Photo: WTB

Every couple of years a new trend pops up in the bike industry and presents new benefits to the masses. A few years ago, this trend was plus-tires. 29ers were sort of new again, but still stigmatized as the wheel size for people who cared more about climbing than descending. 27.5-inch wheels had basically convinced everyone that they would be here for good. Oh yeah, and fat bikes were also emerging around the same time.

Looking through the Singletracks’ archives, most of the publish dates around plus-tire related topics were in 2015-2016, ranging from tire reviews, to press releases for new tires and plus-tired bikes. Five years later in 2020, it seems that plus-tires were quickly forgotten by most mountain bikers.

Greg Heil testing a Scott Spark Plus back in 2016. Photo: Devon Balet

Around that same time, in 2015 and 2016, other interesting things were happening in mountain bike technology. As mentioned above, 29ers had somewhat of a renaissance, 1x drivetrains were taking over, and engineers were dedicating more time to the larger wheel size. At the time, 140mm 29ers were considered “long-travel 29ers”, and 27.5-inch was pretty much standard for park and enduro bikes.

If we again looked through the Singletracks’ archives at press releases and reviews from 2018 and 2019, we’d notice another trend: a lot of information on long-travel 29ers. Now, 29er enduro bikes and 27.5+ couldn’t be more different in their applications, but both of the trends’ decline and rise have a strong connection.

When plus-tired bikes debuted, brands marketed them in a number of ways, whether it was for bikepacking, more traction, combining the attributes of 27.5- and 29-inch bikes, or maybe the most accurate of them all: for “dumbing down” the trail.

Plus-bikes were more widely adopted by entry-level riders because of the confidence they offered on loose or technical trails. By widening the footprint underneath the wheels, riders were less likely to skid out in a corner or lose control on a gravelly descent, though the added traction came with its tradeoffs.

“With plus-bikes, it was poorly executed. The tires were big, so they needed to make them light,” says Eric Francis, owner of Pedal Pushers Cyclery in Golden, Colorado.

“It worked really well for a beginner to ride, but when you stick more advanced riders on them, you’re destroying tires or pinch-flatting them left and right.” For those who rode harder, that meant trying to find the right pressure, which could be tricky. “For me, I always felt that if the pressure was a pound or two too high, then I would radically ricochet off of things.”

The Terrene Chunk Plus tire. Photo: Chris Daniels

Every now and then, Francis gets someone coming into Pedal Pushers and asking about plus-tired bikes, but it isn’t often. Tire brands have seen them decline into a few small applications also, namely on hardtails, for a more forgiving ride and when race-speeds aren’t a consideration.

Salsa Cycles is a brand that was strong on the plus-tire wagon, and still has one of the widest offerings of plus-tired bikes, or bikes that are interchangeable with 27.5+ .

“First, it’s about providing our customers with the flexibility to choose the wheel and tire size that is most appropriate for their terrain and riding style,” says Justin Steiner, brand manager for Salsa. “Some folks like 29” wheels, others prefer 27.5”+ and some terrain rewards one wheel size over the other.”

The other half though is just making it an option since it’s already compatible with the design of the bike.

“Secondarily, 29” and 27.5”+ wheels and tires drive very similar design requirements, so we’re able to offer riders choice in wheel size without sacrificing the performance of either.”

Still, Salsa is seeing consumers that are more interested in its 29er models over 27.5+.

“In the Timberjack hardtail line, we’ve seen a consistent shift in momentum toward 29” wheels,” says Steiner. The Timberjack is an entry-level hardtail starting at $1,250 and available with either 27.5+ or 29-inch wheels.

“In 2019 approximately 75% of Timberjacks were 27.5”+, while the 2020 forecast is trending closer to 50/50. In terms of full suspension [bikes], we’ve seen a much more pronounced shift toward 29” wheels.”

The plus-tired version of the Salsa Timberjack. Photo: Helena Kotala

That shift could be explained by the fact that 29ers offer similar confidence in terms of traction and rollover capability to plus-tires, but the tires tend to be sturdier and less novel.

“I think the real nail in the coffin for the 27.5+ were a few things that culminated in its death,” says Francis of Pedal Pushers. ‘The 29×2.6″ came out, and 29ers came into themselves at the same time.’

When 1x drivetrains pushed out 2x drivetrains, engineers could remove the front derailleur from a frame’s discussion altogether. This allowed them to shorten the chainstays, which 29er wheels would have otherwise interfered with, and by widening the chainstays with Boost spacing, and steepening seat angles, they could be shortened even more.

“29ers got playful,” says Francis. He remembers riding early iterations, when geometry was unrefined, and limited the capability of the wagon-wheeled bikes.

“They were just garbage. They did nothing but go straight. They had no playful aspect to them whatsoever. You were pretty much relegated to flat, cross-country style riding.”

For Pedal Pushers Cyclery, the 29er has been so good in the past couple of years, Francis says he has a hard time even selling 27.5-inch mountain bikes anymore.

“In this store in particular, I’m almost all 29. I can’t give a 27.5 bike away.”

He has large and extra-large models marked down by 30%, and visitors still don’t seem interested. Instead, he gets a handful of people every day that are interested in his best-selling bike ever, the 29er Ibis Ripmo.

California-based tire brand WTB has also seen a decline in 27.5-inch sales, in favor of 29er tires. Currently, their most popular tire diameter and width is a 29er, in a 2.4 or 2.5-inch width.

“What we refer to as mid-plus or tires between 2.4 and 2.6 inches in width are becoming the new normal and what are selling the best,” says Johannes Huseby, the director of global OEM sales for WTB.

Plus-tires have peaked and declined for WTB, and Huseby says that about 90% of their sales are for 29ers now. Huseby sees what brands are selling first-hand, and the forecast in his perspective, includes more 29ers.

The author testing the 170mm travel 29-inch Rocky Mountain Slayer. Photo: Hannah Morvay

Even though 29ers look like they’ll now be the bigger wheel size in every which way, that doesn’t mean that bike brands are eradicating 27.5-inch bikes from their lineups.

“Momentum is swinging in favor of 29” wheels across both hardtail and full suspension categories,” says Steiner, of Salsa. “That said, I believe 27.5-inch bikes will have a place in the industry for the foreseeable future. Bikes with 27.5-inch wheels deliver a lively and playful ride compared to their 29-inch counterparts, largely due to facilitating shorter chainstays and, often, shorter overall wheelbases.”

There’s also the fact that some brands cannot make a 29er small enough for shorter riders.

“Additionally, 27.5-inch wheels allow us to offer an XS size for smaller riders. We’re simply not able to package 29-inch wheels and offer dual water bottle fitment on the Spearfish and Horsethief.”

The answer is even more interesting for Santa Cruz. In 2019, they updated the 29er Tallboy, and Hightower, and introduced a long-travel 29er, the Megatower. They were also one of the first brands to bring a 29er to World Cup downhill racing, and Greg Minnaar was the first person to win a World Cup round on 29-inch wheels. The California-based brand now has four models exclusively available in 27.5-inch, six models exclusively available in 29-inch, and the V10 DH bike is available in both.

“As for wheel size, 27.5 is still really popular. Like, really popular!” says Santa Cruz brand manager Seb Kemp. Kemp said that although they have been remodeling and introducing 29ers more frequently than the 27.5-inch bikes as of late, the 27.5-inch bikes are usually their most widely selling models, although that figure can change.

“Both (and all) wheel sizes have their benefits. Generally speaking, how we look at it is 27.5 is the fun sized wheel size, 29 is great for speed and confidence.”

Santa Cruz has also done really well with the “mid-plus” 2.6-inch wide tire for their 27.5-inch bikes. The Bronson, 5010, and the new Heckler have options to come with 2.6-inch wide tires front and rear, although the full-suspension 29ers do not.

What’s clear is that 27.5 is still going to be in the picture for a while, even if it’s only in the corner of the frame. 29ers are now more popular and anecdotally, offer more confidence, and are becoming increasingly more playful and agile, even when they are beefed up with six-inches of travel. But, who knows, the bike industry’s mind is never made up.

“Cycling is a fashion industry,” says Steiner. “Right now, 29-inch wheels are fashionable. In a couple years, we’ll collectively re-discover the fun and responsive ride of 27.5-inch wheels and momentum will shift back to a balance point. I do not believe 27.5-inch wheels will suffer the same fate as 26-inch wheels have.”