Having heard a lot about the new 27.5 bikes over the last year I jumped at the chance to demo a Giant Anthem 27.5 Advanced 2 while in Durango, Colorado thanks to San Jaun Cycles. While I am by no means a cycle tech expert, below are a few of my thoughts and experiences from this ride.
For those who are not familiar with the 27.5 concept it is the new wheel size on the market. Mountain bikes have traditionally been built with 26 inch wheels, apparently out of necessity as this was the tire size of a ‘cruiser’ which was used on early mountain bikes and since then the size has stayed the same until recently.
Most people will be aware of the 29 inch wheel size that has made big changes in the world of mountain biking over the past few years. Now it seems we are in the depth of big wheel fever. With the 29er offering better control, traction, roll over and rolling momentum than the 26 inch alternative. On the other hand these bigger wheels compromise acceleration, frame geometry, frame stiffness, handling on tight single track and added weight compared to the old faithful 26er.
Enter the 27.5, often referred to as the ‘Goldilocks’ wheel size. ‘It’s not too big or it’s not too small, it’s just right.’ It combines the light weightiness, acceleration and manoeuvrability of a 26 inch wheel, with the roll over, traction and rolling momentum of the bigger 29 inch wheel. See below for a bit of an easy to understand run down on these aspects provided by Giant Bicycles.
All of this sounds good, but how did it ride?
I have ridden a 29er for the past 3 years and as soon as I jumped on the 27.5 it felt somewhat weird having smaller wheels. First impressions aside I headed out to ride the same trail loop that I had ridden a day earlier on a 29er. Starting off on a sealed road it did not feel like it rolled along as well as the 29er. However, as soon as I hit the trails this disappeared. The handling around tight switch backs was something that was really noticeable compared to the 29er, as was the acceleration on the short sharp climbs and out of obstacles. I did however nearly come unstuck a couple of times with the decreased roll-over compared to the 29er. I must have become a bit lazy lifting my front wheel over obstacles during the last 3 years of riding a 29er.
Interestingly, I managed to climb a steep technical section of trail that has until this specific day defeated me in the last 10 meters. Was this the 27.5 or just an improvement in skill and fitness from a week riding at 2000 m above sea level? All I know is that I returned to the same trail again today (the day after riding the 27.5) on a 29er, only to have this same section of trail defeat me again due to not being able to get my front wheel in the right place quick enough on the final steep uphill obstacle!
When it came to the downhill I took on a mixture of really rocky, steep lose sandy gravel, flowing brems and some slick rock descents. The 27.5 was a lot of fun over all of this terrain. The nimbleness around corners and the ‘pop’ it has out of dips were next level compared to the smoother more consistent roll that the 29er has.
So what are my final thoughts? On fun, dry single track this bike was a winner. I can see it being the choice for cross country riders, smaller athletes that find the 29er to big to handle and those wanting a fun bike to play on that captures the best aspects of the 26 and 29 inch wheel sizes. When it comes to the open gravel road/ farm track marathon type of riding and the long open climbs that dominate a lot of New Zealand mountain bike, multisport and adventure races I am unsure that the 27.5 would trump the 29er on performance. Having said that I have not trialled the 27.5 on this type of terrain and I guess only time will tell.
I would suggest if you are in the market for a new ride, that the 27.5 is something that you look closely at and if possible take one out for a test ride before you decide either way depending on what you are after in a bike and your riding goals.