Converting existing bike vs buying new?

[Matt Cooper]

Hi guys, literally only just found out about fast electric bikes when I was looking into getting a moped a few hours ago, anyway I've been reading up on it all since. I don't really need one but they look too cool to pass by (I have always enjoyed cycling). I have a pretty good mountain bike that needs a service, I am thinking of getting either a 1000w or 2000w build, would you advise to fit it (or get it fitted by someone professional) to my existing bike, or to buy a new one with it all already integrated?

My needs are basically a 1000w or 2000w motor with a throttle option. I would buy a kit and do it myself but I'm not sure what the difficulty is like for doing it that way. I also know sites where you can send your bike to them and they will fit it, so that could be an option.

Thanks very much

 

[Trevormonty]

Be careful with fitting high powered drives, standard bikes brakes and tyres are not really design for 30mph+ speeds and heavy weight. A 1000-2000W motor will need a large heavy expebsive battery. In end you maybe better off on legal scooter or small motorbike.

 

[Matt Cooper]

Be careful with fitting high powered drives, standard bikes brakes and tyres are not really design for 30mph+ speeds and heavy weight. A 1000-2000W motor will need a large heavy expebsive battery. In end you maybe better off on legal scooter or small motorbike.

I wasn'taware of this, so thanks for letting me know. Part of the appeal to me of ebikes is the ability to take them anywhere, on road or off road, on trains etc. and also where I currently live I would have to leave a moped or motorbike on the road outside which I wouldn't be comfortable doing.

Are you saying it would be better for me to buy a new bike with a motor already fitted? I know several UK sites that can do this. Or maybe better to consult a local bike mechanic about whether it would be feasible to fit a 2000w motor to my existing bike? It does have disc brakes and I could potentially upgrade the tyres as part of the service I will need to get for it.

 

[Ducknald Don]

Part of the appeal to me of ebikes is the ability to take them anywhere, on road or off road.

You can't take a bike with a 1000W motor on the road, the limit is 250W.

 

[Nealh]

You should really post this in the correct sub forum of 'Speed pedelecs and non Eapc's' .

 

[Deleted member 4366]

Have you any idea ofthe weight of a 2000w bike? Have you looked at the cost too?

Why do you think you need 2000w? There may be better options.

 

[nemesis]

Have a read through this,converting a bike yourself works out cheaper for more power.
https://em3ev.com/hub-motor-info/

 

[Matt Cooper]

Thanks for the replies, yeah I am aware the limit on roads is 15.5mph powered, the bikes I've been looking at have a setting for on road and off road.

The reason I say 2000w is simply because I want to be able to go fast when I can

 

[danielrlee]

The reason I say 2000w is simply because I want to be able to go fast when I can

How fast is "fast"? Or do you mean that you want quick acceleration?

 

[Matt Cooper]

I want decent acceleration and speeds of 30+ mph ideally although I would settle for 30 if more was impractical.

 

[nemesis]

I want decent acceleration and speeds of 30+ mph ideally although I would settle for 30 if more was impractical.

Bafang BBSHD and a high quality battery will do that,i know because that is what i have been running since early this year.
If you do go down this route then you will need high spec brakes and gear system.

 

[tommie]

Bafang BBSHD and a high quality battery will do that,i know because that is what i have been running since early this year.
If you do go down this route then you will need high spec brakes and gear system.

...and i would budget for approx £1k to do this right

 

[Danidl]

I want decent acceleration and speeds of 30+ mph ideally although I would settle for 30 if more was impractical.

That is a death wish. The brakes, the suspension, the wheels of bicycles are not designed for high speed operation. Also the power consumption will be 8 times more at 30 than 15 mph.

 

[nemesis]

 

[danielrlee]

I think that you might be a prime candidate for a DD hub motor build, but you need to get your expectations straight. You're looking at around a £1200+ budget and you can forget 'lightweight'. It'll likely weigh 30kg+ if you want a decent range, possibly closer to 40kg.

What type of riding do you plan to use it for? Road, light gravel paths, off-road, kamikaze downhill?

You mention that you were previously considering a moped. Were you planning that the ebike would serve moped duties?

 

[Matt Cooper]

I'm already prepared to spend up to 2k, I'm not sure what's meant by a high spec gear system but as I say my current bike has disc brakes if that helps.

I would be prepared to buy a pre built electric bike if that would be the best way to go. Ive seen multiple 1500w-2000w models which fall within my budget. And this bike would cover moped duties, would be mainly used on quiet roads tracks and cycle paths

I'm considering talking to a bicycle mechanic about whether my current bike could handle a 2000w motor and if not what upgrades would be needed, could they do them and how much would it cost

 

[Matt Cooper]

I was looking at direct drive vs geared, and I would like to be able to enjoy freewheeling and as long a range as possible before needing to recharge. In fact range is a high priority for me as I would like to be able to go on adventures and know I can rely on the battery to last me until I get near a plug socket

Also I would emphasise that although I want a 2000w motor I certainly don't plan to be at max speeds all the time. I would just really appreciate the extra speed and power if I need it as it seems a waste to spend a grand on something that can only do 15.5mph

 

[tommie]

Ok, just as an example, this was my latest conversion, before and after.


BBSHD conversion, similar to the video above but geared for torque, i`m not interested in `what it will do`
Cost? Around £1k, thats Motor kit, Battery, brake upgrade, tyres, mudguards and all the extras.

If you`re terrain is flat then maybe a hub conversion may suit better and could work out a bit cheaper.

 

[Matt Cooper]

Ok, just as an example, this was my latest conversion, before and after.


BBSHD conversion, similar to the video above but geared for torque, i`m not interested in `what it will do`
Cost? Around £1k, thats Motor kit, Battery, brake upgrade, tyres, mudguards and all the extras.

If you`re terrain is flat then maybe a hub conversion may suit better and could work out a bit cheaper.

So you didn't have to get new tyres or a new gear system to support the added weight and speed capability? Was this a pretty high end bike before the conversion or just an ordinary mountain bike?

 

[tillson]

So you didn't have to get new tyres or a new gear system to support the added weight and speed capability? Was this a pretty high end bike before the conversion or just an ordinary mountain bike?

You need something like the old Honda CUB 90. I’m sure there will be something more modern available and it will do all that you need, 30 mph plus, will have suitable brakes, correct tyres, proper lighting and also have the big plus of being legal to use on the road. If you went down this route, you wouldn’t be putting innocent road users or pedestrians at risk either. It’s an all round win, a no-brainier as they say.