MTB: 27.5 vs 29ers

Excerpt from an article I found googling:

ADVANTAGES OF 29ERS

The larger wheel diameter offers a larger contact patch. In other words, all things being equal, a 29-inch wheel will put more rubber on the ground at once. This means that you’ll have more available grip for cornering, braking, and climbing. The added diameter also reduces the angle of attack when rolling over a given obstacle, which enhances the sense that your bike is rolling through trail features, rather than up and over them. And as previously mentioned, the increased bottom bracket drop yields a bike that feels more planted, which is of particular benefit to both beginners and endurance racers.

ADVANTAGES OF 27.5

Riding a bike with less bottom bracket drop results in a more responsive handling feel. Along these lines, the smaller diameter wheel frees up more room to shorten chainstays, especially on long-travel bikes. With shorter chainstays, a bike tends to turn on a tighter radius, helping the rider to make quicker changes in direction.

Conversely, the use of smaller wheels requires slacker head angles to achieve the same trail measurement. This balance of slacker head angles and shorter chainstays gives the 27.5-inch wheels greater pitch stability compared to a 29-inch wheeled bike with similar handling traits. Ultimately, this is advantageous to aggressive descenders. Additionally, the smaller wheels are both stiffer and lighter, which enhances the lively feel that’s inherent with 27.5-inch bikes.

COMMON MISCONCEPTIONS

The most common misconception we hear about 29ers is that they can’t be responsive. Broad generalizations tend to skirt that fine line between exaggeration and flat-out nonsense, and this is a perfect example. Sure, there are plenty of 29ers that are highly stable and handle best when ridden wide open, but there’s no shortage of quick-handling 29er XC whippets. Granted, when comparing similar bikes, a 27.5-inch bike will tend to be more responsive, but there are other factors to consider, mainly suspension design and your position on the bike. And if someone tells you that 29ers don’t jump well, consider the source. Big wheels love to fly. So most likely, it’s not the bike’s fault.

THE VERDICT

What we’ve found is that, by and large, XC racers, beginners, and fans of all-day trail rides tend to prefer the stable ride provided by a 29er. Meanwhile, aggressive riders with a taste for descending generally favor the more responsive handling offered by 27.5-inch bikes. 27.5 is also an amazing option for those who are hesitant to give up their beloved 26-inch steeds, since it promises both forward compatibility of high-end parts and a ride that’s similar to the old standard. It also provides some distinct advantages in terms of both grip and overall speed. So, if you’re on the fence, do yourself a favor and ride as many bikes of each wheel size as you possibly can. Generalizations aside, there are bikes of both wheel sizes that we absolutely love and that cater to most any taste. Naturally, there are those that will be resistant to the changing tides, but from what we’ve seen, it’s being driven by a genuine desire to make mountain bikes better for all.

Full article:

http://www.competitivecyclist.com/learn/27-5-vs-29

Thanks , useful info!!!

Good comparo...
One factor it doesn't mention  are the limitations of 29ers in smaller sizes, especially full sussers.  It's difficult to design a small size 29" wheel bike to accommodate some rear suspensions. Compromises are made - and in fact, some bike manufacturers simply offer a given model as a 29er in larger sizes and a 27.5 in the smaller sizes.  Smart.  I know my next new bike (eventually) will be a 27.5, given my 5'-9 height.  Every 29er I've tried just doesn't fit right.  Smalls are too small and mediums are too long, even with super short stems. So 27.5 it will be.  I rode a really nice Kona Cinder Cone in Maui - it was dialled bang on for my taste and style.  Hopefully when I'm ready to pull the trigger on a 27.5 there will be even more choices.  That's what's nice about the whole 29er / 27.5 deal.  Lotsa options and choices for everyone.

i'm 5'9 too..going with a 27.5

I am 5'7" and went with the Santa Cruz LTc.  Medium frame with a dropper seat.  Could not be happier.  when I am riding it feels like I am in the bike and not on the bike if that makes sense.

My wife has the Santa Cruz Bronson C.  It is 27.5 and I have ridden it a couple of times.  It seems slow and clunky compared to mine.  Still a great bike, she is to small for a 29er.  I am going to lighten the back end up this summer and see what that does.

There is a comparison out there on U-tube where they tested racers.  The 29er came out on top then the 26 and then the 27.5.  

I'm with TJ, it really depends on the bike.  I am 5'8" and my current bike is a 26 and I would definitely consider a 29er for the next one. In  2013, I test drove three Spec 29ers, all medium frames, on one day. One fit like a glove and felt like it was custom made for me, one felt very clunky and one was somewhere in between. Full report here. I haven't ridden a 27.5 but would like to try one, and really want to try a 27.5+, which I think would be ideal for the kind of terrain I ride in. Kind of mid-fat.

TJ brings up a good point with the "in" vs "on", at first this can construed as the cockpit as feeling a bit cramped. After demo'ing my bike I was sure I'd be cutting a bit of the bars and replacing the stem with a longer one but after riding a few weeks ended up doing neither. The other adjustment was the lower bb. lots of pedal strikes in the beginning but after some adjustment in riding technique love the lower cg, more "ski-ey"!

My biggest noticeable difference between the 29 / 27.5 trances last summer was rolling momentum. A good part of one of my regular ride spots is laid out like a giant pump track and the niner definitely lets me go faster and pedal less in those sections. inverse is true in the techy sections, if something slows you down it definitely requires a bit more effort to get back up to speed. that trade off can be compensated for with riding style (through vs over/around as mentioned above) and wouldn't be a deal breaker either way.

It would be a tough decision, glad I don't have to buy a bike right now (mountain anyway, looking for a cross/touring ride) and again, after riding the same bike in both wheel sizes would go with whatever deal presented itself or came in a cooler color or something... shit I can't wait to get back on the bike!

when I first got the bike I banged the bottom bracket a couple of times hard, first time sent me over the bars.  After riding it a while it never happens anymore...I guess I just adjusted cause I don't pay attention.
29 climbs better as well.  more tire on the ground.  

The Santa Cruz 27.5 for my wife was because of the color.  She does not need a carbon bike but pink sealed the deal.

I'm thinking the 27.5 was the right choice for me. Still been banging the cranks a bit. I feel (vs the 26) lower to the ground and to some extent, more likely to bottom out (need to be careful) and a little less maneuverable.  I really think the 29 would be too much right now.

I'm 6' and a 29er Is Great for me but I could see that someone shorter would prefer a 27.5

Compared to when I had a 26 I seldom have to stand up to climb steep hills.  In fact with the longer frame I feel more grip sitting grinding up climbs.  The big wheels just absorb everything.  I do feel that it corners more sluggish down hill than my old bike.  I don't ride extremely technical trails  that much.

I ride a Kona Hei Hei

i bought a 29er and love it!! ...i'm only 5 9 on a good day..

Not just size, but skill level and terrain right?