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1977 BMW R100 S BUILD

2389 Views 17 Replies 7 Participants Last post by  TrialsRider
What’s up everyone,

I recently purchased a 1977 BMW R100 S. Bike has high miles (30,000 or so), but is in great shape and runs fantastic.
As an A&P mechanic for aircraft, I felt I wanted to take on this build on my own as much as possible.

What do people suggest when it comes to starting out? I planned on stripping the body down to just the frame and engine. I’d like to sandblast the frame and re prime / paint, along with the engine itself. Small amounts of rust are visible on the bottom of the frame.

Any suggestions?

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Whats your riding experience?

Don't fall into the trap that most people fall into, disassembling the bike and never getting it back together.

If its a well running, titled bike, treat the rust in-situ.

Here's what I'd do:
Using a Clymer manual, do a full service of the bike.
-braided brake lines
-fresh fork oil
-fork brace
-superbike bars
-hagon rear shocks
-new stem and wheel bearings (All Balls brand)
-quality performance exhaust
-new tires (i like Avon road riders, but others here have their recommendations)
-new fuel lines and fuel filters
-new coils and electronic Ignition

Each of those individual upgrades can be done in a weekend max, and will keep you riding as much as possible. Not only that, but you'll have a bike that will absolutely perform better than stock.

My riding experience is middle of the road. I’m 27 years old, so not much experience, but recently sold my 2017 Triumph Street Triple. I grew up on Honda dirt bikes. I’m assuming I can get a Clymer Manual online?
BMW's are one of the hardest bikes to get factory manuals for but there is lots out there and lots gets taken down or disappears too. This bike will be mild and uninspiring in power and handling compared to a street triple, but it is the kind of bike you could stick your bank card in your back pocket and cross the continent on. It's a go far bike, not a go fast bike.
That’s one of the reasons for purchasing it. I’ve been riding it around town lately and the horizontally opposed engine was tricky to get used to at first, along with the weight of the bike.

I’ll start stripping it down and see where I end up. I purchased it for a project bike, so I plan to change plenty on it.
What you do depends on what your goals are...

46works built an r75 and an r100rs that would be what I would do. Not sure of all the details but all his builds are built to ride.

The first one is awesome... the second maybe a little more made for the dumb masses.

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I agree with you on the top one… not a huge fan of the bottom picture but to each their own.

This is more what I’m leaning towards.
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