Airhead parts - the dark secrets revealed

Thanks for the good info !!!! Going to get another OEM mirror, used or new or reproduction mirrors if anybody makes them ???? Being that my R75/5 is all orginial, low mileage, and never been molested with, we shall keep it that way and stock up on a few mirrors. Now for the smokin deals to roll in......

I don't think the mod is unreversable - the existing hole is nominally 8 mm with a decent bit oversize for powdercoat , etc, probably 8.2/8.3 mm.

The daylight opening on a 10 x 1.25 tapped hole is 8.75 mm so the difference in opening size is less than 20 thou, which I don't think would stop you refitting it OEM mirrors when the time came to sell.

If you Helicoil or Timensert, you tap a much bigger hole. Then you are reversing the threads on one side so that one is shot...and the 8mm thread will stuff in a 10mm hole but won't fit right. Using brackets is reversible. Take the brackets off.

I am not sure if this relates to the above discussion, but I bought a set of these


mirror adapter 10mm 1.25 pitch to 10mm 1.5 pitch (x2) for BMW motorcycle

http://www.ebay.com/itm/25111200299...iewitem=&sspagename=ADME:L:OC:US:3160&vxp=mtr

To mount normal mirrors, Look up


mirror adapter 10mm 1.25 pitch to 10mm 1.5 pitch on ebay

wise words of wisdom

I have a question for you all that I don't believe deserves it's own thread.

My R65 is annoying and buzzy as hell on the highway. This leaves me to cruise at what I feel is a painfully slow 55mph. Without buying a new bike, how can I fix this gearing issue I am having? Well I came up with swapping out the rear drive (31:9) for something else.

I would like a 33:11 rear drive (3.00 ratio) but it seems they are all on R80s and R100s with disks and my bike has a rear drum. Can retrofit the drum in there or would I have to swap to disks?

Have you been through all the usual suspects? Timing, Valves, Carb sync??

Fitting the drum requires a new wheel, axle, rear drive and a brake rod/nut/spring.

I'd fix the buzzy. Get the wheels/tires dynamically balanced at a shop. power balance the carbs for your preffered cruising RPM. Past that you have to go into the motor and precision balance rods and pistons...not likely needed except to get the last .01%. Make sure footpeg rubbers and grips are 100% and maybe even fit a bar snake---but it's better to eliminate vibration rather than masking it. it's shaking fasteners and electrics, not good.

Losing a wheel weight is a common occult cause of vibration. It also gets worse as tires wear. new tires always feel so good...

Fitting farkel valve caps also throws off the balance.

I had a 65LS when they were new. It had an inherent buzz from around 105-120 kph. It was a matter of "they all do that". A mates R65 also had the same issue.

I did meet a bloke that told me his vibes were cured with free flowing mufflers (read noisy) but I never did ride it to find out for myself.

I believe my LS had 3.57:1 gearing but I never cruised around that slow. I made very free flowing mufflers for mine and it didn't change the way it vibrated at all. Tightening the engine mounts might? Making custom engine spacers so that torquing the engine mounts doesn't stress the frame (bow the frame in) might help. My dad fixed more than a couple of brand new beemers doing that.

No memory of the gearing mine had.
No surprise the free flowing mufflers don't really work to reduce vibes. Too much bullshit around to believe everything one hears or reads.

I apologize for not being clear enough, the buzzy I mean is that the engine RPMs seem too high. At 65mph I am at 4500RPM(ish).
It feels so unnatural to me to cruise around at 4800rpm at 70mph, the exhaust is free flowing and it is loud. The bike is actually pretty well synced and doesn't seem to vibrate much. I just feel that the engine is working too hard for basic crusiing speed and when I want to pass someone at 70-80 it is like it's going to blow at 5000RPM +.

Wanna put an R100RS back end on it? Everything you need, drive, wheel, axle, brake disk, all brake parts, tire...reasonable but not cheap.

I think I may have decided on a 34/11 from an R90. It should give me a much better range and hopefully not take all the guts out of the R65. I do realize that it will make a powerless engine less powerful but I am willing to take that hit.

I think yours is probably a 33/11 which is going to be a little too tall for this engine and the 34/11 has drum brakes so easy install.
Thanks anyway.

And it will take all the guts out of it. I am afraid you are gearing it so tall your top speed will be 80mph. If you have the time to get up to red line in third gear. I use to cruise mine at 6K ALL the time.

You might find greater happiness if you just changed the exhaust back to stock. A stock exhaust R65 at 80 mph feels fine.

That is OK with me. The bike was a slow poke to begin with, if it is seriously a problem I will put the old rear drive back on.

My R65 was happiest around 5500 - 6200 rpm.

That R65 engine is meant to spin a little faster. Lug it by overgearing it, and you will miss the point of what that motor has to offer.

It's peppy and revvy - just don't expect it to act like an R100, and everything'll be just fffiiiiinnneeee.