Advice on bbshd kit needed please

[Sparks71]

Hi all,
My name is Jay and this is my 1st post on here.
I’m in a bit of a dilemma at the moment,I’m looking to have a go at building my 1st ebike and have decided on the bafang bbshd kit.
My problem is this...I have a carbon road bike I would like to fit it to but I’m unsure wether it’s possible to fit the motor to a carbon frame without causing damage to it, has anyone else done this or does anyone know if it’s possible.
It will be used as a light weight commuter for a 9 mile each way trip.
Would it be easier to sell the bike and buy a alloy mtb 29er to do the build on.
Thanks in advance for your help.
Could anybody recommend a uk supplier of these kits too.
Thanks Jay.

 

[Deus]

Hi Jay welcome you would be much better off with a hub motor for commuting unless you have major hills on your commute.

 

[vfr400]

Carbon frames are generally not suitable for conversion. You don't need a carbon frame when you fit a heavy electric kit with loads of power. Find yourself an aluminium MTB, which will be much more suitable and more comfortable.

You have two main problems when trying to fit a BBSHD to a carbon frame. Firstly, you only have 6mm clearance around the BB to slide the motor in. carbon frames are much thicker than aluminium tube, so are likely to be too thick. Secondly, carbon frames normally have press fit bottom brackets, so the BBSHD shaft doesn't fit. you can take out your BB bearings and replace with adapters, but then you have to find a way to stop the motor rotating around the BB. you can't use the standard clamping method on carbon fibre, so you have to fabricate a suitable torque arm and find an anchor point for it.

Anything can be done if you have the will, wallet and know-how. What I'm saying is that a BBSHD on your bike is unlikely to be plug and play unless you have a thin BB.

 

[Fat Rat]

Hi
I cant add to the above advice as its all good
So welcome to the site and enjoy your build which ever way you go .

 

[vfr400]

I just want to add a bit more to this because we get quite a lot of posts from guys that ask about electrifying their carbon-framed bikes.

It takes approximately 1% less effort to pedal a bicycle up any incline for each 1kg of mass/weight you can save, so it will take about 2% less pedal effort to pedal an 8kg carbon fibre road bike up a hill compared with a 10kg aluminium one. That's a noticeable saving. Also each 1kg of mass saved means that you can accelerate approx 1% faster.

A regular keen cyclist averages something like 200W. An average 250w electric bike outputs around 360w max when climbing a steep hill. That's an increase of 180% or 90 times the improvement you get compared with the weight difference between a high spec carbon fibre road bike and a good aluminium one.

If we want to go up to a 52v BBSHD that can sustain 1000W output power, it's 250 times the advantage compared with the weight saving of carbon fibre. Basically, your super light high spec road bike becomes completely irrelevant.

The best advice is therefore to keep your high spec road bike for exercise, and if you want an electric bike for transport, the weight and specification of the donor bike makes very little difference, so you might as well get one that has other characteristics that give you real advantages to your project, like robustness, durability, convenience and comfort.

Light weight always makes an electric bike ride better than a heavy one, so there's still a case for making or procuring a light electric bike, but that means a light motor and battery. There's still little point in taking a light weight frame and adding a heavy motor and battery.

 

[Sparks71]

Thanks for all the helpful replies, much appreciated.
The reason I was asking about a build on a carbon framed bike is because I have a brand new bike I bought but haven't got around to using as when i do get out i either use my full suss mtb or my other giant carbon road bike.
To be fair i bought this new bike on a bit of a whim and I'm in the process of trying to sell it.
Rather than take a big ££ hit on the bike i wondered if i could use it as the base for my build hence this post.
From looking at the responses i have recieved it would seem to back up what i already thought...I'd be better off getting a 29er hardtail mtb to use and selling the road bike ,( even though I'll lose money on it).
It's a shame my canyon mtb only has a small triangle or I'd have used that and had a top quality full suss ebike.
Can anyone recommend a decent hardtail that i could use for a straight forward easy build?
Thanks again Jay.

 

[Sparks71]

Thanks for all the helpful replies, much appreciated.
The reason I was asking about a build on a carbon framed bike is because I have a brand new bike I bought but haven't got around to using as when i do get out i either use my full suss mtb or my other giant carbon road bike.
To be fair i bought this new bike on a bit of a whim and I'm in the process of trying to sell it.
Rather than take a big ££ hit on the bike i wondered if i could use it as the base for my build hence this post.
From looking at the responses i have recieved it would seem to back up what i already thought...I'd be better off getting a 29er hardtail mtb to use and selling the road bike ,( even though I'll lose money on it).
It's a shame my canyon mtb only has a small triangle or I'd have used that and had a top quality full suss ebike.
Can anyone recommend a decent hardtail that i could use for a straight forward easy build?
Thanks again Jay.

So is it possible then to put a rear hub motor (700c) in the carbon frame?
Am I right in thinking they have alloy in the frame where the wheels and rear mech hanger fasten too?
Could anybody recommend a decent hub wheel and battery combination that would be suitable for the build.
It would be great if I could use the bike I have and make a fast commuter bike, my requirements would be something that could happily travel between 25 to 30 mph with my pedal input and a range of 30 plus miles.
Many thanks Jay.

 

[vfr400]

Different frames have different arrangements. Only you can tell us how yours is.

 

[Nealh]

You have to take close up pics of the rear stays /drop outs for us to see.
Also if you axle is maxle/thru axle then you can't do any thing.