Wobbly tyres (Avon Storms)

[Blackbird]

What sort of wear is the rear experiencing on the Bird? I'm surprised how roughed up the Storm gets on the RF - more like a sports tyre than a Sport Tourer - it's actually bubblegummed on the edges by the end of Grays Rd... I haven't gone over the Takas yet but I imagine I'll give them a fair bit of wear on the hill.

As I mentioned, I've done ~6000 km on the rear Storm and maybe 50% was touring the SI when we weren't pushing hard. I expect it to be dead at about 8000 km, but it hasn't squared off appreciably yet although it's torn up right to the edge as it never stops gripping. I'm impressed with Al getting 20000 km out of a front because although my front lasts a little longer than the rear, I always change them together as there is only a couple of thousand km in it. Maybe it's because I countersteer heavily in the tight stuff although the 6mm ride height spacer makes it quite easy to handle.

[BigB]

Hi All

I've had avon storms put on my blackbird and have done 6000km on them. Just off late the front has developed a shimmie which is very un nerving as its really noticeable in low speed corners.

Has any one else had this problem? When I took it in to cylcespot the guy just looked at the tyre and said yeah they have problems and there was nothing he could do.

cheers

Brian

[vifferman]

Hi All

I've had avon storms put on my blackbird and have done 6000km on them. Just off late the front has developed a shimmie which is very un nerving as its really noticeable in low speed corners.

Has any one else had this problem? When I took it in to cylcespot the guy just looked at the tyre and said yeah they have problems and there was nothing he could do.

I asked about this - there isn't a problem with the Storms as such - it's just with Storms on some Blackbirds. The BB is very front heavy, and the Storm ins't an ideal tyre for it, as the carcase is too flexible, especially in the sidewalls. This (apparently) makes the tread blocks flex too much, wearing them unevenly, leading to squirming. You could try running it at higher pressure, but it will take a while to bed in again (if it ever does).

[BigB]

thanks vifferman that makes since. I'll try them with a higher pressure and see if it makes any difference, they have been a great tyre and I'm getting good where.

cheers

[Hitcher]

and I'm getting good where.

Wear is what you're getting.

[Blackbird]

I asked about this - there isn't a problem with the Storms as such - it's just with Storms on some Blackbirds. The BB is very front heavy, and the Storm ins't an ideal tyre for it, as the carcase is too flexible, especially in the sidewalls. This (apparently) makes the tread blocks flex too much, wearing them unevenly, leading to squirming. You could try running it at higher pressure, but it will take a while to bed in again (if it ever does).

Where the heck did you get this info Ian? Largely incorrect I'm sorry to say. Most unlike you!

Cheers

Geoff

[Blackbird]

Refer to thread: http://www.kiwibiker.co.nz/forums/sh...17#post1368317, post no 27. I've attached a draft end of life assessment on the Avon Storms which I prepared for the Avon importers, Dold Industries after comunicating with them on some problems with the front tyre when they were first released. I understand unofficially that the problem has now been addressed.

[BigB]

Hi Geoff

Your report is great, but I've got to say after my trip to Whangamata at the weekend I have no confidence in the Avon that's currently on the front of the blackbird.

Two up going over the Kopu hikuai rd every low speed corner felt like shit, the bars were moving all over the place. I have never felt so unsafe on the bird.

Unless Avon can guarantee that the problem has been fixed I won't be buying them again.

cheers

brian

[Blackbird]

Hi Brian and happy new year!

Yep, it sounds like you have the same magnitude of problem that Dave Easey had, mine was far less. You have every right to ask for redress as it's a known problem. If your tyre dealer won't help, I'll give you a contact at Dold Industries.

Cheers

Geoff

[vifferman]

Where the heck did you get this info Ian? Largely incorrect I'm sorry to say. Most unlike you!

Whelp, before my Storms were fitted, I asked Kerry @ Motohaus if he'd had any problems with faulty Storms, and had there been any issue with them? He said he'd had none, and as far as he knew the only problems with them had been with Blackbirds, and it was because they were unusually hard on front tyres, putting more stress on them than most bikes.
The bit about soft carcases, tread blocks etc is just conjecture on my part, based on my experience with the AV49-SP I had on the bike previously, and what I was told (by another tyre tech) about how soft the carcases were.

[vifferman]

I've heard the Avons are not great for the last 1/3 of their life.

My last set of Avons (not Storms) were terrible in the last few months I had them on: they had plenty of tread left, but wore unevenly and I had little confidence in them.
I don't expect the Storms to go the same way, but I'll be replacing them when I start to lose confidence in them, rather than when they're down to the wear bars.

[Hitcher]

My first set of Storms got a bit jittery at the rear during their last 500km. Mind you, they had lasted over 14,000km by then. I will be interested to see how the new lot goes now I've got an Ohlins rear shock fitted.

[Blackbird]

Well, there have been definite issues with the front but I think that's been solved. Allegedly, it was due to variations in bead thickness during manufacture causing transverse oscillating forces, but I haven't been able to confirm that yet. It wasn't only Blackbird owners that experienced the problem though. As you will see from the photos in the report, my front tyre has worn evenly with no evidence of triangulation which is normally a pointer to carcass flex. This showed up on The Dunlop D220 and Mk1 Azaros I had on a few years back and I have some horrific photos of the wear pattern due to flex. The Mk2 (ST) Azaros solved the problem with an improvement in the belt construction and I'd expect the Storms to be equal or better. The evidence certainly points to this. My next front tyre will be an Avon Viper as Dold want me to evaluate the combination for the Blackbird, which certainly "pushes" the front; although raising the ride height 6mm has certainly helped no end.

Hitch, will be interested in your experience with your new shock as i'm thinking of going down that route sometime this year.

[vifferman]

As you will see from the photos in the report, my front tyre has worn evenly with no evidence of triangulation which is normally a pointer to carcass flex.

That's interesting! My AV49-SP ended up very triangular, and guess what? It had a soft carcase.
It was a real bugger, because before I replaced it, I'd lean into a corner, and when it got to the edge of the tread wear, the profile changed suddenly, feeling like I'd lost the front end.

My next front tyre will be an Avon Viper as Dold want me to evaluate the combination for the Blackbird, which certainly "pushes" the front; although raising the ride height 6mm has certainly helped no end.

Find out what you can about it first, Geoff.
My (limited) understanding is that the Viper is the replacement for the AV49-SP, and after my last experience, I turned down the offer of a Viper front in favour of matched Storms. It was a great tyre when new (as long as I kept the pressure at 38 or higher), but wore badly. The VFR doesn't 'push' the front end quite as much as the Blackbird, but is still somewhat bad for that. Or was, before I put heavier springs in.

[Hitcher]

Hitch, will be interested in your experience with your new shock as i'm thinking of going down that route sometime this year.

Do it anyway. Any additional tyre wear I get will be a bonus. Mr Ohlins knows shitloads more about suspension than Mr Yamaha or Mr Honda will ever know or, more importantly, want to invest in bikes that they market. The ride improvement is significant. So much so that I am soon to do the front shocks as well. Give Robert Taylor a hoy. He or his designated agent will see you right!