scottfsmith

I usually don't replace anything until it is completely worn out, but after 2000 miles my rear tire was getting more and more flats and it also looked really flat on top (like a flat-top haircut). There was still some wear left in the wear indicator so I soldiered on. But recently I managed to bork a fancy carbon rim on a speed bump due to one of the many flats which hadn't fully sealed. After this I decided it was time for new tires, I was being penny wise and pound foolish.

So, now I have new tires. So far no flats, no surprise. What is a surprise though is how much better they handle. I did a screaming fast downhill yesterday and had the same time as a local racer (something I am definitely not). I just felt more confident on the curves so I went faster. It wasn't like I was thinking about the tires, it was only after the hill that I thought it might be the tires.

Anyway, I looked at a few threads here about tire replacement and there was no mention of flat-top being an indication of needing new tires. So I thought I would see what people here think.

If you are curious the old tires were 30mm Specialized SWorks Turbo 2Bliss Rapidair or some such gobbledygook. The new tires are 30mm Conti GP5000 S TR. I couldn't get these Specialized tires any more, there is a new model coming out (it was used in Paris-Roubaix). I don't think it is the tire brand though, I think it is all the wear.

bahula03

Typically referred to as being squared-off, very common with motorcycles on sticky tires that see primarily street use. Definitely a valid reason to replace tires even if they're not otherwise completely used up- the edge that gets created means a) there's less tire surface area making contact with the road at any given lean angle and b) the tire wants to be on either side of the edge, ie upright on the now flat portion of the tire or leaned completely over on the side of the tire, which can get a little spooky. One of those things that happens slowly enough that you don't really notice it until you get the contrast with a new tire, or unless it gets very squared off.

Iride01 

When your tires annoy you enough, that is when to replace them. Assuming it's not your fault for something you might be doing wrong when changing or fixing flats.

I will say that the Specialized Turbo Cotton tires that were on my new Tarmac only lasted a month or about 300 miles before getting replaced because of 2 or 3 tread punctures that flatted them. The Continental GP 5000's that I replaced them with have only had 1 puncture in the two years since.

Usually, I'm good till the first flat after the threads start showing with most tires I've used in the last dozen or so years.

downtube42

I just replaced my rear GP5000 after inspection. With full fenders, it's easy to forget the rear. Wear indicators are barely visible, but more telling are the diagonal ridges indicating the threads. It's paper thin down the middle, with plenty of rubber on the shoulders. Classic squared off.

scottfsmith

Thanks for the replies.. "squared off" is indeed what they were. The LBS said they were OK but I now realize I have a different standard.

cyclezen

really depends on the tire
tires do square off at different rates, and not all squared tires are poor performers...
if I don;t have some 'experience with a tire, and I decide it's time... after removal, I'll cut a cross-section and see how much rubber was left.
The general condition of the tire weighs in also, sidewall, condition where the tread rubber meets the casing, etc.
Most of the tires I now use are multi-compound, so shoulder condition is an important consideration.
When I'm riding a usual season, tires never last very long, time wise. I'll usually have to do 3x rear and 1 to 2x front depending ...
so they almost never get 'old', hard, cracked...
Longest lasting tire I've ever had, have been the COnti GP4Ks at almost 3500 mi, most others give from 2.5 to 3K.
Santa Barbara County roads are brutal rough... Although we are being treated to some nice new tarmac in some places, thanks to recent US infrastructure investment.
Ride On
Yuri