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Offline Milord

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Re: MK1 Cornering instability
« Reply #10 on: 05 September, 2019, 09:23:46 PM »
*Originally Posted by edger [+]
OH ! and by the way what part of the country are you in?
Buckinghamshire! Thanks for reminding me to flesh out my profile a bit more  :028:
« Last Edit: 05 September, 2019, 09:25:15 PM by Milord »

Offline edger

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Re: MK1 Cornering instability
« Reply #11 on: 05 September, 2019, 09:47:32 PM »
Many happy memories of drunken times in Buckingham  :152:

Offline J-man

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Re: MK1 Cornering instability
« Reply #12 on: 06 September, 2019, 09:49:32 PM »
bought mine at 60000km a 2006 model. The bike felt unsafe mid corner. On perfect road deck corners it was OK, but when anything disturbed it started to feel like having a rubber frame. Not cool. But I had already decided to get a job done on the suspension just bc of the 60000km alone. So it had a new bike tailored white power shock and reconditioned forks, all done by pro's.
Same DOT4 oil as standard and keeping the oem valves, that was their recommendation for road use.. The bike feels like on rails everywhere. Now I have more stroke used on the forks and linear springs inside. They did not find play in the mechanics, they said.

Just saying, suspension is one to consider.
I hope you nail your case soon  :028:
« Last Edit: 06 September, 2019, 09:56:35 PM by J-man »

Offline Art

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Re: MK1 Cornering instability
« Reply #13 on: 07 September, 2019, 09:04:43 AM »
DOT4 oil?

Offline Rev Ken

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Re: MK1 Cornering instability
« Reply #14 on: 07 September, 2019, 05:20:57 PM »
The 'wobble' is a common trait and there is a long list of possible causes, but it has nothing to do with stability on corners and isn't worth worrying about as it only takes a light touch on the bars to stop it.

With regard to your riding, two suggestions; First are you gripping the handlebars too tightly? If you feel it becoming unstable, then gripping them makes it worse! You should be able to take any corner with the lightest of grips as that is how it gets around the corner! secondly if the front feels light and you are finding it difficult to 'set it up', drop your chin towards the handlebar grip on the inside of the bend. This helps a light counter-steer and adds a little weight on the front of the bike as well as shifting weight into the corner without putting your knee down!

Coming from a 125 you might find a course with i2i academy beneficial. It is great and even riders of many years experience (in my case over 60) find it worthwhile with practical lessons on just how well a bike performs so long as the rider doesn't interfere!
Yesterday is History, Tomorrow is mystery, Today is a gift....

Offline J-man

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Re: MK1 Cornering instability
« Reply #15 on: 07 September, 2019, 07:06:40 PM »
*Originally Posted by Art [+]
DOT4 oil?
Sorry, good eye, that must be 10W  :034:

Offline raYzerman

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Re: MK1 Cornering instability
« Reply #16 on: 10 September, 2019, 10:36:15 PM »
I'd think two separate issues.. the head shake if the head bearings are torqued properly, can be tire wear or certain tread patterns... I have an aversion to PR4 fronts and some others, prefer Metzeler Z6, T30 or T31, e.g. and have no problem using a PR4 or other brand rear, i.e., not sets.  Keep pressures on the high side to prevent uneven wear... say 40 psi.

As for the wallowing in the curves, first should set preload to your weight, measure sag and adjust accordingly, sag should be about 30mm rear, and 35mm front.  The stock forks will need spacers to increase the preload, but also you'd benefit from a spring upgrade to say 0.9 spring rate.  This will allow less preload necessary so the springs can have a somewhat more plush ride than ones with a lot of preload.  I'd guess a preload on the rear will make a noticeable change for the better.

Unfortunately, on a MkI, neither end can be adjusted for compression/rebound damping so all is a compromise.  If the ride is too harsh, then back off the preload a touch.  These are suspension basics, there are online resources available to help one understand it better.  The full cure of course is adjustable aftermarket suspension.  Just make a few adjustments and see how it works for you.

I found the stock shock adequate, but the front end needs springs (200 lb. rider, solo).  I have some front end wallow and perhaps a little too much dive on braking (not bad), will be adding some preload and seeing what oil was installed, likely will go with 10W.  I came across an Ohlins rear shock with a 900 lb. spring, it seems quite good. 

The bike came to me with new Shinko Raven tires, and haven't had them before.  Just got back from a trip where they were tested in the twisties and in the rain.  They handle very well in the dry or wet, but I can't comment on mileage yet.  I do have an Avon Spirit rear sitting in the wings.

« Last Edit: 10 September, 2019, 10:40:07 PM by raYzerman »

Offline Milord

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Re: MK1 Cornering instability
« Reply #17 on: 11 September, 2019, 08:57:14 PM »
Thanks for the spring info raYzer!

Have no problems with the PR4s just yet compared to the old tyres that were on it. I think the front was a T30 evo but it was so squared off it made turn-in a huge effort. Rear was a BT-something and that was also bald straight down the middle!

I've heard good things about refitting the forks with  hyperpro progressive springs.
In addition, does anyone know of a shock from another bike with preload/comp/reb that is compatible with the mk1? Aftermarket shocks are way too expensive for my taste and would love to get an old one with full adjustment reconditioned and fitted with a £90 hyperpro spring.

I noticed some bar wobble while riding over some white lines today so will be adjusting those head bearings once more! I'll also click up to 5 on the preload.

Liam

Offline raYzerman

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Re: MK1 Cornering instability
« Reply #18 on: 11 September, 2019, 09:07:44 PM »
I'd bet there are some aftermarket cartridges out there.... as for preload, can just use washers to increase the preload... set and forget.  I'm not a HyperPro fan or progressive type springs, they wouldn't tell me their spring rates... prefer straight rate springs anyway.