Pimping the white Brothers groove 200

Hi members,

for some time now a ratteling noise coming from my white brothers groove 200 fork almost drove me crazy. Only audible when riding on bad roads or off road. After disassembling the whole thing i found the reason why. The left arm incorporates a large spring, whereas the right arm uses oil and a couple of seals to damp the ride. Now this big spring has to have some play between the aluminium tube and itself where it´s mounted in. The problem is that this gap allows the spring to vibrate against the aluminium tube. This acts as a resonance body amplifing the sound. The solution is simple. I took some shrink tubing, cut 5 pieces from it and made it shrink appling some heat. This now acts as a cusion preventing noise. I´ve ridden almost 1000 km with this in place, took apart the fork today and noticed no wear, or movement ot these. No big deal, but it really helps and should be done by white brothers straight from the factory.



The pieces inside



The applied shrink tube

Nice mod. Maybe email the company your photos and explanation if you havent already.

Great Fix.

I posted a link to here on ES for the Google Stealth group as many there have that fork ordered with the Bombers they are waiting for.

Thanks for your feedback, i´ve written the company just a few days ago. The problem doesen´t start right away. But once the grease on that spring starts to wear off then there´s nothing to dampen the movement inside the aluminium tube. White brothers does recommend a complete maintenance every 100 hours. This means the thing has to be disassembled completely, the parts inside cleaned, regereased and the dampening oil changed. Well, it´s not an impossible job to do if you have the right tools at hand. While i was at it, i did just that.

Pure genius! I have to remember this for other applications...

That's great that you found the source of the noise.
With that, one can start considering options to cancelling it.

I wonder how many times shrink tube can be flexed (due to spring compression) before it starts desintegrating.
Maybe instead, tiny plastic clips (let's say 3 around the circumference of the spring wire) at about 5 axial length positions would do the same but avoid flex fatigue issues.
Or a thin plastic (Nylon?) sheet strip going between the spring and tube for at least 1/2 circumference would be enough to cancel knocking?
Interaction between the grease and new material introduced (petrolium products can attack some plastics) can be tested separately.

Also, from the before and after pictures it seems like the spring was repacked in grease at the same time as the shrink tube was added. One can wonder what is the contribution percentage of each towards reducing the noise.

Thanks for keeping our rides quiet.
Jerome

Update!! The modified forks have been ridden for 11724 Km. Took them apart yesterday to check the shrink tubing. All still in place with no signs of wear.