Sunbeam S7 questions

Anyone ever had one of these? I've always like the looks. but have been put
off by criticisms of the handling and the worm drive (and the cost!). Any
advantage to buying one in the USA and bringing it back?
Kes.

Kes Green wrote:
>
> Anyone ever had one of these? I've always like the looks. but have been put
> off by criticisms of the handling and the worm drive (and the cost!). Any
> advantage to buying one in the USA and bringing it back?

I've often wondered about that worm drive. Like, a worm drive is a
one-way thing: you can drive the pinion with the worm, but not vice
versa. Think of the machine heads on a guitar - don't exactly unwind
under string tension, do they? If you did something foolish like
finding a false neutral, or pulling the clutch lever in, presumably the
back end would lock up, as the shaft wasn't being driven. Possibly
there's a freewheel of some sort.

--
Platypus
VN800 Drifter, R80RT
DIAABTCOD#2 GPOTHUF#19
BOTAFOS#6 BOTAFOT#89
BOB#1 SBS#35 ANORAK#18 TWA#15

"Platypus" <platypus@ukrm.org> wrote in message
news:3F04B920.3C84CD99@ukrm.org...
> Kes Green wrote:
> >
> > Anyone ever had one of these? I've always like the looks. but have been
put
> > off by criticisms of the handling and the worm drive (and the cost!).
Any
> > advantage to buying one in the USA and bringing it back?
>
> I've often wondered about that worm drive. Like, a worm drive is a
> one-way thing: you can drive the pinion with the worm, but not vice
> versa. Think of the machine heads on a guitar - don't exactly unwind
> under string tension, do they? If you did something foolish like
> finding a false neutral, or pulling the clutch lever in, presumably the
> back end would lock up, as the shaft wasn't being driven. Possibly
> there's a freewheel of some sort.

That final drive is a terrible weakness (1) and there is no getting away
from it but otherwise it's a lovely SOB.

(1) if not using hard or high miles doesn't matter?

--
Hog
hogTIED@ukrm.net (remove bondage to reply)
'89 R100RS '96 K1100LT '02 GSXR1000K2
BOB#5 COFF#22 BOTAFOT#122

Hog wrote:
>
> "Platypus" <platypus@ukrm.org> wrote in message
> news:3F04B920.3C84CD99@ukrm.org...
> > Kes Green wrote:
> > >
> > > Anyone ever had one of these? I've always like the looks. but have been
> put
> > > off by criticisms of the handling and the worm drive (and the cost!).
> Any
> > > advantage to buying one in the USA and bringing it back?
> >
> > I've often wondered about that worm drive. Like, a worm drive is a
> > one-way thing: you can drive the pinion with the worm, but not vice
> > versa. Think of the machine heads on a guitar - don't exactly unwind
> > under string tension, do they? If you did something foolish like
> > finding a false neutral, or pulling the clutch lever in, presumably the
> > back end would lock up, as the shaft wasn't being driven. Possibly
> > there's a freewheel of some sort.
>
> That final drive is a terrible weakness (1) and there is no getting away
> from it but otherwise it's a lovely SOB.
>
> (1) if not using hard or high miles doesn't matter?

I've just dug out an article[1] on the S7/S8, which reckons that the can
of worm would become uncomfortably warm in everyday use, and would wear
out completely in a few hundred miles on the sports model.

[1]Gurt British Motor Cycles of The Fifties by Bob Currie, twa squids
from the local cheap bookshop a couple of years ago.

--
Platypus
VN800 Drifter, R80RT
DIAABTCOD#2 GPOTHUF#19
BOTAFOS#6 BOTAFOT#89
BOB#1 SBS#35 ANORAK#18 TWA#15

I believe it does have a car-type freewheel, I've also read that there's no
engine braking (to reduce wear on the worm drive teeth) so it must
disconnect when you throttle off I suppose. I think that's why the bike
goes all over the place when you blip the throttle. Anyway, it does look
nice.

"Platypus" <platypus@ukrm.org> wrote in message
news:3F04BE75.55FA6B07@ukrm.org...
> Hog wrote:
> >
> > "Platypus" <platypus@ukrm.org> wrote in message
> > news:3F04B920.3C84CD99@ukrm.org...
> > > Kes Green wrote:
> > > >
> > > > Anyone ever had one of these? I've always like the looks. but have
been
> > put
> > > > off by criticisms of the handling and the worm drive (and the
cost!).
> > Any
> > > > advantage to buying one in the USA and bringing it back?
> > >
> > > I've often wondered about that worm drive. Like, a worm drive is a
> > > one-way thing: you can drive the pinion with the worm, but not vice
> > > versa. Think of the machine heads on a guitar - don't exactly unwind
> > > under string tension, do they? If you did something foolish like
> > > finding a false neutral, or pulling the clutch lever in, presumably
the
> > > back end would lock up, as the shaft wasn't being driven. Possibly
> > > there's a freewheel of some sort.
> >
> > That final drive is a terrible weakness (1) and there is no getting away
> > from it but otherwise it's a lovely SOB.
> >
> > (1) if not using hard or high miles doesn't matter?
>
> I've just dug out an article[1] on the S7/S8, which reckons that the can
> of worm would become uncomfortably warm in everyday use, and would wear
> out completely in a few hundred miles on the sports model.
>
> [1]Gurt British Motor Cycles of The Fifties by Bob Currie, twa squids
> from the local cheap bookshop a couple of years ago.
>
> --
> Platypus
> VN800 Drifter, R80RT
> DIAABTCOD#2 GPOTHUF#19
> BOTAFOS#6 BOTAFOT#89
> BOB#1 SBS#35 ANORAK#18 TWA#15
>

"Platypus" <platypus@ukrm.org> wrote in message
news:3F04B920.3C84CD99@ukrm.org...
> Kes Green wrote:
> >
> > Anyone ever had one of these? I've always like the looks. but have been
put
> > off by criticisms of the handling and the worm drive (and the cost!).
Any
> > advantage to buying one in the USA and bringing it back?
>
> I've often wondered about that worm drive. Like, a worm drive is a
> one-way thing: you can drive the pinion with the worm, but not vice
> versa. Think of the machine heads on a guitar - don't exactly unwind
> under string tension, do they? If you did something foolish like
> finding a false neutral, or pulling the clutch lever in, presumably the
> back end would lock up, as the shaft wasn't being driven. Possibly
> there's a freewheel of some sort.
>

It's quite possible to make a worm drive that works on over-run and many car
manufacturers have done it. Probably the ratio involved has something to do
the reversibility. They do tend to need special oils though, you can't
chuck in any old gear oil and expect to get away with it. Peugeot, who only
gave up worm drive on cars in about 1965, used to specify a castor base oil
made by Mobil, though probably old fashioned thick Castrol R would have
worked OK.

Ron Robinson

On Fri, 04 Jul 2003 00:15:44 +0100, Platypus <platypus@ukrm.org>
wrote:

>Kes Green wrote:
>>
>> Anyone ever had one of these? I've always like the looks. but have been put
>> off by criticisms of the handling and the worm drive (and the cost!). Any
>> advantage to buying one in the USA and bringing it back?
>
>I've often wondered about that worm drive. Like, a worm drive is a
>one-way thing: you can drive the pinion with the worm, but not vice
>versa. Think of the machine heads on a guitar - don't exactly unwind
>under string tension, do they? If you did something foolish like
>finding a false neutral, or pulling the clutch lever in, presumably the
>back end would lock up, as the shaft wasn't being driven. Possibly
>there's a freewheel of some sort.

It it a true worm drive, though - or just a short one? I'm thinking a
short one might be able to over-run. Perhaps it's a hypoid bevel and
mis-called worm.

--

Dave

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

I know nothing, but a pal had them and swore about the brakes a lot.

On Thu, 3 Jul 2003 18:07:50 +0100, "Kes Green"
<smoothlysmooth@hotmail.com> wrote:

>Anyone ever had one of these? I've always like the looks. but have been put
>off by criticisms of the handling and the worm drive (and the cost!). Any
>advantage to buying one in the USA and bringing it back?
>Kes.
>

	#1
Kes Green	Sunbeam S7 questions Anyone ever had one of these? I've always like the looks. but have been put off by criticisms of the handling and the worm drive (and the cost!). Any advantage to buying one in the USA and bringing it back? Kes.

	#2
Platypus	Re: Sunbeam S7 questions Kes Green wrote: > > Anyone ever had one of these? I've always like the looks. but have been put > off by criticisms of the handling and the worm drive (and the cost!). Any > advantage to buying one in the USA and bringing it back? I've often wondered about that worm drive. Like, a worm drive is a one-way thing: you can drive the pinion with the worm, but not vice versa. Think of the machine heads on a guitar - don't exactly unwind under string tension, do they? If you did something foolish like finding a false neutral, or pulling the clutch lever in, presumably the back end would lock up, as the shaft wasn't being driven. Possibly there's a freewheel of some sort. -- Platypus VN800 Drifter, R80RT DIAABTCOD#2 GPOTHUF#19 BOTAFOS#6 BOTAFOT#89 BOB#1 SBS#35 ANORAK#18 TWA#15

	#3
Hog	Re: Sunbeam S7 questions "Platypus" <platypus@ukrm.org> wrote in message news:3F04B920.3C84CD99@ukrm.org... > Kes Green wrote: > > > > Anyone ever had one of these? I've always like the looks. but have been put > > off by criticisms of the handling and the worm drive (and the cost!). Any > > advantage to buying one in the USA and bringing it back? > > I've often wondered about that worm drive. Like, a worm drive is a > one-way thing: you can drive the pinion with the worm, but not vice > versa. Think of the machine heads on a guitar - don't exactly unwind > under string tension, do they? If you did something foolish like > finding a false neutral, or pulling the clutch lever in, presumably the > back end would lock up, as the shaft wasn't being driven. Possibly > there's a freewheel of some sort. That final drive is a terrible weakness (1) and there is no getting away from it but otherwise it's a lovely SOB. (1) if not using hard or high miles doesn't matter? -- Hog hogTIED@ukrm.net (remove bondage to reply) '89 R100RS '96 K1100LT '02 GSXR1000K2 BOB#5 COFF#22 BOTAFOT#122

	#4
Platypus	Re: Sunbeam S7 questions Hog wrote: > > "Platypus" <platypus@ukrm.org> wrote in message > news:3F04B920.3C84CD99@ukrm.org... > > Kes Green wrote: > > > > > > Anyone ever had one of these? I've always like the looks. but have been > put > > > off by criticisms of the handling and the worm drive (and the cost!). > Any > > > advantage to buying one in the USA and bringing it back? > > > > I've often wondered about that worm drive. Like, a worm drive is a > > one-way thing: you can drive the pinion with the worm, but not vice > > versa. Think of the machine heads on a guitar - don't exactly unwind > > under string tension, do they? If you did something foolish like > > finding a false neutral, or pulling the clutch lever in, presumably the > > back end would lock up, as the shaft wasn't being driven. Possibly > > there's a freewheel of some sort. > > That final drive is a terrible weakness (1) and there is no getting away > from it but otherwise it's a lovely SOB. > > (1) if not using hard or high miles doesn't matter? I've just dug out an article[1] on the S7/S8, which reckons that the can of worm would become uncomfortably warm in everyday use, and would wear out completely in a few hundred miles on the sports model. [1]Gurt British Motor Cycles of The Fifties by Bob Currie, twa squids from the local cheap bookshop a couple of years ago. -- Platypus VN800 Drifter, R80RT DIAABTCOD#2 GPOTHUF#19 BOTAFOS#6 BOTAFOT#89 BOB#1 SBS#35 ANORAK#18 TWA#15

	#5
Kes Green	Re: Sunbeam S7 questions I believe it does have a car-type freewheel, I've also read that there's no engine braking (to reduce wear on the worm drive teeth) so it must disconnect when you throttle off I suppose. I think that's why the bike goes all over the place when you blip the throttle. Anyway, it does look nice. "Platypus" <platypus@ukrm.org> wrote in message news:3F04BE75.55FA6B07@ukrm.org... > Hog wrote: > > > > "Platypus" <platypus@ukrm.org> wrote in message > > news:3F04B920.3C84CD99@ukrm.org... > > > Kes Green wrote: > > > > > > > > Anyone ever had one of these? I've always like the looks. but have been > > put > > > > off by criticisms of the handling and the worm drive (and the cost!). > > Any > > > > advantage to buying one in the USA and bringing it back? > > > > > > I've often wondered about that worm drive. Like, a worm drive is a > > > one-way thing: you can drive the pinion with the worm, but not vice > > > versa. Think of the machine heads on a guitar - don't exactly unwind > > > under string tension, do they? If you did something foolish like > > > finding a false neutral, or pulling the clutch lever in, presumably the > > > back end would lock up, as the shaft wasn't being driven. Possibly > > > there's a freewheel of some sort. > > > > That final drive is a terrible weakness (1) and there is no getting away > > from it but otherwise it's a lovely SOB. > > > > (1) if not using hard or high miles doesn't matter? > > I've just dug out an article[1] on the S7/S8, which reckons that the can > of worm would become uncomfortably warm in everyday use, and would wear > out completely in a few hundred miles on the sports model. > > [1]Gurt British Motor Cycles of The Fifties by Bob Currie, twa squids > from the local cheap bookshop a couple of years ago. > > -- > Platypus > VN800 Drifter, R80RT > DIAABTCOD#2 GPOTHUF#19 > BOTAFOS#6 BOTAFOT#89 > BOB#1 SBS#35 ANORAK#18 TWA#15 >

	#6
R. N. Robinson	Re: Sunbeam S7 questions "Platypus" <platypus@ukrm.org> wrote in message news:3F04B920.3C84CD99@ukrm.org... > Kes Green wrote: > > > > Anyone ever had one of these? I've always like the looks. but have been put > > off by criticisms of the handling and the worm drive (and the cost!). Any > > advantage to buying one in the USA and bringing it back? > > I've often wondered about that worm drive. Like, a worm drive is a > one-way thing: you can drive the pinion with the worm, but not vice > versa. Think of the machine heads on a guitar - don't exactly unwind > under string tension, do they? If you did something foolish like > finding a false neutral, or pulling the clutch lever in, presumably the > back end would lock up, as the shaft wasn't being driven. Possibly > there's a freewheel of some sort. > It's quite possible to make a worm drive that works on over-run and many car manufacturers have done it. Probably the ratio involved has something to do the reversibility. They do tend to need special oils though, you can't chuck in any old gear oil and expect to get away with it. Peugeot, who only gave up worm drive on cars in about 1965, used to specify a castor base oil made by Mobil, though probably old fashioned thick Castrol R would have worked OK. Ron Robinson

	#7
Grimly Curmudgeon	Re: Sunbeam S7 questions On Fri, 04 Jul 2003 00:15:44 +0100, Platypus <platypus@ukrm.org> wrote: >Kes Green wrote: >> >> Anyone ever had one of these? I've always like the looks. but have been put >> off by criticisms of the handling and the worm drive (and the cost!). Any >> advantage to buying one in the USA and bringing it back? > >I've often wondered about that worm drive. Like, a worm drive is a >one-way thing: you can drive the pinion with the worm, but not vice >versa. Think of the machine heads on a guitar - don't exactly unwind >under string tension, do they? If you did something foolish like >finding a false neutral, or pulling the clutch lever in, presumably the >back end would lock up, as the shaft wasn't being driven. Possibly >there's a freewheel of some sort. It it a true worm drive, though - or just a short one? I'm thinking a short one might be able to over-run. Perhaps it's a hypoid bevel and mis-called worm. -- Dave GS 850 x2 / SE 6a SbS#6? DIAABTCOD#16 APOSTLE#16? FUB#3 FUB KotL OSOS#12? UKRMMA#19

	#8
R Strong	Re: Sunbeam S7 questions I know nothing, but a pal had them and swore about the brakes a lot. On Thu, 3 Jul 2003 18:07:50 +0100, "Kes Green" <smoothlysmooth@hotmail.com> wrote: >Anyone ever had one of these? I've always like the looks. but have been put >off by criticisms of the handling and the worm drive (and the cost!). Any >advantage to buying one in the USA and bringing it back? >Kes. >