Which fork leg should I fit the stronger spring in?

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Demannu
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Which fork leg should I fit the stronger spring in?

Post by Demannu »

To get the correct front sag I've had (about to) to fit different rate springs in each leg.
However 1 leg is rebound only, the other compression.
So...........which one gets the stronger spring?
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Re: Which fork leg should I fit the stronger spring in?

Post by Mussels »

Won't that put a bending force on your forks that they aren't designed for?
Apart from that it shouldn't matter as springs and dampers work independently of each other.
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Re: Which fork leg should I fit the stronger spring in?

Post by Demannu »

Mussels wrote: Mon Jan 10, 2022 8:27 pm Won't that put a bending force on your forks that they aren't designed for?
Apart from that it shouldn't matter as springs and dampers work independently of each other.
Not in my experience.
However only ever done it to bikes with both sets of adjustment on each leg!
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Re: Which fork leg should I fit the stronger spring in?

Post by Mussels »

If there were no springs and the compression damper was on the left then the right hand fork would be lower on the way down, so I'd probably go with the stronger spring on the right.
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Re: Which fork leg should I fit the stronger spring in?

Post by Demannu »

My thoughts precisely.
My reasoning is the stronger spring needs more rebound control.
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Re: Which fork leg should I fit the stronger spring in?

Post by Lutin »

I might be missing something really obvious here, but aren't the springs supposed to be the same?

Just asking for a friend, you understand. ;)
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Re: Which fork leg should I fit the stronger spring in?

Post by wull »

Lutin wrote: Mon Jan 10, 2022 9:34 pm I might be missing something really obvious here, but aren't the springs supposed to be the same?

Just asking for a friend, you understand. ;)
It’s common practise to achieve the required rate, they tend to average out.
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Re: Which fork leg should I fit the stronger spring in?

Post by Lutin »

wull wrote: Mon Jan 10, 2022 10:06 pm
Lutin wrote: Mon Jan 10, 2022 9:34 pm I might be missing something really obvious here, but aren't the springs supposed to be the same?

Just asking for a friend, you understand. ;)
It’s common practise to achieve the required rate, they tend to average out.
OK. Thanks for that. :thumbup:
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Re: Which fork leg should I fit the stronger spring in?

Post by Yorick »

Who said you need different springs ?
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Re: Which fork leg should I fit the stronger spring in?

Post by Demannu »

Yorick wrote: Mon Jan 10, 2022 10:22 pm Who said you need different springs ?
I did
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Re: Which fork leg should I fit the stronger spring in?

Post by Yorick »

Demannu wrote: Mon Jan 10, 2022 10:59 pm
Yorick wrote: Mon Jan 10, 2022 10:22 pm Who said you need different springs ?
I did
Hmm.
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Re: Which fork leg should I fit the stronger spring in?

Post by mangocrazy »

Why do you want to complicate matters unnecessarily? Minimise the number of variables, not increase them. Spring rates can be specified in very small gradations to allow you to set static sag correctly. If you need the contact details of a spring maker I can supply that.
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Re: Which fork leg should I fit the stronger spring in?

Post by Mr. Dazzle »

I'm guessing the OP is trying to get a "half" value between two available rates?

Getting custon springs seems more complicated than fitting one of one size and one of the other. The legs are already asymmetric by virtue of the fact one does compression and one does rebound. Its not like you're gonna anger the suspension gods by making the legs different. They're already different.

But yeah, I wouldn't be surprised if the makes have finer steps available than first advertised. Do that if you can.
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Re: Which fork leg should I fit the stronger spring in?

Post by MingtheMerciless »

Mr. Dazzle wrote: Tue Jan 11, 2022 7:39 am Its not like you're gonna anger the suspension gods by making the legs different. They're already different.
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Re: Which fork leg should I fit the stronger spring in?

Post by KungFooBob »

Who needs suspension, just get tyres with higher sidewalls.
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Re: Which fork leg should I fit the stronger spring in?

Post by Mr. Dazzle »

KungFooBob wrote: Tue Jan 11, 2022 9:38 am Who needs suspension, just get tyres with higher sidewalls.
S'all in the knees.
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Re: Which fork leg should I fit the stronger spring in?

Post by singlesman »

Surely you set the ‘sag’ with the damping adjusters backed right off? So the damping side of things is completely separate from spring rate at the point of measuring sag.
I stand to be corrected, but know with my old speed triple the only way to get the standard forks working a little better was to put in springs for the correct sag, then thin oil in the compression side and heavier oil in the rebound.
Using miss- matched springs wouldn’t have felt right, but maybe I’m missing something?
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Re: Which fork leg should I fit the stronger spring in?

Post by Mr. Dazzle »

singlesman wrote: Tue Jan 11, 2022 10:37 am Surely you set the ‘sag’ with the damping adjusters backed right off? So the damping side of things is completely separate from spring rate at the point of measuring sag.
I stand to be corrected, but know with my old speed triple the only way to get the standard forks working a little better was to put in springs for the correct sag, then thin oil in the compression side and heavier oil in the rebound.
Using miss- matched springs wouldn’t have felt right, but maybe I’m missing something?
I think the OP is talking about something different. If I understand, they're trying to achieve a spring rate which is between two available types of spring.

We usually talk in terms of a "10kg/mm" spring or whatever, but of course there are generally two in the forks. So the total rate is actually two times what you put in the forks (springs in parallel just add up). Two 10kg/mm springs give a total of 20kg/mm and so on. Say you went down to 9kg/mm springs, you're total would then be 18kg/mm. If you wanted a total of 19kg/mm you'd need a 9.5kg/mm spring in each leg - but maybe 'they' don't make 9.5kg/mm springs. So you just put a 10 in one leg an a 9 in the other. S'not as uncommon as you might think.

They probably do make 9.5s though!
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Re: Which fork leg should I fit the stronger spring in?

Post by Demannu »

Yorick wrote: Mon Jan 10, 2022 11:29 pm
Demannu wrote: Mon Jan 10, 2022 10:59 pm
Yorick wrote: Mon Jan 10, 2022 10:22 pm Who said you need different springs ?
I did
Hmm.
Surprisingly for someone on here, I DO actually know what I'm doing re: suspension
I'm just quite fussy, 9.5 is just a little too soft, hard on the brakes, so upping 1 leg to 10 to hopefully get it just right without going too firm!
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Re: Which fork leg should I fit the stronger spring in?

Post by mangocrazy »

Mr. Dazzle wrote: Tue Jan 11, 2022 7:39 am I'm guessing the OP is trying to get a "half" value between two available rates?

Getting custon springs seems more complicated than fitting one of one size and one of the other. The legs are already asymmetric by virtue of the fact one does compression and one does rebound. Its not like you're gonna anger the suspension gods by making the legs different. They're already different.

But yeah, I wouldn't be surprised if the makes have finer steps available than first advertised. Do that if you can.
My point is that if you go to a spring maker you can specify the exact rate you want, to fractions of a kg/mm, lb/inch or N/mm. There is no need to use different rates in each leg to try and arrive at a median setting. It really is just making life diffficult and being imprecise when you don't need to be.

And the damping in both legs of the fork (be they compression or rebound) is predicated on the assumption that the spring rate is the same in each leg. OK, it's not going to be a mile out doing it the way the OP is thinking of, but it's not ideal.
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