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Author Topic: Shock angles  (Read 3818 times)

Offline fearlessfred

Shock angles
« on: May 04, 2015, 10:01:01 PM »
This post is an effort on my part to help fellow member with his desert ride.What I know came from the guy who built my old desertsled and books he had me read during the two long years it took to build it.Its pretty easy to understand. basically everything is figured from the shock centerline and the centerline of the pivot of arm and lower shock mount coming to a right angle or just shy of a right angle when in full bump.full bump is shock fully collapsed with out bumper.the reason this is important is because provides for a smooth rising rate ( In other words the shock shaft speed changes as it goes though travel ) .if you go past a right angle the shaft speed will actually decrease at the end of the travel and if you lay the shock down to much ,the rising rate will become to steep . all this has to be placed with in the limits of travel concerning ride height and components that have limits on there travel

Offline mandom250r

Shock angles
« Reply #1 on: May 04, 2015, 10:22:03 PM »
Ok i think i get it but where does one start as far as choosing parts? Will all no-link swingarms work with any no-link type frame?

Offline Hawaiiysr

Shock angles
« Reply #2 on: May 04, 2015, 10:37:03 PM »
Fred,
Do you know the title of the books you speak of?

Offline fearlessfred

Shock angles
« Reply #3 on: May 04, 2015, 10:52:22 PM »
my reason for showing you the shock angle at full bump was an effort to show that not just any shock length will work ,if you get angle correct the shock becomes to long to to fit and you have to make the lower mount ,lower and the top one higher  If you know how to figure the correct angle you could easily figure how to modify the top mount on a stock frame. A longer shock will have a longer body and that changes were full bump is ,so if you are mixing and matching you will have to figure correct angle at full bump .If you already have no link swingarm ,your only option is to make correct by changing upper mount changes

Offline mandom250r

Shock angles
« Reply #4 on: May 04, 2015, 10:52:56 PM »
Here is what is said to be used on a stock link chassis. Shock is 17.5".

Offline fearlessfred

Shock angles
« Reply #5 on: May 04, 2015, 10:59:46 PM »
Quote from: Hawaiiysr;54041
Fred,
Do you know the title of the books you speak of?
Carol Smith  ,Engineering to win and another one he wrote that I dont remember the name .The books are not directly related to our sport but worth the read

Offline fearlessfred

Shock angles
« Reply #6 on: May 04, 2015, 11:08:07 PM »
Quote from: mandom250r;54045
Here is what is said to be used on a stock link chassis. Shock is 17.5".

I have seen this done by a company in Arizona back in the 90s and was the reason I had mine built .the rising rate is so steep that when you get enough spring to hold the bike up you can not get it though all the travel.They tried to correct with multiple springs

Offline fearlessfred

Shock angles
« Reply #7 on: May 04, 2015, 11:13:15 PM »
In regards to question in chat room

Offline mandom250r

Shock angles
« Reply #8 on: July 07, 2015, 11:19:47 PM »
What do you think fred?


Offline andy@maultechatv

Shock angles
« Reply #9 on: July 09, 2015, 08:10:39 AM »
I have a program that calculates this and you can input where your shock mounts are located to compare.  I would want a little rising rate on the front so it acts like a linkage in the rear but not too much.  Finding that sweet spot with maximum shaft travel is the key.

 

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