Varg spring rates ?


Number Six

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As the delivery date(s) inch ever closer, the window to fine tune or decide on options will be closing.
One item that has been weighing a bit is the user specified spring rates on the bike, a critical consideration.
I recall on the Stark website the suggestion that if the bike is to be used for primarily off road or enduro then it's recommended to go with a one step lighter spring rate than the rate range applicable for ones actual riding weight.
Should not a spring weight always be set for riders weight & then the valving & other variables such as oil height, sag & fork position be tuned to suit ?
Is there something different on an electric bikes suspension behavior that would have Stark suggesting something that on it's face would seem so unusual ?
In my experience, under sprung bikes exhibit a litany of undesirable traits & render them difficult if not impossible to valve correctly.
I'll ask the same of Stark, but figured those here have real world experience tuning suspension on the Alta's.
.
 
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Chadx

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Even though there is an enduro rear wheel/tire and kickstand option, it seems Stark is not going to the trouble and expense of offering enduro suspension. The idea of buying one or two weight ranges lower than ones weight is the simple, and only, option currently to avoid horribly stiff spring and valve rates for trail riding. It is not ideal because, as you say, "soft" suspension should still be sprung and valved to give the appropriate sag for ones weight and desired ride.

In the summertime, I weigh right on the bottom of their 165 - 175lbs (75 - 80kg) range and ordered two rates ranges softer; 143 - 154lb (65 - 70kg). It will likely sit lower in the suspension (sag wise), that it should, but I'm using it for mostly mellow trail riding and single track and that is how I had an ICE bike specifically setup for that use. Other ICE bikes, that I ride harder, I had setup differently but the super soft (overly soft) suspension on that bike worked well for that use case as it was cushy smooth and didn't wear me out like harsh/stiff suspension on some of my other bikes. The only air time it saw was hops over water bars on the trail, so nothing higher than a couple feet of the ground, and it used almost all the suspension travel from that height. Like I said, very cushy.

So, hoping I'll be good by choosing suspension two ranges (really about 1.5 ranges) lower than my weight. And, If not, I'll have it reworked. But it's worth a shot because I know that buying the Varg with the suspension for my weight or only one range lower was going to be too stiff for my use case. If someone plans to do hard/fast trail riding or do any air time more than a couple feet, then perhaps only one range lower might be a better starting point.
 

Number Six

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It would be useful if Stark would publish the fork & shock spring rates that correspond with those rider weight ranges, especially for those of us who plan on most usage to be other than moto.
 

AL_V

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Any suspension tuners out there who can offer professional advice on whether specifying a lower rate is a good idea for enduro type riding?
So far, I have selected one range lower than my actual weight with gear.
 

Philip

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Any suspension tuners out there who can offer professional advice on whether specifying a lower rate is a good idea for enduro type riding?
So far, I have selected one range lower than my actual weight with gear.
Yes, in my semi-professional opinion, it is a very good idea.

Although, this is hoping that the Varg's default spring rates and the front/rear balance will be perfect for motocross, which was not the case with the last two new bikes that I bought from KTM and Yamaha, both of which had too soft of a front end for my liking. We might still have to buy a stiffer or a softer spring, or maybe two. So... it's all a crapshoot.
 
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rayivers

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If I were Stark, I'd inform all buyers of the spring rates their bikes would be coming with well in advance of delivery. For non-suspension-tuners this would provide critical info for suspension shops down the road, and shock/fork tweakers could advise Stark of their preferences & replace guesswork with hard numbers, something I'm pretty sure Stark would appreciate. With enough feedback like this obtained early on, it could be used to adjust their suspension models more in line with what buyers actually prefer.
 

Number Six

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Many of us have experience setting up suspension for a particular use & are aware of what spring rates are in range, If we know the rates we can have a lot more confidence that the choice made is the appropriate one beyond just ; 'choose lighter' or 'choose heavier'.
Contacted Stark asking specifically what the shock & front spring rates were for a given weight range - the response I received was of no use.
Strange that it appears to be so difficult to find out the rates to be fitted for a given rider weight range, it shouldn't be some kind of proprietary secret.
Suspect that such is the realm of the engineering / testing departments & emails requesting such technically specific info as spring nomenclatures likely never get past the gatekeepers of the PR or customer service personnel.
Perhaps such info would be in the manual or parts lists ? Oh, wait ...

C'mon Stark, you're allowing us to choose which is terrific, but take it to it's logical end & let us know what the actual rates are so we can make a well informed decision beforehand.
.
 

Philip

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If I knew the weight of the front end, then knowing the front end spring rate would be very meaningful to me.

The weight of the rear end does not correlate to spring rates as well. This is because the motion ratio is not 1:1, and it is not even linear.
 

rayivers

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This spring calculator has helped me out many times, for both straight-rate and progressive springs. I believe most MC springs are chrome silicon for longevity, but I've plugged in all the material types and the results don't change much. The kangaroo bugs me a little. :)

Springulator Spring Calculator.jpg
 

Number Six

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Received some info from Stark regarding spring rates fitted.
Pretty 1st class of them to dig into it & supply that info IMO. Well done Stark Future.

143-154 weight range ; 5.4 N/mm shock & 4.6 N/mm forks.
154-165 weight range ; 5.6 N /mm shock & 4.8 N/mm forks.

If the progression up the weight range follows the .2 N/mm increments, then it should be simple to know the fitted shock & fork spring rates for the heavier ranges.

What's unknown is the linkage ratio of the rear suspension, but a comparison of suggested rates for a Yamaha YZ 250Fx ( 244 lb weight bike with KYB suspension ) indicates similar suggested rates as Stark does for a given rider weight riding MX.
That is from the Race Tech website so cannot comment on accuracy, just looking for some sort of reference so I don't miss by a mile on the spring choice.

Could be the suggested Stark ranges will be just fine for most Moto guys, where it gets trickier is for enduro / single track terrain.
I Plan on choosing with deference to the correct shock spring as it has the greater influence overall on the chassis & then if needed, buying a single fork spring to zero in on the forks for my specific usage, terrain & most importantly ; balance with the rear.
Of note ; Diverse Spring is one of the few outfits that will sell a single fork spring for that purpose.
Correct springs for intended usage, rider weight & ability will be a 1st step, then there's the bottomless rabbit hole of valving, oil levels, pressure springs & so on to navigate.
Or .. maybe the KYB stuff is valved to have a wide enough operational range that proper springs alone & clicker manipulations will be sufficient.
.
 
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Philip

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If I were Stark, I'd inform all buyers of the spring rates their bikes would be coming with well in advance of delivery. For non-suspension-tuners this would provide critical info for suspension shops down the road, and shock/fork tweakers could advise Stark of their preferences & replace guesswork with hard numbers, something I'm pretty sure Stark would appreciate. With enough feedback like this obtained early on, it could be used to adjust their suspension models more in line with what buyers actually prefer.
143-154 weight range ; 5.4 N/mm shock & 4.6 N/mm forks.
154-165 weight range ; 5.6 N /mm shock & 4.8 N/mm forks.

Now that the cat is out of the bag, and the 118 lbs is a known number, could Stark please publish the front/rear weight distribution and the exact spring rates that they are planning to ship to us?

I am finding myself in-between two choices. Also, I would rather pick my own front fork spring rate (since those are messier to change) and let Stark figure out which rear spring would create a balanced bike feel. @fsfs

1683335705727.png
 

AL_V

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There are only 3 different actual spring rates, the additional weight ranges are achieved by the "clicker" settings.

Thank you for contacting Stark.

The KYB forks fitted on the VARG are 48mm diameter and you will find the different spring rates and set up for each weight category below.
  • Spring rates for (65-70/70-75 kg) is 54N/mm shock and 4.6N/mm fork
  • Spring rates for (75-80/80-85 kg) is 56N/mm shock and 4.8N/mm fork
  • Spring rates for (85-90/90-95/95-100 kg) is 58N/mm shock and 5.0N/mm fork
 

Philip

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  • Spring rates for (65-70/70-75 kg) is 54N/mm shock and 4.6N/mm fork
  • Spring rates for (75-80/80-85 kg) is 56N/mm shock and 4.8N/mm fork
  • Spring rates for (85-90/90-95/95-100 kg) is 58N/mm shock and 5.0N/mm fork
This was very helpful. Thank you. I am near the middle of the third category, so I am not worried anymore.

We will know the exact weight distribution when Bryan gets his bike.
 

Ethos

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I am right on the edge at 160 lbs without gear.
I ordered down in weight range for softer springs. I intend to do more enduro riding than mx.
 

Chadx

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I am right on the edge at 160 lbs without gear.
I ordered down in weight range for softer springs. I intend to do more enduro riding than mx.

Same. I'm 165 without gear and ordered the lightest spring/setup they offer since I'm only trail/enduro and zero MX. Will probably still need to revalve, and maybe re-spring, but the lightest they offer from the factory is a good starting point. Since Stark offers enduro wheel/tire, I wish they offered enduro/trail springs and valving as well since it sounds like around half of the buyers are using the bike that way (in the U.S. anyway).
 

Tuomas

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There are only 3 different actual spring rates, the additional weight ranges are achieved by the "clicker" settings.

Thank you for contacting Stark.

The KYB forks fitted on the VARG are 48mm diameter and you will find the different spring rates and set up for each weight category below.
  • Spring rates for (65-70/70-75 kg) is 54N/mm shock and 4.6N/mm fork
  • Spring rates for (75-80/80-85 kg) is 56N/mm shock and 4.8N/mm fork
  • Spring rates for (85-90/90-95/95-100 kg) is 58N/mm shock and 5.0N/mm fork
Asked also the clicker settings from the support, and they sent the tables for each weight category. Tables attached. Settings from 65kg/70kg on to 95kg/100kg respectively from right to left. Five star customer service from stark future :giggle:

shock settings.png

fork settings.png
 

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