That wave is rolling into shore on a tsunami of longer travel, slacker angled, 27+ based wheels/tires (and maybe 29″ too) and looks to have no end. It is the future of trailbikes.
Back when I wrote this missive about Plus Bikes about a year ago, I knew this was going to be a big deal. I was not sure how it was all going to work out, but I knew it was the real deal. I suspected, as time went by, that it looked like Plus was going to take two directions: 3.0″ or better tires for expedition/adventure bikes, like for bikepacking hardtails, and full suspension bikes with more travel and a 2.8″ (or less) 27+ tire. That has happened. 29+? Small fish, small pond, all on its own. 27+ is growing fast and 29+ is not.
What I was curious about was whether or not bikes would be built to run both wheel/tire sizes…29×2.35″ and 27.5×2.8″…and would anyone want that, and further, how would you make that bike work optimally with both wheel options?
Well there sure have been a few different approaches so far. Note the recent Ibis Mojo 3, a stunning bike really, that eschews the option to run 29″ wheels on purpose, stating that it brings too much of a compromise to the bike’s geometry (chainstay length, etc). It really is a 27.5″ bike that can run up to a 2.8+ tire. There might be a really good reason for this course of action, as there are no compromises in the bike to get it to work with both wheel sizes. It can be just exactly one, pure, thing.
Then there is the bike that I have a 29″ only version of, the Salsa Horsethief. For 2016, it is the same frame as the Pony Rustler, and was tweaked to run 3.0″ 27+ as well as 29″ stuff. To make this work, Salsa added a 130mm fork, up from a 120mm fork, to keep the BB out of the dirt. There is no adjustable ‘flip chip’ option to tune either the BB height or head tube angle if I were to swap wheel sizes. Is this a big deal? Not sure, but I am working on finding out.
But lately there have been two bikes that are even more interesting. The new Trek Fuel EX 27.5 Plus (honestly, it should have had a new name) and the Pivot Switchblade. The Trek is what I expected to see revealed at this last Sea Otter, but we were shown an FS Fat Bike instead. The Trek is a 140/130mm bike with slacker angles in the 66-67° range (depending on the shock link setting) and will accept a 29″ wheel and up to a 2.4″ tire. So you would have the same travel fork and the ability to raise or lower the BB height and adjust the HT angle around the wheel choice…or not. Up to you.
The Pivot Switchblade is yet another bike in this trend, but it has some unique features. They do not have a ‘flip chip’ to adjust geometry, but rather use a spacer at the bottom headset area to get the front end up or down as desired. They also have room for bigger than 3.0″ 27+ tires, and still have very short stays, due to the use of a new 157mm wide rear hub that allows for a 6mm space-out of the cassette. This is an open standard, so there will be some options as time goes by, requiring cranks to match the chainline, etc.
I have also seen the Specialized 6Fattie and one other bike that is a secret (not from the Big S) yet to be revealed that is 150mm front and very slacked out in 27+x2.8″.
And of course, there is the recently announced Rocky Mountain Pipeline 27+ bike in long travel, which is pointed at the most aggressive trail conditions the majority of riders would encounter.
It is interesting to see how the lines are being drawn. Some bikes go way out of their way to run both wheelsets, and some go way out of their way not to. I am not sure how to think about this, what will win out, but I can see a time when there are no 29er or 27.5+ trailbikes, only a trailbike/enduro bike that just IS. And it will run whatever, except for truly wide Plus rubber, and handle 29″ or 27.5+.
27.5″ non-plus as a trailbike application will likely fade and fade and fade till it is only for the most aggressive of bikes.
Or…29″ loses even more ground as 27+x2.8″ becomes the new, basic trailbike we will all be riding in a few years. Normal 27.5″ could never achieve this, but 27+? It might. As one very wise tech editor of one of the biggest sites out there said, “it (2.8-3.0″ tires) is the size that MTB tires should have always been.”
Either way, bikes are getting shorter with sub-435mm stays and 130-150mm forks. The dedicated 27+ rigs seem to be running longer forks, and those who ‘cross-dress’ seem to be settling in at a 130-140mm front. Top tubes are getting longer, stems shorter, and bars wider than anything I rode over the last few years. 67° front ends angles are now common, even in 29ers that are not dedicated AM bikes.
It is a bike geometry that is very fun to ride, giving up little in overall efficiency, especially since the new suspension designs are so darn good pedaling. It is a fascinating time to be in the mix of this, with so much going on. What it will all fall out to look like in 5 years is even more of a guessing game.
Thanks – I appreciate these roundups a lot!
GG happy to speak with you about plus options. The Trek Fuel EX was very good and the new Mojo 3 is fantastic now that I have six or seven rides on it.
Thanks for the nice thought on 27.5+ vs. (+?) 29ers. I’m glad to see more cross compatibility between these two wheels flavors, but I would like to see room for 2.6″ – 2.8″ 29er tires in these bikes, rather than the 2.4″ tires that I can already run in my trail bike. I know that 29+ is not growing, but I guess I don’t even think of 2.6″ – 2.8″ as being really a plus tire — it’s just barely bigger than what I am running now (2.5″ front, 2.4″ rear).
Also, somewhat surprisingly to me (in a good way), we have seen a number of 29″ trail bikes released recently, such as Evil the Wreckoning, YT Jeffsy, etc. These trail bikes give me hope for the continued development of trail and AM 29er’s, and associated components (lower range gearing — SRAM Eagle, stiffer forks for big wheels — Rockshox Lyrik, etc.).
Also, though you may have been disappointed by Trek featuring their 27.5″ suspension fat-bike, I was really excited by it and surprised as well!
I know you can’t mention EVERY +FS out there, but don’t forget the Santa Cruz Hightower. Available in 29 or 27.5+, uses a shock mount chip to keep geometry numbers close to the same.
Just tried 27.5+ wheels and tires on my Santa Cruz 5010 v2 and they fit. Barely…
But now I really want to run this setup for winter riding.
(Our shop has a Hightower so it’s the wheels from that bike.)
I love the Hightower as a 29er, but I see where Ibis is going with the mojo 3- I liked the feel of my 5010 with plus tires slightly better. I hope to see some more 2.6-2.8 tires with smaller diameter on the market. Nobby Nic 2.8 seems like the best option at the moment.
Having spent several years on 29ers exclusively, I have to say I like my 27.5 130mm trail bike better than any of them. It’s not a more capable bike, but it’s s more fun bike to ride. It responds faster to rider input and feels more playful. It’s stiffer and more precise. It takes a bit more finesse to negotiate technical sections which I really like.
I’m riding technical terrain but not big mountains. I still prefer 29″ for my SS hard tail.
I would also still reccomend a 29er to most riders… but I can see plus bikes starting to change that. It will be interesting to see if more companies follow ibis, or if the market goes towards 29/27.5+ bikes as the dominant model.
As always, thanks for the insight and great writing!
Suspension theory and geometry aside isn’t the + designation really about the ability to run as low a psi as possible for your terrain and riding style and the benefits thereof without going to a true fat? Personally I think that wider i30 or more rims have as much to do with the ability to achieve this as wide tires.
I have been successfully running 2.3 tires (that I previously could only get away with 26psi on i20ish rims) on 700c i35 rims for about 2 years now in the 15psi range. Great grip and small bump compliance and as much flotation as I need for a front setup. I have found I do prefer a wider 2.8/3.0 tire, on a 650b i35 rim, in the rear though after some comparative riding sessions.
My bike is a hardtail 29″er with a front shock and I am not a very rad rider but do seek out tough trails so YMMV.
My time has finally come! I did a great deal of experimenting with tire sizes over the past year and 29ers are dead to me here in CT. I’ve converted a 2012 RIP9 and a 2015 WFO to 27.5+ and through trial and error ended up with a Banshee Phantom as my current bike.Adjustable wheelbase!Adjustable BB height!Cane Creek shock!Long reach!Short chain stay!67 degree head angle!120-100 travel!
I’ve found the current crop of 27.5+ bikes to have a BB height around 13.25 inches and if your plus bike is long travel it’s a recipe for pedal strikes. Banshee unknowingly set there bikes up as the perfect conversion bike. So much so that I’m running my Phantom as a 29+ with 650 dropouts because I had a 35mm 29er wheelset and I had to give it a try. The current BB height set in the low setting is 13.75 inches and the bike rides great. Odds are it will end up 27.5+ but I had to try it out. BooYaah!