Advice on new e-MTB build (40mph)

Hi all

I am looking to build a new e-bike. I am based in the UK and have a budget of around £1500, just for the electrical stuff.

I was thinking of a 29", hardtail mountain bike with a rear hub brushless motor (1500-3000watt?), a triangular battery pack (72v/20ah?) and an appropriate controller.

The easier it is to install everything the better as I am a newbie.

Thanks

. If your roads are well maintained a hardtail would likely be fine at 40 mph. If parts of your route are bumpy or otherwise lacking upkeep a soft tail would be a better ride. Im using a hard tail at 40k also own a soft tail that eats up the bumps curbs sticks or anything else thats run over.

Yeah, if you hit a tall enough manhole cover with a hardtail, running 40 mph on just the front wheel is quite a thrill. if you run that fast, knowing every bump on your route is paramount important. Ideally, you do this on a serious full suspension bike, the kind that cost more than your whole budget for just the bike. But a hardtail for now will work ok if you just ride with some sense.


But generally, you will typically cruise closer to 35 mph, which for some reason is a lot less sketchy. As you ride, your volts drop, and you might have less than 40 mph top speed by then.

72v, with a 40 amps controller is the basic requirement for the 40 mph club, with most typical hub motors. Don't get too tempted by more amps, because then your battery needs to get better, costing you an arm and a leg.

Just to handle 40 amps requires pretty good cells, (18650 type anyway) so no way you can choose old recycled laptop cells for a fast bike.

FWIW, the budget gets a lot cheaper if you aim for 30 mph. then you only need a cheapo 48v 1000w kit, (48v with 40 amps controller) A cheap 500w motor, but you are giving it 2000w. This is still a very fun ride!, but much less cost for the battery.