To mullet or not to mullet

The mullet set up is awesome if the bike is designed around it or has the ability to compensate for it. That process-x already has a low bb and a slack head angle and would be even slacker and lower with a 27.5 rear wheel which will make it difficult to ride. If you could correct for the change in geo it could be an option, but I would stick to the 29. I stuck a 27.5 on the back of the previous gen firebird 29 and it was not good. My current bike is mulleted but has a link to compensate for the change in geo which makes it work well, otherwise I would not being running it.

If you find yourself buzzing your arse, maybe.

Edit: Deleted some nonsense I said about wheelbase, I really should have looked up the Process X first!

Because your bike IS designed to run either size wheel, the world is your oyster!

I seem to recall Miranda Miller swapping back and forth with her Process X in one of her vlogs. For her particular pursuit with that bike, she was trying to get more snap but not at the sacrifice of speed.

Ultimately where you decide to go really is preference and that preference is based on your background and what you want to accomplish. Prior to the Process X, did you ride smaller wheels, or have you been on the 29er train for some time? Where are you running your chainstay length now (435 or 450?) Based on the answer to that, do you want more snap from your bike? Are you otherwise perfectly happy with your bike right now? There is also the question of terrain and trails you prefer.

The spiral may be maddening, particularly for someone of your height. Traditionally, I think the consensus for people over the 6-foot mark is to stick with the full 29er but it's a free world and you can do whatever you darn well want to do.

I can only give some questionably useful info/anecdotes to your situation. In short, from my experience playing with mullets at the 6'2" and above height mark... it's a bit of a mixed bag and it's just down to subjective rider feedback.

What I found from trying mullet conversions on my bikes, as well as riding mullet only bikes and bikes with mullet flip chips is that I don't love it, don't hate it and that overall, the differences are some what minor once I adapt my riding style.

For some background:
-I'm 6' - 2" - 180lbs - 40yrs old, aggressive and I'd qualify myself as an expert for steeps, loose, jank, speed and trail features/jumps. I'm an intermediate when it comes to bike park style jumps. I live in socal, ride in laguna so steeps and shit conditions are the norm. I digress...

I would say generally, I prefer 29r front/rear. I've never really had an issue snapping the back end of my full 29r and squaring off corners. I don't have a huge issue jumping a full LT 29r, but the mullet setup was easier to jump and change directions on take-offs, in the air and on landings. The thing I notice most about a properly setup mullet bike vs a full 29r, is really the way the back of the bike continues to come around once you initiate the turn/in. With that, comes a slight of un-willingness for the bike to stand back up on corner exit. Almost like the bike wants to continue to rotate around the bottom bracket. That manifests itself in feeling like I need to deliberately finish the corner by either tugging back on the bars to pull the bike out of being leaned over or needing to shift my hips a bit to get the bike to stand up.

This is definitely something that is very apparent when I do "cutties" on pavement on a mixed wheeled bike. It's as if my hip movements to initiate the loading of the suspension at the apex of the corner, and catapult the bike into the opposite direction are too much. It's as if the bike has a natural tendency to do that on it's own, and when I dive into it with my full 29r riding style, it's too much.

Very quickly I adapt to this of course, and I don't have this sensation as if I need to correct it, likely because I'm not pre-loading when I tip the bike in to square off the corner knowing the bike is going to do that on it's own.

Interestingly, for me, because of this sensation, all things (geometry) being equal on a bike, with a mullet I prefer a longer chainstay then I would on a 29r. For example, on my megatower 1 which I have, and still do run in a mullet setup with an offset bushing, extending the eye to eye in an attempt to raise the BB slightly... when I run it as a mullet, I run the longer chainstay setting. I find that a bit interesting, because I do prefer a chainstay a bit longer then we all seemed to be targeting on 29rs 5 years ago. For example, even though I'm typically on XL frames with a reach of 490-500... I still seem to prefer chainstays in the 435 - 445 range (depending on front center) which tends to be a bit shorter overall then most people that are my skill level and better.

So... I probably didn't fully answer your question. I would say, it depends. For my usage, I think that a full 29r is more comfortable. I like the mixed bottom bracket drop of the mullet setup, but it doesn't really change my approach to riding in general, and it doesn't impact how I ride specific features. I don't have an issue with butt buzz on a full 29r and while I notice that there is some extra room when riding steeps and not buzzing my thigh with the tire (that's really the butt buzz that mullet setups help you with, not really butt buzz, but more thigh buzz), but it doesn't change anything for me. The cornering aspect of a mullet bike vs full 29r is indeed different, and it feels different. However after I've ridden the bike for a bit, I've adapted to my hip position and it's not really anything I notice unless I'm riding blind, trying to hop back and forth over ruts because I'm not sure what the line is. If I know the trail at all, I'd generally want the grip/security of the full 29r because I generally am not trying to change cornering lines last second.

I think overall, as tall dudes, we're just in a much better spot to deal with a 29r rear wheel. Not only for clearance, I think we just have so much more leverage on the bike in general, that we don't have to move our hips as much. Sure we have a higher COG generally, but on a full 29r, that allows us to hang our weight in either direction on the bike and impact the polar moment of inertia and the full stability/grip of a full 29r ends up being something that pairs well.

I feel like this is the same reason that you see people like greg minnar that seem so stable and deliberate when they are riding, almost like they aren't moving around on the bike at all. Until recently, I feel like there weren't a ton of mid height riders that managed to do that... and most of them were sizing down (sam hill for example). Now you see riders like loic bruni, whom despite being on the frame appropriate for his height, he's very motionless like the taller dudes are.. Granted that's his riding style... but you get the point.

I'd say, try it and see for yourself. I think it really depends on your riding style and terrain for us tall dudes. We're lucky in this regard that we can get the benefit of either solution without many drawbacks.