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?

--
Phil, Squid-in-Training

 
Phil, Squid-in-Training wrote:


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.

 

Well there you go.  You couldn't have known you didn't have any braking traction
because you didn't have any brakes.

--
Jack

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My bad.  I thought you had the massive drum front brakes.


I'm still alarmed.  A set for my bike and my wife's is around $500 these days. I
just spooned a set on her bike and there's a set sitting in the basement for
mine.  She also gets a chain and sprockets, which I'll never need.


Yeah, well the peanut man had 4 years to change that and he only made it worse.
Car loans were running almost 20% interest and the cars were piles of junk.  One
of his campaign speeches came back to haunt him 4 years later.  He's probably
always going to regret saying "Double digit inflation is obscene".


That's always going to be true.  This is not a cheap sport.  What you save in
cheap tire cost, you give up somewhere else.  If you can't afford good tires,
you can't afford to ride.  And I'm not even talking about riding gear yet.  A
good Aerostich will cost you nearly $800 now.


I was there.  I found some Bridgestones that were a good balance between cost
and tread life.  But during those days I did run some Chen Shins and some others
that I had never heard of.  I could often be found in the dorm parking lot,
changing a tire with a couple of screwdrivers and a bicycle pump.  After putting
about 20 punctures in a tube one night using the screwdrivers and no light, I
bought a couple of tire irons.  One of them I'm still using 30 years later.  I
would still be using both of them but one had to do duty as a chisel in an
emergency and later it got cut in half for some other dire need.  Ya do what ya
gotta do.


The grooved California freeways ate a lot of my tires.  I haven't ridden there
since 1979.

--
Jack Hunt  IBA#12795, STOC 1870
'99 ST1100, FaST Forward
'95 Suzuki DR250SE
http://www.huntslodge.com

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 Phil, Squid-in-Training wrote:

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.

--
-Fred W