'73 Suzuki GT250 - Part 6 - '79 Suzuki RM 125 rear wheel refurbishment

Since I’m using a ’79-80 RM/PE 250 swingarm in my GT250 I figured that it would be easiest for me to fit same type of rear wheel to go along with it. I made a want-to-buy add to our local vintage MX forum requesting a ’79-80 RM250 rear wheel.

I had almost forgot my add when I received a phone call from a guy nearby. He had a pile of parts from a ’79 RM125 for sale including a rugged rear wheel, which would acquire quite a lot fixing up. Rim on it had cracked from several places and spokes were warped. After being outside for couple of decades lots of rust had formed in the brake drum and bearings were seized in place. 

'79 RM125 rear wheel (right).

Disassembling was the first thing to do and getting the beat up tire out with help of couple of tire irons and some lubricant. I needed to save few of the spokes and nipples so I applied some rust remover to them, screw them out with a spoke wrench and marked them masking tape. I removed the ones that were badly jammed or had cracked nipples with an angle grinder. Bearings were easy to get out after heating the housings with a hot air gun.

Couple of tire irons, spoke wrench, 1 mm cutting disc
for angle grinder and rust remover.

Rear wheel hub, bearings, spacer, spokes and nipples.

Rear wheel didn't come with a brake shield so I bought one from eBay and disassembled it.

'80 Suzuki RM125 rear brake shield

Due to heavy use and load bearing housings on the sprocket side tend to wear out and become loose. One way to fix this is to turn the housing bigger and fit a new steel bushing to it, which then holds the bearing. I send my hub to a machine shop located in Kokkola, Finland, called Konepaja Ågren to get it fixed up.

Pair of 6202-2RSH/C3 rear wheel bearings (15 x 35 x 11 mm).

I marked the worn bearing housing with a red marker pen.

Fixed housing with a new steel bushing inside.

Once I had both rear wheel hub and brake shield I masked them for sandblasting. I used old parts (rear sprocket and bolts, caps etc.) and masking tape to protect surfaces I didn't want blast. I also cleaned the brake drum before blasting with rust remover and a sanding pad. I took blasted parts to one of my local paint shops and got them painted black.

I used old parts for masking to protect surfaces I didn't want
to get sandblasted.

Painted rear wheel hub and brake shield.

I cleaned the brake drum with rust remover and a sanding pad.

I was looking for a new rear wheel rim and I got an offer of a new old stock (NOS) 18" x 1.85" Takasago rim with 36 holes. Since it had a reasonable price I decided to purchase it. Surface of the rim had stained during storage so I cleaned it with some Autosol Metal Polish and Autoglym polishing cloth.

NOS 18 x 1.85 Takasago rear wheel rim.

Storage stains on the surface of the rim.

Autosol Metal Polish and Autoglym polishing cloth.

Surface after polishing.

I picked one inner and one outer spoke from sprocket and drum brake side of the hub (4 total), marked and send them to Wheel Factory Finland, a company which makes custom spokes and nipples. I decided to try stainless steel spokes in this project. I've used their spokes before on couple of my bikes and been very pleased with them.

Model spokes marked and ready for shipping.

New set of stainless steel spokes and nipples.

Dimensions for '79 Suzuki RM125 rear wheel spokes.

I assembled the hub (bearings and spacer) before putting on the spokes. I used an axle seal (20 x 35 x 5 mm) to cover and protect the sprocket side bearing. I will turn a new bushing for it when I start lining up front and rear wheel sprockets.

New axle seal (20 x 35 x 5 mm).

I began lacing by placing all of the spokes to the hub, lubricated every spoke thread with boat tar and screwed them to the rim with nipples. Once I had the whole wheel together I took it to my local village shop. They do lacing for bicycle wheels and were able to line up my wheel and tighten the spokes for a fair price.

Bottle of boat tar.

I lubricated all of the spoke
threads with boat tar. 

Assembled rear wheel.

I've wanted to try white vinegar for rust removal for a while and brake shield parts seemed suitable for this experiment. I set rusted parts to a plastic container and filled it up with white vinegar. Placing the container to a warm location sped up the chemical reaction. Vinegar quickly turned to brown color and after a while to black. Unfortunately after keeping the parts a bit too long in the solution it had build up a black gooey layer on the surface of every part. I cleaned it off with warm water but it left black stains, which I had to soda blast off.

Rust removing with white vinegar.

Parts after white vinegar treatment...

...and after soda blasting.

Now that I had rust free parts I decided to try bluing them. I bought a bottle of Birchwood Casey's Perma Blue, a liquid gun blue. Bluing is simple process, which starts by applying the solution to surface of cleaned and rust free parts. I used a small paint brush. At first the surface turns black for a while. After the solution dried out off the surface I washed it with warm water. Last step was to oil the surface to bring back the black color.

90 ml bottle of Birchwood Casey's Perma Blu

First three stages of bluing: rust free (bottom),
applied (center) and dried and washed (top).

Dried parts after applying bluing solution.

Oiling the surface brings back the black color.

Lastly I replaced some of the worn parts with new ones. I ordered a new OEM bushing (09319-10008), washer (08211-15341) and pivot dust seal (61262-22A00) through my local Suzuki parts dealer. I bought a new TA2225Z roller bearing (22 x 29 x 25 mm) from eBay for a more reasonable price than the OEM one. Unfortunately the new bushing didn't match with the original spherical plain bearing so I have to find another one or use the old one instead. I also bought a pair of EBC S 617 brake shoes.

Bushing (09319-10008) didn't match with
the original spherical plain bearing (left).

Pair of EBC S 617 brake shoes.

Yamaha RD 350 F2 '88 - Part 6 - New rear wheel bearings, seals, X-ring chain and sprockets

While maintaining rear linkage for my RD350 I went and replaced worn out sprockets and chain. The old chain had strained quite a lot during its life time and it was already tightened to its max position. One option would have been to just shorten it but since the old rear sprocket was also in pretty bad condition I decided it was best to just replace all those parts. 

I ended up choosing sprockets made by JT Sprockets and a X-ring chain made by D.I.D. I went with 17 tooth front and 39 tooth rear sprockets. Since the chain needed to be riveted I had to buy a chain breaking and riveting tool also made by D.I.D. There were two types of tools for sale. I bought the cheaper one, which had "02-99" stamped on the side of it. While riveting the chain I found the lower jaw of the tool bending and had to make a cotter out of flat bar to stop it.

I also decided to replace rear wheel bearings while I had the rear wheel out of the bike. I bought a kit which also included right sized oil seal (22 x 42 x 7 mm). I used a gas torch to heat up and expand both bearing hubs in the rear wheel to get the old bearings out and to install the new ones. Depending on the condition (rusty) of the bearings you might need give them a small knock. If you have painted your wheels you might need to use another solution. If you don't have proper tools for the job, there's a lot of shops, which can do it for you. 

Unfortunately I forgot to buy a new bearing (6304) for the sprocket carrier and since it was Sunday and all the shops were closed when I was doing all of this in a hurry to get the bike finished I just ended up greasing the old bearing and replacing worn oil seal with a new one (32 x 52 x 7 mm).

To sum all up here's a list of all parts needed for the job:

-Tourmax rear wheel bearing and seal kit (MCI-WBK-055) 

 or two 6302 bearings (15 x 42 x 13 mm) and oil seal (22 x 42 x 7 mm)

-Oil seal for sprocket carrier (32 x 52 x 7 mm)

-6304 bearing for sprocket carrier (20 x 52 x 15 mm)

-JT Sprockets 17 tooth front sprocket (JTF569.17)

-JT Sprockets 39 tooth rear sprocket (JTR846.39)

-D.I.D 520 VX2 X-ring chain with 106 links

-D.I.D chain breaking and riveting tool (02-99)

There's also one O-ring (93210-40530) in the rear wheel you might need to replace. Since mine was in good condition I just ended up greasing it.

Tourmax rear wheel bearing and seal kit (MCI-WBK-055)
and collar (90387-154A0).

Rear wheel (black) and sprocket carrier (blue) oil seals

Front and rear JT sprockets and D.I.D 520 VX2 X-ring chain.

D.I.D chain breaking and riveting tool.

Parts of the tool... 

...and instructions for it.

Cotter kept lower jaw from bending.

Bearings and other hardware removed...

...and new parts installed.

New rear sprocket and oil seal installed.

X-ring chain riveted and tightened.