Add electric kit to MTB?

[HisBart20]

Hey all
New to this forum & apols if this has already been answered elsewhere -
Time for my young son & I to update our MTBs. I was looking at rugged electric bikes for us, but the $$$s are mucho....bigger than I expected.
So now I'm thinking is it possible to DIY - get a couple of good quality hardtails and have small electric motors retro-fitted.
If that's viable, who does this kind of work?
Appreciate your input.
Best

[10speedsemiracer]

Is important to determine what you mean by DIY..

If you're comfortable in fitting say, a Bafang mid-drive kit, then yes it may be more viable from a $s perspective but the overall end result may not feel as integrated as an OEM eMTB, and the $s differential may not be as big as you would think.

If, however, you're looking at bringing together a new hardtail plus an eBike retrofit kit and then paying an LBS to fit that for you, I think you'll find that purchasing a ready-made eMTB probably makes more sense.

The maths.
A Bafang mid-drive 36v 250w kit is $700-$800 depending on where/how purchased
Add a battery, and decent 36v Panasonic/Samsung/Sony battery packs start at $500 for 13ah and up.
Add $1900 for a Giant Fathom 29er (Shimano Deore, discs)
Add $200+ for an LBS to fit the kit, for a total of (approximately) $3300-3400
plus whatever mods you need to make to the donor bike to cope with the motor/weight, such as uprated tyres

versus

A Giant Talon3 e+ 29er starting at $3k. (Yamaha 36v 250w, Shimano 9sp, discs)

So $3.3k as a retrofit vs $3k for a factory-built. Yes there are some differences in spec between the two bikes, but is still a fair comparison imo.
Other considerations. Warranty, support, retained value. All of which fall in favour of the OEM eMTB. The Giant eMTB I've mentioned above is an example only, others are available.

Yes there are cheaper kits available from other Brands, with mixed reports regarding performance, durability and fit. Bafang are very popular in the retrofit market.

[redsonic]

Good reply above, but I will just mention that a retrofitted kit can be later removed and you have a normal bike to ride. An integrated MTB may have factory specific motor and battery interface that may not be supported well into the future. In other words, if you need a replacement battery in the future, are you going to be able to get one that fits into the downtube?

[10speedsemiracer]

RedSonic raises a very good point, something I'd glossed over under the term 'support'.

Replacement controllers, battery packs, or small parts like brake cut-off switches may be difficult to source for an aftermarket kit, if at all.

Various eBike forums contain varying numbers of posts and threads of people trying to adapt different controllers etc to existing kits or superseded bikes.

Better (imo) to buy from an acknowledged big-name/established brand which uses one of the known motors/components such as Bosch, Brose, Yamaha, Panasonic, Shimano, Bafang etc. That way, parts should be more readily available.

The other side of eBike ownership, and one which a lot of prospective owners aren't ready for, is the often shortened lifespans of driveline components such as chain, cassette and chainring.

[bychosis]

Do you want to ride off road? Ie use your mountain bikes for mountain biking? If so, a cheap conversion is going to compromise handling, especially a hub motor which will add significant weight in to the wheel - which is he worst spot to add weight when off road.

If it’s just for commuting or in road trips then a hub drive will be cheaper to DIY.