getting the background info on the /7 bikes

[malmac]

Yes, beginning for the 1976 models, those made from September 1975-August 1976, the engine opening for the cylinders was increased from 97 to 99mm. So, it's important to get the right parts for the configuration change.

That explains the situation, why some parts are OK and things like Barrels are not.
Thanks Kurt.

Mal

[Werner1111]

1. Left hand switchgear is from a /7. Right side is correct /6 with some homemade lettering on the turn signal switch.
(What is the difference???)
I wasn't able to find a left side /6 switch, but here's the /7. Notice that the high/low has a wing.


And here's the /6 style from the right side. Your thumb rests between two notches. The /6 will have the same style lever on the left/light switch. It's pretty common to see /7 switchgear on a /6 if the parts have been replaced. I think the /6 switches were available for awhile, but it appears they are NLA https://www.euromotoelectrics.com/produ ... tch246.htm

2. The grips are /7. The /6 grips have the same pattern as the footpegs on this bike.
(I will certainly change the grips)
They are available from Motobins and perhaps others.

4. Mine has two more ribs in the fork gaiters, but I'm not sure which is "correct".
(I was thinking should be 13 - is that what you have???)
I have 13. I remember when this was a "thing", and I also think 13 is what came from the factory.

Always happy to help. I'm happy that my years of tweaking out on these issues can add value to someone else's experience.

Regarding '75 vs '76, the '76 bikes (and later) have bosses on the head to mount the rocker blocks/towers, while the older models do not. There is a procedure to line up the rocker blocks found in Oak's Top End Manual. I don't recall it being rocket science, but it is important to note that they don't have locating bosses. I was a bit surprised to learn this having worked only on /7s prior to owning my /6. My R69 is the newest of my bikes and I haven't yet taken the top end off, so not sure how it was pre-1970.

Also, the newer bikes have o-rings around the top cylinder studs to prevent oil leakage, while the older do not. Evidently it happened towards the end of the '75 run. There will be recesses at the base of the cylinders for the o-rings if the bike uses them.

Here are two pictures from my Ian Falloon book about the upgrades from '74 to '75 and from '75 to '76.





After reading all that, I did think that the bright horn on the potential R75/6 looked a little out of place. Falloon indicates that the center would be black starting in '75.

[malmac]

Well you are a mine of information. So many changes in such a short period. One would be prompted to think the later the /6 model the better in terms that most of the changes seem to be improvements.

One of my concerns about buying this bike was that I really do not want too many bikes in my shed. I have my 1200 up for sale and may have found a buyer. If the sale goes ahead I will buy this 750.

Regarding the horn. The chap who owns this bike, I refer to as the bling king. He has had silly bits chrome plated, nothing serious but not necessary. Maybe he sourced an earlier horn as part of the bling regime.

Thanks again for your help.


Mal

[Carott]

Mal, Werner,

The handlebar switchgear on the bike and in Werner's pictures are both correct /6 era switchgear.
The /7 series moved the signal light switch to the left side.
Attached examples of /7 switchgear.

Brett

[schrader7032]

Hmmm...none of those pictures look like what I have on my /7.

[Werner1111]

Mal, Werner,

The handlebar switchgear on the bike and in Werner's pictures are both correct /6 era switchgear.
The /7 series moved the signal light switch to the left side.
Attached examples of /7 switchgear.

Brett

Brett - Thanks for adding to the conversation. The switchgear you posted was seen on R bikes from 1981 until the '90s I think. I'm not as familiar with the later R bikes so I don't know whether they were used until the end of the airheads. When I said /7, I was probably being too literal by referring only to the years 1977 to 1980 inclusive. The switchgear from those years is only slightly different from the /6 switchgear which was seen on BMWs in 1975-76 (1974 /6 bikes still had the switchgear from the /5 bikes). The difference between the /6 and /7 can be seen in the shape of the hi-lo-flash thumb switch on the left, and also in the turn signal thumb switch on the right. Starting in 1981, BMWs sported the switchgear you posted. All of them are equally interesting and remind me of some kind of little toy that would have come in a Kinder chocolate egg.

I've posted the right side /6 vs /7 (77-80) switchgear below.

/6 switchgear - thumb goes between the two notches


/7 switchgear - thumb goes either above or below the wing.

[malmac]

I am learning things that I never knew, I didnt know. It is very interesting.

The other bit of news is that we have bought the R75/6 mentioned in earlier posts and pick her up tomorrow.

My wife and I always name our vehicles.... some do and some don't.

The name for the new green R75/6 is Cucumber.
You might think that is based on it being green and that may or may not be the case.

The truth is I had a dream and a chap in my dream said, so are you going to get "Cucumber"?
We figured it was my brain thinking what a pickle I was in working out to buy or not to buy.

Hence Pickled Cucumbers!!!!

Well you are right I probably need a shrink.

Is their a doctor in the house?????

Cheers


Mal

[schrader7032]

Congrats!!

[Werner1111]

That's awesome! Congrats Mal. Thanks for taking us on the journey.

PS - I dig the name Cucumber. That's a good one!

[malmac]

Well advisory team, please don't log out and disappear.
Really the games have just begun.

My motto is, a jobs not worth doing if it doesn't involve making a special tool.
So I am sure one or two will pop up as things progress.

Cucumber sandwiches will undoubtedly require some sort of jig, tool or measuring device.

Thank you to you for your contributions.

Regards.


Mal