Powerful e-bike commuter/runaround for hilly area

shonik09

1 µW
Joined
Mar 7, 2020
Messages
3
Hi all,

First post after lurking for the past month reading up on stuff. I'm moving to an area which will be 20 mins walking 1/1.5 miles up a 7% gradient to my nearest train station, and next to no buses, so decided to build an ebike to commute to/from the station, and also generally as a run-around alternative to a car. For speed, I'm happy with 30-35mph on flats (40 would be great but would really be for really short bursts), but the key requirement is wanting to hit 25-30mph comfortably on the hills around where I live. Generally the terrain is a lot of up/down hills, with some flats in between.

After some research, my current plan is:

Motor/controller: BBSHD + ASCI 800 controller, something like this kit, but likely I'll get an eggrider - https://www.electroncycles.co.uk/product/complete-72v-ultimate-bbshd-motor-2800-watts-asi-bac-800-controller-45mph/. I initially considered getting a 3000W QS205, but wasn't keen on the additional weight, and I feel there is literally know way to make it look road legal here in the UK, whereas at least with the BBSHD I could run it in a low power setting when necessary (with a 250W sticker :twisted:) and probably get away with it.

Battery: I'm planning on building my own 20s4p with LG HG2 batteries, which I'll put in the G80 hailong shark case - https://www.aliexpress.com/i/4000157438415.html. Should give me 72v 40A 12ah continuous easily.

Donor bike: This is where I'm stuck at the moment, reading around it seems given this bike could hit 35mph-40mph, a full downhill bike would be the most reliable/safe. I was initially considering the Giant Glory 2013, but seems like G80 wouldn't fit in the triangle, and I'm worried there wouldn't be enough clearance to mount below the downtube. I'm now considering the Mondraker Summum 2012 (looks like ample clearance to mount on underside of downtube), or Vitus Dominer 2017 (maybe not in triangle, but looks like more clearance below downtube than glory) as I can get both with decent spec fork/shock/brakes for a decent price.

What do people think of my current plan? Any suggestions on the donor bikes I've listed or others I could use? Any suggestions/advice is massively appreciated!
 
seems good. that small battery you can mount on top tube. i know people dont like it but im fine with it; it looks like a motor bike for me. also, of course you need disc brakes at those speeds.
 
For brakes, Go big, 203 front, 180 rear. I just stepped up to 203 front and it was a long time coming. At only 28 mph only, I find the larger rotor more appropriate, at your higher speeds, you definitely want lots of brakes. I’m using basic tektro brakes still on my Raleigh redux is. (I carry a far amount of weight more than stock commuting, hence need for big brakes)

You can get unbranded Chinese rotors off eBay for cheap if cost is a factor.
 
Thanks for the replies.

bakaneko said:
seems good. that small battery you can mount on top tube. i know people dont like it but im fine with it; it looks like a motor bike for me. also, of course you need disc brakes at those speeds.

Yeah tbh I'm leaning heavily towards a mondrake summum as had confirmation that the pack should fit under the downtube - not keen on above top tube due to weight distribution, or you think having 3.5kg on the top tube won't feel that different?

For brakes I'm defo looking at 200mm minimum, 203 ideal though. Seems like a lot these bikes have sram guide R brakes though - do you think these would be enough, or should I be looking more for zee/magura mt7?

E-HP said:
Are you taking the bike on the train with you, or do you have a secure place to park it at the train station?

I'll be parking it at the station in the bikerack there... was thinking of using this - https://www.addnature.co.uk/879105.html?gclid=CjwKCAjwmKLzBRBeEiwACCVihjXFpXq41xUbClLwqaI59Ly30rMzrP2Ta59pr5O13ibXkN_AW2a0gRoCqTgQAvD_BwE&_cid=21_1_-1_%7Bifpla:9%7D%7Bifpe:8%7D_190_879105_%7Bcreative%7D_%7Bifpla:pla%7D&ef_id=CjwKCAjwmKLzBRBeEiwACCVihjXFpXq41xUbClLwqaI59Ly30rMzrP2Ta59pr5O13ibXkN_AW2a0gRoCqTgQAvD_BwE&ev_chn=shop, and also adding this GPS tracker in the handlebars - https://www.sherlock.bike/en/
 
for steep hills you definitely want a mid drive so you can use the gears to climb any hill. however it's unlikely even with 2500W you are going to hit 25mph uphill, perhaps 15-20? Overdriving it by that much is also likely to kill the motor- if you're using it for a work commuter then you need reliability!

For the frame, suggest KISS- stick with a hard tail downhill bike. full suspension is great for MTB but not really needed on reasonable roads IMHO; and 2nd hand ones are usually thrashed with worn out swingarm bearings and lots of sideways play. Decent front shocks and chunky commuter tyres on a standard frame will provide enough cushioning; plenty of people cycle tour with no suspension at all.

Watch the bottom bracket- make sure it's your standard threaded one as there are multiple press-fit ones requiring unobtainable adapters. and rugged 26 inch rims seem to be much stronger (if a bit heavier)
 
shonik09 said:
Yeah tbh I'm leaning heavily towards a mondrake summum as had confirmation that the pack should fit under the downtube - not keen on above top tube due to weight distribution, or you think having 3.5kg on the top tube won't feel that different?

with that bike, the weight would be minimal difference than it would be on the downtube. man, listen, the whole negative about the battery on top tube is by literally guys that never put their battery on the top tube. 7lbs is nothing; lol i have like 35lbs on my top tube. i would say that there is a huge difference if its on the rear rack. that is a big difference; top tube especially with 7-8lbs is nothing.

get that bike that you like, put the battery on the top tube; i think there are even adapters where u dont even have to drill the bike or just fabricate something nice, and there be done with it. you will be happy with the bike.
 
shonik09 said:
Hi all,

First post after lurking for the past month reading up on stuff. I'm moving to an area which will be 20 mins walking 1/1.5 miles up a 7% gradient to my nearest train station, and next to no buses, so decided to build an ebike to commute to/from the station, and also generally as a run-around alternative to a car. For speed, I'm happy with 30-35mph on flats (40 would be great but would really be for really short bursts), but the key requirement is wanting to hit 25-30mph comfortably on the hills around where I live. Generally the terrain is a lot of up/down hills, with some flats in between.

After some research, my current plan is:

Motor/controller: BBSHD + ASCI 800 controller, something like this kit, but likely I'll get an eggrider - https://www.electroncycles.co.uk/product/complete-72v-ultimate-bbshd-motor-2800-watts-asi-bac-800-controller-45mph/. I initially considered getting a 3000W QS205, but wasn't keen on the additional weight, and I feel there is literally know way to make it look road legal here in the UK, whereas at least with the BBSHD I could run it in a low power setting when necessary (with a 250W sticker :twisted:) and probably get away with it.

Battery: I'm planning on building my own 20s4p with LG HG2 batteries, which I'll put in the G80 hailong shark case - https://www.aliexpress.com/i/4000157438415.html. Should give me 72v 40A 12ah continuous easily.

Donor bike: This is where I'm stuck at the moment, reading around it seems given this bike could hit 35mph-40mph, a full downhill bike would be the most reliable/safe. I was initially considering the Giant Glory 2013, but seems like G80 wouldn't fit in the triangle, and I'm worried there wouldn't be enough clearance to mount below the downtube. I'm now considering the Mondraker Summum 2012 (looks like ample clearance to mount on underside of downtube), or Vitus Dominer 2017 (maybe not in triangle, but looks like more clearance below downtube than glory) as I can get both with decent spec fork/shock/brakes for a decent price.

What do people think of my current plan? Any suggestions on the donor bikes I've listed or others I could use? Any suggestions/advice is massively appreciated!




Did you try to mount the shock upside down vitus dominer ?
 
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