Lowering

Hey guys,

So I recently bought a 1979 KZ650, which is my first KZ. So far I really like the bike, I'm working on bobbing it. I've never had to lower a bike before but the one thing I can't stand about this bike is how high it sits. I was wondering if anyone had any ideas how to slam this thing. I'm not sure what shocks or forks would be interchangeable, or if I'd even need new ones.

If anyone has experience slamming one of these bad boys, please let me know, I'd really appreciate any advice. Thanks in advance.

Forks just need a spacer (limiter they're called) below the top-out spring. This brings the upper tube down into the lower tube. If you leave the main fork spring alone you will preload it. It doesn't make the fork stiffer as the spring rate has not changed, but it will ride higher in the stroke. You can remove the same length of main spring as your limiter but that will slightly increase spring rate.

If you want to do it right, lower both front and rear the same to keep the stock geometry. Otherwise you may encounter some weird handling issues.

If your foks have a preload spacer like the photo, you can just place that below the top-out spring.

Thanks, how do you suggest lowering the rear?

You might be able to install Harley Sportster lowering shocks. eebbaayy search = Sportster shocks 12.5" or 11" or etc.
Measure yours first with the bike on the center stand. The stock Sportys are about the same eye-to-eye length as the KZ650 shocks (around 13.5") & I think the lowering shocks come in a few sizes shorter than that. some of them are called Huggers. some HD shocks have shrouds on the lower end that will probably interfere with the chain guard. I don't know if the shrouds are removable.

Fitment. you'll have to swap the bushings. use a c-clamp & socket. no big deal. the chain guard may rub the Sportster shocks, also maybe not a big deal, especially if yours is plastic. Also, when you install lower shocks, the tire may rub the fender or something.

If it still has a stock seat or a stepped seat like a LTD style, the easiest way to lower is just cut like 6" of padding off the seat. Right away you are lowered 6". Bobbing is easy as well, cut the back off, remove the rest of the useless ugly stock fenders ect. Mounting a license plate is either way up under the tire where it can't be seen, or optional turn 90 degrees and mount on either side. For sure get rid of blinkers as they are no good. Several aftermarket blinkers in 1/2" diameter or so are available.

OutlawShank wrote: Thanks, how do you suggest lowering the rear?

Shorter shocks is the easiest route. You should remove the shock springs (Google shock spring removal zip tie), install the shocks and actuate the swingarm to look for any contact with the fender/chain, etc. If the tire hits the fender you need to install a longer shock bumper or shorten the shaft.

Also, moving the shock up/down the swingarm by repositioning the shock mounts has an effect on the damping. If you take a stock shock and move it towards the engine the rear suspension will become soft because of the added leverage of the swingarm. Just the opposite if you move the shock toward the axle.

Thanks for the response, I've actually heard of using the sportster shocks before. I'm thinking thats what I'm going to end up doing. I love these bikes as they are but man I hate how tall they stand!