Stark Varg “weave” (steering wobble)

[texanate]

I picked up a Stark Varg MX a couple months ago and have put about 20 hours on it so far, trailriding.

I mostly love it, but from that very first ride around the neighborhood after putting it together, I noticed it doesn’t like to stay pointed in a straight line. It kinda weaves, slaloms on its own, or “swims” like a fish. It’s most noticeable on pavement and gravel transit sections but on the trail it’s hard to put the front wheel exactly where I want it - it feels like the front wheel is loose somehow. At first I thought it was just brand new dirt tires on pavement, but the issue persisted.

Things I have tried that have not seemed to help the issue:
- Changing the tires (I wanted to run Tubliss /
gummy tires anyway)
- Tightening the following to spec: Steering head nut (loosening the associated pinch bolt first), fork leg pinch bolts (upper and lower), front axle nut and axle pinch bolts, rear axle nut, docking station (handlebar) bolts, handlebar mount lower bolts.
- Adding rear preload to get proper race sag (I am 240lb, so will install a stiffer spring soon too).
- Checking wheel bearing play (no play)
- Checking front wheel spacers (it would be obvious if these were in there backwards right?)
- Checking the front end for play (i.e. standing in front of the bike, locking the wheel with my feet and trying to pull the handlebars left and right) - no clunking or abnormal play that I could tell.
- Checked front wheel spoke tension. I don’t have a spoke torque wrench but I tapped all the spokes and they all sounded fine.

My next ideas:
- Maybe loosen the steering head a lot and see if the issue is noticeably worse? This same bolt on my Tenere is like 140Nm, is it possible the Stark spec (I forget if it’s 12-14Nm) is way too low?
- Stiffer rear spring (in case this is a geometry issue)
- Get a spoke torque wrench and actually torque the spokes up properly?

After that it might be a trip to the mechanic, and/or finding someone else local with a Varg who would be willing to swap bikes to see if they’re all like this. My benchmark is mostly Yamaha 4-stroke dirt bikes, which are renowned for being very stable, but I feel like no bike would weave like this.

 

[OpaTsupa]

Do you only notice it on asphalt and at higher speed?
If so try balancing the wheels using spoke weights. I've seen reports of as much as 100g needed.

If you are noticing understeer or oversteer than try to check the fork legs alignment using this device:

ForkTru™ - Fork Alignment Tool - Motion Pro

Motion Pro - High quality cables, tools and controls for motorcycles, ATVs, snowmobiles and personal watercraft.

www.motionpro.com

My test for problem in this area is to ride perpendicularly on the steep incline. If the front slips or bucks than there is malalignment somewhere.

Also check the chain/axle alignment.
If you like gizmos, there are laser alignment tools for not much money.

You could also try lowering the forks in the triples. That should settle the front end assuming the rear geometry is correct, but there are tradeoffs.

 

[texanate]

Thanks for the tips. The weave is apparent at low speeds - like 15-20mph on asphalt - it’s not a high speed wobble like I’ve seen on YouTube (but thankfully never experienced). At very low trailriding speeds it manifests as vagueness in the front end. I ordered in the MotionPro fork alignment tool - seems like a more systematic way to confirm front end alignment vs bouncing and guessing like I usually do. Will be useful on my other bikes too, even if it doesn’t solve my immediate issue with the Varg.