Irwin Wheels Carbon 38 Review: Big League Tech / Little League Price

You know Irwin Wheels… You just don’t know that you know. They’ve designed, tested and built wheels and other products for cycling and started as a Moto design and engineering house. The Irwin AON TLR 38 carbon road hoops are built in house from raw fiber to finished product… And they’re good.

Better known by other brands in cycling and moto for their skills, Irwin have solid design and engineering, testing and production partnering chops. They’ve been a go-to company for brands to put together quality products by pooling resources along with a few other top manufacturers to create a family business that’s now on its second generation.

With that second generation, Irwin have also decided it’s time they put their own name on a line of wheels that they’re bringing together from the ground up.

We get a look at their AON TLR 38’S

It seems like there are a swath of new wheel companies or manufacturers better known for other products getting into the wheel business. One of the things that most of these newbies have in common is their use of generic rims…

Irwin are not a generic.

They’ve been putting solid design into carbon products (wheels in particular) and for their own models they decided that a full rethink was in order. With that, they wanted to break down the product right to its foundation which meant abandoning the typical practice of taking a supplier’s prepreg sheets of carbon and stuffing that into a generic mould.

Irwin decided to go the route of starting with raw fiber strand (from Toray)…

This is then impregnated with their own mix of resins depending on where the materials will be placed within the wheels design.

The fibers are than made into either weaved or unidirectional sheets, again depending on the placement / function of the given material.

And then the in-house spec’d materials are cut to suit, and hand laid into proprietary molds.

The resulting product is a clean looking rim, with the unidirectional fibers forming the bulk of the body of the rim and the weaved fibers (and resin) taking their place in the spots where some added strength makes sense, at the brake track…

Irwin also reinforce the spoke bed with weaved material…

Note the molded valve hole and cleanly drilled Spoke holes

They have a pretty cool video of the build process at Youtube:

While weaved materials are in a couple of locations, its not just the “weave” pattern that is critical… This is where making their own fiber sheets from raw strand and their own resin mix comes in to play.

Irwin decided that rather than putting a lot more material at the brake track (or machining the track, or using a roughed surface treatment that can wear out or actually create more heat), that they would rethink the thermal conduction / insulating properties of the materials.

Because, why not stop things from heating in the first place rather than trying to better handle the heat??

This lead them to produce their RaHD (Rapid Head Dissipation) design that puts Boron / Ceramics tech into resin, effectively building it right into the fibre composite at its base level…

Something that other wheel manufacturers have had to discover the hard way is that trying to use “doped” layers of Carbon doesn’t work… (some still don’t get it). When some layers are “the good stuff” and others are not, things expand, contract and move at different rates and you get exactly the kind of delamination that I’ve seen in the mountains with carbon rim-brake wheels over and over again.

Irwin’s process better resists heat throughout the structure rather than in layers or at the surface.

Irwin have a video of a fairly brutal brake testing up as well…

After a summer’s worth of use here in Phoenix, inclusive of some South Mountain descent testing (putting on the knee and elbow protection and pushing both the brakes and a couple of versions of tires), I can say that there was no visible indication of brake track delamination or degradation at all. No “pulsing” feeling either (which sometimes happens when things get very hot and the brake track on inferior wheels starts to deform). I’ve had heat blow outs and have felt that pulsing ahead of those failures with a few carbon rims over the years and am happy when it’s not an issue.

That said, Irwin’s supplied pads are among the louder screamers. Yes you can toe in the pads and reduce this and Irwin’s pads actually have a reasonable wear life, but once pressure (or wear) has them flat on the rim, they squeal. But it’s a tradeoff I’m willing to make for a fairly smooth modulation and the lack of heat issues in my admittedly unscientific testing

Irwin also supply a rim friendly Tubeless stem set as these are set up for Tubeless used out of the box.

Something a few manufacturers are stressing is good pad placement, and Irwin give you the safety sticker to let you know to keep your pads away from the edges…

Irwin specified reasonable geometry for their Hub set. The front having fairly wide spacing…

… and the rear getting decent spacing as well as a mid-high flange.

The hubs are a conservative design with some uprated internals (especially at the price point) in ceramic bearings front and rear…

The engagement at the rear damn near feels like a fixed gear wheel in responsiveness.

I guess that makes sense as there is almost no lag in a system with this many ratchets and 6 pawls, each with 3 teeth…

With 18 teeth, split into two groups of alternating engagement (3 pawls are engaged while the other three are preloaded and ready to drop in) the engagement frequency is silly tight, the drive will engage before the wheel has traveled an inch.

BUZZZ! Even with substantial lube, the wheels are fairly loud when freewheeling as these ratchets and teeth have fairly steep angled cuts and the return springs are strong. The trade off though is strong engagement and what I would guess is a fairly long service life in the case they’re well maintained.

Irwin don’t skimp when it comes to the spokes and nipples. Going with Sapim is a solid choice.

In fact, it doesn’t seem like Irwin cut any corners with this build…

Ceramic bearings, a solid hub design and rims made to spec, from the fiber to density to resin mixes to the addition of heat resistant materials, make for a wheel that’s done nothing but perform in all conditions.

In addition to getting pounded on the road, the AON TLR 38’s have been Gravel wheels for a good portion of the summer.

The rim profile itself is relatively wide and has a shape similar to most of the top spec hoops available today, all featuring the “Firecresty” rounded U-shaped / pattern. These are 26mm wide at the outside of the brake track and 18mm wide at the tubeless ready inside measure…

Irwin’s AON 38’s have virtually all of what you would look for in a $2100 top line carbon wheel set… They compare pretty well with the other models at this price point.

With one slight issue.

Irwin forgot to add 30+% to the price and are putting these on the street for $1600.

This price point is to be expected when a company is trying to push themselves into a fairly packed market place. Irwin are going to have to win some converts and $ is one way to do that.

But this price point alone wouldn’t get the job done unless they matched it with great spec and some solid tech that makes for an all round wheel that could easily be confused with something costing another $500.

Irwin have been making very good product for brands you might recognize for a while… It’s time they started getting some of that attention for themselves and the new AON TLR 38’s are a great start.

These and several other profiles are ready now in both rim and disc Brake options.

You can find more product info at:
Dealer Inquiries to:
Marketing / Communications:

• See the PEZ First Look at the Irwin AON GX35 Gravel Wheels here

Have Fun,
Charles Manantan

Note: if you have other experiences with gear, or something to add, drop us a line. We don’t claim to know everything (we just imply it at times). Give us a pat on the back if you like the reviews, or a slap in the head if you feel the need!

PezCycling News and the author ask that you contact the manufacturers before using any products you see here. Only the manufacturer can provide accurate and complete information on proper / safe use, handling, maintenance and or installation of products as well as any conditional information or product limitations.

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