R100/7T

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CharlieVictor
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R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 1:42 pm

Those "7Ts" (not to be confused with the R100T which was a transition model between R100S and R100CS) were always a mystery... Police-only version? US-market designation (as Butler& Smith also had their in'house designe "/7T)? The interpretations are various and sometimes contradictory.

What exactly makes a Slash 7 a "/7T" -apart as having its VIN come up as such on realOEM_ still eludes me...

https://www.ebay.co.uk/itm/173665848620?ul_noapp=true
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Re: R100/7T

Postby Rob Frankhamr » Fri Nov 30, 2018 2:06 pm

Those "7Ts" (not to be confused with the R100T which was a transition model between R100S and R100CS) were always a mystery... Police-only version? US-market designation (as Butler& Smith also had their in'house designe "/7T)? The interpretations are various and sometimes contradictory.

What exactly makes a Slash 7 a "/7T" -apart as having its VIN come up as such on realOEM_ still eludes me...

https://www.ebay.co.uk/itm/173665848620?ul_noapp=true

I did some research of this a while ago. The R100T isn't a faired machine at all so it doesn't fit between the R100S and the 'CS but in the line of unfaired machines. This is what I concluded based on BMW parts lists and other sources. The machine in question at the time was a '81 machine.
If you want to be pedantic, it's actually designated a R100 (no T or /7) the R100/7 was produced between 1977 and 1980 model years, and the R100T between 1979 and 1980 model years. According to the Spec, the 'T' has a higher compression ratio and a slightly higher power output leading to a 5mph increase in the top speed. The 1981 year R100 gained a massive extra 2hp over the R100T with a consequent reduction in it's 0-100kph figure of 0.1 secs. The /7 and T suffixes were never used for the same bike by BMW. The contemporary parts lists refer to both as /7T because the two models are so similar.
That's the best I could come up with although, as you say, a number of sources are contradictory.

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Re: R100/7T

Postby daz » Fri Nov 30, 2018 2:36 pm

As a new owner of an 1980 R100T I found the information that Rob provided to be factual. More sources agree with Rob than contradict him. I think there were some options for the R100T like two additional gauges.

Now I'd like to speculate (guess). Or perhaps I should put this in the form of a question. It seems to me that the new style air box (after the clam shell) coincided with the larger diameter exhaust and carburetors. And the R100T has the newer air box. Does my guess hold water? Do slash 7s all have the older box and smaller carburetors?
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Re: R100/7T

Postby vmx1200 » Fri Nov 30, 2018 3:16 pm

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Re: R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 3:47 pm

"I did some research of this a while ago. The R100T isn't a faired machine at all so it doesn't fit between the R100S and the 'CS but in the line of unfaired machines. This is what I concluded based on BMW parts lists and other sources. The machine in question at the time was a '81 machine".

Rob,
I'm not talking about the R100T, but the R100/7T.... They are/ seem to be different machines. It's the R100/7T I'm baffled with, not the R100T.

As for the R100T, it is described in the French Revue Technique Motocycliste (and I think in Falloon's book, although I'm not absolutely sure) as a transition model between the S and the new Type 247 A10 engine CS, which allowed BMW to shift batches of old 65hp engines sitting in the factory.
Released in Germany in late 79, then in 1980/1981 in France (and probably elsewhere), the R100T was a faired machine, just like the S, with a few gimmicks such as dual tome paint trim. The R100T was even available with the RS fairing, and known as R100TC.

So, back to the elusive R100/7T... :roll:
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Re: R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 3:54 pm

Not really... It's about the R100T again, not the R100/7T. And relates to the US market where it was sold by Butler & Smith without the bikini fairing.
This is the Euro R100T:

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1978 BMW R100S "Naked"
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Re: R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 3:56 pm

And the R100TC
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Re: R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 3:56 pm

But the R100/7T remains a mystery....
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Re: R100/7T

Postby windmill john » Fri Nov 30, 2018 3:58 pm

Now I'd like to speculate (guess). Or perhaps I should put this in the form of a question. It seems to me that the new style air box (after the clam shell) coincided with the larger diameter exhaust and carburetors. And the R100T has the newer air box. Does my guess hold water? Do slash 7s all have the older box and smaller carburetors?

Not sure if there is any basis, bearing in mind in the same year of the switch, the R65 also went plastic whilst maintaining 32 mm carbs and 38mm exhausts.
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Re: R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 3:59 pm

Not really... It's about the R100T again, not the R100/7T. And relates to the US market where it was sold by Butler & Smith without the bikini fairing, but with the extra clocks and some other local mods (B&S had to adapt the airheads to the American tastes, which were not leaning towards any type of fairing).


This is the Euro R100T:

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1978 BMW R100S "Naked"
1999 W650 RS "Twin with a kick"

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Re: R100/7T

Postby CharlieVictor » Fri Nov 30, 2018 5:17 pm

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1978 BMW R100S "Naked"
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Re: R100/7T

Postby Rob Frankhamr » Fri Nov 30, 2018 10:37 pm

I'm afraid we're going to have to differ on this one.

As I said, there are contradictory sources. The 2002 ETK refers to a R100/7T but makes no mention of a R100/7 or a R100T which I take to mean that they have lumped the two together some 20 odd years after the event. I've noticed that the Mobile tradition lists are suspect in a number of other ways.

The source I have that I believe to be the most reliable is the 1981 year BMW auxiliary catalogue that lists every part of every model from 1969 to 1981 and, being contemporary, is likely to be the best representation of what BMW were actually doing at the time. It's a massive book. The pages aren't numbered but I would guess at well over 1000 pages of diagrams and listings. It tells me (among a lot of other things) that the 's fairing was only offered as standard on the R90s and the R100s (the 'Cs' hadn't been produced in '81) although it was an optional extra on most other contemporary machines. It also makes no mention whatsoever of a R100/7T.

If you take a look at this page http://www.omnilex.com/public/bmw78/ you'll find images of all of the BMW brochures for the relevant period. No mention of a R100/7T and all of the R100T's are undressed.

Of course, various importers also made their own bespoke 'models'. Butler and Smith were notorious for it in the US and there is a deal of evidence that the Australian importer did the same. I've also heard it said that at least one UK dealer would do it.

So, for what it's worth, I'm fairly satisfied that my statement in the previous post is as close to the 'official' contemporary BMW position as I can get.

Rob
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Re: R100/7T

Postby CharlieVictor » Sat Dec 01, 2018 6:45 pm

Yep, it sounds totally credible (although Omnilex displays mostly -only?- US brochures, such as the "Touring" which was an "S" with Lufmeister fairing)
And the R100/7T merged with the R100/7 makes sense. I think we'll have to accept that interpretation.

However there always seems to be another source that contradicts the first one. ](*,)
B&S did remove the fairing and added a small windshield and Krauser valises (thats how the T is featured on the US pamphlets). yet in France and Germany, Ts are shown with the bikini fairing as on the above picture....

And I even found one for sale here :

Image

Image

We won't solve that one today.... :-k
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Re: R100/7T

Postby Rob Frankhamr » Sun Dec 02, 2018 11:02 am

As with all things BMW nothing is simple... especially after thirty odd years. My thought on that one is that in the day, you could order just about any airhead with an 's fairing, even an R60/6. You could even buy an unfaired bike off the shop floor and have a fairing fitted by the dealer before you picked it up. It could also be that there was a shortage of the R100s so some dealers 'made their own'. Who knows. Just to complicate things a bit more, I'm not even sure that the fairing on the red and grey bike is a stock BMW fairing. It doesn't appear to have the same upper mounts that the stock item used... although I am mindful that there appears to be a bunjee cord holding it in place, which may be relevant... or not. It also appears to have a rear disc which, again, was not a stock fitment on the R100T.

The little quirks are quite fascinating provided we accept that we're never going to be 100% sure...

Rob
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Re: R100/7T

Postby daz » Sun Dec 02, 2018 1:38 pm

Image
Here is my 1980 R100T. I changed the air box, starter cover and valve covers from my extra /6 engine. I planned to exchange the engine /6 name tag with the R100. Surprise! R100 is cast as part of the newer starter cover. I will source the proper one from somewhere.
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Re: R100/7T

Postby CharlieVictor » Sun Dec 02, 2018 6:44 pm

"The little quirks are quite fascinating provided we accept that we're never going to be 100% sure... "

I concur.

And to wrap this thread up:

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1978 BMW R100S "Naked"
1999 W650 RS "Twin with a kick"

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Re: R100/7T

Postby Rob Frankhamr » Sun Dec 02, 2018 8:13 pm

Now that is interesting... I hope you don't mind but I've taken a copy of that. Can you tell me where it came from?

Rob
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Re: R100/7T

Postby CharlieVictor » Mon Dec 03, 2018 9:39 am

The Revue Moto Technique (RMT), which I was referring to earlier in this post. It's the French equivalent to Haynes or Clymer.
Let me know if you'd like a copy... They pop up on a regular basis for 10 or 12€, usually rough and greasy!
I can get you one, or you can order it brand new from here:

https://www.librairie-spe.com/rmt-piagg ... 91193.html

Image]
1978 BMW R100S "Naked"
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Re: R100/7T

Postby Rob Frankhamr » Mon Dec 03, 2018 10:31 am

Thanks for the offer. I will try to find one new (The linked site appears to be out of stock) but if I can't find one, I'll come back to you.
Thanks again

Rob
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Re: R100/7T

Postby CharlieVictor » Mon Dec 03, 2018 11:54 am

You are very welcome.
Glad that for once, it's I helping you !
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Re: R100/7T

Postby vmx1200 » Tue Dec 04, 2018 9:43 am

Interesting background, another "little quirk" is that both the RS and the 100T in the photos have silver rocker covers as they have rear discs they must 1978 on so i would have expected black??
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Re: R100/7T

Postby CharlieVictor » Tue Dec 04, 2018 9:57 am

Interesting background, another "little quirk" is that both the RS and the 100T in the photos have silver rocker covers as they have rear discs they must 1978 on so i would have expected black??
This is not an RS, but a TC. As explained earlier, a T with an RS Fairing, T and TC both sold in Germany from 79 to 81, and France from 80 to 81, until the new CS with the A10 engine was released.
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Re: R100/7T

Postby vmx1200 » Tue Dec 04, 2018 11:15 am

My mistake I should have read the caption with the picture #-o #-o
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