Ending The Debate: 29er vs 650B (27.5") vs 26" Mountain Bike | Bike198

With the widespread adoption of the 29er mountain bike in manufacturing and the mountain bike community, the growing debate of 29er vs. traditional 26″ mountain bikes is getting hot amongst riding groups. If you are in the market to upgrade your current mountain bike or get into the sport, your options are wider than ever which is a good thing for the sport but can be debilitating when looking to purchase a new rig.

Due to recent changes in the industry, the 650B mountain bike platform (also known as 27.5) has been growing in popularity. This article was originally written in 2011 and has now been updated to include the 650B wheel size. You can see the addition down below.

There is no “right answer” for every mountain biker, so let’s take a look at the 26″ vs. 650B vs. 29er mountain bike debate and see where it shakes out in my opinion. This topic is probably the most debated in the industry, so you will find that every rider has what they think is the right answer for you (typically what they bought).

The 29er Mountain Bike: What is the big deal?

Before we get into what will work best for you, let’s take a look at this larger wheel size and see how it affects the mountain bike in a general way.

What does a 29er do well?

  • Rolls over rocks and roots easier due to the wider circumference.
  • More distance covered per pedal revolution.
  • Higher air volume in tires smooth out ride.

The larger diameter wheels of the 29er mountain bike can create the sensation of having an 1″ more travel than the bike is spec’ed due to the larger air volume and larger contact patch with the ground. For this reason, it has become the go to size for much of the hard tail and shorter travel mountain bikes in the industry. The racing world has really embraced the larger wheels size for these benefits it brings to the trail.

What are the drawbacks of a 29er?

  • Large size equals larger weight.
  • Harder to maneuver in tight, twisty single track.
  • Longer travel (5.5″ and higher) 29ers feel REALLY big.
  • Sizing and geometry issues with smaller riders.
  • Larger radius needs stiff wheel build and fork to prevent deflection.

Just as with any big change, it is not all good news. While the true 29er zealots will probably tell you these things are not true, the reality is that you are adding bigger wheels to the mountain bike than traditional 26″, so there are going to be negative side affects that go along with the positive changes.

650B Mountain Bikes: What is different?

The 650B wheel size literally cuts the difference between the 29er and 26 wheel size in half at 27.5″. When you think about what the 650B platform in mountain biking does, it is actually pretty easy. It averages the strengths and weaknesses between the two sizes. You get some of the benefits of 29ers without the size and you get some of the nimbleness of 26 while increasing the ability to roll over objects.

What does a 650B (27.5) do well?

  • Rolls over rocks and roots easier due to the wider circumference over 26″.
  • More distance covered per pedal revolution.
  • Higher air volume in tires smooth out ride.
  • Brings a bigger wheel size to longer travel platforms.
  • At this time, 650B based frames, forks and tires are hard to come by (but that is changing quickly)

What are the drawbacks of a 650B?

  • Large size equals larger weight but lighter than an equivalent 29er.
  • Sizing and geometry issues if you are going to try to convert your 26 to 650B.
  • Larger radius needs stiff wheel build and fork to prevent deflection.

26″ vs. 650B vs. 29″ Wheels: Which is right for me?

When you are taking a look at the 26″ vs. 650B vs. 29er mountain bike, there are several personal questions you need to ask yourself as you make your decision. As with all things, there is no right answer that fits all people. How you ride your bike and how you want it to react is the most important factor when making this decision…not what your friend bought and says is the best.

So here is how I see it shake out…

How tall are you?

As the distance from your head to the ground increases, the 29er wheel size actually becomes more proportional to your size. Riders in the 6 foot and up crowd that are looking for a XC to light AM mountain bike should test ride a 29er just to see how they like it. You might find that it fits perfectly and you have finally found a bike that feels like it actually fits. Shorter riders in the 5’6″ range and lower will need to take a serious look at geometry and test ride different frames as they might find the bike feels too big or isn’t able to maneuver as well. I have known shorter riders that have loved the bigger wheel size, but that is typically in hard tail applications.

The 650B wheel size does an interesting thing in this situation. It can bring that proportion that the taller riders see down to mid level height riders in the mid 5 foot to 6 foot range. It can also bring a 29er like experience to shorter riders that are used to riding small bikes.

  • Taller Riders: Yes on 29er and 650B
  • Mid Height Riders: Yes on 29er, 650B and 26
  • Shorter Riders: Maybe/No on 29er; Yes on 650B and 26
How much travel are you looking for?

While the argument that a 29er “adds an inch” of travel is almost true in theory, there is a big difference in 140mm forks and 160mm forks in mountain biking. The thicker stanchions and construction make a huge difference for riders looking to get into the more technical side of riding. If you are in the market for a 140mm or 160mm travel mountain bike, a 120″ travel 29er is not going to give you that same stiffness and confidence from a bike build and component standpoint. Also, as you move up in travel the bike feels bigger and when you add in the larger wheel diameter, that gets multiplied and can hold you back in slow tech and DH situations.

However, if you are looking at lighter 130mm to 140mm travel 26″ mountain bikes and you are taller, the 120mm travel 29er might be a great option. It will roll over technical rocks and roots on most single track easier and you will still be able to keep the overall bike weight under 30 pounds in most cases.

The 650B platform is bringing thicker stanchion, longer travel forks to the bigger wheel market. It is almost as if 650B wheels were made specifically for “enduro” style riding.

In the short travel and hard tail mountain bike market, the 29er mountain bike has almost completely taken over. This recommendations are used in conjunction with the height recommendations above.

  • HT and 100mm travel and under: 29er or 650B
  • 120mm to 130mm: 29er or 650B
  • 140mm: 650B (27.5) or 26″
  • 150mm to 160mm: 650B (27.5) or 26″
  • 160mm+: 650B (27.5) or 26″
What type of trails do you ride?

As mentioned before, 29er mountain bikes do take more to maneuver through tight single track. If all of your riding is filled with tight turns in trees, you will want to try out a 29er on your own local trails before making a decision. On the other side of the spectrum, if your trails are more open and rocky, the 29er wheel size can really excel and bring more speed as you can hit sections faster.

Do a lot of racing and forest service road riding? A 29er is almost a no brainer in those situations. If you don’t believe me…just try to keep up with a 29er rider on a FSR. This adds up with the shorter travel and hard tail mountain bike market. Even 650B bikes will be no contest for a short travel 29er in these situations. If you are looking for a bike that will do a lot of things well and you ride a wide variety of trails (assuming you can only own one bike), the 650B platform might be a great “do it all” option.

  • Tight and twisty: 26″ and 650B
  • Open and rocky: 650B and 29er
  • Racing and FSR: 29er

What do I personally use? 29er or 26″ or 650B?

When I spec out my personal mountain bikes given trail conditions, this is how everything lays out for me personally given my specs. I would describe my riding style as technical/enduro. I like to find the nasty lines possible and make them ridable at speed. For this reason, I typically like to ride mountain bikes with big forks and more travel, but I also like to dip into the XC and race side every now and then as I have a background in those applications. At 6’1″ tall, I fall into the taller side of the sizing spectrum in between large and x-large. To fit my need to find all tech riding, I am on large size mountain bikes to keep the bike easier to move in slow tech.

  • Singlespeed and Hard Tails: 29er
  • Short Travel Race Bikes (100mm and under): 29er
  • Trail bike (140mm and 150mm): 650B
  • 160m+: 27.5″

As of right now, I have not found a 29er mountain bike that has been able to handle what I want to throw at a 140mm travel or higher mountain bike. It has not been agile enough and the 32mm stanchion forks mated with higher radius wheels are not built to withstand the abuse. Given the specs of 29ers, I do not see this changing for me as a rider.

On the shorter travel end, there are a lot of advantages of the larger wheel size that have made a couple of 29ers the fastest bikes I have ever ridden for those applications. I doubt if I will ever go back to 26″ wheels for anything under 140mm worth of travel. The 650B is almost completely tailored to the largest percentage of my riding and brings a larger wheel size without compromises to my ideal travel range at 140mm to 150mm. I get the benefits of a larger wheel without having to sacrifice geometry or stiffness of components. While 26″ would still be the choice for dedicated DH rigs, 650B is taking over trail bike duties while 29ers take up the XC side of things.

What is the right bike for you?

As you take a look at all of these specs, you have to look inward at your body type and riding style to see which wheel size will be the best option for you. There is no right option for everyone and the 29er wheel size is not going to take over the mountain biking industry like a lot of the Kool-Aid drinkers are trying to say. The larger wheel diameter does have some serious advantages in certain situations, but it also does not work for others.

The best option…test ride your top 26″ candidate on your local trail and the top 29er candidate if they are available. I would also swing a leg over a 650B bike to see if that platform works for you…especially in one mountain bike quiver situations. Although, at this point in time, that demo might be hard to line up.

If they aren’t, find the closest substitute. At the end of the day, you are the one making the investment in your mountain bike and you will be the one riding it…not everyone else that is trying to inject their opinion in your buying decision. There are a lot of riders that are going to scream that one platform is better than the other. The reality is that all riders are different and that is why we have so many options. Take an honest look at how you use your bike and what body type you are. This is the only way you will get the right wheel size for you while trying to ignore the fanbois.

2016 Update – The Death of the 26″ Wheel

As of 2016, the 26″ wheel is seeing its way to the “remember when” category. 27.5″ wheels have essentially taken over that market to the point that you rarely even find a 26″ tire on a long travel bike. We’ll now just refer to the 26″ tire as the size dedicated to Walmart bikes. With 27.5, 27.5 plus and other new standards, the 26″ wheel is officially dead.