Bontrager 29-3 Tires: First Impressions

The front/rear specific Bontrager 29-3 tires are mounted and have been ridden. Here are my initial thoughts about this newest set of shoes from Bontrager.


I Mounted the tires to my set of Bontrager Race X Lite wheels using the TLR rim strip. The interface between the tire and the wheel was tight! Much tighter than other Tubeless Ready System tires I have mounted. Since these are pre-production tires, it may not reflect the actual production tires you may get, but if it does, be prepared to work a bit harder to mount these. Not that I am complaining……yet! If ever I flat, I may not like the tighter fit. They hopefully won’t flat, as I used the Caffelatex sealant I am reviewing in the tires.

As I stated, these are pre-production samples, but I was told that they only differ in that the rubber compound used was heavier and a bit thicker on the sidewalls than the production compound. Weight will be less than the tires I have as well, which I found to be within acceptable limits as is. The widths on these tires varies from front to back by quite a bit. In fact, the tires don’t even look like they belong together! The front 29-3 measures 53.4mm/2.10 inch (claimed 2.25 inch) and the rear measures 47.8mm/1.88 inch, (claimed 2.00 inch). Note: These are casing widths, the tread blocks on both tires are narrower.


The tires when mounted look really miss-matched. The rear is so much narrower and has less volume by far than the 29-3 front. In fact, side by side comparison of the mounted tires shows that the axles of the wheels don’t match up. or anywhere close to it. There is just shy of a half an inch differential in diameters between the two tires. These tires are meant to go together? Well, I figured I may as well give them a shot, even though the differences were so huge. Even the tread patterns are not remotely similar. The back resembling a smallish Python and the front a WTB Prowler. Not that this is a bad thing in and of itself, but along with the other differences, these tires looked like a “Mutt and Jeff” pairing if ever there was one in the tire world.


So out I went on a fine day in almost perfect conditions. The trails were tacky dirt with plenty of roots and covered in leaves in some spots. I also had a pretty big sandy section in this loop. The trail starts out with a big climb to a switchback and off camber section. Here the tires showed great braking traction and cornering traction. Climbing was good. Actually, I was quite surprised at how well the diminutive rear hooked up. Even standing on steeps didn’t break it loose. I did get a fair bit of skidding and looseness in the rear around a particularly tight downward turning switchback though. Also, I could feel a tad bit of breakaway on the really off camber parts in the rear. The front end stuck like glue though. No wavering what so ever.


The front tire was impressive in turns and over the rough roots, where the volume of this tire makes up a bit for the lack of suspension on my El Mariachi. I appreciated this very much. Incidentally, I ran 22 psi in the front tire and about 30 psi in the rear. This felt about right from a balance point of view, as I could feel the rim in the rear bottom out once or twice on roots. In the sand the front tire did a fair job of tracking through, but still doesn’t top Bontrager’s folding bead version of the XR. The rear cut down in pretty much on impact with the sand, which is understandable, given its narrow profile. Still, I managed to plow through in an acceptable manner.

A note on the difference in diameter: Obviously, a half an inch in difference here will make a slight geometry change to any rig the 29-3s are mounted to. It will slightly slacken out the head angle and seat tube angle. I did not notice anything while riding my El Mariachi. Perhaps I got used to it immediately, or it isn’t that big of a deal. However; it is worth noting if you get this tire combination for those who think it may make a difference.

The rest of the trail was ridden with no drama. The 29-3 tires corner well, grip on climbs exceptionally well for the size of the rear, and are great rollers. In fact, they roll with little “buzz” at all. Braking traction was great in front, but if you are a heavy rear braking addict, you won’t like the skinny rear.

So, are these tires meant for each other? I would say yes from a performance standpoint. They look odd, but you probably won’t notice that while riding them. Rigid front riders with a bent for racing will like the voluminous front tire and the fast rear. Full suspension riders that race their rigs may also appreciate the combo. That said, there is no reason a rider could not choose to run front 29-3 tires on both ends, or 29-3 rear tires on both ends. In fact, I am told race team members of the Fisher/Subaru squad run the 29-3 rear on both ends at times. To my mind the rear 29-3 looks like the perfect monster cross tire.

I’ll continue to flog these throughout the spring and will report back with a Midterm assessment then.

No Responses to “Bontrager 29-3 Tires: First Impressions”

  1. Willie Says:

    Just wondering, what is the difference in wheel diameter front and rear?
    Would the “slight geometry change” require a change in saddle angle, for those that are sensitive in that area?

  2. Chris Says:

    I can confirm that running the front tire on both front and rear is also a great combo. It probably doesn’t climb as well in all situations, but it’s quite nice. I ran the front 29-3 on both front and rear for several weeks and really liked it. The only times the front, run as a rear tire, was sub-par was in really slippery mud, and a few super steep climbs, but in general, I’d rather have the greater volume of the front tire.

  3. Guitar Ted Says:

    Willie: As I state in the piece, the difference is about a half an inch. Whether or not anyone would require a position change is a case by case situation. Technically the answer would be yes.

  4. prphoto Says:

    Thanks for the test Ted. I think the front sounds like a winner the back not so much. The gentleman who is behind these tires was at our shop last week , I was told he previously worked with the “ain’t that Special” bike co. I think most would agree Trek needed to pull its act together in regard to its 29 tires. Still nothing that compares to the Vulpine or Crow. But its a start. It would be great to hear your complete thoughts on the XR (tubeless of course)

  5. Guitar Ted Says:

    prphoto: The XR tubeless was merely “okay” in light of the former XR folding tire, which in my mind was one of the best sand/dry hard pack tires ever. The XR used to be a voluminous, rounded casing, but the TLR version is smaller in every dimension and has a stiffer casing, which makes it track worse and the lack of float compared to the old XR is disappointing.

    That said, the XR TLR tire is still decent, just a step backwards from the original, in my mind.

    Look for a comparison between these 29-3’s, Conti Race Kings, and GEAX Barro race tires coming Monday. ๐Ÿ™‚

  6. Cloxxki Says:

    Typical, a nice of of Bontrager tires where the rear is kindof obsolete ๐Ÿ™‚

    In 29″, rear traction very rarely is an issue IMO. Not sure a tire even needs to be designed offer special traction. The XR rear sure offered, but the front just rolled so much nicer and seemed to get the job done more than decently, at least for me. And the Nano, that’s actually a great rear in terms of traction, and it rolls mad.

    I’d like to see a rear that rolls AND sheds all kinds of mud, to truely make an allround rear choice. The ultra-racey Conti Twister IS that, just a bit over the top perhaps. The Maxxis Minotaur 380(g) seemed to be better, for a 26″ tire, than the Kenda Karma over all but pavement and in terms of wear.
    Weird how tires that work don’t always stay.

    I wouldn’t mind an old style non-tubeless 2.4 XR front. Or a lower tread depth 2.3″ Nano.

    About the Vulpine. Is it all that special, or just a daring offering that works out, mostly because of it being 29″ with greater grip/traction? Is it that much faster than a Nano? What about the RR?

    Sorry for the hi-jack, I just can’t get enough of these tire reviews. Looking forward to Monday (not sure I ever used those words before).

  7. SinnerSpinner Says:

    Yeah, I agree with Cloxxki… keep the tire reviews coming!
    I would still like to see more semi-slick offerings for the big wheels as I too feel that there is a surplus of traction to “play with” with the larger contact patch. Why not put the technology/weight into the casing and overall tire volume, and go easy on the “here today – gone tomorrow” tread designs? Besides, nothing sheds mud like a slick!

    On kind of a different note: I noticed that you (GT) are rolling around on a set of XDX tires (Caffelatex review). What’s the word on these? They look like a micro-ed down version of the old Comp 3 tread design, and have kinda piqued my interest…

  8. Guitar Ted Says:

    Cloxxki: The Vulpine is fast, but interestingly, (and much like many current WTB designs) it has a stiffer casing, and therefore a touch higher rolling resistance is felt on trails. It also is no lightweight tire, at 650grams. I have a set tubeless, and that seems to aid in making the Vulpine a better roller, but as you know, it isn’t recommended to be run tubeless. Finally, the lack of center tread only seems to work on the driest of trails for me.

    SinnerSpinner: XDX tires are really nice! Big, rounded casing, lots of smallish knobs, and of course, tubeless ready. I find that these work great on dry, hard pack, loose over hard pack, and tacky trails. Rocky, dry trails work too. Anything wet is bad for them. By the way, my older XDX’s (actually, they are called by their old name- “Dry X”) are about 2.35 inches wide stretched. ๐Ÿ™‚

  9. milto Says:

    Hi Guys

    for those of us new to the game can you maybe put some sort of table or report on tyres. What works well in what sort of conditions etc.. How many tyres are out there for 29ers?

    I keep reading about different tyres and I don’t know much about them but am keen to have a couple of different options in the shed for different seasons.

  10. Cloxxki Says:

    With about 70 29″ tire treads out there, that hould be a breeze. I’ll fix something up over lunch.

    I have the same feeling as I’m exploring the “free energy” forums. Clearly those posters know most of what I need to know, but all the info is hid in longwinded (up to and over 300 pages per topic) discussions. Feels like I will never catch up to the point where I’ll be able to contribute with new solutions as I like to.
    Never a summarizing story telling me what I need to know on a subject. Wiki ain’t helping much still.

  11. t0m Says:

    Free energy, never is.

    Unless you’re sitting on a secret worth trillions.

  12. Steve Says:

    Hey Guitar Ted,

    Great article! Incidentally, how would these compare to something like a Kenda small block 8?



  13. Guitar Ted Says:

    Steve: Smallblock 8’s are all about rolling and mad grip on dry hard pack. The Bontrager tires are definitely more versatile and offer options for mixing and matching fronts and rears for totally different set ups. No comparison at all really. Very different tires from each other.

  14. Vandal Says:

    Free energy: It’s amazing how three hundred pages can be written about nothing!

    Thanks for the 29-3 review. Yes, they do look like an odd couple. Sound like a good dirt trail combo but a little out of their comfort zone on Niagara Escarpment rock gardens.
    The original XR pair are my all -time favourites for sand. Their big weakness was the delicate sidewall. That’s where the Mountain King 2.4’s were an improvement and the Panaracer Rampage 2.3’s are better still.

  15. Cloxxki Says:

    Until we find free energy, somewhere, I’ll just pedal my bike and pick fast rolling tires that still allow me to keep off the brakes for corners ๐Ÿ™‚

  16. JeroenK Says:

    I just came back from the Houffalize worldcup, where Sam Schultz rode the 29-3 “rear specific” tire on both wheels, on a dry, but very technical hardpack course. Apparently, he likes that even better than the XR-1’s.

    He did not repeat his very good Offenburg result (16th) though…

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