1973 R75/5 Rebuild Project Journal

[brook.reams]

Nice work!
What did you use on the headers?

Hi PhotoRider,

Just click the link I provided and all is revealed :-)

Best.
Brook.

[photorider]

Aha!
Somehow I missed the link before.
Nice detailed post.
Those things look fantastic! Let us know how long it lasts.

Cool project, BTW. Great documentation. Nice to see that bike getting all that love.

[brook.reams]

As I was putting the handlebar assemblies back together, I discovered a stripped thread in the casting that holds the pinch bolt. I did a HeliCoil repair, which is the first time I have had to repair threads in an expensive part.

I wrote up a web page on how to repair stripped threads in the assembly.

• 32 BMW R75/5 Handlebar Assembly Stripped Thread Repair

Here are a couple the pictures I took along the way.


Stripped Thread & Compression Bolt


Running Tap in from Back Side of Assembly


Threading the Insert into Tapped Hole From Backside of Assembly

Here are the finished left and right hand handlebar assemblies with new powder coating and polished levers. *I think they are going to look very nice on the new handlebar.


Assembled Left Side Clutch Assembly


Assembled Right Side Throttle Assembly

[brook.reams]

I posted a short blog about refinishing the transmission, part of the effort this weekend.

• 1973 BMW R75/5: Refinishing the Transmission and Rear Drive

This is not about a rebuild, but a refinish. The blog has links to both the transmission and rear drive web pages with all the refinishing pictures and narrative. I had "fun" getting the kick start and shift lever tapered bolts out, but I polished the bolts and holes and everything went together smoothly. Here are a couple of the pictures you will find.


Rear Transmission Grunge


Top Transmission Grunge


Front Transmission Grunge


Polished Pieces


Refinished Transmission Top


Refinished Transmission Left Side


Rear Drive Before Cleaning


Inside Rear Drive Showing Brake Shoe Orientation


Inside Rear Drive Refinished with Polished Parts


Outside Rear Drive Refinished

[brook.reams]

I removed and inspected the Boge rear shocks to see if they could be used. I really wanted to retain the stock chrome shock covers if possible. I decided they are still serviceable, so I refinished them including powder coating the springs and removing the deep scratches in the shock covers. I wrote up a web page on this and here is the direct link to it.

• 1973 BMW R75/5: Refinishing Rear Shocks

Below are a couple of the pictures included in the web page write up.


Hose Clamp Spring Compressor


Shackle and Spring Removed


Polished & Powder Coated Parts


Refinished Shock

[brook.reams]

I posted another chapter on this project about replacing the swing arm bearings and powder coating the swing arm. This blog post has a link to the web page I wrote about this.

• 1973 BMW R75/5: Replace Swing Arm Bearings & Powder Coat

I hope this is helpful to folks. Here are few sample pictures from the web page to wet your appetite.


Cycle Works Swing Arm Bearing Puller Kit


Removing the Spacer


Puller Positioned to Remove the Dust Seal


Progresso Soup Can "Sock" Over the Universal Joint


Powder Coated Swing Arm


Swing Arm Bearing Parts-Top to Bottom, Inside to Outside, Left is Drive Shaft Side, Right is Shock Side


Shock Side Showing Bearing Race and Grease Cover Installed


Dust Seal with Sleeve Installed

[brook.reams]

Folks,

I posted a report on this part of the project:
http://brook.reams.me/about/bmw-moto...head-bearings/

that contains a link to a web page I wrote up about what I did:
http://brook.reams.me/about/bmw-moto...head-bearings/

This is a milestone on the project as I am now reassembling parts in the frame instead of disassembling them.

I hope this material is helpful to others. Here are a couple of the many pictures I put in the web page.


Steering Head After Forks Removed


Steering Stem Showing Top Bearing


BMW Steering Head Race puller


Top Race with Vertical Bands Indicating Brinelling


Bottom Bearing Slipped On and Seated on the Steering Stem


Top & Bottom Bearings Packed with Grease


New Chrome Top Dust Cap Really Shines

[brook.reams]

I documented this work here.
1973 BMW R75/5 Rebuild: Measuring Cylinders, Pistons and Installing New Rings

It contains a link to the web page I wrote up with the details of what I did.

I hope this is useful to others who are considering doing this kind of work.

Here is a sample of the pictures I took along the way.


Zeroing Micrometer


Bore Gauge with Dial Indicator


Setting Bore Gauge to Known Length


Measuring Bore Diameter


Measuring Piston Diameter on Wide Side


Inserting Hone in the Cylinder


New Rings, One Over Size


Positioning Ring In Ring Grinder


Measuring End Gap - Perfect