Pre-65 Bikes

Hi guys (and gals?),does any one know what size amal concentric carb works best on a marcelle barrel (for trials).In the box of bits which it came with was a 930,with a 928/ 2 1/2 slide,is this in the right ball park? Thanks.

Hi guys, I was helping my dad clear out one of his garages and in the corner lurking behind an enfield was a old BSA bantam rolling chasis, under a cloth there was an engine and other odds and sods looks like maybe 90% of the bike present. It is obviously a road bike and it is of the twinshock era rather then ridgid. My question is what work and cost would it take to make this basket case into a decent trials machine? Is it even worth the effort of should i do it back up into a road bike and flog it? If i could.convert it i would keep it but i dont have a road license.

A letter has been sent out with regulations for the next events in the above series. Its from the ACU Trials and Enduro Commitee. Basically it says a protest has been received regarding eligibility of certain bikes which have been competing in the series. It goes on to say that at future events there will be strict machine examination for compliance with the regulations especially in regard to class eligibility. Sounds like a good idea, although a shame if things have been allowed to get out of hand in the first place. Maybe it will encourage more to have a ride in this excellent series.

My B40 has a bit of an appetite for plugs, tried different makes with little discernable difference. Also use different carbs, Amal for those where you have to, and Kehin the rest of the time. Burns a bit of oil so plug gets black anyway and difficult to get a proper picture. Runs a ticks over fine (particularly with Kehin) then develops a slight misfire before plug gives up completely. New plug and away she goes. Have heard this isn't unique to my bike. Any ideas ? Thanks Ross

After stripping and checking my cub engine I was disappointed to find I had much the same running problems with not revving past 1/3 throttle and sooting up plugs on reassembly. Convinced I had a problem with my new 20mm Dellorto carb, I tried a friends 22mm Dellorto carb (from his 250 Serco Cub). This appeared to work much better. The engine revved pretty cleanly and the plug even appeared to go from black to straw colour! I must admit we didn't do an extended test due to time constraints but the bike was vastly improved. Bob at UPB kindly exchanged my carb for the larger one. The only difference is that my new 22mm carb has a 100 main jet and the main j…

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Hi, can anyone advise me on how to make adjustments to my Clutch, at present if i select 1st and depress kickstart she moves forward,but if the motor's running nothing happens when gear is selected. Also the chain came off a couple of times yesterday even though it appeared to be aligned ok, any suggestions please. As you can guess i'm new to all this british stuff after 7 years on a TLR!!!!Didn't even have an imperial allen key!

I want to widen and lengthen the rear swing arm on my trials cub. I intend to do the cut and shut myself then take it to a local fabricators for welding. Can anyone tell me where to cut and what to make. I have a pretty good workshop with a lathe and small milling machine. I have 2 standard trials swing arms to play with. I was thinking of removing the LH (brazed in?, cranked) arm from one unit and sticking it on the RHS of the other but this seems wasteful. I have seen a sketch on another post but it doesn't give any sizes. What do you do with the rear shocks when the swing arm is widened as the bottoms won't line up with the tops! Are both sides widened by…

Hi all Anybody know a good starting point with jetting on a Mk 1 Amal carb , its to fit a Villiers 250cc 32A motor Cheers

hi. i was just wondering who sells or modifiys modified barrel and heads for bantams. also i have been told alot of people like the d7 engine more for trials is that true. thanks charlie

Hi, can anyone tell me where I can find any info/pictures etc on Sprite Motorcycles? If anyone's got any literature, advertising stuff I could buy copies of or anything for sale I'd be interested. Cheers, Glenn.

A teaser for the oldies: What's the connection between a Quality Street tin and a trials bike?

Just about to lengthen the swing-arm on my bantam project, anyone know how much I should lengthen it by? It’s a wider type sports cub swing-arm

Hi, I've inherited my late Dad's '60 C15T and, despite not riding Trials (but a motorcyclist for over 50 years), I intend to restore it. I'm not clear yet quite how to go about it, what my priorities are or should be, and... I am NOT a mechanic! But I know my limitations and I don't intend to sod the 'bike up through ignorance. I'm going to convert it to 12v and fit Boyer Bransden electronic ignition (it was a bugger for my poor old Dad to start!) as I'm OK on electrics - I fitted a Boyer Bransden to a Sammy Miller Trials Cub I once owned. Then I need someone good to completely rebuild the engine (with the desirable mods) - someone good and not someone who just th…

I was riding (badly )at scarboro trial on sunday and there was a chap riding a 250 triumph called Duncan McDonald who won the clubman B , The frame on his bike (as well as the rest of the bike )looked very trick , i just wondered if anyone knows Duncan or knows the bike as i wondered if the frame was a "stock" item or some kind of fancy aftermarket jobbie

Hi Guys, Does anyone know the weight of a Drayton Bantam ready to ride with fuel etc. Thanks, Prelit.

WOW, the sun was shining.. no honest really shining, people were taking their coats off at one point. Great Trial , not much water in the burns and with some sections having been eased ( beside the glencoe road) scores should be a lump lower than last years Len Hutty, Tony Calvert, Carlos Casas Alan Wright all riding neat and tidy whilst younger Drommet was nursing a sick Cotton ( but under dads advice 'not through sections') Peter Gaunt dropped a slack 5 on section 4 as he was first to clean the section only to ride out of the section missing the 'ends' cards completely! couple of questions though.. spanish and japanese bikes competing, i had to cast an eye over the…

hello, i'm building a tiger cub and i'm looking for wheels and forks where can i get hubs (alloys) or what do i need to do to improve the stock hubs (i heard i should make the back hub wider) i have a aprilia mono fork (35mm) i would like to modify so it looks pre 65 who are the enginiers that can do something like that anyone has contact data from them ( email or phone ? ) kind regards bob

Hi, The story of my BSA/Burman. Built and ready for race in 1959, sold in 1960. no small- big end rebuild.. http://i633.photobucket.com/albums/uu54/pa...et/66010006.jpg Found and rebuilt 1987. Few changes but no small- big end rebuild..though, same sprockets ..19" replaced by 18". http://i633.photobucket.com/albums/uu54/pa...SA071024006.jpg Rebuild start up 2009 http://i633.photobucket.com/albums/uu54/pa...t/BSA071230.jpg Sprockets and chain 520->420, weight saving 2558g..B&C http://i633.photobucket.com/albums/uu54/pa...sprocket16t.jpg http://i633.photobucket.com/albums/uu54/pa...SA071230117.jpg http://i633.photobucket.com/albums/uu54/pa...SA071230118.jp…

A question to make Charlie P despair! In the lightweight class we have had the James, Triumph Cub and Bantam eras, all machines passed as being pre-65 in style and substance. What might be the next all victorious model in this class.