Round 7, FOAK: 1982 Kawie KZ550 C3 LTD Restoration Options

 

I am about to replace the chain and sprockets on this noble beast and
so begins the Quest for the Unknowable Right Answer:

Should I change the gearing, or in this case, the sprocketing?

It's a cute little in-town cruiser and bar hopper but it wasn't made
for sustained
highway riding.  It's too rev-vy for that:

It redlines at 20 mph in first gear, I rarely take it up to 70 mph.  I
know a few less revs at highway speed in 6th gear would be a bit more
pleasant.

Should I give it taller gears? Would I regret reducing the crusing
revs by about 8 or 10 percent with a corresponding loss of low gear
grunt?

What say ye, oh Fount of All Knowledge?  <ducking for cover>

Biker Dude

 

Biker Dude wrote:

What criteria did you use to come to that conclusion?


Having ridden a number small displacement bikes and having owned an
82 GPz550 which had exactly the same gearing, I would disagree.  If
you rarely get up to 70 mph you have no reason whatsoever to gear it
up.  All you will do is make 6th gear unusable.


Regardless of what sprockets it currently has, replace them with
the original sizes, which is a 16T front and 38T rear.  Chain is
#530, 100 links.  Increasing the gearing 8 to 10 percent higher
would seriously screw up what is a nicely geared bike.

 


Sounds to me like someone has changed the gearing already.

It's more than 20 years since I rode a 550 Ltd but back then I was happy
to run it at a steady (indicated) 100mph. I've ridden a vanilla Z550 & a
GPz550 since then & they were both happy enough around 100mph.

[]

I'd second that - check the gearing & if it's not standard I'd change to
standard.
--
Bob Scott

 


It's up to you. The only way most people are satisfied with the answer
to the gearing question is experiencing what happens when they do it.

You can install a front sprocket with one tooth more (if you can find
one that fits in the space available, or install a rear sprocket with
three teeth less, and you will
usually achieve a gearing situation where sixth gear feels like it's
halfway between
sixth and an imaginary seventh gear.

If you live in flat country and you don't have to fight head winds,
you just might
like such an arrangement.

Oh, get real. I was talking to a guy at a motorcycle hangout and he
said that he and his "partner" frequently rode to San Francisco and
back together on his KZ550 (about 800 miles round trip) and the
biggest issue was that there was no way to carry souvenirs or
antiques ;-) home because the machine was so small.


Believe it or not, the engineers at Kawasaki *knew what they were
doing* when they selected the transmission gearing and the final drive
ratios.

A modern 4-stroke inline-four has a very short stroke in order to
reduce piston ring flutter at high RPM. Kawasaki designed their engine
in order to save wear and tear on the piston rings, so, if you're
cruising along at 5500 to 6000 RPM in sixth gear, you're NOT hurting
the engine.

If you're out on the road on a long trip and you're riding close to
the red zone on your tach for long periods, be sure to check your oil
level every day.


A 7.5% change in final drive ratio will generally put you right
between 6th and 7th
gears, in terms of cruising RPM.

Like i said, it depends on whether you have hils to climb or have to
battle head winds or carry a passenger. If you find that you have to
downshift two gears instead of one gear to pass a truck on a hill,
you've over-geared your final drive.

 



Utter nonsense.


--
BMW K1100LT  Ducati 750SS  Honda CB400F  Triumph Street Triple
Suzuki TS250ER GN250  Damn, back to six bikes!
Try Googling before asking a damn silly question.
chateau dot murray at idnet dot com