Yesterday I posted some of my thoughts on the claimed advantages of the 50/50 bike and how they are not really advantages, or they are misconceptions. The advantages of using a 29 inch rear wheel far out weigh the negatives, so looking at it from that perspective, the 50/50 bike is only half as good as a full on 29"er. It's simply not, "the best of both worlds", as the proponents of the 50/50 bike would have you believe.
The other argument I have encountered regarding 50/50 bikes is that both wheels will work together giving you something that neither wheel size could on it's own. Ahh......no! This is not at all the case. The front wheel is going to react independant of the rear wheel as long as the geometry of the "same size wheel bike" is the same as the 50/50 bike. So, if you run a 50/50, the 26 inch rear wheel will do all the same things that your rear wheel does on your 26" front/ rear bike. The 29" front wheel does not magically make your 26" rear wheel better on a 50/50 bike. It's still a 26 inch rear wheel. It reacts to inputs like a 26 inch rear wheel. The same holds true for bumps, braking, and anything else a rear wheel encounters. Going with a 50/50 bike is only going halfway to the full benefits of a 29"er. Why only go halfway?
You would almost be better off doing a 50/50 bike with a 29" rear wheel and a 26 inch front wheel! The rear wheel is the multi-tasking wheel of a bike, driving the bike forward, carrying the bulk of the riders weight, ( in many cases) and affects rider comfort to a large degree. Since traction is better and rider comfort is better with a 29 inch rear wheel, then it makes sense to have it as a rear wheel, instead of giong with a 50/50 bike.
Of course, 29"ers are not for everybody. Shorter riders, and riders ingrained into the handling traits of 26"ers are good examples. These riders are not going to benefit from 50/50 bikes either. Shorter riders will find their handlebar, toe overlap, and cornering/ climbing techniques negatively affected by a 50/50 bike. Same for a 29"er. If you are 5'5" or under, I'd look into a full on 26 inch bike for off roading.
Finally, I keep hearing folks say to me and others that are not supporting the idea of 50/50 bikes, "you've got to ride one! Then you can talk to me about it. You will change your mind!" To which I say, "ummmm.............no, not so much!" But to help these folks out, I have submitted to building up a 50/50 bike of my own. It is currently very near completion, but I have not gotten it out on the trails yet. There are certain ultra endurance duties that have to be attended to before I can get to testing the 50/50 bike against my full 29"ers. It will happen though, and I fully expect to put this whole notion to rest, at least for myself. The bonus is, I'll actually have riding experience to satisfy the challenges of these folks. For what that is worth!
Look for the head to head comparo sometime this summer. For now, have a great weekend, and ride your bike!