Z650 B1 vs B2 front forks

Probably a daft question, but I have noticed that the stanchions (as well as the lower legs) differ between the B1 and B2 models, but other than the top retaining nut I cannot tell how they differ. I have on fork from each, and each have one really bad stanchion and one decent. The fork top caps differ, as mentioned, but other than that, will they interchange? As in are they the same length and will fit inside each other's lower legs? Or will I need them to go along as pairs?

According to Kawasaki.com the upper (inner) fork tubes are the same on the B1 and B2; the lower (outer) tubes are different. Of course Kawasaki.com sometimes has errors. What reference said they are different? Ed

BikeBandit as well as this www.z650b.com/z650/parts_list/page25.html

Yes, the fork lowers are different between the B1 and B2.

The B1 has the caliper in front of the fork leg, so the caliper mounts are on the opposite side of the fender stay mounts.

The B2 has the caliper behind the fork leg, so the caliper mounts are on the same side as the fender stay mounts.

Note that if you choose install B2 forks on a B1 and move the caliper to the rear you will need a longer speedo cable as the cable has to go behind the caliper.

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configuration

faffi wrote: BikeBandit as well as this www.z650b.com/z650/parts_list/page25.html

Interesting. The 44013-1005 upper (inner) fork tube is the same as on the KZ650-C models, but of course the lower (outer) tubes are different. There are a couple new old stock (NOS) 44013-1005 tubes on eBay (see below). Also, I found one NOS tube at www.spinnin-wheel.se/data.asp ; they are in Sweden. When you search their site you need to replace the "-" in the part number with a "." so the part number for the fork tube should be entered as 44013.1005 I have bought from them a couple times before and have always been happy with the items. If you send them an email (in English) they will send you the price of the item. Their shipping costs are not too bad. Ed

Oops, I misread the post, you were asking about the inner tubes.

I vaguely seem to recall something about the 77 models using a different dampening system (bottom of the fork) than the later models, but I'm not sure if that affects the inner tubes themselves, will have to look into that when I get off work.

BikeBandit take 133 USD and a German company have one on Ebay for about 125 USD. That's the leg for the B1, BTW.

I guess I'll just have to take the two forks apart and see if the legs will interchange. But that will not be until fall (or a long spell with bad weather) as the bad fork leg will carry me through the season and I want to ride first and foremost

OnkelB wrote: Oops, I misread the post, you were asking about the inner tubes.

I vaguely seem to recall something about the 77 models using a different dampening system (bottom of the fork) than the later models, but I'm not sure if that affects the inner tubes themselves, will have to look into that when I get off work.

Post crossed - that would be fantastic if you could do that!

Will do. In the meantime I just checked Kawasaki.com - they list the fork inner tube as OEM 44013-062, used on these models:

KZ650-B1 (1977)
KZ650-B2 (1978)
KZ650-B2A (1978)
KZ650-B3 (1979)

I have an aftermarket catalogue at home that list the tube dimensions, will check and let you know.

Ok, so I didn't remember correctly about the damper (or fork cylinder as Kawasaki.com calls it), according to them and the info I have available the B1, B2 and B3 all use the same inner tubes (44013-062) and the same damper (44022-040), so they should interchange.

Below I have listed the fork tubes and damper numbers I could find. All the fork tubes are 36 mm OD, but the length varies slightly, no more than 10mm though. I suspect this slight difference in length is the reason there are so many different part numbers.

Would be interesting to know for sure, but actually it wouldn't surprise me if all 36mm inner tubes are interchangeable, even the ones for the 900/1000s - note how the damper used for the F1 also fits a number of KZ1000 models, most of which also use 36mm inner tubes.


Inner tubes:

44013-062:

KZ650-B1 (1977)
KZ650-B2 (1978)
KZ650-B2A (1978)
KZ650-B3 (1979)

44013-1005:

KZ650-C1 (Custom) (1977)
KZ650-C2 (Custom) (1978)
KZ650-C3 (Custom) (1979)

44013-1011:

KZ650-D1 (SR) (1978)
KZ650-D1A (SR) (1978)
KZ650-D2 (SR) (1979)
KZ650-E1 (LTD) (1980)

44013-1027:

KZ650-F1 (1980)


Damper (cylinder, fork):

44022-040:

KZ650-B1 (1977)
KZ650-B2 (1978)
KZ650-B2A (1978)
KZ650-B3 (1979)

44022-1004:

KZ650-C1 (Custom) (1977)
KZ650-C2 (Custom) (1978)
KZ650-C3 (Custom) (1979)

44022-1009:

KZ650-D1 (SR) (1978)
KZ650-D1A (SR) (1978)
KZ650-D2 (SR) (1979)
KZ650-E1 (LTD) (1980)

44022-1011:

KZ1000-A3 (KZ1000) (1979)
KZ1000-A3A (KZ1000) (1979)
KZ1000-A4 (KZ1000) (1980)
KZ1000-B3 (KZ1000 LTD) (1979)
KZ1000-B4 (LTD) (1980)
KZ1000-D3 (Z1R) (1980)
KZ1000-G1 (Classic) (1980)
KZ650-F1 (1980)
KZ750-G1 (LTD II) (1980)

So if I understand you correctly, these fork legs are the same despite the different retainer nuts on top? The one with the rubber top sits a little lower than the other, but that can be due to the springs, of course.

Not sure if this will help you are make for more confusion. But here are the pages I have from a B1/B2 parts list. It shows different part#s for the inner tubes and outer tubes on the B1 and B2.