Paging Sweller - Le Mans

Hmm... the R80 does that in a band at 75+ MPH (in 'test' conditions,
obviously). It's likewise set up for dual disks.

I wonder...


Regards,

Simonm.

 

That sounds about right. I recall that it was nothing to do with
efficacy of the brakes themselves, but to do with handling/steering.

 

Airhead boxers are notorious for that - the steering damper on older ones
wasn't just for sidecar use. This was the case with drum-brakes models, and
early disc versions, which had ATE calipers behind the forks. The newer
ones carry their Brembos in front of the forks, and will flutter just like
the older ones.

There's a long straight hill going into Thornbury, where you can take your
hands off and a bike will maintain about 40-50 mph. On any of the BMWs I've
had since I moved here, the bars will flutter through about 30deg until I
choose to stop them. By contrast, my old Silverwing was perfectly steady: I
could stand up and stretch, and sit down again, without the slightest
uncommanded movement from the bars. It had, it must be said, a single
caliper behind the fork leg.

 

Do you mean the one on the northern road, SP to the industrial estate
off the A38? If so I know what you mean exactly!

And probably more engine mass!! I've two friends who've had them, one
with a Watsonian fitted. I still think they're an acquired taste. The
solo m/c was fine for a while then *everything* went wrong, very
expensively. The sidecar one was cool though - beautifully-matched
maroon paint job, although I can't really appreciate the finer points of
sidecar handling!

I've got to replace the hoses and the rubber gaitery-boot things on the
fairing before the MOT (I know the boots don't matter, but they look
dreadful. This obviously involves dropping the forks out, so I'll have a
look at a swap-over then.

It'll be really nice if it's do-able and works, because it's worse when
the front is lightly loaded, and I much prefer using panniers to a tank
bag, so it's a PITA when touring.

<thinks> I might give James Sherlock a ring first. They'll be doing the
MOT, probably, and if anyone knows of gotchas doing this, they will.


Regards,

Simonm.

 

Yep, Grovesend/A38 down to the roundabout on Morton Way. Fine view of the
Severn and the crocked nuke.

http://ukrm.net/BIKES/Honda/silverwing.html

I saw an outfit like you describe outside the long-vanished bike shop on
Cotham Hill, about seven or eight years ago.

One thing to do, if you're taking the old gaiters off, is - before you
remove the forks themselves - cut the gaiters away, and put a bit of plate
glass across the stanchions. If it rocks, your forks are twisted, and
you'll need to sort this out first.

I think you've got more than the usual problem there. My steering only
flutters when I provoke it, otherwise it's fine. This includes hauling wife
and loaded panniers across Europe.

Is that not a bit far to go for an MOT?

 

Well it didn't sell, no surprise. The final bid price is what it's
worth, wonder what the reserve was.
For a rat I don't think it really matters what the tank looks like....it
just need to be painted black!
Single tube spine frame I guess so easy to find an alternative tank
anyway.

'Hog

 

Know it well.

Loads nicer than the pretend-tourer version. I can see that being a bit
more fun, but I can understand your reluctance re- knee-down corners!

Sounds like Roger's but I don't think he owned it back then. He got it
off an old geezer who might well have patronized 'Bristol 6".

Good point.

Maybe. I've been putting off looking at it for a while. I need to work
through the lot - swingarm bearings, fork fluid/springs, head play, etc.

It may just be that I notice it more, or even that I need to tweak the
Koni more carefully (prefer a harder ride, generally, but I can see that
wouldn't exactly damp the oscillations).

It needs some experimentation probably, before leaping in. It's most
probably rider incompetence, as you don't hear of loads of people
swapping the brakes round to fix it.

Incidentally, do you rate those milled triple-clamps that occasionally
turn up on eBay? The top plate does look flimsy, but then it's not doing
as much as the lower one.

Yes, but it's a nice trip, I get to play with something different for
the afternoon, and I get them to service/balance the carbs, etc. at the
same time. It's been off the road for awhile, and the trip down is a
good chance for a legal shakedown before the MOT. If anything's
seriously bogged, they've almost always got the right part in-stock,
which saves lots of grief.

Mind you, I got totally soaked last time on the way there - slow traffic
and thunderstorms near Taunton It's great for 'dryness' at sensible
motorway speeds.


Regards,

Simonm.

 

I reckon you need to go through all the standard remedies before you start
playing around with the brakes. If it's enough of a problem that you're
unable to use the panniers, then that's a lot worse than standard. If
you're down at Sherlock's, talk it over with them.

Hog does. I probably wouldn't notice the difference.

 

It's not *that* bad. I took it heavily-laden up to Scotland about 18
months ago, and it was a nuisance on the M6. Also on regular runs down
the M5 if I push it, but that's usually almost unladen.

Yup. Good advice.

Cheers.

Simonm.

 

If you mean Ultimate Source type top yokes then too bloody right, makes
a world of difference twinned with some Progressive Suspension or Hagon
progressively wound fork springs. I have this with some EBC HH pads and
goodridge hoses. One takes the most amazing liberties on bumpy roads.

'Hog

 

I've a set of Goodridge hoses waiting to go on right now. Will take
another look at the 'Ultimate Source' stuff...

Thanks for the info.

Regards,

Simonm.

 

Sometime around Wed, 17 Aug 2005 08:38:59 +0000, platypus babbled on
about:

I have an '86 r80 with twin disks, it is quite stable all things
considered (1) and seems to hold a reasonable line even at highish speed.
In fact it seems better than the Uberbeast when pushed to 3 figures.

(1) 150k on the clock being one of them.

 

My R60/6 seems pretty well behaved, albeit at the moment it's not pulling
more'n 85 on the flat, I think over the winter some attention to the engine
will be in order. It's crudding up the starborad plug, and smoking a bit,
and rattling a bit - I suspect valve guides. Whether it's worth faffing
about trying to do them/get them done, or whether it'd be better to exchange
the heads, I dunno.

It had a set of rings not that long ago, so they may be OK.

 

Sometime around Wed, 17 Aug 2005 21:29:41 +0100, Austin Shackles babbled

Timing chain is a little noisy and the front disks are shiny otherewise it
is a good un.

 

Ovenpaa says...

Oxymoron alert.

 

Sometime around Wed, 17 Aug 2005 23:22:11 +0100, Lozzo babbled on about:

Dont you call me that!

 

You're nearly there. It's because having the calipers forward of the
fork legs puts the weight and forward (well, duhhh) and thus you've got
a lot of inertial load forward of the fork, which can promote steering
wobble.

I think.

 

The axis around which the forks rotate is a line through the headstock.
This runs down the back of the forks. The further a component is from this
line, the more effort it takes to rotate the forks, and to stop them
rotating. Putting the calipers behind the forks makes the turning effort
less, and the rotation of the steering assembly quicker and lighter.

http://www.american-v.co.uk/technical/handling/geometry/body.html

 

You're nearly there. It's because having the calipers forward of the
fork legs puts the weight and forward (well, duhhh) and thus you've got
a lot of inertial load forward of the fork, which can promote steering
wobble.[/QUOTE]

Umm, that's pretty much what I said. So ner ner nee nerr nerr!