Weave with Michelins

I have just fitted a pair of Michelin Pilot Actives (3.25x19" & 4.00x18") to my 920 to replace the Road Riders. Now at anything over 70 to 80 mph the bike goes into a weave. The bike would sit at any speed before & was rock steady. I can't believe how tyre sensitive Commandos are. Has anyone else tried these Michelins?
Martyn.

Sorry, no idea but this Bonny owner seems to think they're the 'dogs'. Odd isn't it. No Iso's on a Triumph but it's kind of strange...they are surprisingly cheap compared to Avons or Bridgestones though.
http://www.triumphrat.net/twins-technic ... iders.html

Check the tyre pressures, they may need more air than your used to - the Michelin website may help.

Have you gone from a bias ply tire to a full radial in making the change?
I seem to recall that RRs are bias and Michelin Pilots are radial. In general, radials have a more flexible sidewall and are squirmier than bias tires.

My 850MK3 is completely stable at speed with the RRs but goes into a gentle weave if I shift my feet to the passenger pegs.
It does it instantly and every time and corrects instantly on moving back to the rider pegs. Makes me wonder how bikes fitted with rear sets do?

Glen

The Pilot Actives are bias belted as far as I am aware. Unlike the Avon site, the Michelin site is about as much use as a chocolate teapot. All it suggests is to use the bike makers recommended pressures. For modern tyres these are no longer appropriate. So far I have tried 32psi F & 36psi R but as I didn't have a pressure gauge with me I didn't change this. When the weather improves I will have another go.

Can I ask what made you swap to Michelin from Avons, were the Avons causing problems?

What head steady do you have?

I had the exact problem with Avon Super Venoms. Check very carefully how the beads are seated. Are they concentric with the rim? Tire mounting is very critical.

The reason for the change is to see if I can get a few more miles out of a rear tyre. The 4.00x18 RR gave 3,900 miles before it was worn out (less than 1mm). I fitted & balanced the tyres so I know they are right, & the head steady is a Comstock/CNW type. This problem is only due to the change of tyres. I would dearly love to be able to fit nearly any make of tyres without this problem but as I said before, Commandos do seem particularly sensitive.

matchless
what rim width are you running?
Regards,
Thomas
CNN

The weave, in my experience is related to the width of the contact patch of the rear tire. The width of the contact patch is largely a product of the aspect ratio. IMO, for the Commando, a pointy shape is better than a round one. The bikes seem to like the rear tire to be only slightly wider than the front.

Following Jim C's point, right now I have the weave. Against better judgment but because of a super low price, I bought an Avon Super-Venom in a race compound, off ebay, for the rear of my Commando for only $100. The tire does have Avon's cantilevered side wall design so it fits my rim nicely but it still has a contact patch that is too wide, relative to the width of the front tire's contact patch. I now have the worst case of weave that my bike has ever had. I did not change the front tire too, so I do have too great a difference between front tire and rear tire width. I'll pull it off and stick it on my old '86 GSXR, where it's low round curve shape is perfect for the bike.

For my Commando, the weave always immediately goes away, if I move my weight/butt to the rear of the seat. Try going into a tuck, move your whole body to the rear. For me, this is not a total solution since I like to be forward while entering turns but, to avoid the weave, I have to stay back until the moment that I have to shift my weight forward for an entry.

I neglected to say in my previous post that I replaced the original Avon Super Venom with the another Avon Super Venom tire. Weave gone. Nothing else changed, except the rear tire. Although I could have had a bad tire with the original, I suspect the weave was caused by poor mounting. The first Avon I had mounted by a shop, whereas the second I mounted myself. Prior to replacing the rear tire I tore into everything possibly related, tire balance, shocks, swing arm spindle and bearings, frame and wheel alignment, headstock bearings, isolastics, headsteady. Pretty much the whole enchilada, Still the weave persisted. Eventually, I wore out the rear tire and replaced it. Weave gone!

I moved my ageing 100-90-18 roadrunner from the front to the back to "use it up" and put a new same size Roadrunner on the front, result, instant weave above 75mph. The original rear was 110-90-18 and was worn out but didn't weave. I have a 19 front to try but think I'll be going back to a new 110-90-18 on the rear. The problem doesn't manifest itself when I'm two up (bigger rear footprint?)

All of this still leaves me wondering why Commandos are so tyre sensitive. If I get time & it's not tipping it down, I will have a play with pressures tomorrow then report back.

Gripper, there's more weight to rear with your wife on the back.

JimC, interesting. I'm running a 130/70 VB 18 rear and 100/90 V19 front on a pair of WM 3s;
admittedly that rear tire is too wide for that rim and it is too big a step wider relative to the front.

Further, although the alignment lines on both sides of the tire appear to indicate a good set of the tires beads, they are poorly cast with flashing that rises and falls and so are hard to see

I've just been out to road test my new Trispark and during a blast up to about 75 in third, the whole thing started to weave to the extent I couldn't steer the bike. I was heading for the central barrier and was thinking this is it. It's the scariest thing I've done recently. Even my shit was scared. One issue is that, since a recent illness, I'm down to 11 and a half stone. New 110-90-18 back tyre on order.

I found this video very interesting, I had had a bad weave at 90 when I first bought my Norton wish I had seen this

https://www.youtube.com/watch?v=fvsDIq3WwVA

And the thread associated with it is worth the read

wobble-and-weave-t19025.html

Dennis

Dennis C said:

I found this video very interesting, I had had a bad weave at 90 when I first bought my Norton wish I had seen this

https://www.youtube.com/watch?v=fvsDIq3WwVA

And the thread associated with it is worth the read

wobble-and-weave-t19025.html

Dennis

Click to expand...

I dont really miss Phil... I do miss reading Ludwig's posts.

Gripper,
Have you watched the Dunlop film Dennis is referring to. Seems you are just to light. Eat more pies or fit some clipons just above the bottom yoke!! That film is also available in the Dunlop only version without Murray Walker droning on.
Nothing to report as yet with the Michelins, as it's either been raining or just above freezing.