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Made a rough prototype of a new shock preload ring the other day. This gets rid of the plastic adjuster that comes stock, but still uses the stock lock clamp (black part). It also integrates a thrust bearing so the spring can rotate as it compresses allowing for a more free movement.
This was a quick and dirty prototype and there are some changes necessary yet. Most notably the thrust bearing area needs to be slimmed down a touch to fit with some shock reservoirs (MX Tech Tank shown has a larger diameter than stock). KTM also uses an odd (buttress) thread form on the shock since they're using a plastic ring. It's a smart move on their end, but requires some special tooling to cut which we're still waiting on. I cheated on this one and used a double chamfer cutter to mill the threads. Not good enough to use, but good enough to thread on for a fit check. Once we get tooling and revise the design a bit we will start making a few available for sale, but that's at least a month out.
Also shown is a preview of some coatings and anodize on the shock parts.
You can see the completed covers from our previous post in here as well. These have been hard anodized and laser-etched with our logo.
The Shop
I think even lighter (maybe not)
Sorry late to the party - hadn't kept up, still reading through.
Obviously it's a nice part etc etc... call me old school
Wanna bring your theories to my dyno?
how much cerakote did it take to do the frame?
Pit Row
More updates coming, just been a bit busy with other things. But still making progress on the build!
So you really shouldn't see the spring change positions before and after a ride, though I bet it will just because things are bouncing around and constantly loading and unloading. The best thing to do is stick the shock on a dyno and compress it showing the spring rotating with respect to the shock body, but we don't have a dyno available to do that. Maybe someone else does?
Bike build is looking killer.
If you were able to lock the spring in place on both ends, it would be just as good as a spring with a bearing on one (or both) ends from a consistency standpoint. The bearing seems to be the easier solution. But I also want to make sure it's robust and well sealed too. No sense in going to all that trouble for it to gum up with dirt and no longer rotate! Still ironing out the details of all that at the moment.
From an aftermarket standpoint, the issue is geometric. Everything is round - the spring, the spring collars on both ends, the shock, etc. To stop rotation, you need to stop it on both ends, which means locking the spring to something round that is then somehow locked to the shock.It would be a lot of parts to produce and lock together and wouldn't likely end up being very elegant.
So instead of locking everything together to stop rotation, we can "simply" add a bearing to allow rotation and achieve the same result (consistency). Most modern forks do this with a very similar bearing at the end of the spring. But that's in a well oiled, clean, and controlled environment. The challenge with the shock bearing is keeping is well sealed, which sounds like the issue you had with the Race Tech bearing.
There wasn't a change they could have made to the spring directly to increase its resonant frequency out of the excitation (RPM) range as that would completely change the spring rate. And even if that were possible, they'd miss out on the many benefits of reduced engine vibration.
It comes back to cost/benefit. The cost of the balance shaft was justified in the overall reduced vibration, a big side benefit of that being reduction in spring vibration. The benefit of locking a spring in place to keep the rate consistent is much smaller in comparison to the benefit in reducing spring vibration due to resonance. So even if doing so costs far less than adding a balance shaft, the benefit is far less as well. So it doesn't make sense to do so. Hope that all makes sense!
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