Correct sag with a wrong spring?

I have asked around, but no one has answered.

I bought a used crf450r. I get 35 mm free sag and 102 mm race sag, with 5.4 kg spring. I weight 194 lbs with gear. I don´t know if the shock valving is stock, but it has race tech 5.4 kg spring. I know that most my weight riders use 5.7 kg spring.

1) How is it possible I get correct sag numbers, with a spring for a lot lighter rider then I´m?
2) What could be wrong? There must be something wrong internally. Does the pressure plays role in sag?

 

Sag "rules" are not as strictly in reality as most people think.

Seems like the sag rules have been preached for ages and most riders like to have a solid rule to work with.

Even if it feels right, THERE MUST BE something wrong when the numbers are not at the golden figures ;)

Dont get me wrong, sag is very important and the 95-105/25-35 rule isnt around for now reason, but sometimes you find yourself outside of this figures and the bike rides very nice!

 

But you're right, you are most likely better off with a stronger spring.

 

Valving doesnt play a role.

N2 pressure does. But I never really tested what difference in pressure does make a difference in sag...

Bet your over on max preload

Bet your over on max preload

Got 250 mm of pre-load. That is almost standard, and far from over max.

Got 250 mm of pre-load. That is almost standard, and far from over max.

Check your math/measurement. Then check your manual again.

Edited by YHGEORGE

Check your math/measurement. Then check your manual again.

Manual:

Max:          254.0 mm

Min:           240.5 mm

Standard:  251 mm

I got:          250 mm

Edited by sandman1111

With only a few mm of preload it can't be a 5.4 , have you had the spring rated?

With only a few mm of preload it can't be a 5.4 , have you had the spring rated?

No I haven´t. All I can tell is that it is RaceTech spring with a marking of a 5.4 spring :).

Got 250 mm of pre-load. That is almost standard, and far from over max.

You do not have 250mm of preload. Your spring is at 250mm length at the preload applied. Your actual preload is much much much less. For example, my CR250 manual shows standard preload spring LENGTH is 257.9mm.  That does not mean the preload is 257.9. It is probably more like 5 to 10mm. The minimum length of my spring suggested is 247mm. That would be with the maximum amt of preload applied to the springs.

You do not have 250mm of preload. Your spring is at 250mm length at the preload applied. Your actual preload is much much much less. For example, my CR250 manual shows standard preload spring LENGTH is 257.9mm.  That does not mean the preload is 257.9. It is probably more like 5 to 10mm. The minimum length of my spring suggested is 247mm. That would be with the maximum amt of preload applied to the springs.

Okey. BUT I have never seen anyone talk about rear shock spring pre-load ranges (only in manual, and I wrote those earlier). What are the max and min ranges? Do you know any links, where I can read about it? I haven´t measured the full length of the spring, but do you think the RaceTech spring is a lot longer? Otherwise I don´t see it being wrong.

Edited by sandman1111

Rt spring could be longer yes

Okey. BUT I have never seen anyone talk about rear shock spring pre-load ranges (only in manual, and I wrote those earlier). What are the max and min ranges? Do you know any links, where I can read about it? I haven´t measured the full length of the spring, but do you think the RaceTech spring is a lot longer? Otherwise I don´t see it being wrong.

Max and min lengths are in the oem manual. But they all pertain to stock OEM springs. Race tech dimensions are available on their website. Lots of really good info in the Honda manuals concerning suspension and adjustments. If you don't have one maybe a riding friend would. They may also be available on the internet. Good luck.

Edited by YHGEORGE

I do have Honda manual. But it does not tell me what spring I should use, or what kind of sag numbers I get with my current spring. Or if the shock pressure changes the sag. Some ppl say I need 5.7, some say 5.5, and looking at numbers 5.4 is good etc.

Anyways the racetech spring is 257 mm. So I have 7 mm of pre-load.

Manual says, that the stock spring is: Standard (Medium) spring (54 N/mm (308.3 lbs/in)): 240.5 mm (9.47 in)
But manual also says that spring pre-load length (standard spring):
Max:          254.0 mm
Min:           240.5 mm
Standard:  251 mm

How are those numbers even possible, if the spring is only 240.5 mm? 

 

Edited by sandman1111

I have asked around, but no one has answered.

I bought a used crf450r. I get 35 mm free sag and 102 mm race sag, with 5.4 kg spring. I weight 194 lbs with gear. I don´t know if the shock valving is stock, but it has race tech 5.4 kg spring. I know that most my weight riders use 5.7 kg spring.

1) How is it possible I get correct sag numbers, with a spring for a lot lighter rider then I´m?

2) What could be wrong? There must be something wrong internally. Does the pressure plays role in sag?

Where is the rear axle ? Is it pushed forward or back alot ? Where are the forks in the triples ? Is there alot of fork tube above the top triple ? Either of these things can change weight distribution a little...cornering and stability too.

------------------

Bike on a stand = 0

Bike off stand, without rider=staticSag (35-40mm)

Rider,in gear and on bike ---> this number minus bike on a stand measurement= race sag (100-110mm) approx

Usually a spring that can give you around 105 race sag and 35 static is correct for your weight . Approx #'s , the length of the spring is something else

Edited by avocasingletrack

I do have Honda manual. But it does not tell me what spring I should use, or what kind of sag numbers I get with my current spring. Or if the shock pressure changes the sag. Some ppl say I need 5.7, some say 5.5, and looking at numbers 5.4 is good etc.

Anyways the racetech spring is 257 mm. So I have 7 mm of pre-load.

Manual says, that the stock spring is: Standard (Medium) spring (54 N/mm (308.3 lbs/in)): 240.5 mm (9.47 in)

But manual also says that spring pre-load length (standard spring):

Max:          254.0 mm

Min:           240.5 mm

Standard:  251 mm

How are those numbers even possible, if the spring is only 240.5 mm? 

 

It does not tell you what spring you should use. But, it does tell you how to adjust sag and what measurements to shoot for. The rider sag and free sag measurements will lead to the spring you need. Honda cannot give you that exact info in the manual.  And you are confusing pre-load length with the actual(free) length of the spring. I suggest you spend time starting at the first of the Suspension Adjustment section and read it several times and really focus on each section. Pretty soon it will become more clear. Keep it handy because you will probably be reading it some more. Then you can start worrying about valving :banghead:  :smashpc:  :foul:  :devil:  :banghead:  :cry:  :rant:  

Edited by YHGEORGE

Where is the rear axle ? Is it pushed forward or back alot ? Where are the forks in the triples ? Is there alot of fork tube above the top triple ? Either of these things can change weight distribution a little...cornering and stability too.

------------------

Bike on a stand = 0

Bike off stand, without rider=staticSag (35-40mm)

Rider,in gear and on bike ---> this number minus bike on a stand measurement= race sag (100-110mm) approx

Usually a spring that can give you around 105 race sag and 35 static is correct for your weight . Approx #'s , the length of the spring is something else

I got 250 forks (2 mm longer). And triple clamps are flush. Rear axle is in the right place. Chain is just lightly worn. Everything should be good.

 

It does not tell you what spring you should use. But, it does tell you how to adjust sag and what measurements to shoot for. The rider sag and free sag measurements will lead to the spring you need. Honda cannot give you that exact info in the manual.  And you are confusing pre-load length with the actual(free) length of the spring. I suggest you spend time starting at the first of the Suspension Adjustment section and read it several times and really focus on each section. Pretty soon it will become more clear. Keep it handy because you will probably be reading it some more. Then you can start worrying about valving :banghead:  :smashpc:  :foul:  :devil:  :banghead:  :cry:  :rant:  

I see that you can push a lot of emoticons buttons. There is no free length written in the manual. Yes there is a confusing 240.5 mm written, behind the spring specs, but that is probably the Min number. And yes the manual states those min and max numbers as spring pre-load, do you want me to take a picture? Or maybe you should read the manual yourself?

 

OMG, I know how to adjust the suspension!!! I asked how is it possible to get right measurements, with a spring too light for my weight?? Why can´t you answer that question? You keep talking about damn sag and race sag, manual etc. I wrote all the sag numbers etc, just scroll up. They are not wrong!!!

For example MXA states, that 170 pounds a level guy needs a 5.7 kg spring. So how is it possible, that I who weights 194 lbs, can get 35 mm free sag, and 102 mm of race sag, with 5.4 spring? There must be something wrong with my shock, or they are running a lot more free sag. Tell me please. And don´t come to tell me, that I can read it from the manual, or suspension adjustment section.

If you still don´t believe, go read Honda crf450, they all suggest 5.7, but no-one has answer, why I can get those numbers, with 5.4. 

With all due respect, I can see you want to help, but you really haven´t answered any of my questions.

Sorry. And the emoticons were relating to how frustrating it can be to find correct valving.  Not referring to you in any way. I'll go away. Good luck.

Yeah suspension is frustrating. I´m sorry too, I´m getting very hopeless, because no-one has the answer. I guess the post was quite attacking.

 

I have emailed many suspension companies. I get no answer at all, or they just write you something, without even thinking. There was one dude, who basically agreed to help me, but he has disappeared.  

It seems, that I have to contact the local suspension tuner, and let them work on my suspension. It is going to be damn expensive :(. I really wanted to do the work myself.

:thumbsup:  Good luck. I will also be doing all my suspension tuning myself. Really don't want to but I have wasted $$$$ with tuners. All nice guys, just no luck for some reason. I will be using the Race Tech kits, cannot possibly be any worse.

Sure, if your spring is off a bit you can still get the right race sag... but the static sag will be off.  Are you measuring sag with the bike full of fuel, half, empty?  Are you sitting or standing?  Does your bike have a lot of extra bits (handguards, skid plates, larger fuel tank, fender bags, etc...).  Does the bike having lowering or non-standard linkage-links?  There are a lot of variables...  Most importantly is to start with a baseline and then consistantely measure/adjust the sag from there till you find a happy medium.

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