The fresh “plus” size tire standard is getting more and more popular these days, seeing bike manufacturers releasing 2016 products on the market pretty quickly.
Since I tested a few of the “official” release plus bikes this summer (Scott Genius 27.5 Plus, Trek Stache)I have been thinking of the 29 to 27.5 plus conversion. A 27.5 plus is very close to a 29er in terms of outside diameter, so having the bigger volume of the plus size tires seems like it could be a great compromise.
I talked to Fox and Niner about trying that set up, making sure the forks and frame could accept it. As of today, both the companies told me that the 27.5 plus fits in the 29er fork and frame up to 3.0 tires, but not an “official” conversion yet.
I had to try it on my WFO, with WTB i35 rims and WTB Bridger 3.0 and Trail blazer 2.8 in the rear. The WFO has enough clearance for a 3.0 in the frame, and if I knew it, I would have gone for a Trail boss 3.0 or another Bridger with the rounder profile. That Trail blazer is just felt a bit too “square”.
The conversion wasn’t much heavier (half a pound) than my regular combo on 29er+heavy casing tires. The wheels fit in the WFO without any additional adjustment.
On the ride, the bike felt plush obviously, with 10psi in the front and 13 in the back. The desert sand sections became fun, and climbing up the loose gravel hills easier. The grip is amplified, and you can use any line you want. The rolling or handling feeling is not affected and rode the same way than with 29er wheels. The bottom bracket height wasn’t affected, so the overall balance of the bike didn’t change.
Again, the resonance of the tires is disturbing. So far, that is the main drawback of any “plus” experience I’ve had. Going down, on the flat off camber loose gravel corners, it’s just a no brainer. You can charge, and it grips. On the rough stuff though, I could feel how far the tires would fold and could feel the rims hitting the ledges few times! I had to tone it down, and let the gravity do it’s job. I think the tires are limited to how much you can push on it. That is something I’m curious to see evolving, hoping for a stronger casing.
It was an interesting test. Setting up a 27.5 plus wheelset is right around $600-$1000, tires and rotors included. There are no modifications to do on your actual 29er, and you can always go back to your normal set up easily. It gives a different feel to the bike, more plush, with a lot of grip that inspires a lot of confidence in the ride. I think it can really help beginners and intermediate riders find confidence. For more advanced riders, it’s a comfortable ride to go fast and play with the bike.
One piece of advice before you make your decision, I would ask the bike company first to make sure there are no issues, or if you void the warranty.
For Alex’s 3 week update, see here: 29 Minus – 27.5 Plus Meets Niner WFO: Part 2
Words By: Alex Petitdemange
Alex Petitdemange is an enduro racer from Annecy, France now living and training in Sedona, AZ. He raced as a XC JR and U25 pro for 5 seasons while mixing it up with some moto. After 9 years with no racing he jumped back into the sport while living in Moab, Utah and finished well enough for a podium position and was hooked back into racing as a pro in enduro.