DIY electric mountain bike

[tommobot]

Just wondering if anyone on here has undertaken a DIY conversion with the bits of Ebay / Amazon etc..

I've obtained a suprisingly decent 'Claud Butler' old hardtail for free which rides very nicely.

I'd be looking to commute 12 miles each way on this, 3 days a week.

I previously did it on a road bike, but I was fitter and I could never muster the will to do it every day.

The kits look very easy, but i'd be intreuged to see how say £400 worth of kit holds up after a few years of commuting abuse.

Any thoughts and advice more than welcome!

[tommobot]

Ok, so to get my head around the terminolgy here...

Front mounted (front wheel), mid (on pedal spinny thing) and rear hub.

Front does seem to be the cheapest from having a quick look, I presume this would be more of a case of use once upto a reasonable speed as I am envisaging uncontroable FWD wheelspin at low speed

[tommobot]

What sort of prices are you chaps getting these kits (inc battery) for.. I'm probably looking to do this for under £250, all out range is not a neccesity as it would likely only ever be used 15 miles before charging..

[tommobot]

Senex said:

My kit was over £500.

You are going to struggle on that budget, I would search eBay but you will be taking a chance.

Have a look at eBay item number:115368390006

Good luck!

Thanks for that! I'd be happy with that I think.

I've no experience of ebikes but assume that would give some extra ooompth up the hills..

On that kit, would I need a separate throttle?

[tommobot]

Thoughts please... The price seems very good?

I've decided upon front wheel, which is a 26inch which I've been struggling to easily find.

Alli express seems to have plenty though..





I get the impression that the bottle style batteries are a bit conference division, but id only be looking for a max on 30 miles a day really between charges..

[tommobot]

I think i've got my heart / head set on this one at £378..

https://yosepower.com/products/e-bike-conversion-k...

I'd rather go for a 350w but the Yosepower stuff seems to get positive feedback..

I'm limiting myself to a FWD conversion for sheer simplicity I think...

[tommobot]

Never ridden either, but fwd is far simpler to install for sure!!

[tommobot]

I took the bike (I was intending to convert) for a 4mile commute this morning to see what it was like...

Firm, and the back wheel kept moving out of place for some reason..

I'm now contemplating whether to do the conversion (space allowing) on a boardman FS MTB, which has the benifit of hydraulic discs, but obviously weights a bit more.

For a 250W kit, is a few KG of difference between bike going to numb the performance of a lighter frame etc..?

[tommobot]

Senex said:

Your biggest problem with a FS is where to fit the battery.

Its exactly the same as the bike below, so I think space wise it 'should' be OK...

[tommobot]

Starting to get the old classic project creep...

Looking at mid drive kits, for circa £100 extra so £500ish..

48v 13a battery with a 750w mid drive motor...

Probably massive overkill but I'd rather overspec than be disappointed....

With the mid drive kit, as far as I can see, they only come with 1 ring or have I misunderstood...

[tommobot]

Ok, sorry for the constant barage of questions.

I'm not moving towards the rear hub motor I think..

https://www.yosepower.co.uk/products/36v15-6ah-dow...

36V15.6Ah HL Plus Li-ion E-bike Battery with 5 Pins Plug Not Round Pins and XT60 Adapter

Along with this 500w kit here;

https://kirbebike.com/diy-conversion-kits/kirbebik...

This would be £520 ish and would get me a decent rear hub motor and decent battery as far as I can see.

Thoughts please?

[tommobot]

What do you chaps do about charging them, as the one in the link above, even though its a UK kit seems to come with a non UK plug.. Are there plugs that fit readily available?

[tommobot]

Thanks for the comments guys, just regarding the power of the bike or the hub kits.

If i'm doing 40 down a pavement then I can see the issues, but an assisted 15 or 20mph along country rodes..

Surely its the same as having a Mclaren with 700bhp and the ability to go 200mph but as long as you stray within the limits (ish) its ok?

[tommobot]

ARHarh said:

The answer is don't ride like a dick and chances are you will be fine. As in most things in life.

Couldn't agree more

[tommobot]

I've gone and purchased the 350w rear hub kit from yosepower..

Hopefully, will be here early next week and can get along with fitting. Was about £370, for a 500w kit was looking about double so I'll start with it for now...

[tommobot]

I've got the kit, semi fitted and remarkably impressed.

Taken out for a spin down the road and it flew upto just under 18mph on the throttle only...

This was gently uphill and with a slightly binding brake.

Issues that I haven't envisaged:

1) My old hardtail has the gears and brake levers integrated... Didn't want new gear selectors, but did want the brake caliper that came with the kits

2) getting the pedal crank arm off to fit the pedal assist sensor.. the kit came with a tool that is made of cheese and ruined the threads of both the crank arm and tool .. no problems, I'd angle grind off the pedal arm and take off the pedal arm from another bike using a replacement tool. Nope, exactly the same ... Threads chewed up..

Anyway, nothing against the kit... Just my inability with bikes ... Cars I can do no problems, working on bikes just always go wrong for me

Need to get the pedal assist working then I'll be over the moon with it!

[tommobot]

Got the pedal assist working, angle grinded off the pedal and angle gridned off the crank off any even older bike. Problem solved.

Seems to be able to do a pretty solid 20mph everywhere which is more than I expected.

This is without even charging the battery, this is still with the charge from whatever the battery came with when delivered.

Maybe / hopefully a bit more power comes forth with a fresh full charge but we'll see....

[tommobot]

Nope, just angle grinded existing pedal arm and left the central crank element in place...

On spare / older bike completely grinded off the pedal arm and crank and just smashed out remains of crank from the pedal arm in a vice..

Then pedal arm back on the new ebike..

Got busy with the angle grinder and just grinded off the brake levels and remained the gear selectors in place, bit bodgey but everything filed down nice and smooth.

Ultimately, form over function with the bike... Not at all fussed how it looks as long as it gets me to work and back....

[tommobot]

First commute on the E-bike today... Took pretty much 15mins off my usual time on my old crappy road bike.

Flat speed was about the same but on the hills the new bike destroyed it.

Probably going to get moaned at here, but is there a way to change the settings on these basic controllers to continue the assitance at higher speeds as it seems to cut out at 30kmph which is a bit frustrating..

[tommobot]

Excellent, thanks for the spot and generally thanks for the help everyone! Been amazingly helpful...

I've upped the top speed slightly, will be interesting to see what its like on the return leg...