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Wobbly front
Posted: Tue Jun 04, 2013 12:25 pm
by Firestarter
No, not mine (I know what you lot are like

)
As I'm starting to put some decent miles on the Falco for the first time in four years, I'm starting to push a bit harder again. Not hard by most people's standards, but starting to lean the bike over further in the corners.
Had a bit of a wobble turning from a roundabout, where it felt to me that the front tucked, or suddenly dropped a bit, as I pushed the bars harder to crank the turn. Bit quicker than I usually go, this is on my normal commute to work so I've been round here plenty, nice left-hander at the bottom of a motorway slip (downhill). I've felt this before on right-handers/roundabouts as well, again when I've started to get my confidence up so pushing a bit quicker, and it always knocks my confidence so I dial it back down, and don't push the corners as hard as I think I should.
I've got Pirelli Diablos fitted (probably 2-3 years old but only 1000-1500 miles on them), rear is good and not squared off, have had a look at the front and all looks good, although it feels like the blocks to the outside edge are slightly lower than the blocks in the centre (where the tread pattern grooves are). Is it as simple as, I'm not used to leaning that far, and what I'm feeling is the tread pattern as it goes over the grooves, or essentially rolling onto a flatter portion of the tyre? Or is it just due to my (ahem) slightly larger frame? Or just lack of commitment?
Cheers guys
Posted: Tue Jun 04, 2013 2:36 pm
by flatlander
Funnily enough I saw the heading wobbly front and thought what have the web footed ones been up to now ... Didn't even think of squid for a moment ... Nope definitely not :)
I am no expert I think we have all established that :) but as master of the bleeding obvious what were your tyre pressures like ... We're you aiming to go straight through the bend ... Literally as I appear to do or go round it ?
I had something similar once on a bandit and it was a combination of 3 things for me I turned with / into that bend and did not counter steer. It was the first time I had taken that bend at grin factor -10 and the tyres were going onto the chicken strips ( dumb arsed Machi BS expression IMHO) for the first time.
Posted: Tue Jun 04, 2013 3:27 pm
by Dalemac
First thing I would do is check the tyre pressures, I always find it makes a big difference if I haven't filled them with air in a while.
I seriously doubt you will be able to feel the tread....unless you are the princess from "The princess and the pea"

Posted: Tue Jun 04, 2013 5:22 pm
by Aladinsaneuk
Tyres also have a life - no not going out partying but the rubber compound changes over time irrespective of wear....
I would start with pressures 36 front and 42 rear is a good start
I would also be interested to know your fork settings - and when were they last serviced - fork oil degrades over time..... Scare yourself and look up how often Aprilia tell you to service them!
I had my forks serviced over the winter .... Heck of a difference
Posted: Tue Jun 04, 2013 5:28 pm
by bigun
First port of call is the obvious stuff like tyre pressures etc, steering damper (if you've got one) too.
Assuming they're all ok, I'd say onto suspension settings. I had the exact same problem with my RSV and had the suspension set up earlier this year as a result. Turned out the forks were rebounding far too quickly which gave the impression it was tucking under as i turned in harder. I had all the static sag etc set up too and it transformed the bike, best £20 I ever spent on it (still sold it mind!).
Hope you sort it, especially given the current riding weather!
Paul
Posted: Tue Jun 04, 2013 5:46 pm
by fatboy
Tyres can harden up with age so maybe slid over crap instead of flexing ?
Try pushing your thumbnail into the the middle of the tyre, you should be able to leave a small indent which should dissappear in 5 to 10 seconds, if no joy maybe brittle rubber ?
Posted: Tue Jun 04, 2013 7:40 pm
by Falcorob
There's a manufacturing date on the sidewall of your tyres (in code obviously) which will tell you exactly how old they are.
Unless they've been stored extremely poorly a 3 year old tyre with adequate tread, no weird wear patterns, and the correct pressure, will be fine. So if those things are OK then it points at something else.
Check this site out for further info.
http://www.moto-tyres.co.uk/seitenwandb ... ungen.html
Posted: Tue Jun 04, 2013 7:52 pm
by Firestarter
Cheers guys
Forks have probably never been serviced (unless they did it at one of the major services, but I doubt it!)
Tyres OK at 36/42 (checked them today before I posted), did go to Griff's suspension day a few years back but only got as far as the rear sag, didn't really do the front at all (ran out of time when the neighbours complained about all the loud cans

). Have got Maxton just round the corner, so might make a trip there for a tune-up & service.
Will go through the other checks as well on the tyres going off, will feed back
Posted: Tue Jun 04, 2013 7:56 pm
by Aladinsaneuk
Correct rob - but the tyres may have been old stock when fitted.....
Posted: Tue Jun 04, 2013 8:10 pm
by D-Rider
This does remind me of an incident I had a while back on an old pair of Diablo Rossos (that's the original Rosso = not the RossoII or the Rosso Corsas that I have on at the moment)
At the time I couldn't explain it but through the thread I came up with a possible explanation ..... that said, I've never been entirely convinced the theory was correct.
I soon changed my tyres as that I incident completely lost my confidence in that fairly worn set (though not the brand - I love Pirellis)
https://www.ridersite.com/viewtopic.ph ... de&start=0
Posted: Tue Jun 04, 2013 8:44 pm
by Falcorob
Aladinsaneuk wrote:Correct rob - but the tyres may have been old stock when fitted.....
Which is why I pointed him towards the date code on the sidewall.
Posted: Tue Jun 04, 2013 8:58 pm
by bigun
Firestarter wrote:
Tyres OK at 36/42 (checked them today before I posted), did go to Griff's suspension day a few years back but only got as far as the rear sag, didn't really do the front at all
I think you may have answered your own question there. If you've had the rear set up but not the front, I'd hasten a guess therein lies the problem. I'd try that, it's a cheap and easy fix and at least gives you a baseline. If it doesn't change after that look at the more expensive things.
Posted: Tue Jun 04, 2013 9:09 pm
by Firestarter
D-Rider wrote:This does remind me of an incident I had a while back on an old pair of Diablo Rossos (that's the original Rosso = not the RossoII or the Rosso Corsas that I have on at the moment)
At the time I couldn't explain it but through the thread I came up with a possible explanation ..... that said, I've never been entirely convinced the theory was correct.
I soon changed my tyres as that I incident completely lost my confidence in that fairly worn set (though not the brand - I love Pirellis)
https://www.ridersite.com/viewtopic.ph ... de&start=0
Right, where's the wire wool? Possibly some petrol, don't think there's been a burning on here for a while...
http://www.youtube.com/watch?v=eXsP0ayl4Vg
Won't help the front mind

Posted: Tue Jun 04, 2013 9:21 pm
by Firestarter
bigun wrote:I think you may have answered your own question there. If you've had the rear set up but not the front, I'd hasten a guess therein lies the problem. I'd try that, it's a cheap and easy fix and at least gives you a baseline. If it doesn't change after that look at the more expensive things.
Hmm, think you may be right. I have changed the shock (Nitron), which has slightly increased the ride height and was pre-set for my weight etc for sag and I presume rebound/compression, so possible that has caused issues with the front. Will ring Maxton on the morrow
Posted: Tue Jun 04, 2013 9:40 pm
by HisNibbs
There is so much sh_t on the roads that I'd need more than a couple of corners to start suspecting the bike set up.