920 lightweight

The jury is still out on the handling. Knowing that the bike was coming apart again for painting, I put it together with the worn swing arm bushings that were on hand.
I thought I could " ride around" the slack for awhile, then install new bushings at paint time. It's worse than I thought so the bushings and painting will get done sooner rather than later!

Glen

worntorn said:

The jury is still out on the handling. Knowing that the bike was coming apart again for painting, I put it together with the worn swing arm bushings that were on hand.
I thought I could " ride around" the slack for awhile, then install new bushings at paint time. It's worse than I thought so the bushings and painting will get done sooner rather than later!

Glen

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Did you do a Kegler mod on the swingarm? If not, get some of Kenny's light aluminum collars. Or make them yourself.

It was a toss up between Kegler clamps and the MK3 method, so it ended up in the middle .
Built in Kegler clamps machined into the cradle tube-



That part is working well, the slack is all in the worn bushings.

Glen

Found photos of the front iso when that was underway

worntorn said:

The jury is still out on the handling. Knowing that the bike was coming apart again for painting, I put it together with the worn swing arm bushings that were on hand.
I thought I could " ride around" the slack for awhile, then install new bushings at paint time. It's worse than I thought so the bushings and painting will get done sooner rather than later!

Glen

Click to expand...

Riding around on a wet noodle. Been there. Not confidence inspiring.

Had some good test ride weather today. Turns out my smaller rim wider tire on front issue was 2 clicks too much on the steering damper feeding back into the feels funny turning in, and the rear axle was 1/16 further back on the drive side. Hands off the bars downhill test told me the bike was not aligned right. My setup is nowhere near as complex as all your changes. Mostly bolt on with the exception of making spacers and doing some suspension adjustments.

gortnipper said:

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I'm sure Frank Zappa did a song about this kind of thing???
It seems that adding a crappy brown slab seat to any bike automatically makes it 'trendy and desirable'. I saw a CCM prototype at a local tuning shop recently with just such an accessory, and many unkind words were said!

Back on-topic... I inherited some Maney 920 cylinders which had been a little overcooked by being held on the start line (at Cookstown, I believe... somewhat ironically) for too long. Apparently the bike smoked like a pig but still placed well enough to win the championship. Possibly more a function of annealed piston rings than the bores themselves. Steve confirmed they were still within limits dimensionally, but one had a small crack adjacent to a bolt hole, so new liners were fitted (not by Steve - he's packed that in) and sent off for carbide coating.
There was a concern that the barrels would be scrap, but they checked out fine before the new liners were made and fitted.

Looking forwards to seeing this one progress.

worntorn said:

On paper they appear superior in that the engine will cool better.
In reality there is a concern that the liners may go out of round over time. There have been a couple of reports of this with long term usage of the Maney alloy barrels. One owner of a Commando with Maney 850 alloy setup switched his engine back to cast iron after a few thousand miles. There have also been 920 cast iron setups that have been put back to stock after similar problems. So on that basis aluminium doesn't look great nor does the 920 oversize. I have both in one bike!

The other worry is the cam followers running in an aluminium tunnel rather than cast iron.

On the plus side, Roger at RGM says his 81mm kit will holdup well.
Ludwig has put quite a few miles on his 850 Al. barrel, so time will have to tell. I'm looking at the 920 alloy barrel as an experiment, just like the rest of the bike.

Glen

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Glen,
Thanks for the reply.Hope they will hold up on your build.
Mike