# Converting a mountain bike into an e-bike, worth it?



## dude7691 (2 Dec 2019)

Hi guys,

So I've got a Carrera Vengeance 29" mountain bike and I'm wondering if it's possible to convert it into an e-bike, probably with a 250W motor on it. I'm 55kg. I am used to riding a road bike, and can comfortably do 60 miles on it but every time I get to work on it I'm drenched in sweat. I'm selling my car soon, to go full cyclist but I'm thinking it might be a good idea to fit an electric motor to my MTB in order to fill the gaps where I'm not feeling so good, had a really long shift or I've injured my leg. Is this possible and what price range am I looking at? Has anyone done this themselves? Thank you


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## Phil Fouracre (2 Dec 2019)

Cyclotricity - everything on their website


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## dude7691 (2 Dec 2019)

Phil Fouracre said:


> Cyclotricity - everything on their website


Thank you for this  Would 36V/7aH be enough for a 20 mile commute thereabouts? Also with these rack batteries can you just take them out when you get to work and charge them up at the wall?


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## Pale Rider (2 Dec 2019)

Lots of things have an impact on battery range, including type of bike, hills, headwinds, amount of assistance demanded by the rider, and weight of the rider.

Put shortly, 7ah could be tight for 20 miles.


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## Cycleops (3 Dec 2019)

Plenty of bids on YouTube showing how to do it. Simplist and cheapest would be a wheel conversion. Anything from £350 up including battery.


View: https://youtu.be/YtF_16RA2Jo


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## dude7691 (3 Dec 2019)

Pale Rider said:


> Lots of things have an impact on battery range, including type of bike, hills, headwinds, amount of assistance demanded by the rider, and weight of the rider.
> 
> Put shortly, 7ah could be tight for 20 miles.


Thank you, I'll probably go for 9ah or somewhere around there then just to give me a bit more flexibility if there's particularly strong headwinds which do happen around where I live. I'm only 52kg (weighed today) so I'm guessing I'd be alright, pretty strong cyclist as it is.


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## dude7691 (3 Dec 2019)

Cycleops said:


> Plenty of bids on YouTube showing how to do it. Simplist and cheapest would be a wheel conversion. Anything from £350 up including battery.
> 
> 
> View: https://youtu.be/YtF_16RA2Jo



Thanks for this  Will keep doing more research, selling my car in about 2 weeks so plenty of time to get myself acquainted with all the details.


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## keithmac (3 Dec 2019)

I did my Carrera Vengeance Ultimate after it retired as the work steed.

TSDZ2 mid drive with a 36v 15ah battery and a Nuvinci rear hub.

It's quite pokey but I haven't put massive miles on it, more of a project.

Put stupidly big disk brakes on it last time I worked on it.


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## Pale Rider (4 Dec 2019)

keithmac said:


> Put stupidly big disk brakes on it last time I worked on it.



Fair bit of weight/momentum with an ebike so a big disc on the front is far from stupid.


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## Pale Rider (4 Dec 2019)

dude7691 said:


> Thank you, I'll probably go for 9ah or somewhere around there then just to give me a bit more flexibility if there's particularly strong headwinds which do happen around where I live. I'm only 52kg (weighed today) so I'm guessing I'd be alright, pretty strong cyclist as it is.



You weigh about as much as my left leg so you will get decent mileage out of a battery.

The other point to bear in mind is battery capacity decreases with age.

Handy to have more than you need when new which means you will still have enough a few years later.


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## CXRAndy (4 Dec 2019)

Pale Rider said:


> Fair bit of weight/momentum with an ebike so a big disc on the front is far from stupid.



Conversion ebike weigh around 16lb more than non ebike. Not much of a weight penalty. Acceleration is not overly rapid wth standard setups. I agree disc brakes is better reliable option for various weather conditions.


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## Pale Rider (4 Dec 2019)

Plenty of brake is required to control an ebike on a sharp descent.

A standard hydraulic disc will do the job, but there's no harm in having the next size up on the front.


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## keithmac (4 Dec 2019)

I'm sure my front and back ended up at 220mm?, will have a look next time it's out.

New Shimano calipers front and back as well.

Need to put some miles on it really but there's aways something else to do!.

I'm sure I bought the Nuvinci hubbed wheel from an add on here, was a long while back though..


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## Phil Fouracre (5 Dec 2019)

dude7691 said:


> Thank you for this  Would 36V/7aH be enough for a 20 mile commute thereabouts? Also with these rack batteries can you just take them out when you get to work and charge them up at the wall?


As has been said, perhaps go for higher capacity just ‘to be sure’! We’ve got two touring bikes with rack batteries, and, two mtbs with frame batteries. All are lockable and removable, although it’s quicker to just plug in if possible.


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## DBrown67 (10 Dec 2019)

I did exactly this 2 years ago. I bought a 700c kit from Whoosh in Southend and fitted it to a brand new Cube Aim Race MTB. The kit was around £600 but that included everything with the largest capacity battery available. The battery alone was half the cost of the kit.

Of course you can save by buying from China direct but if anything goes wrong or you need warranty support you may as well piss in the wind.

The motor came in a ready made wheel with 8 speed cassette so I made sure to buy a bike with 8 speed cassette. That way I hardly had to mess with indexing etc. It was plug and play just about.

I get around 45 miles from a full charge using level 4 assist (out of 5) so that's pretty decent. Don't skimp on the battery. And by using a kit you get round that crappy 15mph max limit on the assistance. Mine is set at 20. Oh and the kit has a trigger that you can't get on UK stock e-bikes. The trigger is brilliant for just pushing you on through junctions at full power if the lights just change as you're on them. Using the trigger full time eats the battery life though, it's not really for that purpose.


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## JohnE (24 Dec 2019)

I have just done a conversion on my old Marin Rocksprings MTB which was being rarely used. I fitted a TSDZ2 48v motor from Whoosh with a 48v 17ah battery. It was a bit of a challenge to fit on a full suspension MTB - I had to fit the battery on the bottom of the downtube, and had to improvise the fitting of the bridge plate. Mine is pedal assist only, no throttle, so I still get a work out. I have done 3 short rides so far amounting to 47 miles and nearly 2000 feet of climbing, and still have 5 of the 6 bars on the battery still remaining, so am expecting to get over 100 miles from a full charge. This may be optimistic as I'm still experimenting with the power assist level.





It's great fun. I now use it more than my road bike ! It's a lot heavier than the road bike (I think the disk brakes are essential) but it's faster !!


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## confusedcyclist (24 Dec 2019)

@JohnE Well, it's certainly something to behold. Nice job getting it all to work on such an awkward frame! Are those velcrostraps? Other than gravity, what's stopping the battery orienting around the down tube and whacking you in the knee/shins? Also, no fouling of the battery on the front wheel/guards during rough stuff?


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## JohnE (24 Dec 2019)

Yes they are velcro straps. However there are 4 rivnuts holding the battery mounting plate securely in place. Feels rock solid to me. The velcro straps are just overkill really as I wasn't sure how much weight the rivnuts would take. The battery is a bit of a beast. Didn't want it dropping off as I went over the first pothole. 
No fouling on the front wheel ... yet. I've bounced on the forks several times and haven't managed any fouling. But, I'm an old git pensioner and don't do real rough stuff any more ... my off road these days is generally down converted railway tracks on relatively smooth surfaces. Also the front forks are adjusted so there's minimal travel. The mudguard is plastic with a bit of give in it. Hopefully fouling won't be an issue.


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## confusedcyclist (24 Dec 2019)

Sounds like you've thought this through


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## Phil Fouracre (25 Dec 2019)

And by using a kit you get round that crappy 15mph max limit on the assistance. Mine is set at 20. Oh and the kit has a trigger that you can't get on UK stock e-bikes. 

Agree about the trigger kits! Are you sure about the ‘crappy limit’? However you do it, if you exceed the 15.5 mph assist ‘tis illegal🙈


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## Wyn Davies (1 Feb 2020)

dude7691 said:


> Thank you, I'll probably go for 9ah or somewhere around there then just to give me a bit more flexibility if there's particularly strong headwinds which do happen around where I live. I'm only 52kg (weighed today) so I'm guessing I'd be alright, pretty strong cyclist as it is.


My ebike has three modes Eco sport and Power it's claimed 205kl in Eco how do you culcalate what sport mode will do


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## CXRAndy (2 Feb 2020)

Wyn Davies said:


> My ebike has three modes Eco sport and Power it's claimed 205kl in Eco how do you culcalate what sport mode will do


Best way, start fully charged, ride it hard in sports mode till it stops.


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## Wyn Davies (2 Feb 2020)

CXRAndy said:


> Best way, start fully charged, ride it hard in sports mode till it stops.


Brilliant why didn't I think of that .


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## samsbike (9 Jun 2020)

this is interesting, as I want my mtb to be able to be used as a mtb and contacted Whoosh. 

My understanding of their response was that it would not be worth the conversion (to use as a proper mtb) as the rear hub motor, would impact handling, and the mid mount may impact clearance.

Also would need a much better battery solution as the frame is not designed to have that weight thrown around.


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## CXRAndy (9 Jun 2020)

samsbike said:


> this is interesting, as I want my mtb to be able to be used as a mtb and contacted Whoosh.
> 
> My understanding of their response was that it would not be worth the conversion (to use as a proper mtb) as the rear hub motor, would impact handling, and the mid mount may impact clearance.
> 
> Also would need a much better battery solution as the frame is not designed to have that weight thrown around.



If I was going to convert a MTB to an Ebike. I would use a steel frame bike, weld brackets to hold battery more securely. 

I would use a Bafang BBSHD 1000W motor.

I do have a hard tail Kona Honzo donor, one day I'll convert.


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