Chain or shaft

I think it was on Fri, 26 Nov 2004 01:00:13 GMT that "taz"

Belt?


--

Rob
Broseley, Shropshire
1991 Yamaha XV 535 Virago
1997 Rover 623GSi

 

Braces ?

 

This one?

http://www.salad.dodger.dsl.pipex.com/wing.jpg


It's a special - enclosed chain running in an oil bath inside the old
shaft housing.

Honest.

--
| ___ Salad Dodger
|/ \
_/_____\_ GLXR1500SEVRRSP/CBR1100XXX/KH500A8/TS250C
|_\_____/_| .....73063...../..17090.../..3180./.19406
(>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 YTC#4 PM#5
|__|_|__| BOTAFOT #70 BOTAFOF #09 two#11 WG*
\ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4
\|^|/ ANORAK#17 IbB#4
'^'

 

hehe.

actually, the expression of concentration on the pilot's face leads me to
believe it.

and besides, I can;t see any physical explanation for "shafties don't
wheelie", provided it's a powerful enough motor, of course.

 

Austin Shackles wrote

It was explained over in ukrm 4 or 5 years ago and debated by people who
can do sums and hold strong opinions in the face of overwhelming
evidence to the contrary and everything. I was as surprised as anyone
to see that, on paper at least, this appeared right.

However, a year or so later, it turns out that in a sense they was all
wrong. Well those of them who had said that shafties can wheelie and
that they hadn't taken into account the direction of rotation of the
final drive shaft and it was probably an either or thing between
wheelieing and stoppieing or, in most cases, neither.

This didn't go down to well, as a google will tell you, and some really
nasty things were said by both sides about the other. None of which had
any real relevance to the point but made very good evening entertainment
for sad bastards like me with no life and no hope of one, so I
encouraged them.

Anyway, it turns out that the rotational directional thing may have a
grain of truth in it. The proof being apparently that a shaftie *may*
be able to do one but simply cannot do both. Although there was a
school of thought that maintained that as most of the sums included a
variable which was to do with rubber tarmac friction forces, albeit
offset by the turning forces applied to the shaft, any hint of the back
wheel leaving the road spoilt the maths summat horrid and the rest of us
were all muppets and should be removed from the gene pool for thinking
anything else. You don't tend to hear much from them though as they are
the sort of person that nobody likes.

Oddly, the one thing everybody does seem to agree on is the lack of
skills shown by most photoshop users these days.

 

hehe.

however; the fact remains that regardless of which way the shaft rotates and
whether or not it tries to compress or extend the rear suspension when under
power, the ultimate source for the torque accelerating the machine is the
weight of the machine itself. If there's enough grip, and enough power in
the engine, then it'll lift the front of the machine off the deck.
Suspension compression due to the transmission may help this, on machines
where this happens, mostly those with chain drive.

's like anti-dive forks. You can] design a suspension system which has
anti-dive, either using hydraulics or geometry, but at the end of the day if
the brakes are sufficiently powerful and the tyre grip sufficiently high,
then it'll stoppie as well.

 

Austin Shackles says...

I defy you to stoppie a ZZR1100 with very sticky tyres on. I tried and
nearly put myself through the back screen of a Mondeo. Too long, too
heavy and too low a CoG. The front will lock just after the rear comes
up.

 

Austin Shackles wrote

Look, I am the wrong person to explain all this, what you need is a
mathematician. Like I said it has all been done on ukrm a long time in
the past and a google will explain the sums and everything. Including
father Xmas

I'll had anti dive forks. I didn't do no deliberate stoppies though.
My view is that if the back, or front for that matter, wheel ever comes
off the ground then something unplanned has happened[1] and I don't
enjoy that.



[1] Although thinking back to when I used to commute on my 305 that was
how I approached every roundabout and set of red lights. It was
controllable easy fun to have the back just skipping, I couldn't resist
it.

 

yebbut, that's the point, innit. heavy bike and not enough grip (it may be
that no tyre exists with enough grip). But in theory, with a grippy enough
tyre and road surface... you might of course not live to tell the tale, but
since when has that been a facet of the argument?

not likely to find out about the wheelie potential, with my bike. It'd not
wheelie even if it were chain-driven; not enough power.

 

There's no such thing as not enough power to wheelie. There is such a
thing as not enough technique though ;-)

 

very likely. the bike's fairly heavy though, and so's the rider, and it
only had 40 bhp when new.

 

Preston Kemp says...

Very true. I've only found a couple of bikes that wouldn't lift the
front in some small way.

 

yesyes, I know, you can wheelie a C50 if you plant both feet on the floor
first...

actually, ISTR getting the front wheel of my first bike, a Honda H100,
slightly airborne by a combination of too much revs and too
rapid-application of the clutch. But I hesitate to describe it as a
wheelie, as such. More like an
"argh-oh-****-phew-jesus-I-must-look-a-right-tit".

 

Yes.

 

Or 85 quid apiece as I pay for the Tigger:

http://www.busters-accessories.co.uk/products.asp?id=54

Lubing by Scottoiler with a touring reservoir takes that chore to
refilling the reservoir every 8k miles or so. Chain gets adjusted
about every 5k miles.

BMW shafts need dismantling at about 15k intervals to lubricate the
drive shaft splines. The rear drive transfer box needs its oil changed
at about 10k intervals. High maintenance items, these shaft drives...

 

If I was to get the bike engineer doen the road to do it, probably an
hour of labour per change. Worst case two hours = £60, so £240 total.

It must be terrible when a chain completely catches you unawares by
wearing out.

It is, of course, a pefect excuse for owning more than one bike.

Realistically, it's the sort of job that, if you actually want a shop
to do it and not do it yourself, you would ride in and ride out a
couple of hours later with it done.

True. I shall have to find some way of recycling them in future.

I have no great objection to shafts. I do suspect that those who
evangelise about them as the panacea for all ills don't actually know
anything about the subject though.

 

Austin Shackles says...

C50s require use of the foot clutch while moving slowly in first. It can
be done and quite often was when I used to borrow my ex-girlfriends one.

 

Mike Fleming says...

I'll only use DID ZVM spec chain, it's a lot stronger than most OE spec
and costs a bit more. It lasts a lot longer though.

 

It was somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Austin Shackles

First proper wheelie I did was when I was giving a workmate a lift out
of the works carpark on the back of a ShiteOldVespa. Needing more
throttle to take off, I gunned it and performed an impressive (to me, at
the time) wheelie out of the works gates, scattering assorted
engineering types left right and centre.
Much shouting and cursing was heard.

--

Dave

GS 850 x2 / SE 6a
SbS#6 DIAABTCOD#16 APOSTLE#6 FUB#3
FUB KotL OSOS#12? UKRMMA#19 COSOC#10

 

Thus spake Lozzo unto the assembled multitudes:

I had a C70 back in the early 80s and it was easy to wheelie that with
pretty much the same technique.

I also wheelied my first two-wheeler, a (ssshhh don't tell anyone) Lambretta
SX200, on several frightening occasions. I think it was enjoying its
new-found liberty, having been owned previously by a woman who weighed about
25 stone. 'kin 'ell, I'm amazed I survived riding that thing with zero
training or experience. Talk about a baptism of fire...