78 R100/7: A flywheel from the Bay Area?

[bmwwrench]

Reg also raced a BMW built by Butler & Smith in F750. This bike used a Rob North frame and made something like 100 HP. This laid the groundwork for the Superbikes.

 

[pauls1150]

Reg ran a shop in Ventura simply called RPM - Reg Pridmore Motorcycles. Neat guy to chat with. Besides custom machining and building racers, he also sold quite a few go-fast goodies to street riders. I bought a set of S&W rear shocks after Cycle Magazine comparison-tested a bunch of after-market suppliers', and the S&Ws had the smoothest stroke on their dyno (?) tester machine. Adding Reg's reinforced swingarm really stabilized the back end of my R75.
I got his lightened flywheel later - but I don't recall it having that many holes! Most likely he had a couple of versions of that - one for the racers & track-day riders, and one for us street guys. Really made the bike a LOT more fun to ride, and it did not seem to cause any perceived increase in vibration at all. A lot of that is the overall clutch assembly and how well it is balanced. As long as everything is right - including the carb sync! - it really shouldn't shake.
I think the CLASS management has been handed down to his son, Jason.

 

[beemerphil]

Great pics, where'd you find those?



Flywheel looks like what Competition Accessories used to sell, IIRC... but there must've been thousands of shops doing something similar. I used to get them done at Hill Machine in Seattle- (a separate business from Hill Headworks)

 

[kmkahuna]

Excellent comments

What an awesome collection of observations! I consider myself lucky to have a tiny piece of racing history inside my bike. I'll try to do the restoration justice.

 

[lmo1131]

Great pics, where'd you find those?

I knew what I was looking for and just googled "R90s upside down".

 

[pauls1150]

Not to bust any bubbles, but maybe that flywheel came from Luftmeister?
Anybody have one of Matt's old catalogs laying around?

 

[mymindsok]

Not to bust any bubbles, but maybe that flywheel came from Luftmeister?
Anybody have one of Matt's old catalogs laying around?

Yeah, I have one right here but that style fly Wheel isn't in there.

OTOH, there were several other machine shops that offered flywheel lightening back in the 80s and that one reminds me of one I had done in Virginia.

The best and lightest of the lot, were the ones where the outer ring was milled out. They tended to be the lightest and best balanced.

 

[kmkahuna]

Yeah, I have one right here but that style fly Wheel isn't in there.

OTOH, there were several other machine shops that offered flywheel lightening back in the 80s and that one reminds me of one I had done in Virginia.

The best and lightest of the lot, were the ones where the outer ring was milled out. They tended to be the lightest and best balanced.

When I first looked at this thing I was a bit worried, but the thread here has put that to bed. Whether or not it's from Pridmore's shop might always be a mystery, but I will try to ask the PO this week again. On an interesting side note, I went out to my 96 R850R to take a ride and noticed the license plate holder: RPM Cycles.... I bought it last year from another PO up in Thousand Oaks....
Strange and bemusing coincidence...

 

[kbasa]

I watched "long way round" last year, and chuckled quite a bit at the GS phenomenon: I never really see those things with anything but road dust on them, and my introduction to the dirt bike world has been on a CRF230F: small, agile bikes seem to be the way to go in the dirt, vice the gigantic 1200GS's out there, but as I said, I'm a beginner, and I'm probably missing something....If I had as much money as Ewan McGregor, why not?
I will look up "twist the throttle" Mark: I'm sure my neighbor Marc can quote the entire series verbatim...
Here was a good history lesson: last year's ride to the Guy Webster Museum in Ojai..
http://guywebstermuseum.shutterfly.com

Heh.

www.advrider.com

Go read the Ride Reports for a while and be prepare to be amazed!

 

[kmkahuna]

Avrider.com

Hell, just the opening pictures are amazing.....

 

[crazydrummerdude]

I watched half of Long Way Down yesterday and chuckled at how massive/bulky the oilhead GS' are. Yeah, I want one, but damn, what a beast..

 

[kmkahuna]

I just cracked open my 78 R100/7 clutch assembly and this is what I found beneath it.
The bike is a white slash7, with a sport fairing on it, and two other fellow airheads seem to think this might be a San Jose BMW work from the 80s or an old B&S trick flywheel...
I am pretty sure I'm the third owner for this bike, and will follow up with hopefully, the original owner this week.
Sure was a bit of a shock, after reading all the books regarding flywheel removal: the original flywheel has none of these holes...

Well, no joy with the previous, hopefully original owner. His name is Richard Norman Brown, but I can't find any info on him online (I bought the bike from another guy who owns a used car lot in San Juan Capistrano, and don't have his number anymore)...
Anyone know him?