Donnelly EMP 700 X 38 Tires: Getting Rolling

Donnelly EMP 700 X 38 Tires: Getting Rolling- by Guitar Ted

New tires are a big deal for cyclists. Another model to perhaps tame the courses you ride. Maybe it is a specific, “specialist” tire that has a design which will conquer that event which has given you fits in the past with tire troubles. This new tire by Donnelly is, perhaps, just such a tire. A tire named after one of the most well known events on the gravel calendar- The Dirty Kanza 200. In fact, this new tire takes its name from the airport code for the host city of the Dirty Kanza, which is Emporia, Kansas. Let’s take a look at the features of this new model dubbed the “EMP”.

Donnelly EMP 700c X 38mm tires in their point of purchase packaging.
The new EMP- A tire that promises durable, reliable performance in rough conditions.

What It Is:  The EMP was just introduced by Donnelly officially a couple of weeks ago. This is the first of a couple of promised sizes, (others to follow next year in the Spring at the earliest), and it is a bit of a surprise at a 38mm width. That’s a bit on the narrower end of tires that we’ve seen come through in the last couple of years. Let’s take a look at the feature set:

  • X’Plor Series designed for adventure
  • Soft rubber for extra grip and cushion
  • High-volume, lightweight construction
  • Tubeless ready casing
  • Puncture-protection belt under the tread.
  • MSRP is $72.00 each

EMP; Airport code for Emporia, Kansas. Home of world famous gravel roads that reach out to the sky.

Close up of the Donnelly EMP tread pattern.
The EMP features what Donnelly says is “Its most aggressive gravel tread to date.”

The 700c X 38mm tires are black wall only, and feature a very aggressive, deep tread with a chevron arrangement up the center. These are much like a “pumped up” version of  the MSO tread blocks. Then up along each side of the tire we see “U” shaped blocks which are like lateral stabilization knobs with the open end of each “U” shaped block facing outward, which should be good for cornering traction. Underneath this tread is where the puncture protection layer lives. The tubeless bead should be precise enough for simple inflation on most tubeless ready rims. The tires have not been mounted yet, but you can expect to read a word or two about that in the upcoming “Checkpoint” post in a few weeks.

The samples we were sent weighed exactly the same weight at 493 grams each. This was right in the ballpark for the weight we expected these to be at. This compares favorably with many other tires, but not even close to the overall lightweight champ in this category which is still the 380 gm Maxxis Rambler. (A tire that we reviewed which does not have puncture under the tread in the test samples we received but did have side wall protection.)

First Impressions: Yep! That’s some aggressive tread there! Donnelly got that right in their description of this model. There have been several puncture protection type tires that have come through here and in comparison, the EMP feels pretty supple. Generally a puncture protection belt only under the tread can make for a somewhat difficult tire mounting experience, but we will see about that in the next update.

The Donnelly EMP 700c X 38mm tire

The claimed width of 38mm is similar to the WTB Riddler 37mm tires which we have some examples of lurking about the shop. So, I compared casing widths and it appears that the EMP is about 2-3mm wider. This leads me to believe that the 38mm claimed width may end up being more like 40mm, but again- we will have to wait until the “Checkpoint” post to find out.

The only possible nit I have right out of the package is that the deeper, closely packed tread blocks may be a thing that picks up finer bits of gravel and tosses them around. We’ve seen this with other similar tread designs. But other than that, the tread looks great and the closely packed knobs promise a fast rolling tire on harder surfaces.

So Far…… The Donnelly EMP looks aggressive and tough enough with this beefed up tread design. At a claimed 38mm, it falls into a good range of size which many tires don’t cover. The weight seems about right, and if the previous Donnelly tubeless tires are any indication, we expect to have no issues with tubeless performance. The tire features a puncture protection belt which doesn’t seem to hinder suppleness in the hand. Stay tuned for the “Checkpoint” post coming soon.

NOTE: Donnelly sent over the EMP tubeless ready tires at no charge for test and review. We were not paid, nor bribed, for this review and we will strive to give our honest thoughts and opinions throughout.


Author: Guitar Ted

Guitar Ted hails from Iowa. Home of over 70,000 miles of gravel and back roads. An inaugural member of the Gravel Cycling Hall of Fame and Co-creator of Trans Iowa in late 2004- Guitar Ted has been at the forefront of the growth of gravel events and riding since then. Creator of Gravel Grinder News in 2008, he produced the premier calendar of gravel and back road events. GT joined forces with Riding Gravel in late 2014.

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9 thoughts on “Donnelly EMP 700 X 38 Tires: Getting Rolling

  1. If you measured bead to bead and got 2-3 mm longer, then that matches for a 1 mm larger width. You are comparing a circumference to a diameter, which differ by a factor of pi (if the tire inflated to an exact circle) or about 3. CX magazine is a big proponent of reporting bead to bead measurements of tires as that is independent of rim width and have verified the factor of 3 ratio.

      1. Yes, and 2-3mm longer b2b translates to about 1mm wider in width. So 2-3mm longer b2b than a 37mm wide Riddler would make sense that it’s a 38mm wide tire (1/3 of the additional b2b added to 37mm).

  2. I have a Specialized Diverge with Axis 4.0 SCS wheels. The tires are Gripton Roubaix Pro 700 x 30 x 32. Am I able to put the EMP 700 x 38 on this size rim? Thanks Rick

    1. @Rick- Typically, you would be able to mount any 700c tire of that size to that rim, but I cannot say how it would go, or what your result would be without knowing details.

  3. I put a pair of 700×38 tubeless EMP tires on my Renegade. I live in Ohio and I ride some pretty gnarly gravel roads. This past weekend we had a rare early February thaw and I did a 60 mile 4,800ft of elevation ride on them. Every condition a gravel road could be in was represented on that ride and the EMP tire is my new favorite. I ran 38psi on the back and 36psi on the front, I totally ripped and gripped it with total confidence. I’m in the Kanza 200 this year and I’m most definitely riding it with these tires.

    1. Thanks for the real-world review, Patrick. I’m doing the 2019 DK200 as well and am looking at this tire vs. the WTB Riddler. I like having the peace of mind of a puncture-protection layer, so I am going to try these. My only reservation is that up here in the Pacific NW we can run into wetter, muddier dirt sections on gravel roads most of the year, and I can foresee those tightly-spaced lugs packing mud and not letting it go. No such thing as the perfect 4-season tire though!
      I ran Donnelly MSO’s last year in the DK and had zero issues with them, so my confidence is high in Donnelly for the DK’s terrain.

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