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Re: Basket Cases

Posted: Mon May 11, 2020 7:45 pm
by David Lahey
JC1 wrote:Then came an M80 Sherpa

PICT2023.JPG

This bike looks eerily familiar JC1

Re: Basket Cases

Posted: Tue May 12, 2020 8:02 pm
by JC1
David, did you mean to post a pic of what the M80 looks like now?

Re: Basket Cases

Posted: Tue May 12, 2020 8:22 pm
by David Lahey
JC1 wrote:David, did you mean to post a pic of what the M80 looks like now?

No it was meant to show your original posting from page 31 but didn't. I'll try again.

Re: Basket Cases

Posted: Tue May 12, 2020 8:24 pm
by David Lahey
There's more than one way to skin a cat

Re: Basket Cases

Posted: Tue May 12, 2020 8:33 pm
by David Lahey
I've only done measuring, comparing and looking inside the :Bultaco: M80 so far JC1 so no point doing photos yet. It was just that today Greg got me to look at the byzantine design rear brake mechanism on his :Bultaco: M49, also on page 31, and as soon as I saw your :Bultaco: M80 photos I recognised the bike.
The :Bultaco: M80 is not on the front burner. I was going to use the :Bultaco: M80 frame with the running gear from my M49 but I worked out that I would also have to replace the :Bultaco: M49 engine covers with later ones to fit it in that frame so decided to persevere with the series 1 :Bultaco: M49 frame. I've been doing a few things on it over the past weekend to make it easier to ride and am close to showing what I've been up to.

Re: Basket Cases

Posted: Tue May 12, 2020 10:24 pm
by brent j
JC1 wrote:Brent, I love your work, especially on the lower backbone around the relocated swingarm pivot. Very clever use of that small 'gap' in the rear of the engine cases.

Just wondering though if there's a reason you're not taking the opportunity to reduce the wheelbase somewhat given how long the RL is (53.5"/1345mm) compared to all other twinshocks. Just curious.

I do like the RLs even with all their faults. I enjoyed sampling Greg's Squeamish alongside a standard RL at his place a couple of years ago and it made the standard one feel very ordinary by comparison, to put it mildly.

Another one I sampled had minimal mods: 360mm Rockshocks, forks dropped through the triples as far as we could (which is only maybe 15mm as I recall), and footpegs lowered & moved forward as far as possible (which amounted to about 20mm ea way) while still allowing clearance for full kickstarter swing. I thought the steering might have tucked under more with even less trail, but try as we did on some practice ground we couldn't feel any. Admittedly there were no sizeable rocks, logs, sand or steep drops. It too felt a considerable improvment over a standard RL.

This is not it, but I always thought this one, with its subtle changes, looked in better proportion than a standard RL too
RL250 rhs.jpg


But I could never understand why Suzuki manufactured the RL with that obvious design flaw in the gussets on the rear uprights; ie minimal overlap of the two gussets on thin-wall tubing creating the stress concentration point causing the inevitable fractures. Even more that they never fixed it.

Bultaco notably used a single continuous gusset there.

Have often thought they would have been much better served running that bracing tube from above the rear engine mount downwards to the lower gusset for the swingarm pivot instead of going upwards to 'nowhere' (ie nowhere significant)

RL250 bare frame.jpg


And Greg, I'm intrigued by what Squeamish 2 might be. How diff to #1 ??

You both may just have whet my appetite to get back in the shed on one or two trials projects.
(Been given to other projects lately)

I just wish I had half the fabrication talent of you two guys!




Thanks for your comments.
My view is that the RL wheelbase, while long, is ok and the steering problems are more due to the weight bias more than the wheelbase or steering head angle. And I do stand to be corrected here.

I remember the local dealer had an RL and saying they needed an extra 1-2 inches in the swingarm but they didn't want any more length overall.
Both Greg's and my bikes are close to std wheelbase but have longer swingarms.

VIRTUAL RIDING

Posted: Wed May 13, 2020 10:16 am
by Greg Harding
Hi Everyone,
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Kurt wrote:Being pointed at the Sherco Wave after 5mins on the Town bike was certainly an ambush, I don't think I've ridden a more strange feeling obstacle.
The only way to feel some sort of normal is to maintain forward movement with your head, hence the close inspection of the front tyre.

Thankyou for the Virtual ride Kurt, now that you mention it, I did think it strange when you asked why no one ever rides the Town Bike over the (Blue Bumpy Thing)? All I did was to Inocenty ask and point, do you mean that one?

Did you find that hypothetical nail that whitehillbilly was talking about, it looks like you had your hands full when you had a close inspection?
David Lahey wrote: It was just that today Greg got me to look at the byzantine design rear brake mechanism on his :Bultaco: M49, also on page 31

David, I see your byzantine and raise you a ROFL :lol: :lol: :lol:
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Re: Basket Cases

Posted: Thu May 14, 2020 8:42 pm
by Kurt
It would certainly be interesting how Earles forks would effect the handling of a motorcycle as it relates to trials.

A bit of a test for you, In the below photo there are four modifications to the mechanical function of the SWM from the standard trim.
IMG_0450 (1).jpg
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Re: Basket Cases

Posted: Thu May 14, 2020 8:52 pm
by David Lahey
I'm not an SWM person but I'm going to have a go Kurt
The arm on the clutch release mechanism has been lengthened.
Two of the clutch spring screws are different to the other four.
I'm still looking for two more things

Re: Basket Cases

Posted: Thu May 14, 2020 8:58 pm
by TrialsRoss
It looks to me like the return spring on the clutch actuation arm is an add-on. The metal filings on the clutch pack point to some rubbing perhaps.