Engineering- you'realways learning

I thoroughly enjoyfollowing your exploits in CBGand often think what an idealjob you have. Goodfor you, I say. Anyway,without wishingto be patronising or big-headed,Ithought I might be ableto impart some hardlearnt tips on somegeneral engineering topics. Firstly, when assembling crank cases for end float measurement, I think a good practice is to actually bolt the casestogether as if for final assembly.A painto do up and undo,but it gives a much more consistent reading. This principle applies to many similar assemblies, be they motorcycleor not. (Bythe way,I like OpelKadetts or any propercar wherethe rear wheels are driven.)I also think you are correct in sayingthat heat usedto push bearings in may haveaddedto the problemof the clearance closing up. It must be allowed to dissipateto aidthe best possiblereadings. Holetapping - I hope it was a typo when you quoted 5.5mm as the tapping sizefor MS. It should have been 6.8 mm. Trying to tap out morematerialis not generallya good ideaand will leadto brokentaps andpoorthreads.As a generalrule of thumb, if you can't remember all the metric tapping drill sizes,just subtract the tread pitch from the thread diameter. So 8 - 1.25 = 6.75.this is taken up to the next practicaldrill sizeof 6.8.Also,always use lubricationwhen tapping, especiallyon aluminiumas it clogs so easily. I hope I haven'tcausedany offence in my comments,that was not my intention. If you are in needof any machinework for your bike projects send me an email.I may be able to help as I run my own small engineering companywith CNCmachinesas well as the usualmanualstuff, etc. If it's'bikerelatedand dependingon the amount of machining,you probablywon't get an invoiceeither. Keepup the great mag. PeteSelfe.

Matt: Many,many thanks,Pete.It is a learning curveand with advicefrom knowledgeable engineerslikeyourself,we willget there! I hope others find this useful.