brake compatible.

I could either buy a cheap 26" disc compatible wheel for $75 online, or I could just buy an entire bike locally, pull off the 26" wheel, install the disc brakes on the front wheel then install the whole wheel to my 26" mountain bike.

Case and point. Found some random mountain bike locally that looks to have 26" wheels. My guess is these is a walmart bike, but i'm only buying it for the front wheel. The rest of the bike can be for spare parts as far as i'm concerned.

https://us.letgo.com/en/i/mountain-bike_24efab03-9fe9-413a-b533-0691693e1c51

I already have in my posession a set of Avid BB5 front and rear disc brake calipers and 160mm rotors I pulled from another very broken bike I found at my local junk yard + the bolts, so I trust these much better than whatever brakes come on the bike I found above. The brake pads on these calipers look barely worn.

One more question. I have been reading that these generic hub motors that you can find on ebay are actually generally 500w or 1000w golden motor hub motors, or they could be a 9 continent hub motor. Not sure which. I wish I knew wheat kind of hub motor my bike ran without actually going to the hassle of opening the hub motor since this is a commuter vehicle, and I need to got to school every day.

What should I do?

I would pick up new suspension forks and a XT front disc hub off fleabay
 
Since your front has disc brake mounts, you only need a disc compatible hub in your front wheel, or another front wheel that has one. A used MTB wheel that is disc compatible can be found cheap.

The rear is not important. You will be fine with best brake on the front. On snow and ice, you might consider regen for the rear. It does help to shorten braking distance and improve control on slippery conditions.
 
Suggestion-skip the disk brake on the rear and put a set of Kool-Stop tri-compound pads on the V-brake, worth the $24.00 or whatever they cost at your LBS, they are by far the best brake pads I've ever used and they work well in wet conditions too.

On my hubmotor bike I put a decent suspension fork and disk hub wheel because I had an extra hydro disk brake sitting around and figured I'd install it. Put a pair of the Kool-Stops on temporarily front and rear and they were so good I never bothered to put the disk brake on, finally put the disk brake on my daughter's bike.
 
Raisedeyebrows said:
a set of Kool-Stop tri-compound pads on the V-brake, worth the $24.00 or whatever they cost at your LBS, they are by far the best brake pads I've ever used and they work well in wet conditions too.

I heard Salmon Kool Stops are the best, I have seen the trip compound and have wondered about them.
 
markz said:
Raisedeyebrows said:
a set of Kool-Stop tri-compound pads on the V-brake, worth the $24.00 or whatever they cost at your LBS, they are by far the best brake pads I've ever used and they work well in wet conditions too.

I heard Salmon Kool Stops are the best, I have seen the trip compound and have wondered about them.

Somebody was saying KS makes Ebike specific pads, I looked them up it says V2 Ebike pad, undoubtedly good too.
 
Well, even the cheap BB5 disc brake will do better in the snow than a rim brake with any kind of pads. It will also do better when you have a less than perfect rim or wheel trueing.

A big disc brake will do better in any conditions.

If you can have a disc wheel for cheap, it is easy to try by yourself.
 
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