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Author Topic: Bike Suspension Bible  (Read 4453 times)

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Offline Industrial Cafe

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Bike Suspension Bible
« on: October 11, 2009, 08:11:06 PM »
I found this very informative link while searching google.
http://www.carbibles.com/suspension_bible_bikes.html

everything I say is pure speculation and
I have no idea what I'm talking about  ._.


                                    Marla              .:71CB750:.CAFE

Offline HedNut

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Re: Bike Suspension Bible
« Reply #1 on: November 25, 2009, 09:56:38 AM »
VERY COOL!  Nice find~!

Offline mystic_1

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Re: Bike Suspension Bible
« Reply #2 on: November 25, 2009, 01:07:25 PM »
Good stuff, thanks!

mystic_1
"When you are wrestling for possession of a sword, the man with the handle always wins. "  - Neal Stephenson, Snow Crash

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0


Offline Industrial Cafe

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Re: Bike Suspension Bible
« Reply #3 on: November 25, 2009, 01:16:38 PM »
I had a question that page didn't answer, I'm doing a gsxr1000 fork swap and the steering axis is tighter to the neck bolt than stock by about a half inch.

what will that do?
will it give me the shakes without a damper?

edit: it's 2 inches or so wider.
« Last Edit: November 25, 2009, 01:26:41 PM by Industrial Cafe »
everything I say is pure speculation and
I have no idea what I'm talking about  ._.


                                    Marla              .:71CB750:.CAFE

Offline mystic_1

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Re: Bike Suspension Bible
« Reply #4 on: November 25, 2009, 02:14:11 PM »
I'm not following, are you swapping the trees and the new ones have less offset?  If so that'll reduce your trail, but by how much is hard to guesstimate.  You'll have to measure it.

mystic_1
"When you are wrestling for possession of a sword, the man with the handle always wins. "  - Neal Stephenson, Snow Crash

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0


Offline Industrial Cafe

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Re: Bike Suspension Bible
« Reply #5 on: November 25, 2009, 04:13:10 PM »
 I'm swapping the whole thing.
 I have a pic of the difference.
 

edit: what does reducing the trail do to your handling if the rake remains the same?
« Last Edit: November 25, 2009, 08:31:30 PM by Industrial Cafe »
everything I say is pure speculation and
I have no idea what I'm talking about  ._.


                                    Marla              .:71CB750:.CAFE

Offline tbpmusic

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Re: Bike Suspension Bible
« Reply #6 on: November 26, 2009, 06:13:22 AM »


edit: what does reducing the trail do to your handling if the rake remains the same?

That would make the steering a bit "quicker".

Here's a little spreadsheet that will let you determine the geometry fast and easy - you just need a tape measure and a stick. Based on the immutable laws of right triangles.....

http://home.comcast.net/~tbpmusic6/RakeTrailCalc.xls
"If you can't fix it with a hammer, then it's an electrical problem"

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Offline mystic_1

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Re: Bike Suspension Bible
« Reply #7 on: November 26, 2009, 06:29:37 AM »
Yup, bike will steer quicker but will be somewhat less stable in straight lines/high speeds.  Four to six inches of trail is the target zone that a lot of builders go for.  Too much trail isn't so bad (heavier steering) but too little trail can lead to tank-slappers.

mystic_1
"When you are wrestling for possession of a sword, the man with the handle always wins. "  - Neal Stephenson, Snow Crash

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0


Offline Industrial Cafe

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Re: Bike Suspension Bible
« Reply #8 on: November 26, 2009, 06:39:52 AM »
i figured that.
    then it would probably be a good idea to put a steering damper on it...
everything I say is pure speculation and
I have no idea what I'm talking about  ._.


                                    Marla              .:71CB750:.CAFE

Offline mystic_1

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Re: Bike Suspension Bible
« Reply #9 on: November 26, 2009, 06:49:33 AM »
Re-checked by statement earlier btw and reducing offset actually increases trail.  So, you'll be fine.

1/2 inch reduction in offset won't affect the trail a whole lot anyway.  Stock trail is like 3.8" IIRC.  Looks like 1/2 inch offset reduction should put your trail in the neighborhood of 4.2"

BTW I should have said earlier "Four to six inches of trail is the target zone that a lot of chopper builders go for".


mystic_1
« Last Edit: November 26, 2009, 06:55:07 AM by mystic_1 »
"When you are wrestling for possession of a sword, the man with the handle always wins. "  - Neal Stephenson, Snow Crash

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0


Offline Industrial Cafe

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Re: Bike Suspension Bible
« Reply #10 on: November 26, 2009, 06:59:45 AM »
 I noticed the later cb750's had a half inch or so less trail to their trees than my 71.
everything I say is pure speculation and
I have no idea what I'm talking about  ._.


                                    Marla              .:71CB750:.CAFE

Offline Square

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Re: Bike Suspension Bible
« Reply #11 on: November 09, 2011, 09:44:29 AM »
Thanks for the link,

i know its an old post but winter is coming and its time to get so work done..

Offline rklystron

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Re: Bike Suspension Bible
« Reply #12 on: November 10, 2011, 03:34:39 AM »
Great find. I will be building or greatly modifying a stock frame and this information is invaluable. Thanks again IC.
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Offline caferacer750

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Re: Bike Suspension Bible
« Reply #13 on: June 29, 2012, 06:51:16 AM »
very nice write up

thanks for posting it

Offline Trevdawg

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Bike Suspension Bible
« Reply #14 on: June 29, 2012, 06:53:18 AM »
Nice

 

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