Z650 cafe racer; wider rear wheel/tyre

[Webb]

Helloes!

I have recently bought a somewhat messed up Kawasaki Z650 F, with the purpose of restoring it/rebuild it to a cafe racer (wrenchmonkees style - company out of Copenhagen, Denmark).

Now Ive got everything lined up, I just need a decision on the wheels. Whether to keep the original steel ones, or go with some nice wire-spoked. In a perfect world, they would be same-size (17 or 18 inches), wire-spoked with a nice fat rear tyre.

However, the original rearwheel doesnt allow a very wide tyre, and the front tyre is 19". So here is the questions:

1: Can I fit a wheel from another bike to allow a wider rear tyre? Which?
2: Can I interchange the entire rearset (wheel, swingarm etc) with another bike, or will it not work well with the chain?
3: Any tips on an easy-interchangeable frontwheel, wire-spoke in 18"? From which bike?
4: Would it be easier to change the whole front of the bike? If so, from which donor.bike does the frontfork fit?
5: If all else fails; how wide a tyre can i fit to the standard rim? As far as I can gather, its a 130mm...

I havent been able to find this info on my own, but if anyone knows a site with a desciption of a build like this, it would be much apprieciated!

Greetings from Europe!

[metaltriumph]

I think it would be easier to find a set of wheels that you like the look of - and use the rear swingarm and the USD forks from the same bike - saving yourself a whole lot of headaches when it comes to brakes, calipers etc. GSXR or an R1 are usually the choice. The problems arise when your front sprocket doesnt line up with your rear-sprocket.

Ive looked into it for my z650 but i dont want mags - i want my old wire spokes. Although i would love a beefier front end.

Have a look at some sanctuary kawasakis. They tend to still use 2 rear shocks rather than monoshock and usually mate new wheels, swingarms and forks to old zeds pretty neatly

[chimp]

webb
there is a site just for z650's " kz650.info" a few of us here use it.
cheers pete

[Gosling1]

Hi Webb

Al (Metaltriumph) has covered most of the issues. The main reason you can't just 'fit up' a really wide rear rim is the chain alignment. There is not enough clearance between the tyre and the chain run.

What you can do though - is lace up a slightly wider rim to your standard rear hub, and fit a slightly wider rear tyre. The standard rear rim width on 650 zeddies is a 2.15 x 18, running a 110/80 or 120/80 x 18 tyre. You could change this to a 3 x 18 and fit a 130 section tyre - or possibly even a 3.50 x 18 and fit a 140 section tyre. Running a 140-section rear tyre would require a 530 chain. If your bike is currently using a 630 chain, you can change the sprockets to early 650 (76-78) sprockets, these are 530.

I doubt you could go much wider than a 140 section tyre. The width of the swingarm at the front is one of the determining factors.

There are, as a general rule - no 'easily' interchangeable front & rear wheels to make this job easy. There is always going to be a degree of modifiction required no matter what wheel/tyre combo you want to use. What you could try though - is checking the specs from the wheels off a 750 Zephyr. Kawasaki made this bike with wire wheels for a couple of models. One of the issues with using late-model bits is that things like axle diameters are normally larger - which always creates problems when you want to use standard brakes or even standard swingarms - you have to muck around with different spec wheel bearings and perhaps slight machining to the swingarm etc.

You can use a set of forks off any bike you want - if you can source a complete front & rear ends from a donor bike, then just do the machining to make these fit your frame. It is difficult to fit a wider front wheel to a set of standard forks, because you run into problems with clearance for the brakes etc.

Nothing ever just *bolts right up*. It always takes some considerable effort when you change things from stock, unless the changes are only minor.

Good luck