We had oset 20 and bought lipo pack from your man in Kilkeel, Boost batteries. Made amazing difference, expensive and some clever people make their own but to me it was worth every penny for the extra fun it gave. Made bike much lighter and lasted way longer than the lead acid ones
A fully charged 12v battery should read about 12.6v. A reading of 12.2v is only about half charged. 12v is apparently classed as flat.I remember this from testing a dodgy car battery. It’s surprising how little the resting charge without load has to drop to show a faulty battery.
That would explain the lack of power and short life(I assume)
To pass some time try bpvideolibrary.com and type trials in search bar. Classic BP videos from 60’s. Trial and error, champions on two wheels and six days in Scotland.
Seem to recall taking about 1 1/2 litre but that’s not 100% as I haven’t measured it, just fill it up. The oil never gets too hot, Definitely want the return in top of tank above the oil level so you can check it’s flowing fine. It took slightly more than a Terry Weedy tank if anyone can help with the volume for those. Perfectly happy with Terrys tank but I like the high air filter on this unit for the very wet North East!!
I can’t claim any credit for the fabrication as it came with a Faber frame I bought, but this combined air filter/oil tank was made and works well. Uses a modern air filter element from a Sherco or Beta and an in-line oil filter from D&C classic motorcycles. Oil return is into top of tank, you can see this at front of first pic, with breather visible next to air filter. May help with ideas of what can be built.
My lad had a new beta 80, used to start from cold and after few mins the revs would just build and had to pull lanyard off. Eventually found the breather pipes had been cable tied together in factory so tight they couldn’t breath. Easy to overlook
Some people remove the the vent pipes off each side and replace with a pipe connecting them but with a notch cut out to allow breathing. If you have replaced this pipe without notching it then that is probably the issue.
Hope not to insult, is this just from cold or when warm too. I used to touch a bit of throttle when starting from cold with choke and curse the bike for being a pig to start from cold. Then I learned it didn’t like it so with Choke on I don’t touch the throttle at all and it starts great from cold.
Heard of people having issues with Michelin staying on rim at low pressures. Used them on a Fantic and heavy c15 without issue so maybe certain rims. (Mine both akront). I’ve now got IRC and they have been great, to be honest I can’t say I notice any difference in grip without having two sets of wheels to try on same sections. IRC seem more popular with tubes and I’ll be sticking with them on old bikes and Michelin on new
I used to carry a fully charged spare car battery with an inverter and use that to top up charge. Obviously need to check the inverter is correctly rated.
Went through oset 20 and oset 24 before moving to beta 80. Only problems we ever had was water in relay and a dodgy throttle control. I bought a boost bikes lipo pack for the 20 and it made a big difference. Not only lighter but lasted way longer and performance doesn’t tail off the way lead acid batteries do. (Plenty of people make their own packs ) I wouldn’t recommend a bike without lipo batteries. Great for half an hour play round but that’s all. My son used to compete in the kids trial then go and race around for ages on the lipo. Expensive but, to me, worth every penny just for his enjoyment Petrol still much better but the electric was worth it for the experience of riding from young age.
Used one on my Fantic and on C15. Heard other people had issues but mine were fine. I use IRC now and seems the consensus is these are better for staying on. Grip seems as good to me
Hi section swept thanks for the above. Chain tensioner, alignment and clearance all fine. Recently rebuilt into Faber frame from a modified c15 frame. Chain has only come off on steep rocky gulley, still annoying costing 5’s which I can get myself without the aid of the bike!
ongoing project as always but that’s half the fun. I have a fair bit of info to sift through
Top speed not a priority it’s more being able to reduce the rear sprocket size and possibly making second a bit more useable. Think may just try and source a full trials cluster.
Currently running 18t engine 14t gearbox and 64t rear sprocket. First is great, chugs away slowly down to tickover, second ok for hill climbs. Looking to put belt drive clutch in so seems ideal time to have gearbox done too. REH forks on since the photo now just need to ride it better!
I’ve read some older posts on gearing but admit I’m still unsure. I haven’t had the gear cluster out yet to check sizes but the opportunity for these apparently close ratio parts came up. It’s a distributor engine if that makes difference.
I have a c15 which has standard road gearbox, I’ve lowered gearing including primary drive to make first ideal for sections but obviously it makes fourth rather slow and the rear sprocket is large, chain has jumped off couple of times. I’m not very up on gearbox internals so hoping someone can help. If I replace 1st and 2nd with these 29 tooth 40-3176, + layshaft 2nd gear 26 tooth 40-3132 and mainshaft or 2nd, 24 tooth 40-3130 will it make significant difference. Does it lower first gear internally so I could reduce size of rear sprocket.
Personal taste before I upset any 4rt owners. I know they are superb build quality reliable etc and there are far more around than the beta. But, I much prefer riding the beta, find It much smoother from tickover. Power delivery is so smooth and linear just chugs away in any gear. I’ve had 2 and never required anything other than the standard trials bike maintenance.
Seem to remember a post about the carb breather pipes being too long and ending down by the bath plate. Means they would be under water if riding in deep water
Had similar on beta 50 but not rev n go. The flywheel had come fractionally loose knocking timing out. Those little engines don’t seem to like being left ticking over without blipping throttle
Get the 80 assuming the big wheel senior is the right size. Hydraulic clutch and 6 speed. Either great to learn to ride on but the 80 Will be the better bike for progressing into trials. Also the big wheel 80 has better suspension and as the engine has changed very little parts aren’t an issue. Very capable bike and although 80 has more power than the 50 it’s not massive difference and geared so low it’s easy to ride.
Oset 16 power trouble
in OSET Electric Trials Bikes
Posted
We had oset 20 and bought lipo pack from your man in Kilkeel, Boost batteries. Made amazing difference, expensive and some clever people make their own but to me it was worth every penny for the extra fun it gave. Made bike much lighter and lasted way longer than the lead acid ones