16 inch rear tire

On a Z1-B:



I know that they originally had 18 inch tires but I think somewhere along the line an owner wanted an LTD. I am of short nature myself but wondering of the shortcomings from a smaller diameter wheel.

I would also like to know what sprockets would have been original and if it is possible to get the final drive ratio with different sprockets. If at all feasible.

Thanks

George

It lowers the rear a little bit. lowers the final drive to road gearing, Numarically higher (Tire is about 2 inches shorter give or take). The origonal front sprocket is a 15 Tooth and rear sprocket is a 35 Tooth with a 630 chain according to Kawasaki.com. A higher number tooth on front or lower number on back will lower engine RPM for the same crusing speed. Hope that helps.

Kenny

Yea, the 16" is shorter. Some argue with the wider profile ect, the height comes out same as the 400-18. No I'm afraid not. The difference is significant. Not quite 2", but between 1 and 1.5" shorter tire. Around a 10% gear ratio change would be needed to accomodate the 16" tire. The reason for anyone going to a 16" rear tire is purely cosmetic for those that don't like the factory skinny tire look. It seemed to be a popular mod as I barfed at many a used KZ I went to buy purely because of the rear wheel and normally this meant also the addition of ape hanger bars as the two went hand in hand. Didn't make sense to me in looks or function.

It was a cheap way to put a wider back tire on a bike back in the day

Did a little checking on metzeler sizes between 16-18" tires.
A 130/90/16 which has been a common tire size since Ronkz650 stamped the first one at the Carlisle plant back in the 60s falls in at right around 25.2" while a 130/80/18 falls in at 26.2 according to metzeler,which would make the bike 1/2" lower with the 16" rim if all other things are equal.
Although I think 18" tires tend to handle better with the lower profile ,less rubber/sidewall to flex.

wireman wrote: Did a little checking on metzeler sizes between 16-18" tires.
A 130/90/16 which has been a common tire size since Ronkz650 stamped the first one at the Carlisle plant back in the 60s falls in at right around 25.2" while a 130/80/18 falls in at 26.2 according to metzeler,which would make the bike 1/2" lower with the 16" rim if all other things are equal.
Although I think 18" tires tend to handle better with the lower profile ,less rubber/sidewall to flex.

130/90/16 it is... you amaze me! DO you have an 18 in the bunker under the barn?

Ive got extra stock rear wire wheels for kz1000s,I can check on a 900 wheel if you want one.
Youll have to mount a new tire on it though,I don't trust old dry rotted tires.

Overall diameter of stock replacement rear tire per Dunlop:
1976 KZ900-B1 LTD 24.95" or 25.70"
1976 KZ900-A 25.51"

When both bikes have the same rear axle height, the overall tire diameters should also be equal.

The 24.95" LTD tire is shorter than the 25.51" standard model.
0.56" difference = 0.28" difference in axle height.

The 25.70" LTD tire is taller than the 25.51" standard model.
0.19" difference = 0.095" difference in axle height.

Good Fortune!

Well to compare the original tires in 16" and 18" sizes is not all that easy as for the most part those sizes are obsolete. Most use either a 110/90-18 or a 120/90-18, or the 130/90-16 tires in modern rubber as that is all you can get most think at least. Pattons comparison is the 110/90-18 vs the 130/90-16 I would wager to guess in the Dunlop 404 tires. The original intended tires were a 400-18 on 18" wheel and a MT90-16 on a 16" wheel. To do much in the way of comparison these exact tires should be compared by a company that still offers them. Avon Roadrider tires still can be bought and a 18" is 26.4" diameter and the 16" is 25.4" for exactly 1" difference. You can see how much different this is than a common 110/90 or a 130/90 size. The 130/90-16 is fairly close, but look at the intended 400-18 vs a 110/90-18. Nearly 1" diameter difference on a tire that's a "exact replacement". I don't think it's quite the correct tire in looks or function.

Patton wrote: Overall diameter of stock replacement rear tire per Dunlop:
1976 KZ900-B1 LTD 24.95" or 25.70"
1976 KZ900-A 25.51"

When both bikes have the same rear axle height, the overall tire diameters should also be equal.

The 24.95" LTD tire is shorter than the 25.51" standard model.
0.56" difference = 0.28" difference in axle height.

The 25.70" LTD tire is taller than the 25.51" standard model.
0.19" difference = 0.095" difference in axle height....

OEM rear tire on 1976 KZ900-B1 LTD was Goodyear Eagle A/T MT90-16T.
It has been obsolete for a long time, and I don't know the overall diameter.

For 1976 KZ900-B1 LTD rear tire, Dunlop recommends
GT501 130/90B16 overall diameter 24.95"
Optional Elite 3 Bias MT90B16 overall diameter 25.70"

For 1976 KZ900-A rear tire, Dunlop recommends
D404 110/90-18 overall diameter 25.51"

With reference to overall tire diameter determining axle height, not wheel size:


Kawasaki's marketing and promotional advertizing of the 1976 KZ900-B1 LTD doesn't mention anything about it riding any lower than the standard model. And had such design feature existed, one would think that it would have been highly touted.

Good Fortune!

This was a fad of the era. About everyone I knew at the time had a 750 Honda with a 16 rear,6 inch over on forks,and the pipes were four shorties. Most didn't change sprockets.

roy-b-boy-b wrote: This was a fad of the era. About everyone I knew at the time had a 750 Honda with a 16 rear,6 inch over on forks,and the pipes were four shorties. Most didn't change sprockets.

"Slugs" were also available that were used as an inexpensive way to extend the forks. These short extensions in various lengths could be used to screw into top of the fork tubes (where the caps usually went), and the slugs were threaded to receive the caps.

Using the slugs was frowned upon as being dangerous, because they were reportedly subject to breaking apart where they connected to the original fork tubes. :pinch:

As to the LTD's seat height, here's an excerpt from the original marketing brochure:



Good Fortune!