Gtech my ride! - Boardman MTX conversion

stargazer30

Pedelecer
Sep 29, 2020
34
15
Back Story: I already have an eMTB. My daughter has a Gtech City which she loves. Just before xmas I bagged an ebay bargain, Boardman MTX 8.8 hybrid, but every time I go out I just end up using the Ezego as I like the idea of having the electric assist.

I really like the boardman though, nice light, nimble bike, good components. I wanted to do a ebike convo on it but I don't want to add a ton of weight and loads of wiring. I don't need long range on it either. I like the minimal electric footprint and light weight of Gtech's and we already have 2x Gtech batteries. So the "Gtech my ride" plan started to form...

I've managed to source a Gtech controller on ebay and Gtech are sending me the bottom bracket speed sensor so I'm going to attempt a conversion. The 250w/36v 28" hub wheel with a cassette mount was a real pita to source but i finally found one in the UK. Once all the bits arrive its game on. This could end up being a total train crash but hey ho..

Before pic...
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stargazer30

Pedelecer
Sep 29, 2020
34
15
Which motor did you get?
Why does it have to come from UK?
Between COVID and Brexit its hard getting hub motor wheels imported. Most the sites I looked at were either not delivering to the UK, had long delivery times (months) or stupidly high postage costs making it unviable :-(. I've managed to find one now though, Chinese motor still but UK stock.
 

DodgyTicker

Pedelecer
Dec 29, 2020
27
12
I've just converted my MTX 8.8 with a Bafang mid motor, it is brilliant. I did a write up here;


Obviously a bit more involved than what you want to do, but it works very well on the MTX 8.8
 

stargazer30

Pedelecer
Sep 29, 2020
34
15
The Gtech Speed sensor BB arrived today. I tested it on our V1 Gtech City to check it works and its compatible. Once that was done I installed installed it on the boardman. It went smoothly, the only problem was getting the old bottom bracket out, which required a breaker bar and a lot of force!

As you can see in the pic I've used the gear cable guide to help cover the hole the sensor plug routes through, and used a little bit silicone to stop any water getting in. Waiting on the rest of kit so that's it for today.

One potential problem is the front chainrings are about 5-7mm further out on this new BB so I might have chain line problems once its built. Worst case I'll fit a single narrow wide crank and do a 1x convo on it. I won't need the smaller front ring once its electric.

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stargazer30

Pedelecer
Sep 29, 2020
34
15
The motor wheel arrived today. A few hiccups as its my first time building up a wheel. Had to modify my cassette tool to go over the wiring on the electric wheel and getting the tyre onto it required a large vocab of swear words!

Not complaining though as it fitted the bike fine and a bench test of the new wheel and GTECH electrics was all good.
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stargazer30

Pedelecer
Sep 29, 2020
34
15
Chain back on and rear gears setup. As I suspected the front double crank set is no good now, the Gtech BB has pushed it too far out. I can use the smaller ring but the outer has a bad chain line. I have a single crank set on order so will be ditching the front mech and going 1x. Still its good enough for a road test as is.

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Kenlum2000

Just Joined
Oct 24, 2020
3
0
Hi, this conversion looks awesome and is something I'd like to do. Did you photo/video the project at each step?
 

stargazer30

Pedelecer
Sep 29, 2020
34
15
Hi, this conversion looks awesome and is something I'd like to do. Did you photo/video the project at each step?
Hi I did take more pictures. If you send me a PM I can send them to you.

I actually re-did the conversion after a while using a Yose rear wheel hub kit off ebay for £350. In some ways its a better conversion as you don't need to swap out the bottom bracket or mess with the front chain ring, the battery is twice the capacity of the Gtech one and its quicker (can be set road legal at 15mph or will max out at 20mph).

The Gtech kits does have some advantages though. The battery is very light to carry, small and easy to remove if you want to lock the bike up and go shopping. Plus as it has pretty much no wiring its a very neat install.

I attached a pic of the bike with the Yose kit on. The ugly box under the bottle holder was just to hide excess wiring. The controller on the kit is actually built into the battery housing, just like the Gtech kit. I removed that box later and wrapped the excess around the battery base for a cleaner looking install.
 

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Kenlum2000

Just Joined
Oct 24, 2020
3
0
Hi I did take more pictures. If you send me a PM I can send them to you.

I actually re-did the conversion after a while using a Yose rear wheel hub kit off ebay for £350. In some ways its a better conversion as you don't need to swap out the bottom bracket or mess with the front chain ring, the battery is twice the capacity of the Gtech one and its quicker (can be set road legal at 15mph or will max out at 20mph).

The Gtech kits does have some advantages though. The battery is very light to carry, small and easy to remove if you want to lock the bike up and go shopping. Plus as it has pretty much no wiring its a very neat install.

I attached a pic of the bike with the Yose kit on. The ugly box under the bottle holder was just to hide excess wiring. The controller on the kit is actually built into the battery housing, just like the Gtech kit. I removed that box later and wrapped the excess around the battery base for a cleaner looking install.
 

Kenlum2000

Just Joined
Oct 24, 2020
3
0
even with the box that looks tidy.

My main concern is what axle standards the rear hubs can be adapted to. I'm looking to build an electric enduro and modern frames use thru axles e.g. 12/42. That would require being able to source a suitable adaptor. Is the Boardman a standard QR?
 

stargazer30

Pedelecer
Sep 29, 2020
34
15
My main concern is what axle standards the rear hubs can be adapted to. I'm looking to build an electric enduro and modern frames use thru axles e.g. 12/42. That would require being able to source a suitable adaptor. Is the Boardman a standard QR?
All the rear wheel hub kits I've seen are for QR/skewer style axels. My Boardman MTX was QR too. If the bike is using a through axel you'll have probs. TBH though for an enduro bike that's more mid drive territory anyways as you'll need lots of torque at low cadence. I'd be looking at the Bafang Mid drive kits.
 

Coddi

Just Joined
Apr 10, 2022
1
0
Looking to convert my boardman mtx 8.8 2021
Wanted to reach out hoping some suggestions and ideas for installing an ekit
So any thoughts and links welcome
Looking for a lightweight system that would be road and canal town towpath friendly
Aim to achieve range not speed. Torque and preferably rack n panniers
I appreciate there are weight trade offs but my concern is loading a rack and battery up onto theback wheels whether its too much
Want it stealthy and not looking like a diy cable tie effort as its a great looking bike..I feel
Road legal preferred to avoid the b*llache...
Cheers all any input welcome and happy Easter
Dave