This 1981 BMW R100 will live to ride another day!

Hello everyone I'm new to this forum but really wanted to share my progress with this upcoming project. My name is justin, I'm 23 and live In Winnipeg manitoba.

I'm no mechanic by any means but over the last year I have discovered a passion for working on bikes. This past summer I've fixed up 3 Hondas and wanted something different !

I had seen a few BMW airhead bikes and instantly thought wow boner machine I need one. I posted an add on kijiji and two weeks later I bought this


The guy called me b said he had two, one being completely apart... I figured if I wanted to learn everything that was the one for me! He was more then surprised. So I paid $1000 for the bike w\ TOD (or as my gf would say for a couple boxes of parts....)

I'm yet to decide exactly what I'd like to do with it but first things first I plan on sending the frame and other pieces for powder coating this week sometime. Meanwhile this will give me time to reassemble this engine with the $200 worth of seals n gaskets I've just received.

I will post my progress ad or questions I may have along the way. Please if u have ideas or suggestions along the way I would really appreciate it your input, thanks everyone.




Sent from my iPhone using Tapatalk

i was born and grew up in the peg half a million years ago and owned a few airhead that would now be called vintage

i would laugh myself silly if you just found one

Aha well was it a 1981 r100 black n other was 75 r90 I think


Sent from my iPhone using Tapatalk

Nice score .........Airheads make super period looking Cafe Racers.

Thanks ! Very excited to get started on it, first of all I'm kinda going through all the boxes making sure all important parts are there and what exactly I'm going to need. Can anyone tell me if it's a certain set of piston rings I need for this bike (standard bore) or are all airhead std bore piston rings the same ? Sorry wana make sure I purchase the right ones


Sent from my iPhone using Tapatalk

Great bikes and oh so enjoyable to ride. You will be spoiled after you get it together.

I've got an r60/6 so I'll be following along. Sadly I don't think I can help you with spare parts as not much pre 77 is compatible with post 77 airheads.

No worries! Wow Ellwood what sexy bike!! I am honestly just waiting for like 10 eBay packages, I've been doing nothing but research online as well as with my Haynes n clymers manual. My new question I have is what the hell did this guy do? As I'm inspecting the fly wheel and my boxes of parts I find the oil pump rotor and cover.... So I suspect he just re attached the fly wheel so the crank didn't pop forward? I figure when the rear main seal arrives I'll block the crank from moving forward and remove flywheel and hopefully get that end assembled! I will finally get in the garage Tomoro so I will post a bunch of pictures


Sent from my iPhone using Tapatalk

Here's my transmission after a bit of cleaning, just waiting on the rubber boot for the end of the clutch rod and that's will be done


I was a bit concerned to see these 2 little marks as well as the bruised up bottom, can anyone tell me if these should be replaced ?

Here are my valves after a bit of cleaning with a brush. From what I've read the valves seats should be inspected so I just picked up a valve compressor and am Gona learn how to use it.



Sent from my iPhone using Tapatalk

Is ther a special tool to take this off ?
So I can take driveshaft out of swingarm


Sent from my iPhone using Tapatalk

those cylinders need re-conditioning,there are outfits you can send them out for a fresh plating,new pistons would be the way to go as well
go ahead and pull the valves and inspect all that stuff as long as you have it this far
at the minimum you will want to change the valve seals, check the guide/stem clearance and actual condition of the seating of the valves
what is that spline deal the output on the universal joint ?

Thx ! Answers a lot of my questions. I don't follow what your asking about the universal joint .


Sent from my iPhone using Tapatalk

Probably not much help for you. I have found some very informative videos on YouTube. I had my bike gone over by a guy named Clanton Austell. So if you see him pop up on a BMW specific sight he is very knowledgeable. Also you would be good to look up http://www.motoelekt.com for your electronic needs. Very nice on the phone and helpful. His stuff is the best and his prices are reasonable.

Beauty ! I believe electrical will be later on but I will absolutely need some of that. Ellwood have u ever had to remove the driveshaft from ur swingarm? I can't find any info regarding this and am really wanting to send this stuff out for powder coating


Sent from my iPhone using Tapatalk

Great project! I build cafe racers out nothing but BMW's, these bikes are easy to work on and customize, and they ride great when done up nicely. Here's my advice; unless you are going to restore this bike back to bone stock condition, don't powercoat the frame until you've mocked it all up and are happy with it all. If you decide to customize the bike, you will likely end up wanting to remove some tabs, weld up this or that, etc. If the frame is already powdercoated, you'll be screwed. So mock it all up, then blow it apart for paint/powdercoat. Now go have fun, eh?! ;D

Fillionj said:

Is ther a special tool to take this off ?

So I can take driveshaft out of swingarm


Sent from my iPhone using Tapatalk

Click to expand...

Apply some heat to the bell coupler to expand it a wee bit/break the bond, then use a shop press to separate it from the tapered driveshaft.

CafeDude said:

Apply some heat to the bell coupler to expand it a wee bit/break the bond, then use a shop press to separate it from the tapered driveshaft.

Click to expand...

Awesome thanks for the tip, this was
Driving me nuts lol.


Sent from my iPhone using Tapatalk

I didn't know the name of the bell coupler! Now that I know I've found many posts saying it may be a tad easier
To just tape prime n paint the swingarm myself.


Sent from my iPhone using Tapatalk

CafeDude said:

Great project! I build cafe racers out nothing but BMW's, these bikes are easy to work on and customize, and they ride great when done up nicely. Here's my advice; unless you are going to restore this bike back to bone stock condition, don't powercoat the frame until you've mocked it all up and are happy with it all. If you decide to customize the bike, you will likely end up wanting to remove some tabs, weld up this or that, etc. If the frame is already powdercoated, you'll be screwed. So mock it all up, then blow it apart for paint/powdercoat. Now go have fun, eh?! ;D

Click to expand...

Good call, cause I am really not sure what my plans are for this bike just yet. And it allows me to start assembling right away!!

I am just waiting to have a bit of time to take these cylinders to a shop down the street to get reconditioned. Hope they aren't in too bad of shape.

The only down side to having bought this bike all apart is that I did not do the disassembly which would of been very helpful when reassembling. Either way thx again hope I can get it to a roller this weekend


Sent from my iPhone using Tapatalk

Fillionj said:

Good call, cause I am really not sure what my plans are for this bike just yet. And it allows me to start assembling right away!!

I am just waiting to have a bit of time to take these cylinders to a shop down the street to get reconditioned. Hope they aren't in too bad of shape.

The only down side to having bought this bike all apart is that I did not do the disassembly which would of been very helpful when reassembling. Either way thx again hope I can get it to a roller this weekend


Sent from my iPhone using Tapatalk

Click to expand...

Definitely! Just make sure the u-joint is in good shape.