Swapping Forks, wheels, and swing-arm.

General forum on frames, brakes, suspension, wheels and tires

Moderator: rztom

Message
Author
User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#31 Post by Off Road » Tue Nov 19, 2013 11:53 pm

cookie wrote:
Off Road wrote: My only option is shorter dogbones, and that sounds expensive. :smt012
I took a couple of pairs in to my machinist and had them shortened. Didn't cost much at all IIRC, maybe $40 a set?
I've been thinking about having a set shortened, but I need to take some measurements, to see how much shorter to make them.
The FZR400 swingarm has a wide (over 1") cross-brace on it, and it's pretty close to the shock.
If I shorten the dogbones too much, the brace will hit the spring. And then I'd be filing on the swingarm.

Adjustable dogbones, like Jeff showed, would be nice, then I could set them for maximum ride height, without hitting the spring.
But, I'll bet they don't come cheap.
Since I can only get so much ride height increase, it's probably cheaper, (and easier), to have a set shortened.
I need to measure twice, cut once, and get a new machinist. My guy will probably want $70 or $80.

User avatar
kpke
-----
-----
Posts: 2531
Joined: Sun Nov 23, 2008 2:22 pm
Location: Livermore, CA

Re: Swapping Forks, wheels, and swing-arm.

#32 Post by kpke » Wed Nov 20, 2013 12:29 pm

Shorten your bones too much and you get this :smt010

Does not work well :smt018

Image


Stock and "shortened" flavors of fz600 parts
Image

User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#33 Post by Off Road » Thu Nov 21, 2013 1:17 am

Hey kpke. I remember your dogbones, and will have to be careful when I measure mine.
The wide brace on the FZR swingarm is going to be my biggest challenge.
(since this pic, the FZR arm has been modified, so that it has the same dogbone pivot locations, as the FZ600 arm).
I'm hoping I can shorten the dogbones (maybe 1/4" or more), and see if I can get 1/2" or 1" ride height increase.

Image


The current temperature is -15C, and being outside right now, is unpleasant.
That means I'm sitting indoors, with too many vices, an internet connection, and not enough parental supervision.
Probably not a good idea.

So, why would a person spend a ridiculous amount of time, calculating some numbers on a piece of paper?

As usual, there's a long story, and a short story. Which one do you want first?
Too late. You get the long story.
The big obsession started when I saw the tires on my FZR rims.
I suspected the huge rear tire, & tiny front tire, were going to affect the steering geometry,
and I wanted to know if the bike was going to be safe.
I started looking into rake & trail, then made calculations for my setup, and it looked like it was going to be good.

Spring arrived, I started riding the bike, and I was not impressed. The handling sucked.
The front end got really hard under braking, the bike wouldn't turn in to the corners, and it drifted wide on exit.
I started looking into suspension setup. Sag, spring rate, fork oil, compression & rebound damping.
During this search, I read 2 statements that have stuck with me.

"Handling is arguably one of the most important aspects of motorcycling. The entire time you are on the motorcycle, you are using it's handling capabilities".

"The best you've ridden is the best you know." Until you've ridden something better, the best you've ridden is the best you can compare it to".


Well, ain't that the truth. One of our city streets has an awesome set of S's.
Back in the day, when I was still 10 feet tall and bulletproof, I used to take them a more than twice the speed limit.
One day, I'm flying through them on an old Kawi KZ1000, (80+ HP with a bad suspension).
A left, a right, a left, but the bike wouldn't turn left.
The bars started shake really bad, and the bike drifted wide, and the curb kept getting closer, and I could see the sidewalk, and the fence beside it.
And nothing I did seemed to make any difference. I was just along for the ride, which looked like it was about to end, at any second.
Somehow, I didn't hit the curb, and didn't crash. But it was close. Too close.

Then I got the 81LC, and that bike handled much better than the Kawi.
Then I got the RZ, and it handled even better than the LC.
Then I got a 90 RZ, and the 2 piston front calipers are way better, than the brakes on the early bike.
Then I put the FZR400 bakes on my RZ, and they're a huge improvement over the 90 RZ.





Over the Summer, I made some adjustments to sag, fork oil, and damping, and the bike definitely handles much better now.
Then I saw RZResurection's project, using an R1 front end, and a longer swingarm.
I was just curious about how the R1 parts would affect the RZ's geometry.
This started a search for R1 specs and info, and how Yamaha changed swingarm angle to improve traction out of corners.
When I finally got around to calculating Specs for the R1 components, I found that I'd made incorrect assumptions, and math errors, when doing the FZR calculations.
Then pride and ego took over. If I was calculating numbers, I wanted the right numbers.

Finally finished the R1 calculations
Then started to use my new information to re-evaluate the modifications done to my bike.
What have I changed? How did it affect the bike? Can I improve it?

Which got me thinking about a motorcycle "with springs", then re-evaluating the affects on rake & trail, by changing sag and/or ride height, all over again.



So, did I learn anything, other than a couple of new terms, and few definitions.
Sure. First off, the numbers that I calculated for rake & trail, are pretty much irrelevant.
It doesn't matter whether my "calculations" say that the rake is 24* or 26*, the bike is what it is.
When you ride it on the road, it will have certain handling characteristics, no matter what the "calculated" numbers are.
Changes and adjustments will be needed, in order to optimize the handling.


The best part of going through this exercise, is that it has given me a much better understanding of how, and why motorcycles react in the way that they do.
And learning how certain changes affect the bike, and what adjustments can be made to improve the handling, has been very useful.


For instance, my bike with the FZR400 suspension, has awesome high speed stability.
My calculations say that it has a slightly steeper rake, and a bit more trail, than a stock RZ.
The bike also has a pretty small amount of front sag, which will increase the rider-on-board rake & trail.
In addition, the swing-arm angle has been reduced, witch will also increase rake & trail.

I want to try less rake & trail, to see if I can quicken the steering, without upsetting the stability.

First step will be to make shorter preload spacers, and increase rider sag by 10 mm (1/2").
Next mod will be shorter dogbones, to increase the rear ride height.
This will also steepen the swing-arm angle, and increase antisquat.

Stay tuned, I'll post the results of this experiment as soon as the snow melts, in about 6 months.



Now the short version on why I spent all this time looking at suspension tuning.

1- I find the subject fascinating. It seems that every part on the bike, affects its handling, including whether or not, the rider farted before getting on.

2- I'm one of those sick puppies that like to brake late for the corners, turn in quick, be able to change my line if I have to, and then accelerate sooner and harder on exit.
And I prefer to do this without the bike trying to throw me off, and/or scaring the shit out of me.
I'm just funny that way.

3- My bike handles pretty good, but "The best I've ridden is the best I know". Can I make it better? After all, better is...well,...its better.

4- The previously mentioned KZ1000. That moment in time happened over 30 years ago, and I remember it like it was yesterday.
I doubt I'll ever forget it, and I really, really, really, don't want any more memories like that, running through my mind for the rest of my life.

User avatar
kpke
-----
-----
Posts: 2531
Joined: Sun Nov 23, 2008 2:22 pm
Location: Livermore, CA

Re: Swapping Forks, wheels, and swing-arm.

#34 Post by kpke » Thu Nov 21, 2013 1:13 pm

OR, is that swingarm on the left FZR400?

User avatar
RZResurection
Posts: 1233
Joined: Sat Jul 15, 2006 9:51 pm

Re: Swapping Forks, wheels, and swing-arm.

#35 Post by RZResurection » Thu Nov 21, 2013 2:53 pm

kpke wrote:Shorten your bones too much and you get this :smt010

Does not work well :smt018

Image


Stock and "shortened" flavors of fz600 parts
Image
I really understand the problems associated with making these kind of changes. I 'get it', since I've literally changed everything on my bike.

This is where I really think a person needs to have some adjustability built into the system from 2 different perspectives:

1) There will always be problems with trying to find the best permanent position for a new set up. You can try to mimic what others have done, but their mods might not be right for you. Plus, when you don't get it right the first time - it starts costing you money. This is why I will be adding a clevis to the top of my shock mount after I have relocated my top shock mount position.

2) why do we add in new suspension components? Yes cause it's cool and we can. We do it so we can have more adjustability. The new components are 'infinitely' more adjustable than the old pieces of crap.

Why not build in some more adjustability with some rod-end dog bones? I just think it would save a world of hastle and frustration down the road. I'm not saying that it will be easy or cheap (since I haven't did my research on that mod). I'm just saying that it would be well worth it
Jeff

Trying to build a bike that's as fast as my memories
87 Canadian 1WV
OEM Pipes
Gutted Airbox
VF4 Reeds
Milled Head (0.020")
Main 240
Pilot 27.5
02 R1 Front End
R6 Shock and Rims (180 Rear Tire)
84 FJ1100 Swingarm

User avatar
gammaguy21
Posts: 232
Joined: Mon Apr 23, 2007 4:06 pm

Re: Swapping Forks, wheels, and swing-arm.

#36 Post by gammaguy21 » Thu Nov 21, 2013 3:08 pm

Lots of good info here... makes my head hurt though.
Just found this and thought it might help visualize what effect the changes could have.
http://blog.rectorsquid.com/linkage-mec ... simulator/

http://www.youtube.com/watch?v=HCjH7rsiXKE

User avatar
RZResurection
Posts: 1233
Joined: Sat Jul 15, 2006 9:51 pm

Re: Swapping Forks, wheels, and swing-arm.

#37 Post by RZResurection » Thu Nov 21, 2013 5:27 pm

gammaguy21 wrote:Lots of good info here... makes my head hurt though.
Just found this and thought it might help visualize what effect the changes could have.
http://blog.rectorsquid.com/linkage-mec ... simulator/

http://www.youtube.com/watch?v=HCjH7rsiXKE

Gammaguy - I've often thought about transferring my rear suspension set-up into AutoCAD, but have never been that ambitious. I've thought that there must be a program out there that will simulate linkage movement, but figured it would be hard to find or I'd have to pay money.

This is awesome! More things to distract me from actually building my bike. Hey, winter is here. This will give me a reason to stay inside. Shit, I'll have to go to the garage and measure suspension components if I want to do a proper simulation. LOL

Regardless, this is cool. Thanks
Jeff

Trying to build a bike that's as fast as my memories
87 Canadian 1WV
OEM Pipes
Gutted Airbox
VF4 Reeds
Milled Head (0.020")
Main 240
Pilot 27.5
02 R1 Front End
R6 Shock and Rims (180 Rear Tire)
84 FJ1100 Swingarm

User avatar
RZResurection
Posts: 1233
Joined: Sat Jul 15, 2006 9:51 pm

Re: Swapping Forks, wheels, and swing-arm.

#38 Post by RZResurection » Fri Nov 22, 2013 12:08 pm

Off Road wrote:Hey kpke. I remember your dogbones, and will have to be careful when I measure mine.
The wide brace on the FZR swingarm is going to be my biggest challenge.
(since this pic, the FZR arm has been modified, so that it has the same dogbone pivot locations, as the FZ600 arm).
I'm hoping I can shorten the dogbones (maybe 1/4" or more), and see if I can get 1/2" or 1" ride height increase.

Image
Hey Steve, I'm trying to picture what you've done since the picture. You say it has the same dog one pivot locations. Does this mean that the big brace does not have any support function for the linkage now? (like Kpke's swinger) If so, that means that you could cut and rotate the big brace to suit the new set-up with the shorter dog bones.

Looking at Kpke's set he could do the same thing and have the spring clear the brace.
Jeff

Trying to build a bike that's as fast as my memories
87 Canadian 1WV
OEM Pipes
Gutted Airbox
VF4 Reeds
Milled Head (0.020")
Main 240
Pilot 27.5
02 R1 Front End
R6 Shock and Rims (180 Rear Tire)
84 FJ1100 Swingarm

User avatar
kpke
-----
-----
Posts: 2531
Joined: Sun Nov 23, 2008 2:22 pm
Location: Livermore, CA

Re: Swapping Forks, wheels, and swing-arm.

#39 Post by kpke » Fri Nov 22, 2013 12:59 pm

Mine is "fixed" by using stock fz dog bones.

PO had shortened that other set that jammed the shock in to the swingarm.

User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#40 Post by Off Road » Sat Nov 23, 2013 1:05 am

Hey guys.
I had a machine shop remove the FZR400 dogbone pivot, on the bottom of the brace,
Then they plated the bottom of the brace, and installed new pivot points.
The new dogbone pivot location is exactly the same as the pivot location on the FZ600 arm, and I'm using FZ600 dogbones,
which don't need to be bolted into place, with big ugly nuts and washers, like the RZ dogbones. :smt003

If I knew then, what I know now, I would have moved the pivot locations back, (towards the rear axle).
This would have increased the swingarm angle, and raised the ride height,
and saved me from having to spend more money on some shorter dogbones. :smt012

Image

Image

User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#41 Post by Off Road » Sat Nov 23, 2013 1:31 am

cookie wrote:... never make a statement when a speech will fit.
That comment wasn't specifically directed at me, but let's be honest, we all know it applies.
And it really applies to this post.
Just a few highlights of what I think is some interesting reading.

Opened Tony Foals chassis design book, to look for info on swingarm angle and squat, in chapter 9.

http://www.tonyfoale.com/book.htm" onclick="window.open(this.href);return false;


He suggests skimming through the book first, to get a general understanding, before reading it in depth,
So, I was skimming along and found this gem:


Quote: "All engineering design is the art of compromise, the best bike is the one whose designer has achieved the best overall compromise for the intended purpose,"


Stated scrolling again, and got stopped at chapter 2.
Under the Heading of Tyres, sub-heading Friction (Grip).

Quote: "The amount of grip depends on the weight supported by each tyre, increasing the weight increases the grip.
The ratio between the maximum possible grip and the vertical load is called the coefficient of friction.
However, this coefficient is not constant but usually decreases with vertical load (i.e. increased contact-patch pressure)"


So, more weight equals more grip. He said so.
But. more vertical load, (which is Weight), decreases the coefficient of friction, and Reduces grip.
Spent a good deal of time reading the rest of the paragraph, (and searching the internet), trying to get that straight in my mind.
Here's the rest of what he said.

Quote: "A further complication is that this relationship is not linear.
This has far-reaching implications and is one reason for the general increase in tyre section on racing and sports machines, because, for a given wheel load, the bigger the section the lower the contact-patch pressure and so the greater the coefficient of friction, hence the grip on the road.

Heavy braking (when as much as 100 per cent of the total weight may be supported on the front tyre) provides an interesting example of the effects of the relationship between load and friction coefficient.
The forward weight transfer increases the pressure on the front contact patch and reduces that on the rear, so reducing the coefficient at the front and increasing it at the rear. Therefore, the tyre with the reduced coefficient of friction is carrying most of the weight and vice versa.
Hence, the total frictional force available for stopping is less than it would be on a machine with a smaller weight transfer.
In other words, for maximum braking we need a long wheelbase and a low mass centre."



Simple stuff
A wider front tire will improve braking, but it's bigger & heavier and will increase the unsprung weight and slow the steering.
A longer wheelbase will decrease weight transfer, and improve braking, but it will also slow the steering response.
Hmm, tough choice.


Other interesting quotes from the book on wheel size.

"For a given tyre section, the area of rubber on the ground is generally greater with larger diameter wheels.

Wheel size also effects gyroscopic forces. It was the continual widening of tyres for improved cornering ability that was probably the main driving force to reduce diameters, in order to avoid excessive gyroscopic reactions, which tend to slow the steering responses.

a smaller wheel drops farther into holes, similarly, it feels raised bumps more sharply.
.... a smaller wheel must mount a step in a shorter time than a larger wheel, this increased vertical velocity places more demands on the suspension system and transfers more shock back to the sprung mass of the bike.

The self-steering effect of trail and rake mentioned earlier is emphasized by the use of smaller wheels."

For purely structural reasons, smaller wheels are stiffer.

For a given tyre section, a small wheel reduces both the unsprung mass (to the benefit of roadholding) and the steering inertia. This is welcome in all cases."


So, smaller, lighter wheels & tires, for better handling with a rougher ride.
Or, bigger heavier wheels & tires, for better grip and braking.
Another tough choice.


Then there a few pages on Sprung, and Unsprung Weight.

Less weight improves acceleration.
Less Unsprung weight, improves road handling.
But he ratio of Sprung to Unsprung weight is also pretty important.


Quote: It is often stated that we always benefit from having the highest ratio possible.
This is not true in all cases as the demands of roadholding and comfort are often opposed. Roadholding (tyre grip) calls for the minimum unsprung mass.
For comfort we want the minimum force transmitted to the sprung part, this is helped by a high unsprung mass when hitting a raised bump, but not for hollows.

Quote: "For roadholding (quick response of the unsprung mass) we need the highest possible ratio between the two.
Unfortunately, there is a limit to how light we can make the unsprung mass, so an increase in sprung mass and spring rate, enhances roadholding on rough roads and also quickens the response of the unsprung mass, so keeping the wheels in better contact with the surface."



Interesting.
If I put my bike on a diet, and remove 50 pounds of sprung weight, and keep the same wheels, tires and brakes (unsprung weight),
then it will reduce the ratio of sprung to unsprung weight, and reduce the wheels ability to stay in contact with the road.


So, nothing really new here. Most of this is all stuff that we already know, but don't really think about.
Like this information on cornering.

Quote: 'Another consideration, often overlooked, is the effect of cornering forces, where banking angles may exceed 45 degrees.
This represents a 41 percent increase in the static suspension loading."

Quote: "Imagine negotiating a series of opposite-hand bends at high cornering speed.
As we bank into the first bend the suspension compresses under the increased loading, but when we straighten up and heel the other way, it first extends as the cornering load is removed and replaced by an outward centrifugal force (due to the rapid roll velocity), and then compresses again."

Quote: "This not only reduces the suspension movement available in the bends for absorbing bumps but also subjects the rider to an up-and-down movement that does nothing to improve his control.
If the machine has telescopic forks there is a change in wheelbase too.
This is another example of how suspension settings can affect the handling characteristics."


Then he gets into a detailed explanation (drawings, graphs, formulas, etc),
on how suspension movement, and corner roll, affect stability.
Then on to a discussion on how Damping controls the suspension movement

Wow. It seems that every paragraph I read contains more interesting information.
It's literally going to take me 100's of hours to read through this book, and then 1000's of hours to begin to understand it all.
I'd highly recommend his book to anyone interested in this subject.



And finally, one last "interesting" comment that was made in chapter 4, on Balance & Steering.
Once again, it's something that we all know, and that we all do, without even thinking about it.

Quote: "How do we actually initiate the turn? we have already seen that a moving motorcycle has an automatic tendency to stay upright?
Do we lean first or steer first?"


Let's see. I come flying up on a corner, brake hard, let up on the brakes, and I ......turn. Hmmm. :smt017

According to Tony, we don't have any say in the matter. It's all determined by Newtons third law, "for every force, there's and equal, and opposite force".

User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#42 Post by Off Road » Sat Nov 23, 2013 1:44 am

Quote: "How do we actually initiate the turn? we have already seen that a moving motorcycle has an automatic tendency to stay upright?
Do we lean first or steer first?"

The short answer.

Quote: "a turn can be initiated by steering momentarily in the “wrong” direction.
Termed “counter-steering”, for most riders this action is accomplished subconsciously.
Briefly, it is the combination of gyroscopic moments and centripetal force that requires this counter-steering action, we don’t have a choice in the matter."


A brief explanation of what really happens when you coutersteer.

Quote: "• A steering action to the right, will cause the machine to start turning right, and
centripetal tyre force will cause a lean to the left. This is the major banking influence.
• This steering action as we have seen, will also produce a small precessional tendency to lean the
machine to the left. This is a small effect when the wheels are on the ground, as shown later.
• Gravity will then initially augment the banking effect, but this will become less important as the tyre cornering force builds up and balances the gravitational moment completely, when the bike reaches the steady state lean angle.
• The velocity of banking or roll rate will give rise to gyroscopic torques which oppose the rider’s counter-steering input helping to steer the front wheel into the curve.
This gyroscopic torque is in opposition to the rider applied steering torque, and in fact balances most of his input and hence works against rapid steering. However, without this “negative feedback” the bike would be rather unstable and very hard to control, as we shall see."



Steering by leaning the bike.

Quote: "However, counter-steering doesn’t explain how we can corner “hands-off”.
So let us consider what happens if we try to lean without being able to steer.
As there is nothing solid for us to push against, the only way we can apply bank is to push against the machine with the inertia of our own body.
To lean the bike to the left, we must therefore initially move our body weight to the right.
The left leaning bike will now generate camber forces from the tyres tending to lean both rider and machine over to the right, the roll rate will again cause a gyroscopic steering torque which helps ensure correct balance.
The initial bike lean to the left might well be considered as a ‘counter-lean’, analogous to the ‘counter-steer’ of hands-on turning.
Anyone that has tried changing direction ‘no-hands’ will know that we have far less control over the machine with just body movement available.
The mechanisms involved with counter-steering produce much greater response and more finesse of control."

Quote: "In practice, that which we regard as riding in a straight line, is really a series of balance correcting curves, if we could look at the actual paths taken by the centre-lines of the wheels, we should see that the front wheel path continually crosses that of the rear."



And in the Conclustion of chapter 4, he says.

Quote: "Modern racing techniques demand rapid lean-in to corners, so therefore we need to optimise the use of the rider’s input as much as possible.
From fig. 4.12 we can see that during the initial counter-steering phase the rider’s torque is opposed firstly by the tyre force induced steering torque, followed shortly afterward by gyroscopic steering torque.

Thus to make better use of the rider’s effort we need to minimize the tyre feedback torque and the gyroscopic torque.
The tyre feedback is largely dependent on trail and this is one of the prime reasons for trail reduction to speed turn-in, although there are competing influences on the selection of trail.
Gyroscopic reaction is dependent on the polar moment of inertia of the wheel and so a reduction in general in wheel weight will also result in improved lean-in."



Less trail, and smaller tires make the bike turn quicker.
Not really a news flash, but it's interesting to know why it happens.



Man, if I don't start skimming faster, it's going to take another 2 days to get to the swingarm info, in chapter 9.
But damn, chapter 5 looks interesting, 30+ pages on aerodynamics.

Full fairings reduce drag, and improve top end speed, BUT, think of an airplane wing.
Air rushing past it creates a side force, called lift.
A full fairing bike behaves in a similar way to a wing, and the side forces created, cause instability.

So, Naked bikes rule. :smt003

RuZty
-----
-----
Posts: 3584
Joined: Fri Oct 03, 2003 11:11 pm
Location: Southern Ontario, Canada

Re: Swapping Forks, wheels, and swing-arm.

#43 Post by RuZty » Sat Nov 23, 2013 10:26 am

RZResurection wrote:
gammaguy21 wrote:Lots of good info here... makes my head hurt though.
Just found this and thought it might help visualize what effect the changes could have.
http://blog.rectorsquid.com/linkage-mec ... simulator/

http://www.youtube.com/watch?v=HCjH7rsiXKE

Gammaguy - I've often thought about transferring my rear suspension set-up into AutoCAD, but have never been that ambitious. I've thought that there must be a program out there that will simulate linkage movement, but figured it would be hard to find or I'd have to pay money.

This is awesome! More things to distract me from actually building my bike. Hey, winter is here. This will give me a reason to stay inside. Shit, I'll have to go to the garage and measure suspension components if I want to do a proper simulation. LOL

Regardless, this is cool. Thanks
It looks interesting, but I haven't had a chance to play with it. It's nice to see the dynamic relationship of the parts, but you need numbers to compare the effect of changing or adjusting any one dimension. At the end you need to see how the spring compression rate changes as the suspension moves through its travel.
The forks are linear, compressing the fork an inch compresses the spring an inch. The linkage on the rear allows this relationship to be non-linear and far beyond 1:1. Early R6 and CBR600 ride and weigh similar, yet the CBR has a rear spring that's twice as stiff, it's all in the linkage.
Bottom line is you don't want to change something that will make your suspension getting softer as it compresses.

User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#44 Post by Off Road » Sat Nov 23, 2013 9:01 pm

Hey Gammaguy, thanks for the link. I'm interested in seeing what that will do.

User avatar
Off Road
-----
-----
Posts: 2070
Joined: Thu Oct 01, 2009 1:31 am
Location: Alberta, Canada

Re: Swapping Forks, wheels, and swing-arm.

#45 Post by Off Road » Sat Nov 23, 2013 9:05 pm

So, with absolutely no engineering knowledge, you, and me, and a few of other people, decided to design a motorcycle.
That's what we did. Isn't it?
We hand picked new suspension components, and then built a bike to our own specifications.

By doing this we have specified the rake, trail, sag, preload, spring rates, shock lever ratio, damping, swingarm angle, fork length, ride height, wheelbase, weight bias, and wheel/tire size,, and...
Now all we have to do is fine tune these modifications in order to optimize the handling the new machine.
And after all, that's the main reason that we installed the new parts, Right?
So that we could run better tires, and have more suspension adjustment, and improve the bikes handling.

Sometimes, I almost wish that I'd have done something easier than suspensions mods, like maybe engine porting, or pipe design.
Or maybe I should have stuck to polishing aluminum, which was the original plan for my bike. :smt003

Post Reply