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?

ibis cutWell 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.

pr cutThen 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.

1164600_2017_A_1_Fuel_EX_8_275_PlusBut 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.

switchblade-detail-13The 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.

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