This is our overview and review of the 2013 Michelin Pro 4 clincher tire line. To me, Michelin is in a unique position in triathlon. Specifically, I think the way that their 2013 product line is organized sets a perfect example that other manufacturers ought to pay attention to. It is clear and easy to understand, and has almost every option we could possibly want.

It works like this. The core line that you’re concerned with – and we’re reviewing today – is called Pro4. As you can guess, the Pro3 came before that, and Pro2 before that. Michelin also sells a few other road tires – mainly for lower price points – but they’re not aimed at the bulk of the triathlon aftermarket, in my opinion.

Within the Pro4 line, there are four distinct flavors of tire. First is the Pro4 Endurance, the more training-minded tire of the bunch. It is a little bit heavier and a little bit more robust than the others, but shares similar ‘guts’ – the beads, the basic design, and so on. Next is the ‘standard’ Pro4, called the Pro4 Service Course (seen in the above photo). This is your do-it-all training/racing/one-legged-wheelie tire. It is available in a whole mess of sizes and colors for the picky or fashion-conscious among you. Third, we have the Pro4 Comp Service Course, which gets a higher thread count casing than the standard SC, but still has a puncture-resistant belt. It’s for the person that says, ‘I want to race, but I also don’t want a race-only and/or super-flat-susceptible tire’. Last but not least, the fast and flamboyant Pro4 Service Course Comp Limited. This tire gets the high thread count casing, no puncture belt, lowest rolling resistance, and most difficult name to say quickly.

Are you confused? Just so you don’t forget the important points for the exam, Michelin provided me with this wonderful crib sheet that explains everything:

I’ll decode what Michelin is saying in the above graphic. They’re saying that all of the Pro4 tires are better than the Pro3 (why wouldn’t they say that?). The new ‘standard’ – the Service Course – appears to be slightly more robust than the Pro3, perhaps at a slight penalty in rolling resistance (Crr). In the past, Michelin has intermittently offered a ‘Light’ version of their Pro tires. My understanding is that the old ‘Light’ was akin to the new Comp Limited. You had the standard tire OR the race-only tire. There was no in-between. I think Michelin has very wisely added a middle-ground tire – the current Comp.

The beauty of this system is that they’ve filled all of the gaps, and done so in a way that we can understand. It doesn’t take a genius to understand what ‘Endurance’ might mean. Comp and Comp Limited aren’t as descriptive, but at least they all start with Pro4. In my opinion, the only competitor who also pulls this off is Continental, with their various iterations of the Grand Prix. I see many other tire manufacturers trying to give each model its own unique name. I certainly think that the mountain bike tires and road tires ought not have the same name, but tires with a similar intent or target customer should be named and marketed similarly. We want to be able to understand the offerings with the least amount of time and thinking possible. Marketing lesson over? Let’s move on.

Specifications and Details

Before we dive to deep, let’s cover the basic specs of the whole line.

Michelin Pro4 Endurance

MSRP $65
700X23C (23-622) / 110 TPI / 225g / 87-116 PSI / grey, yellow, red
700X25C (25-622) / 110 TPI / 225g / 87-116 PSI / grey

Michelin Pro4 Service Course

MSRP $75
650X23C (23-571) / 110 TPI / 200g / 87-116 PSI / black
700X20C (20-622) / 110 TPI / 200g / 87-116 PSI / black
700X23C (23-622) / 110 TPI / 200g / 87-116 PSI / digital blue, dark blue, black, ivory, white, pink, red
700X25C (25-622) / 110 TPI / 215g / 87-116 PSI / black

Michelin Pro4 Comp Service Course

MSRP $80
700X23C (23-622) / 150 TPI / 180g / 87-116 PSI / dark blue, red, black

Michelin Pro4 Comp Limited Service Course

MSRP $80
700X23C (23-622) / 150 TPI / 165g / 87-116 PSI / black

As you can see, the standard Service Course has the most options in both size and color. You may also notice that the Endurance and Service Course have the same 110tpi nylon casing, and that the Comp and Comp limited have a higher 150tpi casing. Higher thread count means higher cost, but lower rolling resistance.

Unboxing

Let’s take a look at some of these tires. Michelin sent a few to me: 700x23 Service Course, 700x25 Service Course, 650x23 Service Course, and 700x23 Comp Service Course.

This is the bread-and-butter – the 700x23mm Pro4 Service Course:

If you’ve used older models of Michelin tires, these will feel familiar.

The Comp version makes a small, but important distinction on the packaging:

This is the back of the boxes; Comp on the left, SC on the right. The width and pressure specifications are identical:

One of the first things I noticed, however, is that the width of the Service Course and Comp are not the same. Here is a comparison of the two tires – Comp on the left, SC on the right:

Just eyeballing it, it looks like about a 1mm difference in total width.

Let’s flip those tires over (Comp left, SC right):

As we can see, these are clearly not the same tire. Often times you’ll see other tire manufacturers offer different levels of tire that are essentially the same thing, but with different layers added or subtracted inside. Not here.

I noticed that, in addition to the width difference, the Comp is slightly more flexible in your hand – suggesting lower rolling resistance. It also has much more pronounced ridges that run radially on the inside of the tire.

This is a comparison of the 23 and 25mm Service Course tires:

Forget those 25mm tires that are barely-larger than their 23mm cousins – these are clearly completely different tires. While at a Shimano press event in February, all of the bikes were shod in Michelin clinchers. After riding the 23mm version for a day, I wanted to swap to the 25mm. On a narrow rim, however, the tires just looked huge. In fact, they wouldn’t even fit inside of my Colnago loaner bike; I had to stick with 23’s.

I mounted the 25mm Service Course up to my pair of long-term-test Hed Ardennes+. These are the super-fat new version of the Ardennes, which feature a 20.6mm internal width, and 25.3mm external width.

On the fat rims, these ‘25mm’ tires measured a whopping 28.0mm. I asked Michelin’s Eric Doyne to provide me with a measurement on a narrow 15c rim (a Shimano C35 clincher), and it measured 27.9mm (both were measured at 90psi).

Don’t get me wrong – I’m a huge fan of fat tires. I’ll include more thoughts in my Hed Ardennes+ review, but I’ll say that these are perhaps the best training tire I’ve ever used. Tires like the Pro4 Service Course are wonderful – durable enough for training, but not so stiff that they beat you up. At 75psi, the ‘25mm’ tires ride unbelievably well. On all but the worst debris-laden roads (where a super-thick and uncomfortable becomes necessary), these Michelins are a perfect choice.

My only gripe is with the labeling. This is not a 25mm tire. At best, I could give them the benefit of the doubt and call it a 27mm tire. I would love to see the label change on this tire, and add a third option of a real 25mm for those with limited frame clearance.

Performance

Like most of you, I wanted to know about performance. How fast are these tires? I inquired with Michelin’s US marketing agent, Nick Legan. He writes,

“Michelin makes a point of not discussing its tires' performance relative to [competing brands]. They do, however, disclose whether a tire outperforms a former Michelin model. I can provide you with information regarding the Pro4 Service Course and know for certain that the new Comp version is the fastest clincher (rolling resistance) that Michelin has produced.

I also know that while Michelin has certainly looked at aerodynamics of tires, they feel that the gains are marginal and that making an ‘aero’ tire is less important than a tire that rolls efficiently and can get a rider safely through a corner. Michelin will not provide aerodynamic data on its tires.

Based on internal testing at Michelin, the new Pro4 Service Course Comp has 7% lower rolling resistance than the Pro4 Service Course. Interestingly, and this is of note to your readers, the cornering grip and mileage (durability) of the tire remain the same. This is due to the 150 tpi casing (other Pro4 clinchers have a 110 tpi nylon casing), a first for the cycling industry.”

The most interesting point – to me – is the point on aerodynamics. How dare they attack our aero?! Perhaps they’re just being honest. While I won’t say that aerodynamic properties of tires do not matter, the overall consensus from most of the tire geeks seems to be that, indeed, rolling resistance tends to matter more in terms of required power output from the rider. Of all the key Crr and aero testing gurus out there, I see them all choosing tires based on Crr first and aero second. With the aero side, most seem to simply pick tire width based on wheel width; if it’s an older narrow rim they pick a 20mm tire. If it’s a new wide rim, they pick 23(ish).

Being the curious types, we wanted to test these claims for ourselves. Slowtwitch contributor, avid forum member, and bike-tech-dude, Tom Anhalt, kindly offered to test tires for me. Michelin sent samples of both the Pro4 Service Course and the Comp Service course to me (the Comp Limited were not yet available). Tom had already performed roller tests on a pair of Pro4 SC’s that he had, so I sent my pair of Comps to him. If you are unfamiliar with Tom’s meticulous testing methods, check out his blog - http://bikeblather.blogspot.com/

Here are Tom’s results:

MP4CSC Tire #1: width=22.6mm, mass=178g, 'on road' Crr = .0042, Power for a pair @40 kph=39W

MP4CSC Tire #2: width=22.5mm, mass=176g, 'on road' Crr = .0041, Power for a pair @40 kph=38W

Tom tested both tires individually (hence tire #1 and tire #2). The tire width was measured on a 15c Mavic Open Pro rim (internal width of 15mm). He then lists the official Coefficient of Rolling Resistance (Crr), and then the power required to spin a pair of tires at 40kph. Like golf, lower is better.

To compare, here are Tom’s results for the standard Pro4 Service Course:

MP4SC: width=23.3, mass=202g, 'on road' Crr = .0043, Power for a pair @40kph=40W

Tom said, “So, in short, it appears that the Comp versions are ~25g lighter and ~.75mm narrower with the resulting Crr being within .0001 of the non-Comp tire. By the way, as a measure of consistency, I also ran the 20C Conti GP4000 (black) tire that I have and it was within .0001 of the previous measurement as well.”

Tom also added these tires into his master database, which can be seen here:

Here is the same in watts-per-pair-of-tires:

What does this tell us? According to Tom’s data, the difference between the Service Course and Comp is not as great as Michelin claims. Of course, testing protocols differ. We don’t know exactly how Michelin is measuring. Perhaps they’re using a drum that is much rougher than Tom’s, or they’re using a different load or speed. In any case, our Comps do indeed test faster than the standard tire, but by a relatively slim margin. We can also guess that they are more aerodynamic than the standard tire, due to their narrower width.

What we don’t have – and I’d love to see – is how the Comp Limited compares. The older Pro Light tire was always a very fast roller (like the new Pro4 Comp Limited, it had no puncture resistant belt). With the new 150tpi casing, we can guess that the new tire is even faster. Michelin was able to provide the following information on the Limited:

“This tire is exclusively given over to the quest for extra speed. It is the range's fastest tire and allows cyclists to cover four additional meters per minute for the same input compared with the MICHELIN PRO4 Service Course. Powered by a 250W motor, the distance covered by the assembly in 60 seconds is 544 metres, by which time it is travelling at a speed of 38.4kph.”

Just because the Pro4 Service Course and Comp are not at the very top of the Crr chart does not in any way assume they’re not good tires. As I mentioned previously, I think tires like these work phenomenally well for training on all but the worst roads. That also means, in my opinion, that they work well as poor weather race tires, or for courses that you’re unsure of. Haven’t ridden that new Ironman course? Don’t know how the pavement is? For me, whenever I’m doing a course that is brand-new to me, I always err conservatively on tires. Looking back to past punctures, almost every one happened when I ignored this rule.

Tire choice is always a balance of priorities – I think that Michelin has a great bunch of tires here that will satisfy the wants and needs of the vast majority of the market.

Note on latex inner tubes:

Some of you have caught wind that Michelin discontinued their latex inner tube; the US Michelin reps confirmed this. I’m going to go out on a limb here and pass along the reasons why – reasons that did NOT come from the Michelin reps. Rather, they came from other sources in the industry.

Why would Michelin discontinue such a cool product? My sources tell me that the number one reason was warranty and scrap rate. They say that latex inner tubes are incredibly difficult to manufacture, and that the scrap rate is high. Entire boxes and pallets can be lost in an instant if the humidity in the factory goes wrong. In addition, consumer error causes the warranty rate to be very high – on a product that sees low volume in the first place. Installation is always much more tricky, and the cost of a mistake is many times that of a butyl tube. Let’s be honest – most geeky tire connoisseurs are not ‘average’ consumers. In the hands of the less-educated or experienced, latex tubes are in certain peril. My guess is that Michelin’s accounting department saw a net loss on the product, and cut the cord.