FE/FC front end wobble

i bought a 2015 fe501s with 330 miles on it.the wheels were balanced,still has the stock competition enduro tires.i changed sprockets to 14 48.at 65 to 70 mph the front end would start wobbling and if you didnt slow down would get really bad.i bought a longer chain,and lowered the forks in the trees a small amount.it helped but still get a slight wobble at around 70 mph.asking for any suggestions.
could it be the aggresive knobby front tire?maybe need to check the wheel balance?i have also sat the sag.

I have brass wheel weights with set screws on the spoke caps. Opposite of the rimlock and bladder holes. 3 sizes 3 spokes I big ,med, small. On each wheel and I run the Tubliss system. I balanced them on the bike by simply retracting the brake pads with the chain off on the rear. Nothing really accurate. Just a rotating and settling guess as the wheel would "hop" a bit at speed. But I never had to back off. Never had a speed wobble, ever. At over 100+ mph many times. I'm on my 3rd front tire. 85 hours. The last 2 fronts have been GT216AA "Fatty's" on the front.

I also run 14/48 gearing. Forks set at second line on the top tree just barely visible. Get the forks revalved professionally unless you are an expert. Many people think they are and consequently never leave their forks alone. Unless you are one of these fork experts. Have them done. I also recommend you get a Steering stabilizer. This would likely stop the wobble immediately.

I have ran the "BRP" Rubber bar mount, Submount set up since the bike was almost new. With the stiffer hard, bar mount bushings and a "Scotts" steering stabilizer. I ride a lot of sand washes and it is a life saving, must here. I won't even consider riding a dirt bike here without one.

Got it from "Slavens Racing". Be sure to request the included shorter height, thinner headed center bolt for the steering stem that should be included. Or the stock one will have to be ground or turned down as it will hit the stabilizer once it's installed. There is no charge for the special matching head stem bolt.

I set the steering stem bearing tension after regreasing everything so the bars just slowly fall when nudged to the stops with the bike on a center stand. Do this during installation of the Submount with the total weight of the bars installed and then install the stabilizer after. I use Bel Ray waterproof blue grease. Bearings should be set with just a little drag, Don't want it to clunk against the stops.

After the bars are removed to mount the stabilizer to the submount and its all back together. Reset the frames steering stop bolts back to allow it to turn as far as possible but not past the movement limit of the stabilizers slotted arm.

I know it's money but the stabilizer is money very well spent. It will never speed wobble.

Is it a wobble where the bars go back and forth or a bounce from the tires? Wobble at bars is a high speed and can be corrected by dropping the forks a little IF your suspension is correctly set via. sag and spring rate. If your suspension is not correctly set then start there first.

105-110mm race sag on rear
Forks at 2nd line from top

my forks are on the second line.ive thought about droping them a little more.the wheels are balanced but now that i look at it i think its only for the rim lock so maybe i do need to balance it for the tire,maybe also check the steering stem tension.i have ridden a lot of bikes and have never experienced this before.and my sag and spring rate is correct
i have made it better.it was violent but now just barely doing it.starts around 70 mph.a stabilizer isnt in the budget at the moment.i want to buy some supermoto wheels next summer but need to get this straight first.thanks for the help and any more ideas are welcome

ok i checked the steering stem bolt and you could loosen it by hand.hopefully that was my problem.find out tomorrow if it doesnt rain

The stock tires on these bikes are poor offroad and very poor on the highway. I bought my 15 501s brand new. I noticed it had Dunlop 606s. I asked my dealer about this. He said I could have the stock tires if I wanted them. He said that he felt they were unsafe at any speed on the highway. After wearing out the Dunlop s I tried the stock michelins oh man! My dealer was right they were so slippery I could not snap a wheelie on the asphalt with out the rear tire spinning. The front was nightmare material and was super Scarry on the highway. As far as you wondering if it caused wobble because it was a knobby I have a few things to say. NO I run way more aggressive knobbies on my 501 dual sport. Right now I have a Dunlop at81 out front I added up to about 19 pounds on the highway. I'm very impressed at how little it wobbles. Even my last front tire a Maxxis IT desert produced less wobble worn out than the stock Michelin did on asphault. I will try and attach a pic of the worn out Maxxis just to emphasis how bad the stock Michelin was and to assure you its not that your tire is a knobbie but rather a piece of dumpster liner. I only ran my stock Michelin tires for a few miles before I threw them away. One more thing you are riding a dirt bike on the street some wobble should be expected I'm not sure what you're used to but to me a wobbling front tire on a dirt bike on the highway is kind of like milk on your cereal hard to get one without the other. Especially if you ride fast do a lot of hard accelerating. That tire is barely on the ground!

Big Timmy - I'm looking to replace the front tyre on my '15 FE350 and have read several positive reviews of the Goldentyre 'fatty' front tyre (GT216AA 90/100). What do you consider to be the pros and cons of the fatty? cheers.