27,5+ is it innovation or a way for industry to convince consumers to buy new bikes?
No buns intended but + tires have really blown up this year. Most of the buzz right now
centers on 27.5+. Because you can already squeeze 27.5+ tires into a lot of 29er frames out there.
Antte riding in Finnish Lapland with Santa Cruz Hightower with Surley Dirt Wizard 27,5+ x 3” tires. In this condition the + tires really shined.
On the beginning of the summer I was about to buy new 27,5” wheel sized mountain bike. The 27,5” or 650B wheel size is considered as a normal by todays standards. But as it turned out the shop from where I was about to buy it from didn’t have this specific bike anymore so I had to look something else instead. Santa Cruz bicycles had launched their new bike earlier on the spring called Hightower and it had sparked my interest.
Santa Cruz Hightower with Surley Dirt Wizard 27,5+ x 3” tires
This bike is designed around both 27,5”+ and 29” wheels. Before I hadn’t spent too many thoughts on the new emerging wheel size of 27,5+. I knew that it had the same inner diameter of 27,5" tyre but the outer diameter of 27,5+ tyre is somewhere close of an 29” tyre. The bike had got really great reviews and I decided to ”pull the trigger” on one and I bought the bike with 27,5+ wheels. So just like that I was riding on the + sized bandwagon with boost hubs and all.
On the upper photo Santa Cruz Hightower with Surley Dirt Wizard 27,5+ x 3” tires and on the photo below Santa Cruz Hightower with Maxxis Minion DFH 29 x 2,5” tires
First rides with the bike on the somewhat mellow home trails felt great. With the 27,5+ tires I had on the bike I
could just monster truck over rocky and rooty sections on the trails. They were also incredibly stable, grippy and for sure confidence inspiring. Have to say that one thing you really have to really pay attention to with plus bikes are the tire and suspension pressures, especially on dual-suspension models, because the two dynamically affect each other. All-tough the plus tires works as a suspension as well taking a way the small chatter on the trail it is still important to to keep the suspension supple. I can´t highlight the
importance of right pressure settings enough because specially on + bikes it can really make or break a bike. On my bike I have rims that are 40mm wide. Personally I wouldn´t go narrower than 40mm on + size tires. Although brands like Specialized ships some of their + size bikes with 30mm wide rims.
It was in our trip to Åre bike park - Sweden when the + tires began to fall short. There my riding got more aggressive and pick up more speed. Then I started to experience the tire roll and I punctured somewhat 4 tires during our stay there. The weakness of the system seemed to be the tall sidewall of 27,5+ tyre. The 27,5+ tires I had on the bike where Maxxis Ikon and Maxxis Rekon. Those tires both were 2,8” wide and weighted only a bit more than regular 2,35” wide 27,5 tyre. So obviously the 27,5+ tires must be made with thinner sidewalls to keep the weight down. Thin and tall sidewalls are prone to punctures and to fold over when ridden aggressively on a rough terrain. The tires should be really burly to not fold over and withstand the higher speeds on the rough stuff. Unfortunately this would also add up the weight of the tires.
Whit this special flip-chip on the Santa Cruz Hightower you can keep the geo somewhat same with both of the wheel sizes 29 or 27,5+. On the left it is on the 27,5+ position and on the right it is on the 29 position.
After the trip to Åre I changed my setup on the bike to 29” wheels and rode the bike like that for good amount of time. On the late autumn I decided to change back to 27,5+ tires and remembered why in the first place liked the + size feel so much. My home trails here in North Finland consists of rocks and roots and are still usually fairly slow paced. With the smooth feel of the + size tires it really is a joy to ride these trails and one can ride longer periods of time without stepping of from the saddle. What you get with really wide tires is extra floatation over rough terrain and, because the contact patch is so huge a great amount of traction.
I was bit of surprised by this comparison and the fact that how much smaller the outer diameter of the Surleys is when compared to Maxxis Minion DHF. Maxxis Minion DHF 29 x 2,5" on the left and the Surly Dirt Wizard 27,5+ x 3" on the right.
After riding both 29” and 27,5”+ wheels on the same bike during the summer. My opinion is that the 27,5+ tires are great for general trail riding, xc loops or even some bikepacking adventures. The traction that + size tires offers gives you great amount of confidence in wet and slippery condition and also on when there is some snow over the trails. When used with 29” wheels this bike absolutely crushes the downs and works great with more aggressive riding. Something about this bikes capability on the downs tells the fact that the Santa Cruz enduro team used the Hightower as their race bike on this years EWS (Enduro World Series). One of the ideas I had with this bike is that I use 29” wheels during the summer and 27,5+ wheels in winter when riding on my local snowy trails around the town. I will write more about that and how the 27,5+ performs on snowy conditions during the winter.
Over all I feel that there is some real benefits you can get with the 27,5+ tires and it is not just a gimmick. But when I want´t to ride on my local Enduro or Downhill trails I will change to my 29 inch wheels ( at least for now).
Antte enjoying the confidence on slippery conditions that the tracton of the wide tires provides.
At the time I´m writing this I just got the new couple of months ago announced Surley 27,5+ x 3,0” Dirt Wizard tires to my bike. In my opinion these tires are the first 27,5+ tires made for aggressive riding. They are also quite heavy, weighting in around 1300g each but the sidewalls feel really solid and thick. Unfortunately we are so late in the season here in the north that you have to wait full review of these tires until next summer. First initial impression of these tires is positive. On fast, aggressive and more downhill oriented riding these might the best 27,5+ tires you can get. But on the flats and more like mild to normal trail riding these are quite heavy to pedal and you would be better suited on some more lighter tires. Next year is going to be really interesting on the + size market when Maxxis and other major tyre brands as well are launching their ”agressive” 27,5+ offerings. Stay tuned.