E: Engine Imperial or Metric - Pros and Cons

[oexing]

Metric fasteners do exactly nothing to the classic looks and spirit of classic bikes, you´d need a vernier to check. And I am nobody to care the least about concours events - or speculative sale money in times to come. Big question is can you sell your stinker in a few decades when you cannot get any gasoline then ? Museums will be crammed with classic bikes one day so why should I care ? What I care about is spoiling the traditional look of classics by components which come from a very different, more modern period, obvious to Joe Public , like car alternators , teleforks and disc brakes, well, specials then, but not consistent period style. Time is too short to plunge into grotesque imperial/British fasteners thread discussions as shown here or in MPH when even natives cannot tell what exactly they deal with in certain places on Vincents. Amusing for me . . . .

Vic

 

[Peter Holmes]

I would not argue with Vic that he has every right to modify his bikes in any way he chooses, a lot of what Vic does I greatly admire, I just find it hard to understand why Vic finds it necessary to make an entire Vincent metric, when it is currently so easy to purchase top quality imperial spanners and fasteners, and it really isn't that difficult to understand the various imperial sizes used, and the spanners that are required, it really isn't, we are not talking Einstein's Theory of Relativity here, a copy of Know Thy Beast tells you all you need to know, what is used and where, and if you fear losing a couple of nuts along the way you can always carry a couple of spares with you, although in 56 years of ownership my journeys have never been halted because nuts have dropped off, although I did once lose a gearbox cover inspection cap, a really nice HRD one. I very much doubt that if the thread had been metric that it would have retained it any better, I recon I just carelessly left it loose.
I am guilty of being one of those people that has a non standard alternator fitted, but I only fitted it in the knowledge that it is a totally reversible modification, I could revert back to my Miller 6 volt dynamo tomorrow, i didn't even have to carve away any of the crankcase casting to fit it . . . .

 

[Martyn Goodwin]

Your adjustable wrench will fit every thing Vincent, no worries just carry on .

Marcus, you should be more precise - an adjustable BSW/BSF spanner will fit them all. for the full range if imperial you also need an adjustable UNC/AF spanner. With metric you can get away with just one adjustable metric to cover any metric possibility.

Moving onto screw heads .........................

 

[oexing]

Martyn,
it doesn´t end with adjustable BSF spanners, I´d have to get imperial hammers, imperial screw drivers, punches, chisels and so on. Plus some taps and dies in BSF or whatever - not cheap to get today. And I am just a lowly retired toolmaker so my resources are limited. It is just so simple to convert to metrics when almost all of the Argentinian old iron was knackered and get all modern fasteners in two days . In places I get my Helicoils in metric for easy repair. Not so much now with ordering from UK (ahmm, politically correct today UQ - United Queendom ?) with Brexit . . . .

Vic

 

[greg brillus]

I hope magnetoman doesn't read this thread............

 

[oexing]

Each to his own - at least I am not a rivets counter, and turned to a very liberal man - in some respects . . . .

Vic

 

[Peter Holmes]

Anyone that can identify a 4-5-6-8mm thread by eye alone could probably become just as competent with imperial, only requiring a little a practice, and no vernier required, I have zero engineering training and even I can do it.

 

[MarBl]

I just love imperial sizes.
Its pretty much the last useful imperial stuff we are allowed to keep in Germany since the abdication of the Kaiser. So I try to use it as much as I can and certainly do need it more often than my metric tools.

 

[Magnetoman]

I hope magnetoman doesn't read this thread............

have never seen the logic to look up files about bolt threads to know the type of hexagon and spanner. In metric world nobody cares about threads, you get your vernier onto the hexagon and see in same second what size of spanner you take

Logic? You own a British bike and you expect logic?

OK, you obviously approach working on your bikes differently than I do. You carefully measure the size of the metric hexagon with calipers then select the size of the spanner that fits. I can understand why you do that, since it ensures you never make a mistake. In contrast, with my British spanners I haphazardly select the spanner than looks like it will fit, and if I discover I made a mistake and it does not fit, I select the next size larger or smaller, as appropriate.

The difference is, with your technique you never make a mistake when selecting a spanner from the tool box, but mine leaves me wide open for making mistakes. Clearly, your technique is much better so, in light of your post, I will make an improvement to my technique. From now on I'll use digital calipers to measure the hexagon of the British fastener, look up the corresponding BS or BSW size (some of my spanners are stamped with both, but others are stamped either just BS or BSW, so two sets of tables are needed), and from now on unfailingly select the proper spanner from the toolbox. No more mistakes for me!

Addendum: In light of your post I should be ashamed to admit the following, but I'm shameless. For twenty years I've kept a BSA in Ireland to use in the annual Irish Rally. Over the years the bike has acquired a mix of fasteners, but I put together the following set of ¼"-drive sockets for the toolkit that I carry on the bike, that fits all the BA, BS, BSW, CEI, and A/F fasteners across the relevant size range within acceptable, but definitely non-Germanic, tolerances:

5/16", 11/32", 12 mm, ½", 14 mm

 

[Vincent Brake]

Another,

One of the reasons an imperial bike might not be up to the task is:

One thou is still 0.025mm...

To big for noting tolerances on a decent drawing...

Hence....

Writh in metric its easy...
0.001mm or even 0.01.
Needed for bearing tolerances.

Awaiting Marcus or Mr old steel....