I've owned both these bikes and have gotten several questions about my opinion of how they compare, so thought I'd just post it here for all to see.
I had an XL BronsonC for about a year. It was stolen, and insurance came through for me big time, so I got an XL Mach 6. Notably, the Bronson had a 2014 Float fork while the M6 has a Pike. Both at 150mm.
The bottom line is that both bikes are awesome, and I'm certain that 95% of owners of either will never really test the limits of either design. Neither of these bikes is going to hold you back on the trail. I'll ignore differences in parts spec, but identify two main frame-intrinsic differences: geometry and suspension feel/performance.
1) Geometry. I was on an XL in both cases, though I think these observations apply to other sizes. Both bikes have similar measured top tubes, but the Bronson has a steeper ST angle; this effectively "pushes" that top tube forward, so the Bronson has a longer reach measurement. The Bronson also has a much shorter HT, over an inch shorter than the M6 in XL. (Caveat: reach and HT are related, and the M6 is not quite as short on reach as it may seem. Reach is horizontal distance from BB to top of HT, and the HT is obviously sloped, so the taller the HT the shorter the measured reach, all else being equal.) Finally, the M6 has shorter chain stays and wheelbase.
The upshot of all this is that with the M6, the seated rider's center of gravity is further back, more over the rear wheel (slack ST + short chain stays). Also, standing up in the same position on the M6 puts ones knees nearer the bars (short reach), so the M6 rewards a sharper bend at the waist when standing, to get the chest down and keep the bars in front of the rider.
The effect of all this on the ride is that I find the M6 to be a more playful bike. Short wheelbase and short chain stays make it positively whip around tight switchbacks, and it's noticeably easier to lift the front end, either over obstacles or to manual. Nothing seems too steep on the M6, just hold on and keep the rubber side down. It's also a blast in the park, where you can really get up high on wall rides and boost jumps off everything in sight. The downside is the up; it requires a noticeable weight shift to keep the front end planted when climbing steep terrain on the M6, where the Bronson lets you just sit and spin. And the Bronson struck me as a bit more stable on fast/rough descents (longer chain stay and wheelbase). I've had to adjust to the shorter reach of the M6, learning to stick my ass back to stay behind the bars when standing up on steep descents; once I got used to this though, the M6 has been a blast. I think the M6 might better reward a skilled rider looking to play all over the trail, where a Bronson might be more confidence-inspiring for those wanting to just haul ass over rough terrain.
Suspension VPP and DW both work well, and I should note that I had a normal Fox CTD on the Bronson but a FloatX on the M6. With that said, I find the DW to offer noticeably better small-bump compliance, while also yielding better mid stroke support. I found the VPP to feel a bit stiff early in the stroke over small bumps, but then open up and wallow into its travel on larger hits (still not a big issue; it's not like an FSR bike). DW by contrast feels super-supple on smaller bumps but gives a nice, supportive feel on bigger hits. This is similar to the difference in feel of a Fox Float fork and a Pike; the DW and Pike both ride fairly high in their travel and provide great small-bump sensitivity. The only issue is that with the DW (and the Pike) you need to carefully dial in rebound dampening; the progressiveness of the suspension means that it really bounces back at you on bigger hits, and if you're under-damped you can actually feel like the bike is trying to eject you on landing. This is the case with all suspensions to some degree, but the DW deep in its travel really accentuates this feel in my opinion.
Both suspension designs yield nice firm platforms when pedaling. I'd give a small edge to the DW in this regard, though when climbing I'd probably prefer the Bronson due to geometry.
Bottom line: Both these bikes are awesome. If I had the choice between them, identical spec, I'd pick the M6. It's just a bit more playful and feels like it will stay composed over any terrain, jump, drop, steeps etc. If I were ONLY using my bike to race Enduro-type courses, or to cover lots of rough trail as quickly as possible, I might consider a Bronson. You really can't go wrong with either.
I had an XL BronsonC for about a year. It was stolen, and insurance came through for me big time, so I got an XL Mach 6. Notably, the Bronson had a 2014 Float fork while the M6 has a Pike. Both at 150mm.
The bottom line is that both bikes are awesome, and I'm certain that 95% of owners of either will never really test the limits of either design. Neither of these bikes is going to hold you back on the trail. I'll ignore differences in parts spec, but identify two main frame-intrinsic differences: geometry and suspension feel/performance.
1) Geometry. I was on an XL in both cases, though I think these observations apply to other sizes. Both bikes have similar measured top tubes, but the Bronson has a steeper ST angle; this effectively "pushes" that top tube forward, so the Bronson has a longer reach measurement. The Bronson also has a much shorter HT, over an inch shorter than the M6 in XL. (Caveat: reach and HT are related, and the M6 is not quite as short on reach as it may seem. Reach is horizontal distance from BB to top of HT, and the HT is obviously sloped, so the taller the HT the shorter the measured reach, all else being equal.) Finally, the M6 has shorter chain stays and wheelbase.
The upshot of all this is that with the M6, the seated rider's center of gravity is further back, more over the rear wheel (slack ST + short chain stays). Also, standing up in the same position on the M6 puts ones knees nearer the bars (short reach), so the M6 rewards a sharper bend at the waist when standing, to get the chest down and keep the bars in front of the rider.
The effect of all this on the ride is that I find the M6 to be a more playful bike. Short wheelbase and short chain stays make it positively whip around tight switchbacks, and it's noticeably easier to lift the front end, either over obstacles or to manual. Nothing seems too steep on the M6, just hold on and keep the rubber side down. It's also a blast in the park, where you can really get up high on wall rides and boost jumps off everything in sight. The downside is the up; it requires a noticeable weight shift to keep the front end planted when climbing steep terrain on the M6, where the Bronson lets you just sit and spin. And the Bronson struck me as a bit more stable on fast/rough descents (longer chain stay and wheelbase). I've had to adjust to the shorter reach of the M6, learning to stick my ass back to stay behind the bars when standing up on steep descents; once I got used to this though, the M6 has been a blast. I think the M6 might better reward a skilled rider looking to play all over the trail, where a Bronson might be more confidence-inspiring for those wanting to just haul ass over rough terrain.
Suspension VPP and DW both work well, and I should note that I had a normal Fox CTD on the Bronson but a FloatX on the M6. With that said, I find the DW to offer noticeably better small-bump compliance, while also yielding better mid stroke support. I found the VPP to feel a bit stiff early in the stroke over small bumps, but then open up and wallow into its travel on larger hits (still not a big issue; it's not like an FSR bike). DW by contrast feels super-supple on smaller bumps but gives a nice, supportive feel on bigger hits. This is similar to the difference in feel of a Fox Float fork and a Pike; the DW and Pike both ride fairly high in their travel and provide great small-bump sensitivity. The only issue is that with the DW (and the Pike) you need to carefully dial in rebound dampening; the progressiveness of the suspension means that it really bounces back at you on bigger hits, and if you're under-damped you can actually feel like the bike is trying to eject you on landing. This is the case with all suspensions to some degree, but the DW deep in its travel really accentuates this feel in my opinion.
Both suspension designs yield nice firm platforms when pedaling. I'd give a small edge to the DW in this regard, though when climbing I'd probably prefer the Bronson due to geometry.
Bottom line: Both these bikes are awesome. If I had the choice between them, identical spec, I'd pick the M6. It's just a bit more playful and feels like it will stay composed over any terrain, jump, drop, steeps etc. If I were ONLY using my bike to race Enduro-type courses, or to cover lots of rough trail as quickly as possible, I might consider a Bronson. You really can't go wrong with either.
