Instabilty at speed, but a road issue?

So I haven't (until recently) really opened my VFR up and let her romp.
I am a fairly sane rider these days and I am careful of my situations and keeping things within my abilities.

So the other day I get her up to 70 (i've been really keeping it close to speed limit which is 55 around here on the highway). The front end feels super squirrely. I'm like crap. So I start troubleshooting take it back home, kinda nervous with the bike now. I check the tire pressure, front was a little low as was back (checked it when it was cold) So I put air in, I double check the steering bearings, those seem fine. Grab the tire and see if I can feel *any* play in the front bearing.

All is fine. So I say screw it go back to that stretch of road, get the bike up to 70 again, same thing. Front end just feels like it wants to wander on it's own. So I head off to a dealership near here, I'm a chatty guy sometimes and I have a decent relationship with the service guy there. I think he used to race professionally at one point but now just runs a service department.

Tell him my story, he takes the bike for a spin. Comes back and says it's fine. Suggests I watch my hand pressure and that some of the roads around here might cause issues like that.

So armed with that knowledge, I go out and open it up. First cruising at 70 on a different road then take it up 120 and back down slowly. no issues....

Went over to another highway and merged on, some guy in a M3 was being a bit of a douche and not moving over to let people merge. So i romped it and let the engine breath the whole way. wow I love this bike! I know there are faster bikes but I was glued to the road, the cam gears howled and the 2 brothers exhaust is music to the ears.

So then I go back the stretch of road that caused me all the consternation and I feel it again. I did lessen up on the handle bars some this time and that actually helped but nothing wrong with the bike, just some oddity of the road i guess.

I was just being paranoid as it's a new to me bike and I start doing the oh crap, did i get a bike that somehow has something really wrong with it, etc,etc.

 

how many miles on the bike ?

 

Check your tyre wear for cupping. worn tyres can feel very strange.

 

13K miles on the clock. brand new pirelli diablo rosso 2 tires, less then 200 miles on them. No wear on them.

now it's possible that a tire is out of balance, but the guy i mentioned from the dealership said he took it up to 100 and let it gradually reduce speed, and took his hands off the handlebars and that the bars didn't waver or do anything odd. I rode quite a bit back in the day, and quite aggressively, but I don't have quite the balls to do that just yet (take my hands off the bars at speed).

has anyone else experienced weirdness due to road conditions? I'm going to experiment a bit more.

 

The bike may be fine - it sounds like the surface is suspect.

Plenty of sections of the original M25 Orbital motorway around London were slab concrete which quickly deformed as thousands of heavy goods vehicles pounded lengthway ruts into the surface, especially the inside lanes. When things got really bad, rather than grub up the base and start from scratch, they went for the cheap fix option and just applied a thick new asphalt top layer. Sadly this only worked for a few months before the ruts in the sub-layer started to be replicated in the new top surface. A few years later they had to launch a massive repair programme to basically do it right, and at the same time improved the base strength of the former breakdown lane so it could be used as a normal running lane under "smart motorway" improvements.

Whilst the ruts were not hugely problematic for cars and trucks, anyone riding a motorbike really needed to pay attention especially when planning any change of lane, otherwise you could find the steering reacting weirdly sort of like being trapped in the ruts in one lane. Things got far worse once the tyres broke out of the rut in the lane as suddenly the extra amount of steering effort you have already applied to force the bike to climb out of the rut can catch you out by causing an abrupt change of direction usually towards the central crash barrier. I have only experienced it a few times but each time it was quite unnerving and certainly felt like the bike had picked up a puncture or developed a fault.

If you only get this problem on the same stretch of road then either avoid it or just back off until you are clear.

Take Care ATGATT


SkiMad

 

well i'm fairly certain nothing is wrong with the bike now. I went on a few more spirited rides with narry an issue. I then went back up the highway section that was causing me grief and felt it again, i changed lanes and it went away. Sorry for being a little bit like chicken little, the nearest I can liken to is the feeling of grooved pavement or a metal grate bridge in the rain. But the road doesn't really have any obvious issue. I believe it's the center "hump" and how it touches the lanes. It was just an unsettling feeling and of course I'm learning this bike as it's completely new to me. But other stretches of road I haven't been worried about opening it up some and like I said no issues there. --chicken little out...

 

Thanks for the update - If nothing else this shows you are developing a feel for what is right/normal - that way you will also pick up on when things are not quite right, and know when to investigate.

Have fun - But if you plan on testing the limits of what your VFR can do watch out for smokeys.



SkiMad

 

Great you got it figured out, poor road surfaces can feel really weird.

 

Exactly what I thought when riding up the west coast of Ireland on the undulating Wild Atlantic Way where in some places the surface felt quite unstable. But the amazing views, great pubs and friendly people mean I will definitely be coming back to the Emerald Isle.

SkiMad

 

New bits of road are great now in places, but you can run into an older section very quick without warning, local knowledge helps, some of the best biking roads in the world in Ireland, hope we can get back to normal before too long, my own touring in Ireland has been limited this year and my planned trip to Scotland had to be cancelled.

 

Here in Houston there's a stretch of the I-10 freeway that was redone over the past few years. I HATE driving on it either on my VFR or in my STI.

They used grooved/cut concrete (I'll link to an article below so you can see what I mean) and in my car I can feel the steering wheel shudder slightly anytime there's the slightest bit of unevenness between the grooves. In the motorcycle the front end feels like it's a bit floaty on this surface because the front tire is often moving from one groove to another. I think the main benefit for people is noise reduction but I'm not a fan personally.

https://www.houstonchronicle.com/ne...ares-to-cut-into-traffic-noise-on-9200425.php