Spring recommendations for open cart/rear shock setup for Desert Racing

[pgeldz]

Hey guys, I'm finally getting into the Tenere build now that my racing in MotoAmerica is finished for this season.  I might have a Pro card for Road Racing, but I'm a beginner as far as off road goes.  Need some help with spring rates.

 

I weigh 74.8 kg without gear.  I'll be wearing ADV gear, and added weight to the bike itself would be Outback Motortek crash bars, OEM accessory skid plate, and R&G side luggage rails.

 

I plan to use this bike in off road desert racing type environment, with light jumps, whoops, as well as sand dunes.  

 

I'm having trouble figuring out the correct spring rates.

 

What would you recommend for the parameters above?

 

In reading up on the subject through this forum as well as speaking with industry professionals, my initial initial thoughts were 6.0 or 6.3 springs up front, and 7.5 or 8.0 out back.

 

Any help would be greatly appreciated.

 

 

- Paul

[Goldentaco]

3 hours ago, pgeldz said:

Hey guys, I'm finally getting into the Tenere build now that my racing in MotoAmerica is finished for this season.  I might have a Pro card for Road Racing, but I'm a beginner as far as off road goes.  Need some help with spring rates.

 

I weigh 74.8 kg without gear.  I'll be wearing ADV gear, and added weight to the bike itself would be Outback Motortek crash bars, OEM accessory skid plate, and R&G side luggage rails.

 

I plan to use this bike in off road desert racing type environment, with light jumps, whoops, as well as sand dunes.  

 

I'm having trouble figuring out the correct spring rates.

 

What would you recommend for the parameters above?

 

In reading up on the subject through this forum as well as speaking with industry professionals, my initial initial thoughts were 6.0 or 6.3 springs up front, and 7.5 or 8.0 out back.

 

Any help would be greatly appreciated.

 

 

- Paul

I'd probably ego with the 6.3 and 8.0.  Both the 6.0 and 7.5 are real close to stock.  Are you doing a cartridge kit or just modding the stock internals?

 

I'm 220 in street clothes and 240 geared up.  I went with the 6.4 front and 95 rear.  I could have stepped down on the rear and the front is ok for cruising but when riding it hard it's perfect. 

 

My stock shock was just barely able to keep sag maxxed out but after riding it hard for a few thousand miles, it was not up to the challenge.  Good news is if you don't like them, they're super easy to swap out.  Fronts you don't even need to remove the bars.  With proper tools, the rear can be out and switched and reinstalled in less than an hour.

 

Great info for a do it yourself here: 

Tenere 700 suspension info | Adventure Rider

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Here is a bit of info for you T7 owners. I will build on it as i do more. Spring rates. I have calculated these. They are very close to what a tuner...

 

 

 

 

J

[Murska]

Your weight is 6.3N on the front and RR 80N on the back. If you put a K-Tech spring then choose 75N because 80N can feel too hard.

 

I weigh 90kg and have driven the K-Tech 75N spring, it is clearly stiffer than the standard spring but nicely soft. But ... is too soft to jump and bounce. The K-Tech spring is longer than the standard spring and the spring comes with a lot of mounting preload which is not a good thing.

 

Now I have a K-Tech 6.3N (change later 6.6N) on the front and a Tractive 85N spring on the rear. Fork and shock is revalving and the suspension is pretty good. On the bike I don’t have any accessory that increases weight, I don’t carry stuff or a passenger.

 

The rear I recommend the Rally Raid (Tractive) spring and the front K-Tech spring is a good choice.

[pgeldz]

I probably should have mentioned I'm probably going with the K-Tech ORDS cartridges up front and their piston kit out back.

.

I have a great relationship with K-Tech and currently use their products in my road race bike.

.

@Murskaknowing I'll be using the K-Tech piston kit in the shock would you still say the K-Tech 7.5 spring is too soft, even though I weigh 15kg less than you do?  Should I go to 8.0 K-Tech spring?  I ask because I've read their piston kit has great bottoming resistance...

Edited October 16, 2021 by pgeldz

[Murska]

If you are driving hard and fast offroad then the K-Tech 80N spring, if the driving is softer then the 75N spring is probably ok. You should ask K-Tech for an opinion.

 

The K-Tech rear spring rate cannot be directly compared to a Tractive / Rally Raid spring. K-Tech is 245mm and RR 235mm long and K-Tech comes with more installation preload. The K-tech gets to be 5-10N looser when the Tractive / RR spring, otherwise you may not get the adjustment sag right and the rear stays too high.

 

I weigh with gear 97-100kg and the K-Tech 75N spring has a 6 click preload and the sag is 65mm. Tractive / RR 85N spring 3 click preload and sag is 65mm.

 

Surely you understand what I mean by spring stiffness from different manufacturer because the free length of the spring is different?

I don't like the spring which is a lot of installation preload.

[pgeldz]

3 hours ago, Murska said:

If you are driving hard and fast offroad then the K-Tech 80N spring, if the driving is softer then the 75N spring is probably ok. You should ask K-Tech for an opinion.

 

The K-Tech rear spring rate cannot be directly compared to a Tractive / Rally Raid spring. K-Tech is 245mm and RR 235mm long and K-Tech comes with more installation preload. The K-tech gets to be 5-10N looser when the Tractive / RR spring, otherwise you may not get the adjustment sag right and the rear stays too high.

 

I weigh with gear 97-100kg and the K-Tech 75N spring has a 6 click preload and the sag is 65mm. Tractive / RR 85N spring 3 click preload and sag is 65mm.

 

Surely you understand what I mean by spring stiffness from different manufacturer because the free length of the spring is different?

I don't like the spring which is a lot of installation preload.

I understand.  I think I'm this case the 75N would be perfect, since I weigh less and I won't be fast right out if the gate, as I'm new too off-road.

.

Can we talk more about the front?  6.0 vs 6.3?  I was thinking because of our weight difference, and the fact that the K-Tech cartridges have adjustable preload, maybe the 6.0 would be better a match than the 6.3?

[Murska]

The 6.0N front spring is only slightly stiffer than the standard spring. The 6.3N spring front end does not dive easily when braking than standard or 6.0 springs, but is not too hard and works great for off road driving.

 

I have driven 6.3N / 75N with K-tech springs and the bike balance is good with those springs. Slightly soft for my weight but perfect for a lighter 80kg driver.

 

[pgeldz]

37 minutes ago, Murska said:

The 6.0N front spring is only slightly stiffer than the standard spring. The 6.3N spring front end does not dive easily when braking than standard or 6.0 springs, but is not too hard and works great for off road driving.

 

I have driven 6.3N / 75N with K-tech springs and the bike balance is good with those springs. Slightly soft for my weight but perfect for a lighter 80kg driver.

 

Ok perfect, thanks!