Kawi Kwestion

Your bike has 4.5 inches of trail. As a sidecar bike it will steer heavy, you could live with it or you can reduce trail. To reduce trail the front wheel needs to move forward, this is not done by changing the rake as changing the rake would have very little change on the trail. Often people will use triple tree's that change the angle of the forks in the tree and they more often then not call it "raking" the front end. It is not. To rake the front end would require that the frame be cut and the steering head welded at a different angle and like I said while this would change trail, it would not change it by much. When people do use the triple tree's that change the angle of the forks many people think that there is some "magic" number that is correct, Usualy around 6 degree's. This is not the case for many bikes more then 6 degree's would be better but there is not enough room with the frame mounted fairings for more. Others simply do not know and so make them with around 6 degree's. What you are looking for is trail reduction and how much depends on where and how the bike is going to be ridden. A bike that spends most of its time out on flat highways more trail is nice in that the bike is more stable. A bike that is ridden more often on winding roads you may want less trail for lighter steering. The rider also had some bearing on what final trail numbers are best. A large very strong person might find having more trail to be less work to ride then a bike with very little trail while a much smaller not as strong person might find that with a lot of trail they can not ride the bike for very long. When we reduce trail we do so many different ways depending on the bike. Today in the shop we have one bike that we have built "leading" legs that bolt to the bottom of the forks. (V strom) We are building a set of leading links for another bike with out floating calipars (XS850) and another with floating calipars (Convert) yet another bike we have installed new from billet triple tree's we had made. (Jackal) and another bike that we had the stock triple tree's modified (R100RS) One that we made a new from billet ball joint mount for the Telelever front end (R1200GS) and one that we made an off set plate for the telelever front end (R1100GS) On the BMW Telelver we are also doing one right now that we are decreasing the rake and also changing the ball joint mount so that the wheel end up in the same place but trail has been reduced. On the BMW this can be done with out changing the frame of the bike as the telelever arm an be changed. We have one more that we kept the front end stock but added power steering. (FJR1300) These are just the bikes in the shop today. In general for most people trail needs to end up around 2 inches, some will like more others not so much. One bike that I built for my wife (R100S) we ran 1.2 inches of trail as it had very narrow handle bars, Some people found that they almost could not ride the bike but after an hour or so on the bike found it to be great.
To answer the second part of your question. Trail can not be messured in degree's as it is a distance not an angle. If you ran a line down the center of the steering head of the bike to the ground it would hit the ground ahead of the front axle of the bike. Mark this point (if you can figure out how) Then go straight down from the axle to the ground and mark it. Then messure between these two marks. This is your trail number. Just changing tree's that do not change the angle will not change trail unless the tree's also change the off set. So if there is a set of tree's that the forks are further ahead of the steering stem this would change trail some.
There are many more ways trail can be changed, different forks that have the axle in front of the fork, if your axle is behind the fork tubes people have mounted them backwards changing side to side. Hub center steering can also be done, different wheel diameters will change the final trail a bit. The list of ways is almost endless.
Jay G
DMC sidecars
www.dmcsidecars.com
866-638-1793

Thanks for the detailed answer. Main reason for sidecar is disability: limited use of legs and some pesky balance problems at the wrong times. Living in a very mountainous area in southern Sierras, all local roads extremely twisty, tight turns, steep grades, challenging narrow tracks with off camber turns, exagerrated crowns and some poor road surfaces. Steep drop offs, no second chance, rarely in a hurry now.

Usually 2 round trips, 50 miles each per week to nearest town, about 1/2 hour each way. Other use for rig is long trips on various normal roads once I get out of here. California south-central valley about 50 miles away. My normal ride is a 7,500 lbs 47 year old 1 ton diesel truck with manual trans, heavy clutch and manual steering. Keeps my upper body strength tuned up. I can handle some fairly heavy steering but want the ride manageable and somewhat enjoyable too.

Used to rake the neck 50 years ago on choppers. Okay for the highway, a bear for tight turns. Seen lots of leading link designs but consider that as a last resort, if at all, too complicated. My buddy is a journey machinist - bike mechanic with a garage full of machine tools, I'm a lifelong mechanic - fabricator. He's made custom triple trees before and apparently has the equipment now.

Stock Kawi KZ1000 forks are about 3 3/4" to 4 1/2" trail, mine being 4 1/2". Not sure how much effect 1/2" fore or aft would have; must be notable for the factory to bother with changes. Another mystery is the notation in Service Manual of 63* of 'Castor' on this bike. Most discussions including here are talking about 5*-6* of rake, not sure what that refers to either. 6* of 'Rake' would have forks laying almost flat on the ground. My lower fork aluminum castings have axles dead center so no turning them around.

Anyways, it sounds like trail can be changed by reboring to change fork angle in triple trees relative to steering stem angle. I've read where Harley's had adjustable fork angle triple trees at one time, seems like a good idea. Guess I'll leave things as is but I'd sure rather build it right the first time and not tear it all down again.

Thanks!

I found this image on the internet. The adapters move the axle of the modern Indian forward. The trees stay the same and the fork angle stays the same, but the trail is reduced. Has anyone thought of making these for the Harley Electra Guides?

They are ugly enough. I would think the Tri-Glide trees might cost about the same without the odd appearance and fender mods.

Lonnie

Looks like a version of leading links. I agree with Lonnie, they're ugly just like probably all leading links even if they are functional. The triple tree would be just as functional and your bike wouldn't loose any of it's stock appearance.

That's looks like a pretty easy and simple approach, no rocket science. Simple enough for a home builder to fab up with modest tools, which isn't the case with modified triple trees. The idea seems to be good but the execution as shown lacks, way too clumsy, more than it has to be. Seems more billet or plate could give a much nicer appearance than the various tubing.

I'm now looking into building my own leading link but it's true they take away from the simple eye appeal of stock forks.

We call these "leading legs" and make them for a few bikes, mainly bikes where there is not enough room in the fairing for a angle change on the forks. On most Harley's we would go with triple tree's as the best option.

Jay G
DMC sidecars
www.dmcsidecars.com
866-638-1793

Thanks for further info, Jay. Looks like I currently have a few choices: use original forks off another Kawasaki with different trail, modify the original forks to correct trail, or make up a set of leading links.

Just scratched out a new design for a link type front end that hasn't been done before, near as I can tell. Uses much of the stock components and I can build it myself.

Still need to find out more info on the various stock Kawi triple trees and about how much improvement can be expected with the fairly minor changes in trail. Seems it may be an inch or more difference, don't know how much improvement that would be?

Would you guys say a 1" decrease in trail would cause a significant difference in handling?

Another question: I downloaded what is supposed to be the official KZ1000P Police Service Manual. In that manual it gives the 'Castor' [yes, that's how it's spelled there!] as 63*. Seems to me something's wrong with this picture if caster * is actually rake *. Most references I've ever seen for rake are in the 20's and 30's in stock configuration, not anywhere near 63*?

Don't know if it will help any, but take a look at the RB Racing Rake and Trail Calculator here: http://www.rbracing-rsr.com/rakeandtrail.html

Thanks for the reference there! Unfortunately I don't have all the required info to run the numbers plus I'm not all that bright on math. All I have is : Castor 63*, Trail 114mm - 4.5", Rake 27* from the manual. Unknown what the 'Triple clamp offset' or 'Triple tree rake' is. Thanks for the info though.

I think rake is measured in the oposite direction of caster(one the angle is at the top and the otherthe angle is at the bottom ) with that, if the caster is 63* on a car measurement then on a rake measurement would it be 27* ? the remainder of the angle from caster?

which you answered in your last post

Thanks for the help, Doug!

Sorry to say there's still some questions. That rake measurement of 27* I gave is a vague guess based on other KZ1000 bikes, not the mid 90's KZ1000P series Police bike. The Police series manual is frustrating because all it states is 'Castor' 63*, Trail 114mm/4.5" with no rake measure or figure given. No idea why they didn't include it but it was an internet downoad manual. I know the Kawasaki factory didn't mis-spell 'Castor' like this manual does so I'm also suspicious of even that 'Castor' number!?

I'll try to get some gauges on it and figure things out. Just noticed I have two other sets of forks, a Suzuki GS550 and a Honda 450, may be of some use somehow, more measurements!

Thanks!

I don't know if it will help you any,but when I built my links I moved the axle forward 1 3/4" and it has worked out great on the Goose. I run very hard and fast on gravel and a little less on pavement as it doesn't slide.