It’s about time I started again on the Cub prep. I’d appreciate your opinions on the following

2nd gear 26/19 - is it worth the effort and expense?

PVL or HPI - the only experience I’ve had with PVLs is to understand they are pretty basic with little advance.

thanks in anticipation

 

Lower 2nd gear is most definitely worth the effort - it is much more useable in sections!

I have used electrex world on all my cubs - fit and forget

Thanks for that. I’ll look to go for the 2nd gear mod then

Looking at the gearbox I have here, It looks like I’ll have to remove the small ‘end gear’ which looks like it’s pressed on to get to the new pinion. Any idea how I can do this? Is there a special tool or will I need to make one? It’s currenty 17t so will need changing anyway.

Also it’s been a while since I’ve had a Cub engine apart. Is it possible to remove the sprocket attached to the sleeved high gear and take the gearbox out or is it a complete crankcases apart job? I ask as the gearbox in the engine, which my late father built, has a std gearbox fitted

thanks

If your engine does not have the removable plate behind the clutch I think you have to split the engine I also use Electrex world ignition on both my engines and had not bother The gear on the lay shift is secured by two half moon clips I could not refit mine and it seems to run ok after two years running 

It is a very good idea to fit the access plate - well worth the effort since the final drive sprocket lasts 2 seasons if you are lucky with all the gunge that gets dragged around! It is then just a matter of taking the clutch off to replace it..... Note you need to mill the access plate surface area flat since the crankcase casting behind the clutch is not guaranteed to be parallel to the crankcase centre line.

Regarding the lower second gear.... I have fitted this set up to 3 cub motors. Be aware that there is a hardened splined thrust washer that sits behind the layshaft 4th gear in a recess in the back of the gear on the existing shaft. This is designed to let the layshaft 2nd gear rotate but not rub against the 4th gear.

If you pull against the existing 2nd gear to get the 4th gear off this thrust washer gets damaged and I could not source a replacement. It is best to pull the layshaft 4th gear off with a puller if you can manage it although it can be hard to shift!! That's Triumph precision engineering for you.....

FYI I managed to get round the damaged thrust washer by substituting with two gudgeon pin type circlips in the groove on the layshaft which gave the correct clearance for the new lower 2nd gear. There is little or no side thrust on the gearbox shafts (or shouldn't be!!) so this worked OK for me. Hope that helps....

I went to the GP... he diagnosed Cub Mania.... there is no known cure apparently.....

Thanks for the replies. Can I also ask what length rear shocks people use on trials Cubs. Mine look too short. I'm looking at the Betor jobs. Any good or is it Hagons or NJB?