At Frostbike I mentioned to Chris from Loose Nuts Cycles that I didn’t get why companies were producing 27.5+ mountain bike tires given the dearth of production 27.5+ bike frames. His response: 27.5+ tires are for your 29er. At that moment scales fell from my eyes and I saw the future.

Ok, so maybe I didn’t see the future of mountain biking or even fat biking per se, but I do see a 27.5+ conversion coming soon to a 29er in my stable. I absolutely love how fat bikes ride on dry trails, especially when paired with suspension–I just can’t afford to buy a FS fat bike yet.
The WTB Trailblazer 2.8 is designed to be a fast roller so you probably won’t see this one on the snow. Word is the tire was explicitly designed for 29ers.
WTB also offers their own 27.5+ rim called the Scraper for a complete solution. My bet is the Trailblazer + Scraper will be one of the more widely-compatible setups for 29er conversions, but only time will tell. WTB sold through all their test market orders quickly, and some shops will have been waiting close to a year on their pre-orders for this highly sought after tire.
Vee Rubber
Never ones to let a new tire size catch them off guard, Vee blasted out of the gate with three 27.5+ tires, the largest of which is a 27.5×3.25-inch tire. Look for smaller options as well, including a 2.8-ish tire and a 3.0-ish version as well. All these options should make it possible for consumers to find the max tire size that will work with their particular 29er conversion.
Panaracer
Panaracer is producing a 27.5+ version of the Fat B Nimble that’s listed at 27.5×3.5, though honestly it doesn’t look much wider than WTB’s 2.8-inch tire. But that’s a good thing–most people won’t be able to jam a true 3.5-inch tire into a 29er frame, even if it is mounted on a 27.5-inch rim.
Conversions are never a perfect solution as they often negatively affect a bike’s geometry, but having the ability to, say, run two different wheelsets on a 29er is a nice one to have.
Stay tuned as we test our own 29er to 27.5+ conversion.
Aaron pointed out that the weight on the card in the WTB Trailblazer photo shows 895g which is pretty light. The WTB website actually lists the weight at 980g which is a big difference so we’ll have to investigate further…
This. Looks. Awesome.
I’m guessing the limiting factor will be width in the chainstays. I would LOVE to do this conversion on my 29er, but I highly doubt that I could fit even a 2.8″-wide tire in the rear stays on my 29er.
Yeah, that’s the part I need to see for myself. I get that using a 27.5-inch rim takes care of height clearance issues but I’m still not sold on how the width will work out. I suspect it will take some experimenting with different tire and rim widths.
Agreed. Interested to see how your test goes!
I have a hardtail with long (455 mm) s-bend chainstays which have a lot of clearance for even 2.4 Mountain Kings on Flow EX rims. I tried the narrowest 29er plus tires (Vee Trax Fatty) i could find on the rear. The clearance above the tire was perfect, and there was about 3/16″ clearance on both sides so I decided to give it a go. Out on the trail this proved not to be enough side to side clearance and the chainstays would rub the tire on hard turns, etc. So, I suspect an even wider tire on a 27.5 rim would cause worse problems.
How wide were the Vee Trax 29+ tires you tried?
Trax Fatties are listed at 3″, but I think they measure out at 2.85″
I already have rubbing with 29×2.4 Ardent EXO’s mounted to Velocity Blunt 35’s in my Canfield Bro’s Yelli Screamy under hard cornering as well, so I don’t see my self making the swap either, but I’ve seen other people do it with success.