Topic: Any BMW fans out there?

[grumpy]

There'a a '75 R75/6 for sale near here.
41,000mi

Any advice?
Are parts difficult to find?

[calj737]

They are excellent bikes. Parts plentiful and the motors are often extremely durable. I have a '74 90/6 and am wicked pleased with it.

There are a couple of special tools required to fully disassemble them, and they are available stock or aftermarket. Tons of great info on the BMWMOA site and forums too.

[Davidov]

Excellent motorcycles. One of the only brands I would consider as a replacement for my CB750. Realoem.com has all the parts diagrams.

[grumpy]

cool, thanks

how do they ride compared to a 750?

One of the only brands I would consider as a replacement for my CB750.

well, that would have to be the case if I got the BMW.
the wife would never let me have 2...

I don't know if I could ever get used to the heads sticking out sideways.
man, laying those down must do some nasty damage to the motor...

[calj737]

Pretty hard to lean one of these over far enough to have that problem unless you're being very aggressive. If you're concerned about an accidental impact, crash bars are widely available though, they create other risks.

Should you happen to damage a cylinder, replacement jugs, pistons, and heads abound. Simple and well engineered motors and very easy to service.

[Head]

Very nice bikes!

[jas67]

I love mine!

1973 R75/5:


I also have a 1980 R100S in the works.

[Terry in Australia]

The R75 is a great bike mate, much smoother and easier to live with than the two R100RS' that I've owned. My brother had an R69S, and two R75's, and they were magnificent bikes, they handled better than a CB750, the later disc braked R75/6 stopped better, and while they weren't quite as fast, they could be ridden all day at indecent speeds with no major issues.

The electrics could be troublesome though, the charging systems were weak and it wasn't hard to flatten a battery if you rode in traffic with the lights on. Thankfully there are kits available to fix that, and I installed one on my last R100RS and was very happy watching the voltmeter sitting on 14 volts at idle.

As has been said previously, they are tough bikes, I dropped my first R100RS at speed (over-cooked it in a corner) and it slid on the valve cover for 20 yards or so, and was still able to ride it home. You can install a big bore kit in only a couple of hours, and you can even change your big end bearings with the engine in the frame, try doing that with a CB750!

I don't know if I'd sell your CB750 to buy it though, maybe just tell the wife you sold it and hide it at a friend's house? Cheers, Terry.

[calj737]

Stock paint, Terry? Looks to be in brilliant shape after all these years. Nearly time for a refresh on those pipes though, eh? That seems to be the only soft spot on the Boxers, is the damn chrome on those pipes. Then again, after 30+ years I guess they're bound to be a bit knackered.

[Terry in Australia]

G'Day Cal, thanks for that mate, the paint was re-done by a PO but the pipes are actually stainless steel "Staintune" (Aussie made) replacements, and as grotty as they looked in that pic, they weren't rusty, they go brown if not regularly polished.

The bike had been dropped at one time in it's life, and there were signs of repairs inside that beautiful Hans Muth designed fairing. When I bought it I replaced the original seat (which is still hanging in my garage, as the front hinge in the metal base was broken off) and the tach which had crapped out, installed the better recharging system and rebuilt the front master cylinder, and it ran like a swiss watch.

I tried to love it, but unlike the 750's the 1000 engines were pretty harsh vibey things, and the gearboxes could have been designed by Massey Ferguson so I sold it, and used the money to buy my 1986 Goldwing which is a much better bike.

I had enough left over to also buy a CX500 Custom which I did a bit of work on, then sold (for more than the R100RS) and bought my 1989 K100RS SE. While the R100RS will never go down as one of my favorite bikes, it did get me the 'Wang and the K bike, so for that alone, it was a great investment. Cheers, Terry.





   

[calj737]

I just parted with my old KRS to fund new projects and the boys University. After 240,000 with it, I'd have to rate it as my second favorite of all time, right behind the K75s I had prior to it (265,000 on that one).

I've just picked up an R90/6 to work over. It'll be the first Boxer for me, so a bit of an orientation on this motor and trans coming. I'm wondering about whether these old transmissions benefit from undercutting the gears as some of our CBs are alleged to? Been spending so much time with Sam G in hospital, the Old Bird's put me to thinking about performance and durability of everything 

[Roach Carver]

I have never had a bmw jump out if gear so my guess is no on the the undercutting. I love my boxer but I would be reluctant to part with my cb. Two different bikes, two different experiences.

[azuredesign]

I enjoyed my lwb ' 71 r75 4 speed. Big flywheel, definite lateral torque effect on gasing it from a stop. I think the '75 is a 5 speed and the torque effect may be lessened. A friend of mine had one and changed the top end to a 900cc, straight swap, as I recall.

I currently have 3 BMWs,  including a later model r100rs than Terry's. I don't find the motor is difficult to deal with as Terry described, although the tranny is idiosyncratic at best, much smoother than my r75 was,  and very different from a cb750.

I agree with Terry, you should keep both!

[calj737]

One thing about the '75 is the change at the flywheel and crank. The post 11/74 R motors switched to heavier flywheel bolts from a 10MM 1.0 . With this improved crank, swapping to big bore kits and other performance improvements is much safer.

Mine on the other hand, is pre- and thus not a great candidate unless I replace the crank and flywheel.

[simon#42]

I just parted with my old KRS to fund new projects and the boys University. After 240,000 with it, I'd have to rate it as my second favorite of all time, right behind the K75s I had prior to it (265,000 on that one).

I've just picked up an R90/6 to work over. It'll be the first Boxer for me, so a bit of an orientation on this motor and trans coming. I'm wondering about whether these old transmissions benefit from undercutting the gears as some of our CBs are alleged to? Been spending so much time with Sam G in hospital, the Old Bird's put me to thinking about performance and durability of everything 

the gearboxes were modified many times over the years , its pretty much the latter the better . also for the best change you need the light flywheel that was fitted after 81

this is the best bmw site i have found , it goes in to depth about everything !

http://bmwmotorcycletech.info/technical-articles-list.htm

cal i have been thinking about a k75 recently [ to go with the 75 and r80 ] i take it from your post you would recommend one then.

[calj737]

Mine was an 87, S model. Absolutely loved that damn bike. Could 2-up, saddles and tank bags all day and still track with my buddies on GPz, KZ, and a 750 Paso through the BRP here.

Ride it from DC to Chicago straight thru many times (+1200Km) and still could ride the next day. Only mods I ever made was a Corbin saddle and replacement rear shock after about 120,000. I'd buy a new version if they ever made it again (been replaced with their new F-series).

Only reason I even bought the 91KRS was having some trans work done (service neglect on my part, and a recall) and needed to ride to California. Also, wanted to try the ABS bike.

[grcamna2]

I love the ergos on those old beemers,makes it nice when you put lot's of miles in;the pegs are set up just where you need them to support yourself over the long haul: Excellent machines all the way around 

[Terry in Australia]

I currently have 3 BMWs,  including a later model r100rs than Terry's. I don't find the motor is difficult to deal with as Terry described, although the tranny is idiosyncratic at best, much smoother than my r75 was,  and very different from a cb750.

Yeah mate, my comments weren't a swipe at all of the 100's, the post 1981 R100RS was a lot smoother than either of mine (1979 and 1980 models) but were detuned significantly to smooth them out. The earlier engines were hotrods in comparison, but a tad harsh. Cheers, Terry.

[Sgt.Pinback]

Bought a R75/6 this week. Will get her here soon.

My first Non-japanese bike since 37 years.

[Roach Carver]

What year /6 did you get. Looks very clean.

[Sgt.Pinback]

She´s from 1976. Not perfect but unrestored.
Less than 30.000 miles.

Drives good. I was surprised how good 50hp can do. Very relaxed riding.

[Roach Carver]

That's perfect. I have a 74 which has the questionable transmission. They are great bikes.

[calj737]

That's perfect. I have a 74 which has the questionable transmission. They are great bikes.

Roach - while researching my '74 R90 rebuild, I've spent heaps of time with a local airhead guru. He's been very kind and generous with his expertise. He's shown me that a lightened flywheel, pressure plate, and crank produce a much smoother motor, faster spinning, and much smoother trans/shifting. I rode his R100 that had this exact work done and I gotta tell you, it was like using a hydraulic clutch compared to the notchy older BMWs.

Now he didn't indicate nor has he encouraged undercutting of gears, but the darn thing seems to synchro so much better with the lighter mass.

[grcamna2]

That's perfect. I have a 74 which has the questionable transmission. They are great bikes.

Roach - while researching my '74 R90 rebuild, I've spent heaps of time with a local airhead guru. He's been very kind and generous with his expertise. He's shown me that a lightened flywheel, pressure plate, and crank produce a much smoother motor, faster spinning, and much smoother trans/shifting. I rode his R100 that had this exact work done and I gotta tell you, it was like using a hydraulic clutch compared to the notchy older BMWs.

Now he didn't indicate nor has he encouraged undercutting of gears, but the darn thing seems to synchro so much better with the lighter mass.

it should also save his trans. I would imagine.

[Roach Carver]

I have thought about doing that swap but I am unsure what parts to buy. From what I understand the older trans will work but the input has to be modified? Not sure the exact procedure but it sure would be nice to ditch that heavy flywheel.