Front end stability

[Moley551]

For my next problem, I've got a very unstable front end it's fine upto 100mph but soon after develops a vibration that buids quickly into pretty exciting shake, you can hang on and it settles a bit but doesn't go away. Anyone got a clue...
2010 990s KTM Adventure 8k miles, virtually new front tyre.

[Gimlet]

I had serious bar wagging problems on my SMT above 80 mph and it turned out to be purely a tyre issue. I was running Z8s and it hated them. No amount of suspension adjustment or tyre pressure changes made any difference. Then I changed to Dunlop Roadsmarts and instant calm was restored like magic. I'm now running much sportier M7RRs ad its still fine.
Bit of a different situation on an off-road biased Adventure with its big skinny front wheel and limited tyre choice but it your suspension settings are stock or close to it but your tyres are not and assuming there are no mechanical problems like shakey front wheel bearings or shot head races, I'd start with tyres. There is an after market steering damper available for the 990 Adventure - http://www.rally-raidproducts.co.uk/ktm ... ing-damper" onclick="window.open(this.href);return false; - which suggests this is a known issue but I think you should be able to go a lot faster than 100 kph before you start having problems. The fact that it starts as vibration which turns into a wag does suggest there may be a mechanical issue. Check bearings first.

[goatpants]

Not balanced properly I suspect.

[billinom8s]

We suspected shite balancing (tyre changed by Bridge) on Katas gixxers as he had a wobble at those kinds of speed.
Turned out to be crap tyre wear. They didn't look bad until you looked at the tread only to find out there were hard and soft sections where the rubber had gone off..

What they were doing putting touring tyres onto a k5 gixxers is anyone's guess.

[Moley551]

Not balanced properly I suspect.

I think your on the money, I changed the last front tyre because it seemed to hop and had an uneven wear pattern accross the tread, maybe run with low pressure, the previous owner only did 2.5k and looking at the rear tyre it was done in a straight line. When I replaced the rear tyre it highlighted the front hop and a sort of tramline feeling, under a ton+vat it handles beautifully now, considering the style, wheel size and tread pattern.
It's got slime in both tubes so when the tyres were fitted they didn't balance them, I'm starting to think the slime has a limit to what it can balance and I just found it, new tube and wheel balance next?

[billinom8s]

I think you just listed your check list there.

[Kata]

Yep changing the tyres made the whole vibration thing go away. Tyres and bike were fine up to about 115-120 then all hell broke loose.

The Metz tyres as recommended by Si/Gee work a treat. Even managing to stop bike / hedge contact during recent / track days.

[podrick]

100 mph on a 990 adventure with a 21" spoked front wheel is a fair speed

[Moley551]

To be honest there is no problems until way over that, the scorpion tyres are V (240kph) rated so well within their limit. The majority of my bike history has 21" front wheels with 17/18" rear, it just feels right to me.