Interested to see what the opinions are on a more gravity oriented RFXesque 29er?
Was in the middle of a climb this past week and it popped up in my head that an alloy version would be really good.
Would you buy an 'aggressive geo' alloy RFX 29er?
seems like this would be a good bike in the line up.
From my last 29er enduro experience, I would say "hell no".
IME, 29ers work good in the short to mid-travel range, when you go beyond that, it starts to magnify the disadvantages significantly, to the extent where a smaller wheel does better for me overall.
Some of the issues I had were:
-Wheel flex when pushing the bike hard (solved with carbon rims).
-Harder to pedal bike up to speed for an obstacle (double, tabletop, gap, etc.), this really starts to show when you are a bit more tired.
-Slower in mid-radius turns at high speed. Had to slow down or the gyroscopic force would simply cause me to skid towards the outside of the turn, in either case it would slow me and I'd have to pedal harder to get back up to speed.
-Harder to pop off of objects/obstacles. Wheel and tire weight contribute a lot here and are going to always be heavier.
-Bike tends to jump flatter and longer, which can cause overshoots.
Some of the advantages were:
-Wheel-catchers were non-existent/ability to roll down steep chutes.
-Ability to maintain speed during large-radius turns.
Things that were not issues:
-Making tight turns: Modern 29er geometry makes this a thing of the past, goofy 18.5"+ chainstay bikes are gone for the most part. Maneuverability doesn't seem to be an issue at all, except for what I posted above.
Some other notes: 180-170mm SC 29er forks have a massive axle to crown and not a lot of overlap relative to the overall length of the fork. Even if they did, it won't lessen the higher bending forces on the crowns, this is not a good recipe. 1.5 steeres came about due to longer travel SC forks and going this far on a 29er probably needs a 2" steerer or a dual crown design to be correct for the intended usage. I've always gone between 2.3 and 2.5" for DH tires, for real abusive resort and rock riding, I like a meaty 2.5, but man those 29er tires are just boat anchors. Lots of traction, but once I made the mistake of taking them on an XC ride that had a few miles of pavement thrown in for good measure. 29er wheels will always be more flexy than smaller ones, not an issue IME with carbon as I said above, but still, some may experience this. It also gets harder to have useful gearing to go uphill, the extra rotating mass is also harder to pedal due to the worse mechanical advantage. More rotating mass OR a longer distance requires more brake to slow down, this has caused some brake manufacturers to go to and consider 220mm rotors. Just one thing that you need more of with bigger/heavier wheels.
Bottom line is that riding Enduro and park DH is very abusive on bikes and needs components and rubber beefy enough to handle it. When you go to 29er tires and real rubber/components, it doesn't make for the quickest bike out there IME. I got 2nd on the 27.5 RFX on the first enduro race on it, the bike killed it and on those medium-radius turns I noticed a big difference in the speed. It's not that you can't ride a 29er DH/Enduro bike, you can and they are a lot of fun. You can jump them. In my experience though, they are more work for less gain. Certain conditions may favor them, but I find that to be a pretty narrow range of conditions and I'd go for a 27.5 for this kind of riding every day and Sunday.
If I could only have one bike, I'd probably have a mid-travel 29er, 120-140mm, that would rip and I would have tons of fun on it. I think at that travel-amount you can keep the overall weight reasonable enough to avoid many/most of the issues. Since I can have more than one, I choose the RFX for most stuff and a lower-travel 29er when I need to go much more "XC" style.
I am glad there are "real" enduro/AM 29er options these days, like the Wreckoning, Ripmo, etc. I wouldn't revisit that catagory any time soon, if ever though. They end up just being massive overkill much of the time IMO. What they possibly gain for roll-over is more than offset by the weight/gyroscopic stability/rolling resistance, etc., IMO.
