Wednesday, 29 September 2010

Airfix kit with no instructions and with some pieces missing!

The plan was to dry assemble everything, so that i knew what went where, what fitted what needed doing to what etc before any paint or powder coating was applied to anything. this meant that the build may take a little longer but that when final assembly came along everything would fit as i'd already fitted it once before.
first things first preserve the frame.
as picked up from the M6 it was in bare metal with its bronze brazed joints loud and proud. There was plenty of flux visible so as soon as it landed in the garage i took out the plumbers  Yorkshire Pad and gave the frame a good rub down to clear the flux and and slight surface corrosion.
this gave me a chance to give the frame a close inspection and a good coat of looking at. first impressions were that the brazing was first class and that the joints were all well made with no lugs in sight. the headstock was long ( circa 150mm) and wide (52mm) compared to my previous cub and bantam frames and that at the rear upper shock mounts the bike seemed quite wide about 40mm wider than both cub and BSA yet narrower at seat/ tank junction than both by about 10mm. 
the rear shock position seemed more 'laid down than both the other bikes and the 'engine room'  significantly shallower than both bikes ( at least 25mm) overall the impression was of a strong frame with robust proportions that coupled with the T45 tubing would make it up to the job of supporting my svelte like 100kg frame!
I'd hoped that removing the motor from one bike it would drop cleanly into the other and initially this seemed to hold true withe the engine complete with carb lifting cleanly into the frame of the James/FB. the reduced height was immediately confirmed but was adequate with no immediate issues. the front engine mount was perfect the bolt went straight in, and the middle/lower seemed to do the same , unfortunately the rear was approximately 5mm out and the engine mount would require re drilling also concernedly the mount was 3 mm too wide on the near side of the bike and 4 mm too wide on the off side.checking the lower/ middle mount I found that although the bolt holes were perfectly in line the off side Mount was approximately 8mm too wide.
the lower mount was easiest to solve by maching a spacer from 5/8 inch aluminium rod/ bar. the rear mount is more complex as it is also the mount for the clutch cable and silencer.
on to the biggest looking issue was the size of the headstock it was about 25mm longer than either of my existing bikes and thus seemingly too long for either of my bolts on the.other bikes. setting that aside it was massive internally compared to the other bikes the cub and BSA both having and id of circa 42mm the james/fb was 47mm. Alan had recommended a bearing size of 47x25x10 sadly that was never going to fly as both my head bolts are imperial sized 3/4 inch which comes out at 19mm give or take. 

No comments: