KZ400 Rims and Tire Question

Rims front-and-rear appear to be 1.85x18 and the rear tire looks to be a 3.5x18 (90 series?).

I don't plan on running a front fender, or at least not a stock one so rubbing isn't going to be too much of an issue.

What's the best tire size to get a high-sidewall look, and a decent rounded profile without being too big for the rim? 110/100? 100/90? 90/100?

I plan on running front tires front-and-back depending on the configuration, and just oppose the rotation on the rear for grip. (Probably safer than running a rear on the front.)

Attached is an image of what I'm shooting for. My guess is they're running 16 or 17 inch rims on the stock hubs, which may or may not be an option.

I wouldn't go wider than a 100 front. In back some guys go to a 110 on a 1.85 rim but it's not an ideal fit.

The bike in the photo looks cool. I like how the rear end isn't as chopped off looking as so many customs these days. A longer fender would look better than that mudguard extension but I'm just quibbling. The plank seat looks uncomfortable as hell. A compromise for sure, and not a good one if the person actually likes to ride. It's clear that 90% of all the customs on the road put fashion in front of function and that's a shame. Form should follow function, not the other way around.

Nessism wrote: I wouldn't go wider than a 100 front. In back some guys go to a 110 on a 1.85 rim but it's not an ideal fit.

The bike in the photo looks cool. I like how the rear end isn't as chopped off looking as so many customs these days. A longer fender would look better than that mudguard extension but I'm just quibbling. The plank seat looks uncomfortable as hell. A compromise for sure, and not a good one if the person actually likes to ride. It's clear that 90% of all the customs on the road put fashion in front of function and that's a shame. Form should follow function, not the other way around.

+1 Anyone considering such a seat should first try sitting on a 2x6 board for an hour or two so they will know what to expect. Also, real front fenders actually do serve a purpose - they keep road slop from being thrown up onto the rider (I rode without one for a short period on my BSA - not good). At least he kept a rear fender to shield the pods and the rider. Of course those tires look like they should be on a 1938 Buick rather than sport bike, but I guess if one is riding slowly it may not matter. Putting form ahead of function results in a bike that may be fun to look at but not fun to ride. To anyone who actually rides motorcycles bikes like that scream "poser" not "rider". Ed

I think it takes a lot of skill to make a bike look like that. Anyone can plop a fat but on a bike. very few have the will to create something. Good luck with it and don't let the stock snobs get you down .

punisher11b wrote: I think it takes a lot of skill to make a bike look like that. Anyone can plop a fat but on a bike. very few have the will to create something. Good luck with it and don't let the stock snobs get you down .

Nothing wrong with modding a bike, as long as the mods are intelligent. Therein lays the rub.

Bobbers with a ridged rear are the dumbest mods. A chopped exhaust is the most annoying. Stinkbug rear ends with the frame rails chopped at the shock junction are the sign of a guy watching too much TV (of bike building shows).

If you don't plan on using a front fender, you should invest in a fork brace
Pete

Nessism wrote:

punisher11b wrote: I think it takes a lot of skill to make a bike look like that. Anyone can plop a fat but on a bike. very few have the will to create something. Good luck with it and don't let the stock snobs get you down .

Nothing wrong with modding a bike, as long as the mods are intelligent. Therein lays the rub.

Bobbers with a ridged rear are the dumbest mods. A chopped exhaust is the most annoying. Stinkbug rear ends with the frame rails chopped at the shock junction are the sign of a guy watching too much TV (of bike building shows).

Exactly. It has nothing whatsoever to do with being a "stock snob"; it's simply a matter of choosing mods that enable the owner to actually ride the bike without suffering discomfort or performance problems. As an example, a Corbin seat is not a stock item and doesn't look stock, but it would certainly offer more comfort than sitting on a short ironing board. The fact that a mod takes skill, money, etc. to achieve doesn't mean it results in a bike one would actually ride.

Here are just two examples of bikes that took enormous skills to build, and both look good - but which would be a better ride?

Heavily modded KZ650 (1400cc ):


Midget KZ650

Thanks for the responses.... I'm sorry, looks like you all thought I'm trying to copy-cat that build. Not in the least. Just the wheel presence and stance is all, hence the question about wheels and tires.

0 front fender = fork brace, that's obvious. I've built a couple bikes in the past, but this is my first Kawasaki, and my first sub-750cc street bike. I built up a GS750 and an MT250 a few years back. It'll give you an idea of my style.

If you notice... the seats are untouched originals. The only real "mod" to the GS750 was the bars, other than paint and finishes. The MT250 was 99% original other than a frame chop and modern plastics.

You'll see my "themes" in these two builds and where I want to take one of the KZ400's to "café" or "brat" style with the original posting kind of as a "stance guide".

Since I have 2 KZ400's.... I'm thinking of doing one up with all the best bits as a "survivor"... probably the blue one, but swap the forks off the drum brake model onto it. Then, build a brat bike out of the remaining frame, engine, plastics, tank, and running gear... with a disc brake front end.

Suzuki Before:


Suzuki After:


MT250:


75' KZ400-


74' KZ400-

You'll have to keep the disk front end intact. The drum one would make a good duel sport.
Steve

Looks like you do very nice work! Ed

those look like the stock 18" wheels on the kz400 in your inspiration photo. I put 90/90f and 100/90r on my 400 before i sold it handled great with the smaller tire upfront. I think the Firestone classics have an exaggerated sidewall to start so i don't know how much oversize you would need to go to get the look you want. Like others have said, this will make the bike handle worse, but its YOUR bike so do what you like.