Help, R75/6 speedo ratio wanted

[Duane Ausherman]

I need the number on the face of a R75/6 (1976 if it matters). It starts with a 1 followed by a few digits. I need those asap.

[Kurt in S.A.]

Snowbum article here:

http://bmwmotorcycletech.info/ringgears.htm

He shows 1.186 with a 32/10 final drive. If the final drive was 37/11, then 1.244.

Kurt in S.A.

[melville]

1.186 on mine, with a 32:10 final drive.

[Duane Ausherman]

Thanks, it was a 37/11, so the 1.244 is correct. This bike was crashed by a couple of friends some 15 years ago. I offered to do some fixing on it. The speedo cluster was destroyed, but I happened to have spare 1.244 and 1.144 units.

This was a high speed crash and both parties were injured and never fully recovered. One died two weeks ago, but from another illness.

Riding double on a nearly bald front tire at near 100 mph.

[Ken in Oklahoma]

Riding double on a nearly bald front tire at near 100 mph.

I can't help wondering, was it a sudden loss of air pressure or a wobble at speed that "caused" the crash? Or something else?


Ken

[Duane Ausherman]

I don't think that they knew what happened. Both were life long riders, but neither knew much about it. The facts of the accident prove that they knew little about safety.

[tenni128]

This is kind of interesting. Over on one of the Guzzi forums we are having a similar conversation about "extreme tire life stretcher guys" that seem to think it's okay to wear bike tires down to the cords. One pic posted was a guy w/ a TL1000 (not a easy bike on tires to start) that only changed on account of the rear no longer holding air. It seems to me this is as irresponsible as the idiot kids in the sportbike/stunt crowds who think it's cool to ride wheelies down the freeway, but to some it's chalked up to bang for the buck.

worn back.jpg (55.66 KiB) Viewed 1158 times

worn front.jpg (79.1 KiB) Viewed 1158 times

[Major Softie]

This is kind of interesting. Over on one of the Guzzi forums we are having a similar conversation about "extreme tire life stretcher guys" that seem to think it's okay to wear bike tires down to the cords. One pic posted was a guy w/ a TL1000 (not a easy bike on tires to start) that only changed on account of the rear no longer holding air. It seems to me this is as irresponsible as the idiot kids in the sportbike/stunt crowds who think it's cool to ride wheelies down the freeway, but to some it's chalked up to bang for the buck.

It's never made any sense to me. I'm not saying I never did anything that stupid in my misspent youth, but that doesn't mean it wasn't stupid, only that I was.

If a tire costs you $100, and you get 8000 miles out of it, that's 1.25 cents a mile. Getting an extra 500 miles saves you $6.25. During that time you have a FAR greater risk of puncture or catastrophic failure, and your wet weather traction is severely compromised. On a risk vs. reward basis, the math just doesn't make any sense to me.

[tenni128]

Agreed. Admittedly, I have had tires that looked fine due to the tread design (like the pirellis on my Goose) start to show steel only 20 miles later. It just happened on my last tire, actually. But I parked it and came back with my truck. Certainly not interested in risking it all on a vehicle supported by only two small patches of rubber. One of the guys mentioned, however, that in his neck of the woods (New Zealand, I think) he was looking at 400-500 for a set of decent tires. Ouch!! Still, if you can't afford the consumables, a bike may not be your best bet for transport.

[Duane Ausherman]

I well remember that once we had 10 wrecks in the shop. That was a high number to have all at the same time. I walked around and 8 of them had worn out tires. Chicken or the egg?

I am a believer in good tires with lotsa tread.