[markwoolam967]

Hi there never been on here before and not sure I'm posting this right place even I have 1987 ex 500 Ninja and a qs 12kw 17" x6" hub motor wondering if anyone knows if it will fit this bike haven't started tearing down bike yet but the swingarm looks to short for taller tire and rim.dose anyone know the answer . Thanks

 

[yorkie]

get a tape measure and measure it all should be simple enough to see if it will fit.

 

[markwoolam967]

get a tape measure and measure it all should be simple enough to see if it will fit.

Thank you for reply I did measure and appears to be short did the later models have 17 " rim and is the swingarm the same.

 

[yorkie]

yes, and no. yes the gen 2 (disk rear brake) had a 17in rim. but smaller profile tire. 70% instead of 90% on the 16in rim.
the swing arm fits but wheel attachments are different and the swing arm is wider to accommodate the disk brake (by about an inch) length wise about the same. however other Kawasaki swing arms also fit. like ZZR, GPZ600, GPX, and so on so you may get lucky with one of those if the gen 2 isn't big enough.

 

[bpe]

Something else to consider if you want to switch to 17" rims. You will have to set up the entire rear wheel hydraulic brake system if using EX 17" rims. Even including modifying the rear fairing to accommodate the master cylinder. Its been done and documented on the site, but I'm having trouble finding it.

 

[yorkie]

this is true however considering the news.

a qs 12kw 17" x6" hub motor wondering if anyone knows if it will fit this bike

it seems the OP is considering some sort of electric drive on the bike. of course this would mean considerable modification to everything on the bike.

 

[FlipFlop]

I would like to see an electric conversion done with these bikes. I have thought about it myself and quickly realize, I do not have the energy to do such a project. I would love to watch it being done though.

 

[kensei]

The minimum tire size stated for the hub motor you listed (from the QS website) is 180/55-17, which would only be about 0.6" longer/taller in measured diameter. It seems your problem with the stock swingarm is going to come in the additional two inches of width required for the new tire. Seems @yorkie is spot on, as usual, here with the suggestion of a swingarm swap to one that was already designed for a wider tire. I will add, though, after a brief site search for "swingarm swap" my initial feeling is that most of the swingarms that will swap into the EX with relative ease may still be too narrow for the 180 tire as most original posters indicate their desire to go to a 160 width tire. No experience on this one, just spitballing from the search results...

Its unfortunate that you already have the 12K motor as the 8K wheel listed on their website is spec'ed exactly for an OEM EX size tire. Maybe you can find someone on an EV group who would swap...

I would like to see an electric conversion done with these bikes. I have thought about it myself...

@FlipFlop - here's your chance! QS 8K Hub Motor

 

[yorkie]

hi, @kensei I cannot find my research notes I did on the construction of the cruiser, (probably buried in a corner somewhere) so those models are a guess more or less, from memory the ZZR has a tire size of 190/50-ZR17 so should be ok.
one thing I do remember is Kawasaki has a habit of cross using parts between models, and while certain individual parts may be different the overall dimensions for a unit are the same (or very similar) provided you go far enough back to where it is the same.
I believe the distance (or gap) of the swingarm at the point of fixing (at the swingarm bolt) are all identical but of course anything after that point would have to suit the ZZR model.
I fitted a GPX swing arm and GTR 1000 rear wheel. along with a full set of ZZR 600 forks (with anti dive units and twin brakes) to the cruiser, not easy of course but doable, I had to go right back to the headstock before finding a same measurement everything after that was ZZR and fit straight on.