Tyre grip vs tyre age

[Metal_Mickey]

Hi All,

Simple question first... Can a tyre begin to lose its grip (specifically in corners) through "old age" rather than just through using up all the available rubber ?

The background to this question is that I have a GSX-R600 which has been running on a set of BT 014's since mid May and which have been put through probably around 2500 miles. A couple of weeks ago I managed my first KD (left knee at the cloverleaf in Redditch) and then promptly binned the bike trying to get my right one down on a roundabout. Finally got things sorted on the bike and went out for my first proper ride today. Unfortunately the bikes grip just didn't feel right (specifically when taking right hand corners and roundabouts) and despite pushing myself to continue for a while, I ended up turning around and going home.

Checked the tyres and they are at their tread limit in the centre according to the TDI, but there is still loads of tread left at the edges of the tyres. I know it isn't the tread that gives you the grip but I would have thought that if the tread is deep enough at the edges then that would give an indication that there is still plenty of rubber. For this reason I am assuming that there is still plenty of rubber left at the edges.

So if there is still enough rubber on the edges of the tyre then that leaves two possibilities for my unease today...

1) It's all in my head - This is the most likely explanation which is why I pushed myself to continue for a while.

2) The tyres are just losing their grip - Although I have only recently got my knee down, I have been pushing myself to lean the bike over and have taken it to the edge of the tyre on both sides (more so on the left). This has led to a reasonable amount of wear on the sides, but I still believe that there is a fair bit of rubber left on the sides.

So there is the reason for the question i.e. If there is still rubber left on the sides of the tyres then the only way that I see for option 2 to be the case is if tyres can lose grip through old age and repeated cycles of being heated up and then cooled down.

Either way I am going to have the rear tyre replaced (the front looks ok, but I may replace it for "peace of mind"), but it would be useful to hear your thoughts on whether tyres can lose grip through old age or any reason other than lack of rubber.

[.....]

Don't like to say it mate but update the 2005 BCF Spill Counter

[MarJay]

not since mid may!

My old NS125R was running on ten year old tyres and they definately didn't grip as well as the tyres on my TZR250... That may have been because they were shite tyres though, I can't remember!

It sounds to me as though this is one of three scenarios:

1.) Your hugger is rubbing on your tyre and so making the rubber slippy and slick giving you a genuine lack of grip

2.) Your Scottoiler has broken and is set to 'prime' pouring oil all over the tyre

3.) You have just lost confidence.

My advice is to get the tyres changed, because this will give you your conficence back. G mentioned that BT014s didn't 'feel' very nice when he test rode a CBR600RR, so may I suggest some nice Pirelli Diablo Corsas? He actually crashed the bike whilst 'testing grip levels' so it may be that 014's either don't heat up enough on the road, or aren't as good as people say they are.

My suggestion would be to stick to road rubber where possible, because sticky road tyres are grippier on the road than full on track tyres like 014s. That said, people on here who run supercorsas (or Mezeler Rennsport - they are nearly the same) seem to like them.




____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[gavin]

if you have significantly less tread in the middle than at the edge, it could just be that the tires are "squared off" and as you are pitching in you are crossing the boundary between the relatively flat middle and the more curved sides. this gives the impression that the bike is tipping in too suddenly and losing grip, which isnt necessarily true. your hightened awareness to grip, or lack of grip, since your spill will be a contributing factor, too.

tires do 'go off' with age, even if they have just been sitting in a warehouse gathering dust.

[Metal_Mickey]

I will admit that the whole "age" thing is pushing it considering I only got them in mid may, however I am not sure what is considered old for performance tyres which have been used in the fashion that I have used them in. This is why I am opening the question up to the collective wisdom that is BCF

As for your points...

1) The rear hugger sits clear of my tyre
2) I don't have a Scottoiler
3) I don't think it is quite a matter of confidence as I don't mind pushing it, I just don't want to have to pay to fix my bike again If being wrong and crashing the bike meant that I didn't have to pay to fix it and wouldn't be without a bike again, then I would happily go and push it to the limit tomorrow.

I think the BT 014's are great and I had enough confidence in them to get my knee down on them with only 8 months of riding experience. The thing is that they just don't feel "grippy" anymore and I am trying to understand if this feeling can have a basis in reality or if it is just in my head.

Thanks for the info though

[Kickstart]

Hi

I have had tyres turn really rubbish with age. They were a decade old though. It is UV light that wrecks tyres with age.

Gavin is most likely correct that it is the way the tyres have squared off that has caused the issue.

Other thing to check is the tyre pressures. When were they last checked?

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[VTR SP1]

[Dom_]

They should still be ok imo, i bought my bike which was 5 years old and still on it's original tyres (Pirelli MT75's) and managed kd on those. Your 014's are 10x better, maybe the surface was dodgy and now you've just lost confidence?

[Metal_Mickey]

[Metal_Mickey]

[MarJay]

[VTR SP1]

Metal Mickey,
Thanks for a sensible reply and not a load of abuse. I don't get my knee down on the road and even after lots of enthuastic riding have never needed to to get round a corner. I think it's more important to learn how to corner, read the road and position the bike correctly. If you can do this ok then you should not really need to get your knee down to get round.
I think that with only 8 months experience these are more important skills to learn as they are more likley to keep you alive.

Marjay,
I was not really trying to preach but I don't understand why people with little experience want to take so many risks. Just look how how many people have crashed on the 2005 Spills thread. I have never crashed but this does not mean I am slow and I do have a lot of fun. I think riders are to worried about looking good which is important but not worth risking a crash.

Back to the point. I use 014's and they are very good however I think if you are on the tread depth marker you should change them. When the tyre is squared off going over the ridge can give the feeling of slipping.
Get new tyres.

SP1
____________________
I rode the Nurburgring backwards.

[Jrod]

I'm using 014's. The front tyre is only about a month old with the rear about 6 months old and reaching the end of its life.

Today on kd the front tyre let go and the front of the bike slid away from me (not fun ) luckily I didn't bin it.

I don't know if it was just the way I was riding but the rear had more grip than the front even tho its older.

[Dom_]

I don't like the sound of 014's theres been a lot of offs due to slippage without much warning.

That lad with the cbr + tarty paintjob.
G on his test ride.
Metal Mickey.
Nearly zxr400er.

I've never used these tyre so have absolutely nothing to say from experiance, but personally i would avoid them. I'm sure they are good tyres, i just don't like all these scary stories.

[Rookie]

[cc123]

Could be a case of losing confidence? I know after my smash I totally lost all confidence. I'd say its only now that I'm back to or better riding than I was before.

If someone wants to GTKD then so be it, I know after I started scraping pegs I was at it too, about 4/5 months into riding!! I find that I'm quickier if I'm shifting my weight, hanging off a little and concentrating more on the road and a nice line than scraping the knee.

Remember its also getting to that time of year where the road and ait temp are getting lower and outright grip on the road is fading fast.
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Old bikes >>> https://www.bikepics.com/members/cc123/

[Chriss]

I know my friend had a problem with his Diablos after two trackdays on Daytona 600, by the third trackday, he ended it early nothing felt right.

An expert said it was to do with "Heat cycles" (whatever they are). Anyone with knoweldge explain what they are and if they might have been a factor?

Thanks
____________________
TheShaggyDA: I've got 3 or 4 pairs that predate my wife, so at least 11.5 years old.

[Rookie]

Don't quote me on this, but I think it's when the tyres start to lose traction on the tarmac because of the number of times they have heated up and cooled down? I'm not sure it's even of relevance though, whether it's something that actually happens. However, if it does it would explain why the tyres are losing grip.

[lurker]

the reason you have no confidence in your tyres is due to the fact that there is no longer enough rubber in the centre of the tyre to hold an adequate amount of heat when warming them up.
youve only got a thin layer of rubber in the centre of the tyre trying to heat up a thick layer of rubber on the edges.
therefore the tyre has a problem heating up and even when it does it has a problem retaining the heat cause the centre is worn down

[Jrod]

My front tyre was the one that let go, thats only a month or so old.
The rear was fine and thats nearing the end of its life. I guess I just worked the front a bit hard.


I Will probally go for a different tyre setup this time, I've been using 010 / 014's for a year now, time for soemthing new.

[Metal_Mickey]

Thanks guys, that has been of help.

I don't believe it is a "confidence" issue per se as the reason I turned back yesterday wasn't because I was concerned about injuring myself, but rather of binning my bike on some silly little roundabout and then paying to fix it.

I noticed the other thread on overheating tyres and also did an Internet search on tyre heating cycles. Both have talked of a "blueness" that becomes apparent on parts of a tyre that has been overheated and some have talked of tyres losing their grip / becoming hard after going through too many heat cycles. This "blueness" is something that I noticed after spending seven hours riding around on a scorching hot Saturday, trying to get my knee down. Another rider commented on it and said it was just the chemicals in the tyre rising to the surface, so I thought nothing of it. I went out again later that day but decided not to continue trying to get my knee down as the grip just didn't seem right (the fact that one of my crash bobbins went AWOL sealed that decision).

I am not arrogant enough to say that none of this is in my head, because I am sure some of it is. However at the moment I am leaning towards the idea that I may have overheated the edges of my tyres on that day, after spending so long trying to get my knee down on such a hot day. The added heat cycles since then of me trying to get my knee down, stopping at McDonalds for a drink and then going back to trying to get my knee down probably haven't helped. These actions may have caused my tyres to have prematurely hardened. Who knows, maybe that is why I low sided in the first place.

I know this may seem like I am trying to blame everything but myself for things "not feeling right", but I like to explore different possibilities

So despite my decision to get my tyres changed, does anyone think that this whole heat cycle / overheating theory is BS ?

[Rookie]

Get your tyres changed, if only to improve your confidence. If you can't go to your limits you won't enjoy the bike. And let us know how you feel on the new tyres!

[california_rookie]

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[Suzuki]