Fixie bicycle chain trick

So fixed-geared bicycles have the same system as a motorcycle goes, both
external gears driving and being driven all the time, with only one gear
ratio.

Fixed-gear and single-speed bicycles can flip the cogs backwards to double
the sprocket life. Can this be theoretically done on motorcycle sprockets?
I'm sure there are fit issues, but could a double-sided sprocket be made?

 

[Leaving aside possible safety concerns]

The vast majority of motorcycle sprockets that I've heard about aren't
symmetrical, so flipping them over either wouldn't work at all, or would
cause alignment and clearance problems.

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

Cheap aftermarket countershaft sprockets are made of softer cold-rolled
steel plate and are laterally symmetrical so the aftermarket
manufacturer can make fewer part numbers that will fit many
motorcycles.

Soft steel wears out quickly, on the leading side of each tooth, since
the sprocket is pulling the chain.

The sprockets can often be flipped over to last twice as long. Since
the steel is so soft, the spline inside is also wearing as it frets
against the harder material of the transmission countershaft.

OEM sprockets are often made of much harder steel that wears better and
costs three times as much and are often not laterally symmetrical. OEM
sprockets will often have sound-deadening materials and chain guides
added to the basic sprocket.

When replacing an OEM sprocket with an aftermarket sprocket, it's
sometimes necessary to add large spacer washers on the countershaft
between the sprocket and the crankcase so the chain won't rub the
crankcase.

That's what I had to do with my GSXR to get rid of the troublesome
chain guides.

Rear sprockets are sometimes slightly counterbored on the outboard
side. To flip a counterbored sprocket, you can use extra washers
between the sprocket and the sprocket carrier.

A rear sprocket will wear about 1/3rd as much as a front sprocket. It
will wear on the trailing edge of the tooth, since it is being pulled
around by the chain. Since there
is less tooth wear, manufacturers can make rear sprockets out of
aluminum instead of steel.

 

Generally the front sprocket at least is assymetric, being offset to one
side or the other. This would cause the chain to track crooked
(misaligned front and back planes). Otherwise it might work.

 

Thats news to me. I've changed many of fronts, going smaller or bigger.
What are you working on??????? I just changed one yesterday dorped a tooth.
Hope it dont fall off. lol Sorry couldnt help myself. Most fronts will
go ether way.

 

The Circle Industries aluminum sprocket on my GSXR has about 30,000
miles on it and it doesn't show any wear at all.

I used several Cheng Shin tires on my GT-750 water buffalos when I was
doing a lot of commuting on concrete freeways

 

Just changed one on a Ducati, that was assymetrical. Maybe I would have
been more correct saying "some" fronts are assymetrical.

 

Don't be such a Jack. I was always able to stop the motorcycle. I had
all the brakes I needed, with dual caliper front disks.

I was getting alarmed about the cost of tires for what I thought would
be an economical form of transportation. That was during the recession
that Carter inherited from Nixon when he devalued the US dollar.

The unemployment rate in large cities was 10%. Most of the riders I
knew were collecting unemployment insurance. We were stuck in the blue
collar triangle. If you're working and own a motorcycle, you don't have
much time to ride. If you're not working and have a motorcycle, you
don't have much money for gas and tires.

So, we improvised. We found ways to economize on tires. And we did a
whole bunch of riding.

I realized that I was going to be buying a new $50 rear tire every
three or four months and I wouldn't be able to afford to go anywhere on
the motorcycle if I spent all my spare money on tires.

The original equipment Inoue rubber only lasted 5,000 miles. I had one
Irish-built Dunlop K-81 that lasted less than 5000 miles and that
convinced me that a much harder tire was in order for straight up long
distance riding.

Concrete pavement has about 33% more traction than macadam, so it wears
out high traction tires rapidly.

I talked to a cheapskate who rode a BMW and he told me about the
inexpensive $35 Cheng Shins he was using and how he was getting over
20,000 miles on a rear tire in touring use. He was a fat guy with a fat
old lady. But his boxer BMW was a lot lighter and less powerful than my
water buffalo.

Besides the Cheng Shins, I used $50 Nitto tires that wore like iron,
they would go 12,000 miles.

Carlisles were cheap at $32 each because Sears sold them, and I also
ran $50 Dunlop K-81 Mk II's that would last 15,000 miles on the back.

 

Not sure I agree with that - you might not be able to afford to ride a
fast, powerful bike but...

then again, I've just spent £60 on a pair of Chen Shins for my wife's
commuter GN250.

I remember Chen Shins from the early '80s & was very dubious when our
tame mechanic Jim suggested putting a pair on the GN250 a few years ago
but there wasn't a lot of choice (IIRC it was Chen Shins or wait a month
until the Metzelers arrived).

Jim swore that Chen Shin had come a long way in the last few years and
I've got to admit he was right - that pair of Chen Shins did 4 years
commuting (about 10000 miles?) and there's still tread left but the side
wall is cracking. Last year we bought a beater GN for spares & it had
recent Metz tyres on it so I just swapped the wheels over. She's put
about 800 miles on the Metzelers and is insisting that they're lethal
compared with the Chen Shins. I'm not sure I'd go that far, but I
certainly found the Chen Shins a lot more confidence inspiring.

Don't think I'd try them on my Laverda (that's a lot of bike) but I
wouldn't hesitate to put a pair of them on something midrange like a
Bandit 600.

 

My memory of them from way back was how lethal they were in the wet but
the GN is the commuter bike so it gets run whatever the weather[1].

Seems that the Chen Shins gripped better in the wet than the Metz that
they were replaced with and are more confidence inspiring in heavy rain
than the BT45s she's got on her Bonnevile. If you ask me the relative
weight & power of the GN & the Bonnie have something to do with that.

Oh, and it seems that the Chen Shins don't give much grip in the snow so
she used the train on the rest of the snowy days

Tomorrow I'll be putting the shiny new Chen Shins onto the manky old
wheels, what fun.

bob

[1] and we get a lot of weather hereabouts

 

California is a lot drier than the rest of the country and I feel
little urge to go out riding on days that aren't sunny and warm. Wet
pavement grip doesn't matter as much to me as ultimate mileage. I have
nothing to prove in the canyons anymore.

I don't like the BT-45V's. They are an economy generic replacement for
many OEM tires.

The tread blocks are too flexible. My friend who owns three Hinkley
Triumphs says that BT-45's start out with enough traction but that they
lose that grip soon.

I wish Dunlop still made the old generic K-591's. I would rip those
BT-45V's off my old GSXR in a hot second if I could get 591's.

Cheng Shin is trying to leave their reputation behind by re-branding
their tires under the Maxxis label. They have some tires that are rated
for speeds far in excess of the 149 mph Z rating.

I had good luck with Cheng Shins for commuting and touring in the
1970's and 1980's,
even though they could not get a grip on detergent oil soaked streets
when it rained.

That's why modern rubber compounds contain silica to enhance wet
pavement grip.

Cheng Shins were regarded as "crap" back in the days when the
motorcycle magazine routinely told riders to remove the original
equipment tires that came on their machines from the showroom and
replace them with a "premium" tire. Like Dunlop, Pirelli, Michelin, or
Metzeler.

Even Japanese OEM Dunlops were criticized for being mandated by the
"bean counters" in order to save a nickel per tire. The Dunlops that
came on my FZR-1000 had excellent traction, but the front tire only
lasted 1900 miles before it was worn out.

The absolute worst tire I ever had was a Bridgestone Mag Mopus.It was
hard as a rock and I had zero confidence in it. I tried the various new
Bridgestones as they came out, and they were all crap, the Spitfires
and the dual tread compound Bridgestones sucked.

Honda riders seem to love the OEM versions of Bridgestone Battlaxes. I
was amazed to see the Erion Brothers racing team actually using
Battlaxes at Laguna Seca one year.

Sport riders don't seem to mind changing tires every month or two. I
want my tires to last a year.

The only Bridgestone that was ever worth the money in my book was the
BT-020 sport touring *rear* tire. The BT-020 front sucks, it's too
pointy and too tall, it actually makes my FZR-1000 feel like it has a
19-inch front tire instead of a 17-incher.

Metzeler used to make some good tires back when the Me-33 Lazer was the
hot front tire. it had very little tread on it though. And the
ancestors of the Me-1 and the Me-Z1 and Me-Z2 were good sport tires,
but too expensive for commuting and touring.

I was using Me-Z2's on my FZR-1000 to sport tour and I went for a
canyon ride with a
friend who was using soft compound Dunlop 207's on his YZF-750. He
wanted to know why I was going so slow through the turns. I told him
that my rear tire was slipping away even at the slow speeds I was
going. He was willing to spent $300 or $400 for a set of tires that
would only last for a few rides, but I wasn't.

I never had a Michelin tire that didn't suck. Endurance racers I know
chose
the original Michelin Hi-Sports because they would last through a
complete six hour race and they had such low traction the team riders
wouldn't try to sprint race during their turn.

The most ridiculous Michelin I ever bought was an M-89X or some strange
number. I looked at the thin carcass of that tire and said to myself,
"I bet I could turn this tire inside out like a bicycle tire." And I
did turn it inside out.

You could never do that with a Dunlop tire. They have really stiff
carcasses.

 

Ah In most cases it is the jap bikes that go ether way on the front and
some rears.

 

Those have been superceded by the GT501's. Put a set of those on my wife's
700 Nighthawk and it handled like it was on rails in all sorts of weather.
This was a commuter bike, but we do live in the Ozark Mts and the commute
could be 100 miles of twisties or 20 miles of 4 lane. Give the 501s a
chance if they didn't discontinue the size for your GSXR.

Eric