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Author Topic: Rear Shock Length and Handling  (Read 865 times)

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Offline cafe750

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Rear Shock Length and Handling
« on: March 16, 2008, 07:59:05 AM »
So, I've got two shiny new sets of Progessive shocks in front of me, and I'm trying to decide which set will be best for playing in the twisties.The bike is a '75 CB750F. One set is in the stock length , and the other is an inch longer, stock length for the CB900F. Im running the 105/140 progressive springs, to help support my 230 lb a$$.  I should also mention that Progressive springs are on the way for the front, as well as a Tarozzi fork brace. Im currently undecided about what oil I'm going to run in the front, I'll have to experiment when I get the springs. Which length should I use?
« Last Edit: March 16, 2008, 10:03:32 AM by cafe750 »
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Offline Geeto67

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Re: Rear Shock Length and Handling
« Reply #1 on: March 16, 2008, 09:59:45 AM »
inch longer. Racers use it, it was considered a performance upgrade back in the day, it just makes sense.

jacking the bike up in the back will decrease your steering angle, making your turns sharper. It will also decrease your trail making your bike slightly less stable at high speeds in a straight line. The secret is finding a good trade off. A lot of road race guys I know will jack the back up an inch and lower the forks an inch to gain sharper turning, a lot of drag racers I know will try to maximize trail without going into steering flop by lowering the rear.

Not knowing how much you weigh and how much the bike settles with you on it having inch longer shocks may put the bike at the angle the engineers intended all along (if you are heavy) so it may not make all the much difference. figure out how much the bike settles when you sit on it and then lower the forks in the trees that corresponding amount and you will see an  definite difference.
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Offline cafe750

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Re: Rear Shock Length and Handling
« Reply #2 on: March 16, 2008, 10:37:34 AM »
Thank You, thats the info that I needed!
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Roy, Washington

Offline turboguzzi

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Re: Rear Shock Length and Handling
« Reply #3 on: March 16, 2008, 02:24:24 PM »
After a few races with +0.5" at the rear I went up to +1.2" and the steering become much quicker and precise. Didnt lower the front as you actualy loose ground cleareance doing that. Got a steering damper just to make sure things dont go out of control and planning to install new triple clamps to get the trail back. from my calculation it is now down to 80 mm from the original 100 mm or so due to jacking up the rear.

All this was done to my CB500 racer but I'd guess that on a 750 you should feel the same improvement.

TG   
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