Clip-Ons and Triple Clamps

bmccrary

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Never thought I'd see sine and tangent mentioned in a message here.:thumbup::thumbup:


Heck I remember when I first learned it and said, "Heck, I will never use this stuff again."

I hated math in highschool, I hate math in college... I enjoy math when it relates to real life senerios. I guess thats wh I enjoy engineering.

-bryan
 

husker

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Bertmoog
Which year CBR 1100 clip-ons did you get for the Fazer (or will any fit)?
 

bertmoog

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Ok so just because I an engineering major and a bit of math nerd (they tend to go hand in hand) I decided to play around with a little trig and geo to give you some numbers to go along with what I was talking about earlier.

So based off some quick measurements I measured my forks to be 29.5 inches long from the top of the body to the center of the front axle. (while on centerstand)

The rake on our bikes is 25 degrees. (The larger the rake angle the longer the wheel base and vis-a-versa.

The length from center of front axle to center of rear axle is roughly 57 inches.

Now you can make a triangle if you draw a line using the fork tube as the hyp. down to the axle, then draw a line going parrallel to the ground intersecting an imaginary line going straigt down off the center of the stearing head.

The short line parrallel to the ground we will call line X.
Base line calculation with forks even with tripple trees is 12.47 inches.

However, you said that you lowered the bike roughly a inch and 5/8 which comes out to 1.625 inches. I didnt know if you moved the forks up that much of if you lowered the bike that much. Those are two different directions. So I did both senerio's:

If you moved the forks up, making the distance between the top tripple tree and the front axle shorter, then line X's new value is 11.78" Which is ~0.7 inches shorter, making the wheel base now 56.3 inches long.

If you lowered the bike overall 1.625 inches. Then using tan as apposed to sin to solve you come out with the line X value to equal 11.706." Which is a 0.76" change to make the wheelbase now 56.24" long.

Which in the grand scheme of things really isnt that bad. However just for grins and giggles...

Our front end has ~5 inches of travel. So doing this same calculation....
When the front end is completely bottomed out the distance between the top tripple tree and the front axle is 24.5" and the value for line X is now 10.35". Thus making the wheel base 2.115" shorter!


So by moving the forks up you were able to make the bike turn a bit tighter. Which would come in handy on some of the more tight and technical tracks. However like everything else in suspension tuning, every advantage has its disadvantage. With the shorter wheel base the bike would not be as stable.


You have probably noticed the effects of moving the forks up, but if your riding style is as you say then you have more than likely adjusted for it. You should however notice the bike turns alot better inside your garage when moving it around. (I can turn circles around my buddies GSXR)

I would say take the clips ons off and try riding the stock set up and you would probably notice the difference. However that would be a bit hard to now :Flash:.

I hope some of you other out there found this helpfull as well and understand some of the dynamics of chassis set ups and Harely's really can't turn with their large rake angles.

-bryan

Thank you for the math! :thumbup: I love trig. So, from what youre saying, I can derive that the rake angle will decrease and the angle in relation to the road will increase as I move the forks up in the triple. What I dont get is how the bike would become unstable if the rake angle was decreased. I guess I can see that if the forks were perpendicular to the ground, that would be unstable. It seems like the gyroscopic force really becomes noticeable at about 20mph, at which point it is as solid as I would ever want it to be. Of course then again I can ride the bike at less than 1mph indefinitely with my feet on the pegs. Oh well, great post.:rockon:
 

bertmoog

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Bertmoog
Which year CBR 1100 clip-ons did you get for the Fazer (or will any fit)?

The ones I got were 97-98 model. I knew that the forks were 43mm in diameter for that year and I looked at the picture to estimate the rise. Now that theyre on the bike, I'm not so sure that the rise even matters. Maybe someone can back me up or correct me on this (defyinertia, hellgate?). If it doesnt, you can find clipons for 43mm tubes all day long on ebay.

eBay Motors: f4i cbr 1100xx zx7 zx11 clipons clip on handlebars 43mm (item 270256849341 end time Jul-27-08 20:28:55 PDT)
 
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bmccrary

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Thank you for the math! :thumbup: I love trig. So, from what youre saying, I can derive that the rake angle will decrease and the angle in relation to the road will increase as I move the forks up in the triple. What I dont get is how the bike would become unstable if the rake angle was decreased. I guess I can see that if the forks were perpendicular to the ground, that would be unstable. It seems like the gyroscopic force really becomes noticeable at about 20mph, at which point it is as solid as I would ever want it to be. Of course then again I can ride the bike at less than 1mph indefinitely with my feet on the pegs. Oh well, great post.:rockon:

The rake angle is constant, it is always the same, because the frame is fixed. As the forks move upwards, due to the angle, the front wheel is actually traveling backwards as well. This is because the forks are swept backwards from the front axle.

Things get unstable as they get shorter.... They can become more nimble as well, but depending on the geometry and the power supplied determines how unstable things get and at what point.

-bryan
 

madmanmaigret

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wow looks really good. any plans on other polishing?



Pete, you jealous yet..........? :D
dont get me wrong yours are awesome but the coin saved.........
 

bertmoog

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any plans on other polishing?

Actually, I already polished my wheels since my last wheel thread. I wanted to see what would happen to them if I didnt clear cloat them and, as it turns out, nothing. They still look shiny and mirror like. I dont know if the clamp will stay that way, I may have to eventually clear it or paint it.
I dont know whats next...golf clubs? :rolleyes:
 

hot4teach

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The rake angle is constant, it is always the same, because the frame is fixed. As the forks move upwards, due to the angle, the front wheel is actually traveling backwards as well. This is because the forks are swept backwards from the front axle.

Things get unstable as they get shorter.... They can become more nimble as well, but depending on the geometry and the power supplied determines how unstable things get and at what point.

-bryan

But the front of the frame would be moving down. This tilt would cause the rake to change(slightly).
 

bertmoog

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But the front of the frame would be moving down. This tilt would cause the rake to change(slightly).

I agree with you; I understand the angle of the fork never changes in relation to the bike but the angle in relation to the road changes and thats what matters when talking about handling.
 

bmccrary

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Not exactly. The rake is always the same. The angle the forks are positioned on the bike are always the same. The front doesnt fall independant of the forks. The suspension compresses, the wheel base gets short or longer, for a sec if you take in consideration the rear end, but the rake is always the same.

-bryan
 

marke14

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Just saw this thread - awesome write up and even better job - I am stunned that you did this at home w/ an angle grinder and a polishing wheel! It looks freakin' STOCK man, great job!

Glad to hear you didn't have any clearance issues.
 

bertmoog

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How hard was it to mount everything up to the clipons? drilling?

Not quite sure what you mean but if youre referring to the switches housing then yes I had to drill a little hole in the underside of the bar for the positive placement tit on the housing. Not a big deal... I would say total time to take off the switches and grips and put them on the clip ons... maybe 25 - 35minutes. Let me know if that doesnt answer your question.:thumbup:
 

Sawblade

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Any 43mm clip on will work, but you need something with a decent rise to clear the tank at full lock.
 

hedmisten

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Any 43mm clip on will work, but you need something with a decent rise to clear the tank at full lock.

Thanks! Are there any other type of clipons that previous converts will recommend? I'm pretty sure i'm interested in converting to clipons or a bar without so much rise.
 

OneTrack

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Heck I remember when I first learned it and said, \\"Heck, I will never use this stuff again.\\"

I hated math in highschool, I hate math in college... I enjoy math when it relates to real life senerios. I guess thats wh I enjoy engineering.

-bryan

Heh heh...I hear you. I can still remember the little rhyme that I had to use to remember that most simple of Greek formulae:
Tommy On A Ship Of His Caught A Herring :D
 

bmccrary

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Heh heh...I hear you. I can still remember the little rhyme that I had to use to remember that most simple of Greek formulae:
Tommy On A Ship Of His Caught A Herring :D

Man thats a tough one.

SOH-CAH-TOA thats how I memorized it.

Apparent it is a rather regular way to do so. After our first test in physics the prof. asked what this SOH thing was, everyone that had taken the test had it wrote somewhere. He thought we were cheating, lol.

-bryan
 
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