DIY electric mountain bike

DIY electric mountain bike

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tommobot

Original Poster:

674 posts

214 months

Thursday 23rd March 2023
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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!

Mammasaid

4,265 posts

104 months

Thursday 23rd March 2023
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I converted my MTB three years ago with a front drive kit. It was the easiest to do and worked out fine.

I would say that the mid-mounted kits are the best but cost the most, you pays your money etc.

I'd also say get the largest battery you can, I've found now that I have it, I go out on the bike for longer compared to before.


ARHarh

4,245 posts

114 months

Thursday 23rd March 2023
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I built mine from a cheap Chinese kit 2 years ago. Rear hub 1000w jobby. Now covered 5.5k miles on it. Built on a 2009 SPECIALIZED ROCKHOPPER.

Things I learnt quickly.

The wires were not thick enough to cope with the current involved, therefore I suffered some breakdowns till I upgraded the cable.
The build quality of the wheel was shocking and all the spokes needed tightening.
The freewheel cassette was made of chocolate and lasted about 1000 miles.
The wiring really needed a lot of work to make it reliable, so if you are confident with wiring you will be OK. Things like fuses and plugs not being rated for the current drawn..
you may need different brake switches to those supplied if you have hydraulic discs.

Things I have suffered from in use over those miles, I ride up some very steep hills so it does get used hard.

It is shockingly heavy.
The gearing was all wrong so needed changing.
The brakes needed upgrading as the weight was too much for the original ones.
My controller blew a few weeks ago not sure why but that was a long ride home that day.

Stuff I would do differently if starting again today.

I would go for a mid mount motor, they cost more but will give more flexibility.

But most of all it has allowed me to cycle where I live. I live on the north Wales border and have always cycled a bit for pleasure, but mostly in the flat lands of Hampshire. When we moved here the hills were just to much for me and I stopped cycling. Being nearly 60 the hills were too much for me. Now weather permitting I cover 20 miles a day during the week. Which may not be as much exercise as I could get on a normal bike, but if it didn't have a motor it would still be sitting in the shed unused. I still pedal all those 20 miles and it wont do the 25% inclines without a lot of help from me.

Do it but go in with your eyes wide open.

tommobot

Original Poster:

674 posts

214 months

Thursday 23rd March 2023
quotequote all
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 biggrin

ARHarh

4,245 posts

114 months

Thursday 23rd March 2023
quotequote all
tommobot said:
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 biggrin
You are correct with the motor descriptions.

With a hub motor they will not have the power to wheelspin unless you really try. Or you are on a loose surface.

Not tried a front hub motor but it will probably affect the steering in some way. If you set off normally the motor will have to shift a lot of weight and in reality will build up speed gradually. I start off with a quick bit of throttle and then the peddling takes over.

Remember about the legalities of these bikes, no throttle, less than 250w and no more than 15 mph. If you are caught breaking these rules / laws you can end up getting points on your licence. But ride sensibly and no one will care.

Whichever wheel you power will result in difficult to repair puncture as the wiring gets in the way. I have a junction box near my wheel so i can disconnect it easily.

Here I am teaching the local cows how to fix a puncture.



cml24

1,444 posts

154 months

Thursday 23rd March 2023
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I've just built this using a hardtail I had already.

Bafang 250w mid drive. Only road legal option. Powerful enough for me, great on the hills, especially when towing my daughter.

All kit bought from a real UK shop for peace of mind and quick delivery. Only a 10Ah battery pack. I get 30 or 40 miles offroad use.



The same shop has got some short cables in stock now, so I plan to replace the coiled up wires with a straight run to tidy it up.

Edited by cml24 on Thursday 23 March 15:02

Senex

3,077 posts

183 months

Thursday 23rd March 2023
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I fitted a legal 250w rear wheel hub kit to my bike.

It was pretty straightforward but you do need some basic bike tools and working-on-bike skills.

I got my kit from Woosh Bikes in Southend, good quality kit and very good advice and customer service.

Some things I learned:

You do not need brake cut-outs if you do not have a "throttle". Woosh give a discount if you do not order these parts.

The left-hand pedal sensor is the easiest option pedal sensor but you need a bit of space between the left crank and the bottom bracket, if you do not have that then you can either fit a longer bottom bracket or opt for the right-hand pedal sensor.

The rear wheel axle has four washers, the two plain washers need to go inside the drop-outs and the two anti-rotation washers need to go outside the drop-outs.

It takes a bit of thinking on how to to tidy up the cables.

I had to add a Rivnut to my frame to fit the battery. RJ The Bike Guy on Youtube shows you how to do that, if you don't fancy tdrilling holes in your frame you can always buy a Hailong Battery Mounting Bracket from eBay.

Concerning rear wheel puncture contingency, it is possible to buy inner tubes that can fitted without removing the rear wheel. The brand name is Gaadi.




Edited by Senex on Thursday 23 March 15:23


Edited by Senex on Thursday 23 March 15:30

Gareth79

8,017 posts

253 months

Thursday 23rd March 2023
quotequote all
cml24 said:
I've just built this using a hardtail I had already.

Bafang 250w mid drive. Only road legal option. Powerful enough for me, great on the hills, especially when towing my daughter.
I've heard good things about the Bafang mid-drive system, if I was doing a conversion I'd definitely use it. Apparently there is a gear which can get chewed up and people replaced with steel, but they might have solved that now?



tommobot

Original Poster:

674 posts

214 months

Thursday 23rd March 2023
quotequote all
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..

Senex

3,077 posts

183 months

Thursday 23rd March 2023
quotequote all
tommobot said:
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..
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!

ruwokeenuff

409 posts

20 months

Thursday 23rd March 2023
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swytch are relaunching soon

Fundoreen

4,180 posts

90 months

Thursday 23rd March 2023
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If you live in london they are not allowed on TFL. You see them though as the staff must be too thick to figure out the difference.
I guess if one catches fire a whole tube line could be out of action. Hope they bill the owner for the losses.

colin_p

4,503 posts

219 months

Thursday 23rd March 2023
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Another here with a Bafang mid drive. Mine is a 750w BBS02b which I obviously only use on the private country estate. I have re-mapped it (yes, you read that right) but not for more speed or power but for torque and increased range. A wonderful piece of kit but cost me about £800 and is installed on a Boardman hybrid.

A major consideration when buying any kit, is the system voltage, 48v is far more preferable than 36v in terms of range.

Hondapower

11 posts

41 months

Thursday 23rd March 2023
quotequote all
I fitted a cyclotricity 250w front hub drive to a Halfords bike about 4 years ago. I must have done 5000 miles since and it's been great. The battery gave up after about 3 years so I bought another and all good since. I commute to work every day and it's often used to tow a kids bike on weekends. Battery gets charged once a week and used on medium power so I still get some exercise.

tommobot

Original Poster:

674 posts

214 months

Thursday 23rd March 2023
quotequote all
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?

Senex

3,077 posts

183 months

Thursday 23rd March 2023
quotequote all
tommobot said:
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?
First of all, you don't actually need a throttle, you turn the pedals and the sensor detects that and power is applied to the motor (and power is shut off when you stop pedalling).

Secondly, I can't a see throttle in the pictures but they are easily available.

I would contact the seller and ask them if I was you, but I still say you're taking a gamble with an ebay kit like that, up to you.

ebikes definitely give you extra ooomph up the hills, you should try and have a go on a demo, I guarantee you'll enjoy it.


defblade

7,607 posts

220 months

Thursday 23rd March 2023
quotequote all
I'm with Senex - I got the complete kit from Whoosh; I'd be a little worried that the ebay kit there might be a case of buy cheap, buy twice.

And I wanted a rear hub kit, as I'm heavy and using panniers as well, so the front might well have got a little light for traction at times if the motor was there.
I've also moved the kit from one bike to another when I decided the original build didn't suit me after all, so there's a plus point in flexibility there for the aftermarket kits.

I have overcome (most, touch wood) rear puncture worries by fitting Marathons with fairly heavy inner tubes and then adding slime as well! Weight is low on the list of concerns when you've got an extra 250w available wink

seyre1972

2,839 posts

150 months

Thursday 23rd March 2023
quotequote all
cml24 said:
I've just built this using a hardtail I had already.

Bafang 250w mid drive. Only road legal option. Powerful enough for me, great on the hills, especially when towing my daughter.

All kit bought from a real UK shop for peace of mind and quick delivery. Only a 10Ah battery pack. I get 30 or 40 miles offroad use.



The same shop has got some short cables in stock now, so I plan to replace the coiled up wires with a straight run to tidy it up.

Edited by cml24 on Thursday 23 March 15:02
Care to share the shop name , or send it via messenger please ?

stargazer30

1,641 posts

173 months

Friday 24th March 2023
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My old converted bike. Yose hub kit, these cost about £380 now all in. The bike is a £300 2nd hand boardman mtx 8.9.

Senex

3,077 posts

183 months

Friday 24th March 2023
quotequote all
seyre1972 said:
Care to share the shop name , or send it via messenger please ?
I too wouldn't mind knowing the shop name.

I bought one of these 1-2 cables from China for $6.



It is 60cm long but I don't really need the throttle connector.

They do a 1-4 cable too but it is 140cm long.

https://www.topbikekit.com/12-extend-cable-ebike-w...