Spring weight for Off Road bikes.

[BigIvyI]

This topic got started in a recent thread, but was sort of a hi-jack so I thought I'd post it here.

Generally speaking, a lot of tuners seem to believe that springs are for supporting the weight of the bike and rider only. So you should use the same weight springs whether you are riding motocross or trail, or whether you are a beginner or pro. All the changes are with valving.

But, the Honda crf250x has lighter springs than the crf250r (.42 vr.s .45) and (5.o vr.s 5.2)

This is in spite of the fact that the X model is 25 pounds heavier.

If the bikes weighed the same, Honda might have gone lighter still on the X.

Maybe lighter springs ARE in order for off road riding? ?

[KTM-Lew]

If the factories had it all figured-out there wouldn't be any aftermarket suspension builders, would there?

While in theroy the springs rate should be a plug & play deal for weight only the riders speed/preference has some "weight" in the final decision. If you rode XR's or a KDX for years then you will likely prefer the "new" bike to be pretty cushy. The opposite also applies...

The problem with going by what the rags "rec" is they are trying to "fix" the GOAT of mx'ers, CR-CRF, by just replacing springs. They couldn't brag on how great they are stock if they had to admit the stock valving is as bad as any WP/KTM...

If the CR-CRF came valved better then they wouldn't have to rec .49 springs for "everyone"...how can one spring rate be right for "everyone?

If putting stiffer springs in is the correct way to tune a bike for MX then what fork springs do you suppose RC or JS is using? .60's, .65's? NO! I bet they aren't using springs any stiffer than stock! LOTS-O-VALVING though!

[SC_Spode]

This topic got started in a recent thread, but was sort of a hi-jack so I thought I'd post it here.

Generally speaking, a lot of tuners seem to believe that springs are for supporting the weight of the bike and rider only. So you should use the same weight springs whether you are riding motocross or trail, or whether you are a beginner or pro. All the changes are with valving.

But, the Honda crf250x has lighter springs than the crf250r (.42 vr.s .45) and (5.o vr.s 5.2)

This is in spite of the fact that the X model is 25 pounds heavier.

If the bikes weighed the same, Honda might have gone lighter still on the X.

Maybe lighter springs ARE in order for off road riding?

Geez, you get out of summer school and this is the first thing you get up to! Shouldn't you be out chasing coeds? ?

The springs are used to support the combined mass of the bike and rider... but what is the goal?

Perhaps there is a different goal in general for off-road versus MX, etc.

My experience is that for off-road there seems to be a preference for a softer rate and I think you'll find this to be true of how many tuners calculate their spring rates. Check places like MX-Tech and RT and I believe you'll find that the calculated rates for off-road are softer than for MX, all other parameters being the same.

And like Lew said, that huge can of worms known as "preference" (not to mention "perception") can't be ignored.

Lew: C'mon man, you know that's why they have those ginormous tubes on those factory bikes - so they can slide those 1-ton Ford coil springs into them!

[BigIvyI]

Well, my esteemed colleage, I haven't checked MX Tech, but RC recomends the same spring weight whether you are are MX or trail. It is also the same whether you are fast or slow.

...and everybody knoes RT is the cutting edge. ?

Seriously though, it seems sensible that you would want slightly softer springs for trail.

[SC_Spode]

I checked the RT calc and you are correct. However, they spec stiffer springs for AX and SX.

I also checked the MXT calc and they spec softer springs for enduro vs MX but spec the same springs for hare scrambles vs MX.

Like I mentioned previously, I guess it depends on the goal of the builder.

?