1975 BMW R90S Restoration

[skychs]

I guess the fork brace was removed at some point? The pictures above show the stock stainless steel unit.

Depending on your weight, consider stock replacement fork springs. The progressives can be stiff too.

No worries on the parts.

The fork brace was sill on the front end when I rolled it into the garage. Right now the plan is to leave it off and see how the front end handles. If it wonders all over the place I will reinstall it to see if there is a difference. Im getting new IKON's for the rear. Not sure about the front yet.

Jim .... all the parts went local yesterday. I appreciate all the help/input. If your ever in this area please stop by and say hello.

[skychs]

The swing arm came back from the mechanic with the drive shaft installed so the rear end is back together. The front forks are in. I now have a rolling chassis.

The last photo is a tool I picked up this week. I wasn't too sure how it would work but I have to say it works well.

[khittner]

Your aftermarket fork brace is a Telefix. Opinions may vary, but some seem pretty confident that the devices tend to engender more fork stiction than anything else. The /6 and /7 airheads' forks and frames are pretty "flexible-flyer-ish" from the get-go, and these reportedly didn't do much to change/improve that. The PO of one of my 90S bikes had installed one, and I thought it rode badly; removing it (and selling it to the first "go fast" wannabe) improved the ride on my bike, FWIW.

[skychs]

Thats what Im thinking as well. Im not racing the bike. I doubt I will need all the extras the PO installed. A good set of springs on the front and IKON's on the back should make it a sweet ride.

[skychs]

Im sorry. I had to do it. Once it became a rolling chassis I had to grab the tank to see what its going to look like. I just sat there and looked at it for several minutes with a huge grin on my face. Im really starting to enjoy this build. Im sure the grin will be gone when I start on the electrical system.

[rayburtappraisal]

Do you mind if I peek over your shoulder on this? My 76 R90S has been sitting in the garage with the front end off for the past two years. Started to work on the front forks, then "stuff happened" and it has been collecting cobwebs ever since. Trying to pick up where I left off and your progress to date has been very helpful.

[skychs]

Do you mind if I peek over your shoulder on this? My 76 R90S has been sitting in the garage with the front end off for the past two years. Started to work on the front forks, then "stuff happened" and it has been collecting cobwebs ever since. Trying to pick up where I left off and your progress to date has been very helpful.

The fork gaters just came in so I have to pull the front end one more time. How can I help you. More photos? If so ... what specifically?

[ksiemon]

Observation / Comments...........

Looks like your "kickin but" on your project! Great work so far! I know this is your first /6 and "S". I don't know if your trying for a spot on resto or just putting back as you got it. And I may have missed your comments on other posts. You have a aftermarket top triple clamp, and also a newer braced swing arm. These were a popular and unnecessary "Handling Upgrades" done in the 70's. The same with the fork brace add-on. If your vintage racing.......then yes, it'll help. Also the "S" and "RS" bikes never had gators, but a lot of BMW guys liked the looks. If you like your mods, then buy all means keep them, It's your bike! Duel plug heads same thing. In the day they helped with "detonation" when premium leaded went away. The other mod they did was to put a /6 base gasket in to lower compression. Mine still has points and single plugs, stock compression and runs fine on todays fuel. Koni shocks were to stiff for me. (I was like 150lb in the day) so I just ran stock stuff. I did use them on my 79 RS when riding two up and they worked great. Gave them to a friend who needed a set. And yes there are plenty of springs out there to fit your needs. Running stock stuff now.I do like the shock covers. Check your throttle cables where they run in the elbows coming off the carbs. They rub there and will break. Mine was made into a R45S in 79 in Florida. I do like the looks of the elbows. All you can get from BMW is a straight carb top nipple and cable to fit. Moto-Bins in the UK has the ones for yours if you need to replace. If you have the $$ just get a new master cylinder from Moto-Bins. Mine finally gave it up last year. I did rebuild it but still has the old tank (reservoir) I checked every where for one, none to be had. Should have just got the whole unit new. I love that it was covered under the fuel tank. All the racer ass's bitched in the day there was "no feel" because of the cable. Again more BS. I also have a K100 I purchased new. About 4 years ago the front master cylinder took a crap. Guess where the fluid went? on the painted radiator shroud. My 43 year old S and 39 year old RS all good, as far as paint damage, no free lunch! My seat finally needed over-hauled
and got a base and foam from Two-Valve. The cover came from Meyer in Germany. If your mirrors are shot like mine were ( it got all fogged out) plus blasted buy the miles, Meyer also has curved Bumm ones. 89 euro's each.

Wish you the best! You'll love it when done. And all motorcycle people love the "S" bikes. They were really ahead of there time!

The biggest Modification I ever wanted for my S.... I got in 1995.........The God Damn 55 MPH speed limit repeal!

[skychs]

Ksiemon .....

Thanks for all the input. I learn a little bit more every day.

This restoration is for one purpose .... (ok, maybe two) .... it’s to restore a vintage bike back to its original condition “and” make it a daily rider. I’m not going to race it or enter it into any fancy show. I’m going to ride it, admire it and take it to the local bikes nights for fun. The extra modifications were a sign of the time but to be honest, the ride sucked. My /2 rides better. I can’t do anything with the reinforced swing arm or the dual plugs but the triple clamp and fork brace are probably coming off.

I’m 200+ so the new Koni shocks should be fine. The throttle cables have already been upgraded and the bike has an upgraded electronic ignition. In regards to the front master cylinder the plan is to rebuild it and hope for the best. Oh, I’m getting a new seat from Sargent and the original mirrors need some paint but are in great shape.

I hope that addresses everything. I can assure you it will enjoy most of its life over 55 mph.

[ksiemon]

The most important thing as you know..... is..... make it yours! Didn't want to bum you out, just make it the way you want. If you change
the top clamp your going to need new (used) head light ears. They were cut down to install the top clamp. The stock clamp is less than a 1/4 thick and is steel. There are some on ebay now. It'll be $100 (ears) $20 clamp. The other stuff can also be changed if you want down the road. Swing arms with shafts are cheep. All /6 bikes used the same. Just plug your lower spark plug hole, go back stock. Now if your "S" road like crap, and a bike that was designed in the 50's rides better than one in the 70's.... both ends are screwed up! Stiff aftermarket springs, too heavy oil in the forks. much the same in the rear. Those aftermarket fork braces did mis-aline / bind the fork travel. The previous owner (or mechanic) when changing the clamp, swing arm screwed with the bearings. The swing needs centered in the frame and the bearings torqued to the correct spec. Same on the front end. If you don't get the steering head torqued correct that bike will wobble like a drunk! Your going Ikon in the back? What about the front? I've been down that road. I bet it's got way to stiff springs in the front!

What service books did you come up with? If you want to look at the factory stuff I will help you. Let me know!