I spoke to Chris And a few others at Stretton, and said I fancy building the GN Thunderbug. I’ve got the garage empty now and the first job will be to construct a building table, about 600 high. Then I can layout chassis etc...
I’ve acquired some 17mm kart spindles, and I think they will fit the design well.
I fancy a rack and pinion ( see other thread!!)
I’ve also picked up some bike engine bits in order to build a realistic looking v twin.
It will add weight but it is necessary.
What approx. Diameter is the final drive sprocket on the rear axle.

72 teeth on 0.5 inch chain is approx 11.5 inches in diameter
(72*0.5/3.14)

Gemini Karts Rushden, good products VERY fair  pricing, and they support the hobby.

Right guys..some 17” wheels arrived today. How do I get the bearings out to replace with 17mm ID bearings?

Thanks Stephan. Yes, that inner tube gets in the way, there’s not much of an edge to get the drift on!

TBH, I have never had too much trouble. As you are not going to re use the bearing who cares how much you damage it. I use a steel , sharp edged punch, first hit is to move the "crush tube across one way so you get a an edge on the inner of the bearing. Don't worry about getting to the outer race.
Once it has started moving, even a tiny bit, I just go from side to side giving the bearing a reasonably hard hit with a reasonable size hammer. Small hits with small hammer is more likely to cause damage.

Next issue...TAV modifications.   Engine and TAV have arrived and preliminary tinkering suggest a 10. o clock setting. This needs removal of some webs.
I know this has been done but are we OK with the process?

Ok I’ll check that out tomorrow. I see some karts use 4o clock. I’d rather not remove the webs.