Head Steering Shake Downshifting

[brownbandit]

Hi Everyone,

I need some help digging into a nasty head while while Downshifting. It recently developed on a new R18 Roctane after I did a R18 Classic windshield install.

While I rule out the windshield, has anyone else had this issue and how did they solve it? Maybe tighting the steering head but if it's lose? I'd be surprised that's the issue given it's a brand new bike

 

[Star-Lord]

Ummm what...??

 

[Anibal]

Hi Everyone,

I need some help digging into a nasty head while while Downshifting. It recently developed on a new R18 Roctane after I did a R18 Classic windshield install.

While I rule out the windshield, has anyone else had this issue and how did they solve it? Maybe tighting the steering head but if it's lose? I'd be surprised that's the issue given it's a brand new bike

Not sure what you meant. Please provide a bit more information

 

[brownbandit]

Not sure what you meant. Please provide a bit more information

Basically, when I'm slowing down and downshifting, the handlebars shake on their own at a certain speed and RPM. This is the best visual explanation I could find; not as violent as this but not a good thing.

 

[Anibal]

Wow, normally that would happen if you are going faster than your guardian angel can fly, incorrect tire pressure, worn out parts, landing badly after a wheely, excessive front brake pressure etc.
If you are riding at normal speeds and applying normal breaking pressure (your ABS are on standby to prevent any nastiness) then I would inspect the steering column and look out for play etc. Not sure if the Roctane has steering damper, the B and TC has. Check those things out but also do take it to the dealer for inspection.
The wind shield should not create a massive aerodynamic change or the top box you installed, bearing in mind that the bike was not designed for those features.

 

[Star-Lord]

Physics causes that wobble when the front wheel and the rear wheel are not aligned i.e. a poor landing after a wheelie.. which I doubt is the root cause on an R18...

 

[Rufus]

Think you’ve answered your own question, obvious thing to rule out is the windshield. Remove it and test ride the bike again. The Classic has a very different set up, balloon tyres on a 16 inch wheel so unfortunately what you have installed may not work.

 

[Ulrich]

For what its worth ... If I ride hands off at slow RPM my handle bars 'wobble' a little back and forth as well ... I contribute it to 2 very large cylinders firing side to side ... as soon as the revs go up it goes away ...

 

[brownbandit]

For what its worth ... If I ride hands off at slow RPM my handle bars 'wobble' a little back and forth as well ... I contribute it to 2 very large cylinders firing side to side ... as soon as the revs go up it goes away ...

Great feedback to have thanks!

 

[Noelpolar]

I assume you had to replace the top fork triple tree bolt down caps (screen connection point as per the Classic) that bolt through to the fork stanchions? Anyway, maybe some small fork aligment issue might have been introduced?

Here's a video about front fork alignment.... watch from the 2min mark.... I'd suspect the 21" front might be a bit more lively then the other R18 wheel sizes.

 

[brownbandit]

I assume you had to replace the top fork triple tree bolt down caps (screen connection point as per the Classic) that bolt through to the fork stanchions? Anyway, maybe some small fork aligment issue might have been introduced?

Here's a video about front fork alignment.... watch from the 2min mark.... I'd suspect the 21" front might be a bit more lively then the other R18 wheel sizes.

Thanks for this I'll try it out; yes I did have to replace the fork caps and something may have been pushed out of alignment when I tightened the fork caps. I'll report back on my findings.

 

[brownbandit]

Update on this for the group; after a bunch of testing taking off parts installed; making sure the wheels are aligned I took the bike to the dealership.

They struggled to find the issue: tightened up the neck bearings, wheel balance. It turned out to be a bad wheel bearing causing the issue. My concern is that the bike only has 1000 miles, they mentioned it's not the first they have replaced.

Has anyone experienced failed wheel bearings?

 

[brownbandit]

So update on this after 2 months of the dealership checking and changing all kinds of parts on the front end, it turned out to be a bad tire causing the wobble.

They changed the wheel and neck bearings, tightened the stem nut multiple times and no luck. Eventually tested another front wheel and tire from another Roctane and was able to pin point it to the tire.

Going to get the tire, parts and labor covered under warranty, has anyone else had issues with their front OEM tire?

 

[Ulrich]

I didn't experience the 'wobble' ... just a very noisy tire and bad deterioration ...

 

[Star-Lord]

Not to be a Monday morning QB; but, I would have suspected the tire at the tippie-top of my list of things to check...

It sounds like they went through the trouble to change the wheel, but not eliminate the TIRE..?

Glad to hear - problem solved..!!!

 

[Rambler358]

Has anyone experienced failed wheel bearings?

I “think” my 2023 TC may have this issue. I’ve got 6,600 miles on the bike, and just had the 6k service done. When going around turns it seems like the front end is a bit loose or slightly unstable. I’m not sure if it’s the front wheel bearings, but it just doesn’t seem right.
I think I’ll take it into the dealer to have it checked out.