Might wanna grab a fresh beverage before starting in on this one: It is verbose.
I got my first taste of 29+ full suspension back in July of 2013. It was eye opening, in many ways. The Knard tires were sub-optimal for our local trail conditions and no one had yet delved into what geometry tweaks would allow us to get the most out of *any* 3" tires. This is said bike, on Andy's trail near Grand Junction, just before sunset on that July evening 5 years ago.
Despite those rather glaring drawbacks, plus the fact that there didn't yet exist a fork that could readily take 29+ rubber, I loved the concept and knew that it would figure prominently in my future. We just needed to start chipping away at turning the problems into solutions.
Along the way we've gained fork options from all the major players with travel options from 80 up to 160mm, while tire choices have gotten better and more numerous by leaps and bounds: Many tread options, many casing options, almost exclusively tubeless ready.
With fork and tire options aplenty, what was left was to sort out frame geometry. Before you can understand where you're heading you need to define where it is you want to go. Back in 2015 I wrote this WRT 29+:
Will this morph into a big-hit bike to replace the LunchBox? Will it shine on all-day techfests, or will multi-day bikepacks prove to be it's raison d'être? Can this genre transcend silly marketing boundaries and become a true quiver killer?
The truth is we just don't know yet: The jury is and will be out for a bit -- lots of variables to pin down.
My answer to the above rumination is that I both want 29+ to be a quiver killer, and I believe that it has arrived at that place. In the intervening years I've experimented heavily with myriad combinations of fork travel, frame travel, frame geometry, rim width, tire casing construction, and, of course, tire pressure. Each iteration was ridden bunches on the types of trails that matter to me. I wasn't able to find a truly bad or even average combo, but I definitely found certain preferences along the way.
It isn't surprising to note that I've settled on preferring a 5" bike, give or take a few millimeters. The bulk of riders nowadays are in that same range for everyday riding, mostly because it's adept at such a wide range of tasks.
At some point I decided to take a step back and color outside my own narrow lines a bit by experimenting with a carbon chassis. The Farley EX is a FS fatbike by design, but I couldn't see a good reason *not* to stick 29+ meats into it and give it a whirl. I knew going in that the geometry was far from my ideal, and that was proven out immediately and repeatedly. What I couldn't have predicted was how much I liked, even preferred, the muted trail feel of the carbon chassis. Below it's pictured with 27.5 x 3.8" tires, but it easily fit and was fun to ride with 29 x 3" too.
Given enough time to think about a project -- say, over the course of a northern hemisphere winter -- it is not remotely surprising that I found myself flinging out emails to prospective builders. The goal: To improve the genre, of course. Specifically, I wanted to try a different frame material and to tuck the rear center tighter than had been done before. The result -- the Waltworks Braaap pictured immediately below -- can be read about in some detail here with additional photos here.
Within a week of receiving the Waltworks Trek released their new Full Stache -- a bike that targets the same short rear center goal while also using 29+ tires. I hadn't planned to buy one, but seeing how close the numbers were to Braaap I simply had to know how they'd compare. So after briefly demoing my friend Greg's I sourced a frame and built it the way I'd want to ride it.
As you'd expect, I've ridden them bunches the past ~month, all on the same trails where I've been riding the various other 29+ FS sleds I've owned for years. Which gives me a pretty good basis to compare what's currently out there and available in this genre.
My goal here was not in any way to do an exhaustive iterative test to prove which was the bike to end all bikes for every person everywhere. There is no such animal -- we all have different preferences and tolerance for compromise. I just wanted to ride all three on my home trails, comparing them directly to each other in as similar a fashion as was reasonable, in an effort to determine if there were substantive differences in geometry or suspension performance. And then to think about those differences, if any, in terms of what makes the most sense for me, living and riding where I do and how I prefer to.
These days you can go to Outerbike or fat tire festivals and demo lots of bikes, on trail, on the same weekend. But they never have 29+ FS bikes and few of the demo venues have much in common with my backyard. So effectively I created my own demo day which, admittedly, cost a lot more. It also lasted a lot longer, happened in my own backyard, and allowed me to fine tune each bike to my preferences.
In addition to tweaking the suspension on each chassis to match my preferences *before* I started thinking about all the other things happening, I also fine tuned the position to the Nth degree. All 3 bikes used the RockShox Pike up front and I ran all 3 bikes with 130 and 140mm of travel before settling on 140. All were fine with less, all were better with more.
I experimented with carbon and aluminum rims, steel and polymer spokes, and many different tires on each bike. These are all known quantities to me, and while they *do* affect the overall ride (and weight) of a bike, they weren't the focus of these sessions.
Without further ado, here are the conclusions I drew from comparing the Trek Full Stache, Waltworks Braaap, and LenzSport Behemoth 29+.
The Trek's rear suspension feels incredible. Might be the best overall stock setup (not just with 29+, but across the spectrum of bikes I've ridden, ever) I've ridden when factoring in the big picture of top end suppleness, mid-stroke support, and end stroke ramp. Cannot be overstated how good it is. I think that's the benefit of a big-box player coming to the table -- they buy such volume that they can ask for, and receive, custom valving mapped to the particulars of the chassis.
The Trek's overall geometry feels good. I like high BB's so I flipped the Mino to high and stretched the fork to 140. This resulted in a very neutral, natural feel for me, where I live and ride. I wouldn't argue with another 1/4 or even 1/2" of bottom bracket height, but for a stock bike it was really good.
The Trek's frame weight *really* surprised me. 8.2# including shock, seat collar, and rear axle. Gulp. You'd need close to five figures and a few tricks up your sleeve to get this bike under 30# without giving up wide rims, competent 3" tires, and a dropper.
Rear end flex surprised me. I don't think of myself as particularly picky when it comes to that metric, but I can't *not* notice it. I've rubbed the tire on the chain many, many times when climbing, cornering, and descending. Not just when the chain was in the big cog, either. Some of this is because I run my ring flipped inboard to bias the chainline toward the (friendly) gears I spend the most time in, but even with the ring flipped out and no buzz happening I still notice the wiggle when bursting up a stinger or slamming into a corner. I don't take myself so seriously that I think this matters in the overall, I just find it unsettling when it happens. Feels like the tire is low on air or the thru-axle is loose, even though neither is true.
Braaap's strength lies in it's ultra-short chainstays. 410mm with a 29 x 3" tire is mind-bending. All that traction combined with all that suppleness. The bummer is that I'm so old and so weak, because I can't begin to get every ounce of performance out of this bike. It begs to be climbed like a singlespeed: Out of the saddle, hammering and slobbering away, cleaning the steepest, most technical pitches imaginable. It is a league apart from any other bike I've owned when it comes to steep, technical climbs: The harder they are, the better it is. And then once you crest the top you can either choose to get low over the front end and carve the shiznit out of corners, or sit back and manual, hop, and pop over everything. The geometry of Braaap is incomparable to anything else that exists in Plusland, and better than 99.9% of the rest of what's available, too.
The top-end suspension feel on Braaap is a bit harsh when compared directly to the Trek -- think riding both back to back on the same trail on the same day. Ride them a day apart and that difference is minimized. When I find some time I'll undoubtedly be pulling Braaap's rear shock apart to figure out how to better the top end, which might include switching shocks entirely.
Weight on Braaap was almost identical to the Trek -- less than one ounce lighter.
Straight out of the box I was able to rub the tire on the chainstay yoke when bursting -- out of the saddle -- up a steep climb with good traction. Walt recognized that he might have chosen anemic dropouts, so I dropped it off at his place and he beefed up said dropouts. I didn't bother to re-weigh the frame but I'd guess that he added 2-3 ounces of steel overall. And in so doing more or less eliminated rear end flex from this frame. Since getting it back I've been able to rub the tire to the yoke twice. Both times were in very high traction/very high body english situations -- scenarios that I don't encounter every ride. Is tire rub once every 4-5 hours of riding a problem I need to be concerned with? Especially given how awesome this chassis feels? I'm still ruminating on that. As Walt has said himself, "Maybe 410mm chainstays is flying a hair too close to the sun". Maybe, but damn it feels good up there.
The Behemoth is the 29+ chassis that I've spent the most time on. I've had some small part in it's development through the years, largely because Devin Lenz is an old friend, but also because we share a similar philosophy on how bikes are supposed to feel and we have similar trails on which to ride them. If I have an idea on how to improve something he usually listens. If he has an idea I'm usually cutting him off and saying "Take my money!" before he can finish.
Probably the best way to start describing the Lenz is not with what it does so much as what it doesn't: Meaning, it doesn't flex and it doesn't weigh -- at least not compared to the two bikes above. I am sure there is someone out there strong enough to touch tire to frame or chain when bursting up a steep, grippy climb, but I haven't yet been able to do it in *years* of trying. That fact might be especially noteworthy given that the Behemoth weighs 6.8# with rear shock, seat collar, and rear axle. Lightest *and* stiffest of the bunch.
I can't say that I notice the heft of the Trek or the Walt when pedaling, but I really notice both when I need to pick the bike up or carry it for any reason. I can't say the Lenz feels any lighter when pedaling, but it seems substantially so -- again -- when I need to heft it. Perhaps the real takeaway is that it's been too long since I've lifted weights?
On the trail the Lenz has the most neutral, composed, predictable feel of the three. The geometry is quick but not overly so. It is stable but not ponderous. It can be manualed through chunk at will, hopped with a hip snap and set down *exactly* where needed, or -- if you're going so fast that you've run out of talent -- just hang on and plow. The suspension doesn't complain, doesn't seem to necessarily mind nor reward any given riding style. Of the three being discussed here it holds the middle ground of not doing any one thing exceptionally well, but doing everything well enough to not get in the rider's way.
Scorecards are stupid.
If sporty geometry is the most important thing to you, Braaap.
Want the most composed suspension feel? Full Stache.
Want a good blend of both, with less weight and no flex? Behemoth.
I'm happy to answer questions on things I've inadvertently omitted.