fork of sheet metal

worntorn said:
The primary cover is beautiful, there must be a lot of hours in. Did you keep track of te time that went into it?
Ive considered making a sheet aluminum primary for my Vincent project bike which has a belt drive. I expect there is more work in making the primary cover than there was in the alloy tank which took me roughly80 hours to complete.
Glen
Click to expand...

A sheet metal worker would make a primary cover for a belt drive in about a day, but then that is a skilled worker.
Easiest way is to make a wood former the shape of the outside of the belt drive, one strip of alloy metal slightly larger than the with of the belt is clamped in place and a larger sheet alloy welded to form the front. A cut-out for the clutch and crank as needed.
Look up on Google images on Manx, commando or any British racing bike for ideas.

http://images.search.conduit.com/ImageP ... =105&pos=8


http://www.rgmmotors.co.uk/items.asp?ca ... ansmission

http://www.pushrod-performance.co.uk/service6.htm
 
Just to clarify, I didn't intend to jump on here to embarrass the discussion in any way. I noticed a spike in my website traffic and followed it back to this site.

I'm thrilled to find people interested in the function of motorcycle components because I spend much of my time trying to make a part that works better, not just looks better. This in an industry dominated by the latter.

Structural concerns are well warranted! I'm sure many of you are familiar with the experience of riding a newly assembled motorcycle, and even under a simple wheel replacement, small bolt torquing details are things that begin to haunt you as you come up to speed.

The best analysis I can gather at the moment is these clamps should indeed be very strong, and for this type of load steel has more favorable attributes in every aspect over aluminum (save for weight), but nothing more specific than that. I've enlisted the help of a thermo/fluid science engineer to run analysis using ANSYS and LS-DYNA, but even he agrees the most practical information will come by way of comparative destruction tests.

I'm as excited as anyone for the results, and while I'm now tooled up to build multiple sets, further construction won't continue until testing is complete.

Having said all that, I'm putting the current set on a personal off-road bike of mine and riding the hell out of it. I've got a good helmet and health insurance, mind you, but wish me luck just the same.
 
Hope for good results with the testing and analysis. Notice I did not say "good luck" as you appear to be a master of your destiny.

Your riding the living hell out of it will probably render some of the initial information.

What was your intent regarding purpose? Dirt, road race, street or show?

Beautiful work.

As for jumping in here and embarassing the discussion on this list, there's one or two highly qualified list participants that takes care of that for the list.

As for myself, I would welcome periodic updates on your endeavors showing up on this list.
 
Oh my Joe, I about wet my self on seeing the internal braced Steel sheet metal frame member! Nothing known yet beats the weight for strength AND toughness of this type construction, Especially when cold formed into load distributing arcs.

For comparison, I bought hi end RGM Al billet yokes milled out with under braces, it only weighs 1/2 lb less than the cast iron like Norton issue. IIRC Norton with the stem post was 7 lb while hollowed out billet 6.5 lb. Only steel can take the flex loads for long time unless the alloy part is over built like Norton Al rods so much it eliminates the fatigue life issues with Al stressed to flex levels.

http://www.rgmmotors.co.uk/search-result.asp
1835 AYC PAIRS OF ALLOY YOKES COMPLETE WITH ALL FASTENINGS (CROWN NUT, ADJ, NUT, WASHER AND PINCH BOLT TO SUIT COMMANDO (2 13/16" OFFSET) £ 209
fork of sheet metal
 
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