Designer & bike rider in British Columbia, Canada

R80 19 Go Down Swinging

Since we’re still waiting on the engine I figured let’s start thinking about ride height tests and light mounting points and other parts you can’t really get a sense of on the stand. But that requires having tires on the bike, which requires wheels, which requires a swing arm to attach to.

More powder coat overspay. Then soak to degrease bearings.
Repacked by the power of plastic tube with moly lube.
The swing arm pivot bolts are bored to allow grease gun recharging while on the bike—cleaning out the old stuff here.

Had made the decision before paint not to replace the bearings. Prefer the only-buy-it-if-you-need-it approach at this point. Ditto for the swing arm seals: we’ll replace them, if we need to, after the first 1000km maintenance check later this summer. So everything was cleaned in-situ this time, which I discovered some old gasoline works best on. Since the swing arm bearing recesses are filled, I could leave some gas sitting in them to soak the old grease out of the bearings. Repacking worked alright as the spout of the LM47 grease tube fit snugly over the bearings and I could pack some pressure to get in there.

Interference fit of the bell on the drive shaft. Must be very clean or it’ll spin and wreck.
New drive shaft bell (flange) nut.
Big vice for 150 ft-lb torque. Secure the input coupler between wood to keep from marring.
Make sure the gap is equal on both sides (supposed to be o0.02″ I believe), then preload the bearings to 15ft-lbs, then back off to 7ft-lbs.

If you the bike to go you need a shaft in the swing arm. Putting this back together was much easier then getting it apart (which we had done to paint the swing arm). In this case leaving an old nut at 150lbs on one of the most essential interfaces on the bike felt too laissez faire, so I’d already ordered a new one with the last Wunderlich order. It’s pre-locktighted and just needs…whoa, 150lbs of torque. Which required a bigger vice, which required a trip to Home Depot to get bolts to secure the vice to hold the drive shaft (I tried it without securing it, standing on the vice on the floor…not recommended). Which a big enough lever: no problem.

It comes apart. I wish I’d known earlier.
New gasket.
Protect the seal!
Buttoned up.
Brake shoe pivot points.
Old copper crush washers, new aluminum ones.
New stainless fill and drain plugs.
Baby’s got some new shoes.
New gasket here, too, and stainless nuts with collar (no washers needed).
OK now Ii can put a wheel on.

Can’t attach a wheel without a final drive. I recall my younger days (a month ago) when I spent hours, days, in fact, trying to clean the old (copper-based?) grease of the drive splines? Turns out the spline assembly easily taps out of the final drive with a mallet. Thanks Wunderlich / Boxer2Valve video. Now it’s truly clean. New gasket, and a neat trick from the same video tutorial using a beer can to protect the main spline seal while you heat and slide the assembly half back on.

Since we’re in here might as well put the new brake shoes on, new crush washers on the drain plugs, then button the thing up to the swingarm (new gasket there, too).






One response to “R80 19 Go Down Swinging”

  1. greg ingegniero Avatar
    greg ingegniero

    That Molson is the best tool in your box… ha!

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