I purchased a copy of Classic Bike issue 148 August 2003 about a chapp called Roger Kordas who built a 90 degree crank Norton Commando fitted into a Featherbed frame without any anti-vibration mounts. The report was very complimentary about the bike and its performance but I can't find any further information on it, at least not after acursorysearch. Has any one heard anything more about this project?
Previously wrote: I purcha…
Previously wrote:
I purchased a copy of Classic Bike issue 148 August 2003 about a chapp called Roger Kordas who built a 90 degree crank Norton Commando fitted into a Featherbed frame without any anti-vibration mounts. The report was very complimentary about the bike and its performance but I can't find any further information on it, at least not after acursorysearch. Has any one heard anything more about this project?
Hi David You can check the…
Hi David
You can check the following links - www.offsetcrank.com
www.xs650org.de/tip/rephase-e.htm
www.offsetcrank.com/norton.htm
www.xs650.org.au/smoothness.htm
www.offsetcrank.com/thefirst.htm
There are more I could put on the list, also, Mr Nourish does modified cranks.
Pazon do an ignition unit for this modification.
I have considered applying this modification to a Navigator - might make it vibrate less (continually having to retighten the head steady bolts) and,
I don't thinK it would be too difficult with the one-piece steel crankshaft it uses. Any thoughts anyone?
Regards
Derek Ambler
Hi David,
I've done one of these myself many years ago in 500cc form. I also built and balanced a very fast 500 short stroke with a 650ss head on it, it's as quick as a stock 750 commando, and very smooth. I never tried this commando compo, my buddy has who own's the bike now. The 750 Atlas twin which set and held a few local Ontario, Canada, track records, also had a stock 360deg crank and was pretty smooth. I got to race the two 360 traditional layouts, but only very quick riding on back roads with the 500/90deg, I was at a 100mph+ for a while and it was quick and smooth also. I don't really think unless you are racing or looking for the ultimate in smoothness,it's worth it, considering the added expense, cams to and timing.
If you buy nice light pistons, treat them, evenstretchtotitaniumcoated pins, have your/or do the rods:- lightened, balanced and peened, lighten your crank and have it peened also especially the fillet radiuses, and treated, use the larger dia crank bolts and or weld it. Carefully balance the combustion chambers and ports/valves, you will have a bike which is pure Norton, and close to if not as smooth overall. plus the cash involved is put to better use, making parts morereliableas well asbetterperforming.
All 3 that I did were carefully setup and internally balanced, all were much smoother than stock. The 90 deg primary forces don't offset each other requiring acounter weight, however the secondary forces add and so are higher, and then there is a rocking couple to deal with now. If you go to captain Norton's notes, someone there did all the math for you, and you can compare the loads if you are technical.
Ed gee cranks in Toronto does the conversion and it's quite popular at the moment, I believe he has a website if your looking.
They act much like a Ducati's to ride overall, in a rigid mount frame,but not as smooth, it's not a free lunch more asandwichswap,at best, they probably have the edge, a couple over here have been made to go very quickly. Personally I would rather put my cash elsewhere and I have a atlas myself. This conversion is not for commando's no matter what anyone say's.
All the best Ian