Latest project hardtail, 20" wheels, fat tyres

[littleskull99]

Hi folks,

Here is my latest build, nearly complete. My first ebike was a 26" mtb with a 1kw rr hub, 6 fet controller and 44v of old lipos. It was fast enough (around 30mph) and comfortable enough but the acceleration was very poor. My second ebike was a bmx with a 1kw rr hub, 12 fet controller and 74v of slightly better lipos. Went around 40mph but has very poor brakes and a harsh ride. Also bmx's tend to have no frame space for battery so ran it in a backpack. With the new bike i wanted the best of both worlds so tried to build a bike that ticked all the boxes.
Spec below-
dmr trailstar frame
20" wheels
3" fat tyres
shimano hydraulic brakes and large rotors
marzocchi four cross forks
18 fet controller
74v 10ah lipos
1kw hub

frame


Had to get the front wheel built as no-one makes a 20" with diskhub and 20mm bolt through axle.


Pretty much finished minus paint and CA.


Dash/top plate. The two sets of deans are just switches so i can properly turn it off without unplugging lipos inside the box. One on negative line and one on positive. The rest is precharge, temp and volts untill i can afford a CA.


Sorry for the craptastic photos. This bike was a really fun build. The 20" wheels are defo the way to go for acceleration.

Thanks for looking.
Matt.

 

[k90211lee]

I like fat bike, it look cool! Good job!

I'm thinking of making battery box inside the triangle frame as well. Noob questions, What's material do you use? Aluminum? how thick? You just mount with 3 screws only? No welding at all? Thanks!

Kav

 

[littleskull99]

I found some 100mm wide aluminium plate with right angle bends. I had a local frame builder braze some threads (like water bottle threads) on the inside of the tubes. Drilled the alu so the inner box is rigid. The side plates bear no load and just for finish. Here is a pic, hopefully clearer than my explanation..

 

[Modbikemax]

Are those motorcycle rims and tyres?

 

[littleskull99]

Modbikemax the tyres are 20" x 3" I got them from missioncycles.co.uk, the wheels are bmx wheels.

Matt.