How to recognize a bad tire?

Question

The most expensive "consumable" while operating a bicycle would probably be tires. Enthusiasts endlessly debate the relative merits of different sizes, profiles, tread patterns,inflation pressures and just about anything else that might help define the best tire.

I use my bike for primary transportation and moderate cardio averaging 15K - 20K daily. The terrain is fairly level but the traffic is dense and the road surface varies from virgin concrete to "what road?". For the time being I'm still running 27 X 1 3/8 (37-630). Unless I want to pay obscene import prices my choices are limited.

Is there anything to look for on a cheap, odd brand, tire that would provide clues about how long it will last? What do you look for when trying to assess how well a new tire rides? Like I said, to me a tire is a consumable. I'd rather have something usable that I bought cheap enough I can throw it out without an internal struggle when it gets worn or damaged, than running something I paid so much for I'm trying to squeeze every last K of service life out of it. What is the average life of a tire in my sort of riding?

Additional info.

On the bike; Badly weather checked, practically treadless, Bridgestone. If it fails catastrophically in local traffic I'll probably die.

The choices (low to high); Leo Tires "Diablo", Philippine made, under $10 including new tube. Other tires in same price range from other nearby countries that have rubber plantations. Paying for a rim swap to let me use mid-price tires with known name brands. Paying astronomical single unit import fees to get those same brands in my current tire size.

The budget doesn't allow a rim swap for at least a couple of weeks. So I'm mounting the Diablo before I leave the driveway again. There are no visually obvious defects or damage. Are there less obvious but still noticeable things I should look for? Small details that might keep this piece of crap from killing me if I catch them during a pre-ride inspection?

Answer 1

Quality of tires is mainly quality of rubber.

The rubber is responsible for

• the grip of the tire (braking and cornering)

• time to wear down

• rolling resistance

The second strongest indicator for quality is the carcass.

This determines things like

• puncture resistance

• behavior when cornering (you don't want to ride tires that "crawl away" in the corners)

• rolling resistance

All other features of bike tires (ignoring size, thickness is very important for application) are mainly cosmetic.

This includes the tread: You simply don't ride a bike at speeds that require tread to deal with water. A fine tread may deliver better grip as it can lock into the stones within the road's surface, but a tread that looks like water-channeling does not give you significant gain in wet performance. A good tire still works fine when it's a complete slick, a bad tire won't work with the "grippiest" tread.

TL;DR: Quality of tires is largely invisible.

You have to try a tire to gauge its quality. Or check what other people say about the brand. But you cannot judge a tires quality without taking the invisible stuff into account, which means you have to go by brands. Sorry, I really hate having to say "look at the brand", but for bike tires, it's the only good quality indicator short of riding it.

Answer 2

There are many factors that go into determining the performance of a tyre. The material and thread count (TPI) of the carcass, the rubber compound, thickness and tread pattern. Tubed vs tubeless, and many different varieties of puncture protection layers.

Unfortunately as a consumer (especially with lesser known brands) its virtually impossible to be sure of the exactly how the tyre will perform without trying it. This is why bike forums are always full to the brim of threads about x/y/z tyres.

The average life of a tyre varies significantly, based both on the tyre construction, the weight and riding style of the rider, and the terrain being ridden. A light rider riding tyre 'X' on flat smooth roads may get 4500km out of a tyre, but give the same tyre to a heavy rider in hilly terrain and a coarse surface and it may only last 1500km.

If you are looking at a tyre purely as a consumable item, and only care about how many km you can get out of them, then you probably want to look for tyres that are advertised as 'touring' tyres. They typically have thicker rubber and a harder compound for durability, along with thick puncture protection layers which whilst designed to provide reliability in remote areas, also work superbly in urban environments

Answer 3

Andy's answer is excellent.

In an attempt to add a little value...

It is difficult to know which tire will last longer when comparing between brands without experience. However, within a brand you can get a pretty solid idea which tire will perform best based on the criteria you select by checking the company website.

Tire makers create products with specific characteristics and they rank their tires according to those characteristic.
For example (not a recommendation):
Schwalbe = Rolling, Road Grip, Off-road grip, Protection, Durability
Vredestein has: Rolling resistance, Comfort, Grip, Durability, Puncture Resistance
Continental - Does not have categories like Schwalbe and Vredestein but they do provide information that will tell you which tires fit performance categories.

As with anything, some companies provide clearer information than others.

If you are looking at two (or more) off brand tires you can get a rough "best guess" on durability by comparing the feel of the tire.
Max mileage will be found in tires with harder and thicker rubber which means they tend to be heavier.

It's all about trade-offs.

One of the trade-offs is cost. It would take a lot of work to arrive at a miles per dollar statistic for enough tires to have a meaningful comparison. For example, if I buy a tire for $20 that lasts 2000 miles and another tire for $40 that lasts 4000 miles (just making up numbers as an example) aren't I getting the same miles per dollar?
To really get picky you'd have to add in how much your time is worth to trade out tires.

It might be possible to get better value from multiple less expensive tires than from one expensive one.

Answer 4

Also worth noting, that some brands offer models of tyre that initially look the same. Sometimes you will see a "bargain" online. But manufacturers often ship lower qulaity OEM tyres (those that come with the bike) to those that are sold separatley. It used to be the case that some Panaracer where made in Japan, but others came from China, with poorer quality rubber, threads per inch etc. Other brands like Maxis might offer half a dozen variants of the same tyre, ranging from the cheapest rubber, to duo or triple compound versions, twin wall etc, which might cost twice the price.

Answer 5

Answering the follow-up

There are no visually obvious defects or damage. Are there less obvious but still noticeable things I should look for? Small details that might keep this piece of crap from killing me if I catch them during a pre-ride inspection?

I don’t think a sudden, catastrophic failure is likely. I’d inflate them to the maximum pressure or slightly higher, then release air until you are at the desired pressure. This is always a good idea to make sure the tire is properly seated and the tube isn’t pinched anywhere. Make sure the tire isn’t bulging anywhere. As long as the treads are intact even cracks or cuts in the rubber shouldn’t be an issue.

I think it’s a bad sign if a tire is really easy to install, since this could mean that it also comes off easily.

You can get an idea of the grip on various surfaces by braking with the rear wheel until it locks up. I’ve had tires with terrible grip on wet surfaces, especially surface markings or manhole covers.