Pre-65 Bikes

I'm trying to hold of an alloy gear lever for a Burman gearbox, I think they were made back in the day. Does anyone know where I might be able to get hold of one, been searching on flea bay with no luck. Thanks all

I spent a very enjoyable afternoon in the workshop today doing a dry build of my HT5 gearbox with the new gears as supplied by Mick Ash.All fitted together beautifully,and was a joy to put together - till I got carried away and mounted the new Jawa speedway clutch to the end of the mainshaft..... Its too long by around 10-12mm,so the outer cover of the clutch fouls the end of the mainshaft. So my question is,from memory Sammy Miller used a shorter mainshaft to narrow his bike down.What were the standard lengths of shaft ? Mine is 1 and 1/16" of an inch from the end of the clutch splines to the very end of the thread.There is room to cut the end off the shaft and put a bit…

Does anyone know where I can get a 19T 520 (5/8, 1/4) for a Burman GP gearbox, or will I have to get the grinder out? Thank

Hi, Im searching for any kind of graphic description of Burman- and BT-H brand logotypes. Have any of you ever seen any of these brand logos? Cheers, Pat

Hi all, recently I have been thinking about buying a pre 65 bike. I ride twinshock at the moment and would like a Tiger Cub bike to occasionally ride some easy routes on. I understand that some started life as a factory trials bike and some were converted from road bikes to trials. I think I’d rather get a factory trials machine. Is there any advantage to either? And is there a definitive way to identify exactly what model the bike is, can you tell from engine/frame numbers? Any help would be much appreciated. Many thanks.

Hi Guy’s I am looking for a alloy barrel to fit C15 is anyone making new ones Cheers John

The small (17 tooth) gears on each of my C15s transmission shafts is a press fit on the splines. I used a gear puller to get them off. What is a good way to press them back on? I tried tapping with a hammer but they got stuck. Then I tried using a mill as a press and snapped off the hand lever (3/8"). I can see that the gear was not going on straight. It seems like they need to be pressed on very straight. Thanks!!

Can someone recommend what type of overall 1st gear ratio is good for a C15? Currently I'm at 23:1 which is too tall. (this includes 1st gear, primary and final) I have seen recommendations of 30:1 and 35:1 for other bikes but am not sure what is appropriate for a C15. Local events have very tight turns. Thanks!

Does anyone know if there is a modified or purpose made swing arm and rear sub frame for the C15 / B40 trials available anywhere?

My C15 has a clutch actuator (pivot) that threads into the timing cover. I have been told the Cub is the same. It interfaces with the cable and rod. When rotated into the correct location, the threads are not tight. Does this matter? Will it flex around an destroy the threads? Is there a standard correction? Is seems like the threads should bottom as the correct position is met.

Hi All, I'm new to the forum so go gently on me! I'm building a C15 for chugging up and down green lanes and the occasional really easy trial. I've decided to fit lights and have converted to 12V using a solid state regulator/rectifier. My question is, can anyone suggest a battery I can use? I just wanted the smallest, lightest 12 Volter I can tuck away somewhere with enough capacity to spit a few sparks out when I start the bike. it would be highly advantageous if I could fit it in any orientation so sealed or AGM would be ideal. I'm not particularly concerned about being able to keep the lights at full brightness at tickover. I don't really understand electrisity …

Hi, on stripping C15D engine with timing side bush, bush was seriously shot. Phosphur/bronze bush had either spun or been fitted incorrectly as the oil feed visible (pointing to anti sump valve) had closed to a eclipse equally about 10% of throughway. After removing bronze bush to replace I noticed that even though the steel case insert has machined faces to locate it vertically when fitted in case, the oil feed holes here do not align correctly. There is a devience of a few degrees. To open the oilway fully I would have to enlarge one side of the oil feed holes (in the case I would have thought preferable). Which of the two is less likely to cause a problem, opening the …

Does anyone know what the part numbers are for the main bearings on a c15 (side points model)?

Does anyone know what size clutch hub puller (extractor) is needed for a BSA C15? It looks like a 7/8-20 thread but that does not seem to meet any standard.

Is there a preferred direction for insertion/removal and should there be any restriction on movement?

Can someone please help with advice on crank end float for a C15. Based on Rupert Ratio and Google I am not clear whether it needs shimming to control the setting between crank and main bearing or is used to centre the con-rod in the barrel. Either way it seems to need a ‘dry’ build to measure the clearance but assume this will not take account of any gasket material between the crankcase faces, although this will be minimal. I have had the crank refurbished by Alpha bearings including a timing side bush to bearing conversion. Any experience/advice gratefully received.

Hi all, Got my engine in bits at the moment and while fitting an 18t crank sprocket, I`ve found it rubs on the casing, where it protrudes for the oil seal.1st of all, is this normal? I haven`t got the clutch back on yet so I can`t put a straight edge across, although the bearing hasn`t moved, the spacer is the same, and the new sprocket is the same width as the old one, so unless it was way out before, I`m guessing I may have to relieve the casing? Secondly, I`m thinking of drilling through from the drive side into the crankcase,, a la the `Rupert Ratio` book, to provide `weir` lubrication to the drive side and possibly improve breathing. Anyone have any tips or d…

I have noticed something really odd about my C15. After riding, it will not leak oil for two days but then starts to leak at what I beleive to be a constant rate. It seems like there is some type of internal leak that fills up "something". Once that "something" fills up, it starts to leak externally. Oil accumulates on the bash plate so I can't find the exact source. Does anyone have any idea what this could be? This bike does have a right hand side kick stand. I have heard of wet sumping but the bike does not smoke at start up. It does leak while riding but I don't know if that is constant or just after start up.

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I'm assembling a C15 and see that the drive chain hits the inside of the engine cases. By inside, I mean the clutch side. This is a 428 chain with the smallest (13 tooth?) sprocket. I know you can run a 520 chain so something must not be correct. Can someone tell me what a notmal or expected clearance should be? A couple of pictures are attached.