Pre-65 Bikes

My apologies for posting in the wrong sub-forum but this crowd typically will know most about the BSA unit single and it's application in trials. I am building up a B25 motor/modded B44 frame with old Bultaco suspension and wheels. I am ready to make my skid and have a few questions based on zero trials but other technical knowledge. Thinking 5mm/3/16 plate which ill heat treat to T6 after welding. Do I need to extend beyond the frame rails? I weld aluminum daily and was uythinking keeping the skid narrow and patching the covers when/if they get damaged. Will I need a spare in my tool box? How much case contact are you making? i would like to add I re…

Just bought a BSA B25 and stripped it down for a service, on inspection I found quite a lot of sludge/carbon in the oil tank strainer, is this normal? Don't think its dirt as the bike's never been offroad When I collected the bike it ran fine, All the bikes I’ve previously owned have always been clean

Further to my post regarding the Cub oil return mod, I have now started stripping the engine to find a cause for the smoking. The engine was built from bits and pieces and put in my spare frame for my Son to ride. It starts and runs ok. He entered its first trial and almost completed the first lap with no issues. It then started smoking badly on tickover so we retired the bike. I carried out a number of the usual mods when I built it including adding a blind camshaft bush and putting a large breather in the unused distributor hole, Alpha big end, etc etc. I also fitted a new (later type) oil pump. I measured the clutch and gearbox oil when I removed it …

Dad has said I can give this a try if I promise to not get it dirty or crash in a big heap. That was 4 years ago and I still can't make that promise. But he's gonna let me ride it anyway. Boxing Day trial perhaps. Just need the right venue. Midlands area

There have been many questions over the years concerning carburation problems on 4 strokes (mainly cubs and B 40s) in which riders complain of a flat spot or hesitation on opening the throttle relatively quickly from idle. There seem to be two approaches to tuning a 4 stroke, namely fit the engine with soft cams and a high compression piston or with sporty cams and a low compression piston. I wonder to what extent the perceived carburation problem is also a function of valve timing. I would expect the sporty cams would be more difficult to setup at the low end and perhaps aggravate the problem rather than the soft cam approach. Does anyone have any opinion or direct exp…

B40 on t' bay, how much did it go for ? http://cgi.ebay.co.uk/BSA-B40-TRIALS-GB-WD...%3A1|240%3A1318

Any recommendations for the best soldering iron to make up cables? I've been struggling with a gas torch which is just simply to hot. Also any hints on the best solder to use?

Anything better for polishing up alloy ?

http://picasaweb.google.com/Vinnied55/Pre6...nWvurV7a9i0IHA# Vinnie

Some pre65 2012 Pics https://picasaweb.google.com/Vinnied55/Pre65_2012

Anyone seen the regs for this trial yet? I thought the regs for the PJ1 rounds usually appeared on the Poachers website but they don't seem to be keeping the Northern Bike section up to date this year and there's nothing on the South Liverpool site

Has anyone any photos they could place here on TC of the Spanish made bikes that were ridden in this years P65 Scottish Trial.

So, I'm getting to the point where I feel the need to invest in an electronic mag for the old girl, especially as the rest of the factory team has taken the leap. What do people think of the BTH electronic mags, I hear they now have a new model for off road use which allows the guts to be mounted up out of the way of mud and water? Are there any alternatives to the BTH? Please send me a message if you'd prefer, cheers all

What spark plug are you fellow Triumph Cub riders using please, is one with a projected nose better or stay with the ordinary type, if NGK should it be a 5 or 6 heat range?

I've been using an NGK B5ES in the Ariel (spark is thanks to Interspan unit) and was just wondering what everyone is running. I had a plug break down on Sunday and people are starting to say Champion are better that NGK etc etc. So I started wondering if the nose is the same would I be any better off using one of the new all singing all dancing plugs or just try a Champion equivelant? What is the preference NGK or Champion? Thanks

Can anybody confirm that A Bosch WR8DC is the same as NGK BP5ES ? Thanks in advance Ross

All the talk about period correct Pre 65 trias motorcycles and I havent seen any mention of modern tires. My guess is if a specification tire such as a Chang Shin C186 was mandated then the sport would be much closer to the magic pre 65 than by limiting any other modification? Maybe this has been discussed already?

Hi, I need the right angle speedo drive box for the British Hub Co. full width alloy hub on my Greeves and of course these hubs were fitted on many lightweights of the era.The threaded mounting hole in the hub is 10mm or so in length and the drive cog on the hub sits about 19mm in from the outside of the hub plate. I wonder if anyone knows of a source of these or is it a case of scouring the autojumbles?. If anyone knows the part number or original maker of these, that would be interesting too.

Hi guys, I have noticed that more and more twinshock and pre 65 bikes now have hollow ali spindles. where would you find theese or are they home made? Cheers

Hi, For swinging arm spindle and bushings, I do have room for tiny needle bearings 20mm/32mm. The present design, bushings and hollow steel spindle, worn out.. idea *spindle of ally 6026 *bushing of bronze 5640 *seals and grease nipple Do you think this will work or will seize? Cheers,