77 kz650 top speed & cruising speed?

What is considered top speed and top cruising speed for one of these?

Thanks,

I have a 77 650B and have had it just a tad over 100mph. I rode it everyday to work for about three years on a 110 mile round trip ride. I rode at 80 most of the time on the interstate and it was reving pretty good at 80 with no problems. 100 mph on this bike is working it pretty hard. If I want to go over 100 I ride my 900.

kz.chris wrote:

What is considered top speed and top cruising speed for one of these?

Thanks,

A 650 in good running condition can push about 115-120 (give or take) or so top end. I have done an indicated 128mph but that was pushing (only did it once 20+ years ago) 10,000rpm. My 650 with stock gearing (16/42) cruises at 70mph at about 5800rpm. That is 2/3 of the total rpm range. I cruise on the freeway at 6000rpm going about 72-73mph comfortably. Cruising at 80+ will have you at 7000rpm or more with a 9000rpm red line. Higher freeway speeds are better left to 1000/1100's.

I have re-geared my '82 KZ650 CSR and the rear tire is one size over stock. So at a true 70 MPH (verified with a GPS), it is turning 5,400.

With calm wind, the bike does good up to about 85. Above that, or with a headwind, it requires more throttle opening than I would like. With a 15 MPH headwind, about 70 is OK. You can do the math for other combinations.

Top speed with this gearing is right at 117. Would probably get several MPH better with lower gearing, however I was turning almost 9,000.

Thanks for the info.

I dont know what gearing I have off hand but I just did the coquihalla highway in B.C.(400 kms) cruising at about 150km/h which works out to about 95mph with no problems. Bike was revving at about 6000rpm and hummed along nicely

To believe your 650 model is capable of attaining 120+ mph.
I have the stock 16/42 sprockets on my 77 KZ 650 B model. No engine work done. I found a low mileage KZ last year, 1,746 miles on the odo. This bike of mine seems very close to a new bike in terms of the engine just getting out of break-in. I taken it up to about 110 mph indicated. I had not reached redline at that point. This was with running the original stock suspension front and back. The front end with my 220 lb bulk got pretty "floaty" over 90 mph. I have upgraded the forks recently with heavier Race Tech springs, spacers, new seals and 15 weight fluid. It is much more planted in the front but the stock shocks are way too soft causing too much "wag" in sweepers. My point is when going up towards the max speed on this bike, you better have your chassis sorted.