Jamis Dakar Sixfifty B Pro: Thoughts About 650b Wheels

There’s been a lot of hubub around the interwebs of late about the potential explosion of the 650b wheel size. Much of the commotion is around the very substantial rumor that Fox and Rock Shox are both developing 650b forks, leading many to believe that several major bike brands will be rolling out 650b-specific rigs.

I’m not much into hype, but if something new is going to work, then it’s going to work. If it’s not… well, then it isn’t. Regardless, I want to make my own decision. The recent Southeast Bike Expo provided the perfect opportunity to get some hands-on experience with the 27.5″ wheel size.

Jamis Dakar Sixfifty B Pro

In order to get a feel for what 650b wheels can do, I headed straight for the Jamis tent. All the talk about big-name brands going 650b is still officially just rumor, but Jamis has been a supporter of the wheel size since at least 2010. When asked about the potential increase in 650b bikes, one of the reps I spoke with commented that they wanted to remain on the cutting edge of 650b technology, and plans are in place to roll out many more 27.5″ wheeled models next year.

Out on the trail, I had a ripping good time on the Dakar! With 5+” of travel, this ride was super plush and absorbed everything in its path. It was fairly nimble too, taking to the air with grace and returning to the earth with ease.

This Pro model was smartly kitted out with a full SRAM X0 2×10 group and a White Industries fork.

I wasn’t all that happy with the performance on the climbs, though. I’m not sure if I just needed more calories in my system or if the rear shock needed to be tuned better, but the Sixfifty B Pro felt rather sluggish going uphill, even compared to other 5″ travel bikes I tested that day.

I thought perhaps the build was just rather hefty, and off the top of my head I guessed the complete weight to be about 32 pounds. When I got home and checked the website, I saw that it actually tips the scales at a claimed 27.75 pounds.

Also, I found that I really had to focus to keep the front end from wandering on the climbs. It could have been a result of the cockpit not being set up properly for my body, since this was just a quick demo ride.

I would need to spend more time on this rig to really figure out what’s going on with these small issues. If Jamis is down, I’d love to have the opportunity to spend more time with this bike.

Comp model tested by trek7k.

Thoughts About 27.5″ Wheels

But how did the wheels perform?Well, you’re going to hate my response, but they performed exactly like you’d expect them to.No, seriously: they’re a perfect blend of 26″ wheels and 29″ wheels.

They roll over roots and smaller obstacles better than 26″ wheels but not as good as 29″ wheels.

They’re more stable at speed than 26s but not as stable as 29s. On the flip side, they are more maneuverable than 29s but not as maneuverable as 26s.

Actually, having spent a significant amount of time on both 26ers and 29ers over the past year, I really enjoyed the beautiful blend of stability and maneuverability in the 27.5″ wheel size. I love the stability of 29s, but sometimes they’re not maneuverable enough. I love the maneuverability of 26s, but sometimes they’re too twitchy. 650b blends both of those elements well.

According to one of the Jamis reps I spoke with, they think that 650b is the perfect wheel size for 5″ travel bikes (and up). There are obvious geometry issues with trying to squeeze 29″ wheels into a long-travel frame–650b may be the perfect compromise for the long-travel market.

Of course, with bikes like the Niner W.F.O. getting such rave reviews, their argument might not be quite as strong as they think it is.

What’s the Big Deal?

Not, “what’s the big deal with Jamis?” but rather, “what’s the big deal with Fox, Rock Shox, etc.?”

I’m really not sure why there’s been all this buzz surrounding the potential increase in the production of 650b bikes. The fact of the matter is, if you want to ride a 650b, there are already great 650b bikes on the market! Jamis produces several great bikes, and Haro and KHS also produce 650b’s.

Then there’s the issue of the fork. Honestly, who cares what Fox and Rock Shox are doing? Sure, they make great products, but White Brothers is already producing fantastic forks in the 650b size.

I’ve read negative reviews and I’ve read positive reviews of White Brothers, but I have to say, my experience on their fork this weekend was excellent. It provided smooth, predictable action with more plushness than you can shake a pogo stick at.

Bottom Line

Is another wheel size necessary? No.But does 650b offer a real difference in performance compared to both 26″ wheels and 29″ wheels? Yes.

In the end, as with most things, it’s all about personal preference. I would personally love to spend more time reviewing a 27.5″ wheeled bike, but I don’t know if I’d buy one at this point or not.

650b is not going to be for everyone, but if you think it’s for you, what are you waiting for? Try one out now!

Your Turn: What are your thoughts on the 650b wheel size?