• Howdy! we're looking for donations to finish custom knowledgebase software for this forum. Please see our Funding drive thread

Wheel building help [first time building]


1 µW
Apr 17, 2022
I bought an abandoned e bike project and now I need some advice how I should go on building this bike.
Worth mentioning is that my bike knowledge is very limited, but I have access to a nice work shop where I can manufacture whatever I need basically

I want to build a mid-drive e bike with both PAS and thumb/twist throttle that can handle speed up to 40[edited so no ones feeling is hurt) kmh

The parts I have :
Qulbix 76 frame
Nucular 12f controller
LMX motor
Usd dnm suspension front and rear
19" moto rear wheel
26" front bicycle wheel
And some less important parts..

I´m in the process of designing a rear hub where I can fit a freehub on one side and and a go kart sprocket on the other side. This is where I need suggestion on how to do things.
Should the spokeholes be parallel or offset to each other?
How thick do I need to make the flanges, and does the diameter on the flanges play a roll here except determine spoke lenght?

Or is there a rear wheel strong enough off shelf that I could buy and modify to fit a go kart sprocket?

Heres some pics of the moto wheel I have and the hub that is in work in progress :


  • IMG_20230402_162007.png
    544.3 KB · Views: 4
  • IMG_20230402_162024.jpg
    137.3 KB · Views: 4
  • rear hub v1.png
    rear hub v1.png
    118.1 KB · Views: 4
Last edited:
Your pedals won't do anything worthwhile for you. That bike configuration is too heavy, wide, unergonomic and draggy to be effectively propelled by pedals. At 50 km/h, pedaling increases drag by a larger amount than whatever power you're likely to generate at the pedals. It doesn't help.

Please don't pretend your unregulated homemade motorcycle is a bicycle just because you put pedals on it. It's not, and it does a disservice to people who ride actual electric bicycles when you perpetuate this nonsense.

Ouh okay a bit grumpy today huh? :LOL:
Qulbix themself sell pedal option with their 140 model wich is even bigger then the 76.

Anyway lets say pedals is up to 25kmh and whenever I want to go faster I have the throttle option.
Call it a motorcycle if it makes you feel any better.
Thanks for stopping by!
No reason to make a hub from scratch. The 6 bolt disk brake flange is plenty strong enough for a gokart sprocket. You can buy or make adapters to do this. I have managed to fit 219 kart chain sprockets and a disk brake caliper on an 135mm wide hub. Its tricky and brake caliper choices are limited but you can do it. With the 150mm hub width on your qulbix it should be easy to fit.
A couple examples to think about.
The 6 bolts holding the disc in place on my 450 pound 990 KTM with a 130 mph top speed are 6mm.
Disc is 230mm diameter with a bolt circle of 120mm.

6 bolts on a bicycle disc are 5mm.
Same for a SurRon or Segway 260.
Bolt circle is much smaller and so is the disc when compared to the 100 hp gas powered motorcycle.

DanGT86 is correct ... No reason to make a hub from scratch.
Hedge your bets, use top quality bolts.
Appreciate the suggestions!
So i`m re-thinking my build. Found these wheelsets that are in my price range. I tried searching for 32h spokes version but can´t seem to find anything in the 3-500€ price range for a set.

Anything specific I should look out for?

Same wheel just shimano vs sram