650b, 27.5″, ‘tweener: no one can decide just yet on what to call the newest wheel size to enter the mountain bike mainstream (though it’s actually an old wheel size). I’ll stick with 650b (at least for now) just for the sake of taking a stance.
The 650b wheel may be a godsend for many riders, whether they’re tall, short, hucker or racer. For many short riders, finding a 29er frame that fits and still handles well is a challenge, never mind the complexities of adding rear suspension in already tight quarters.
Many tall riders still have a fondness for the quick handling and light weight of 26er wheels and have avoided 29ers so far. With the 650b, the intrigue of better obstacle rollover and increased traction may prove to be too hard to deny for these riders.
For gravity riders, the larger wheel has all the same benefits stated above and manufacturers can still easily build long travel bikes around 650b wheels.
I’ve been eager to ride a 650b bike for some time. When I walked out into the Press Camp expo area, the first bike that caught my eye was the Turner Burner. I’ve always heard good things about Turner’s suspension designs and attention to detail. When I made a beeline to the tent, David Turner was there himself to discuss the bike and he personally set it up for me.
Now I normally ride cross country style bikes. A 100mm travel 29er is typically my sort of bike. But there’s no denying that a bit more travel can be more fun (especially when you’re in Park City). The Burner is a 140mm travel (front and rear) 650b trail bike.
The beauty of this bike, with its 140mm travel front and rear, is that both all-mountain and cross country riders will see potential for a great bike. Build it up with an upright position, a dropper post, a set of bomber wheels and powerful stoppers and you have yourself a bike ready for everything but the biggest lines on many trails.
Invest in a 2×10 group, some lightweight hoops, smaller rubber and slam the stem and you have a great endurance racer/fun bike to compliment your stable.
The Burner is still four to five months from production and Turner debriefed every rider that took one out for a ride on how it handled. For my tastes the bottom bracket was a bit low and I should have flipped the stem to get closer to my preferred XC position. But on the trail, both going up and coming down, the Burner is amazingly composed and yet still flickable.
The Rock Shox Revelation 650b fork has a roomy 140mm of travel and a Maxle thru-axle. I toyed with the compression settings (locked, climbing and open) while I tooled around the expo. But I left the fork on its plushest setting the entire ride as there were few steep uphill sections that required a lot of standing.
The dw-link rear suspension on the Burner worked its magic, isolating pedaling input while keeping the rear wheel active. The rear Monarch piggyback shock was wonderfully active when flying through roots and rocky sections. I only locked it out once to make sure that it worked, then quickly returned it to the mid-compression setting.
To keep everything working well and nicely aligned, Turner uses a 142x12mm rear thru axle. Instead of threading the frame though, Turner has his own design for the derailleur hanger that acts as the nut for the thru axle, very clever and very replaceable. We can also expect to see Turner’s zerk stainless steel grease fittings on the pivots, making maintaining your suspension easier than ever.
The use of a 44mm head tube means you have plenty of options, whether you want a straight or tapered steerer tube fork. Though right now there aren’t too many 650b fork options, both Rock Shox and Fox have entered the segment, previously dominated by White Brothers.
Part of what made the Burner ride so incredibly well was the killer wheels on it. The Enve 650b XC rims (with Chris King hubs) and WTB Wolverine 2.25″ tires were perfectly matched to the bike’s capabilities. The light weight of the wheels made changing my line easy and flattened the climb noticeably. The traction of the Wolverines was good, with predictable cornering and low rolling resistance in a straight line.
SRAM XO 3×10 group is a great spec for a bike like the Burner. Having a granny gear and a large chainring is something that you don’t miss until you ride a bike with a triple again after time on a double ring crank. Fortunately, the smaller wheel size does mean that going to a 2×10 setup is easier than on a 29er if you do a lot of climbing.
If you can stand the wait, the Burner will cost $2,495 for the frame with a Rock Shox Monarch shock. Weight for a medium frame and shock is currently at 6.8 pounds. Turner’s personal rig (size medium) with a 2×10 drivetrain and Enve carbon wheels weighs 25.5 pounds; not bad at all for a trail bike with 140mm of travel.
Time will tell if the 650b wheel size will serve the needs of mountain bikers or just be an answer to a question no one was asking. But if Turner’s 650b creation is any indication, maybe it’ll only take critics one ride to see that the potential is huge.