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I was curious what you guys think. I have been hitting more jumps at my local trails lately and I want to progress and feel comfortable on them more. So, I couldn't help but think if a 650B or Mullet setup would be better than a full 29er at Jumps. I have a Transition V1 Sentinel and there is an option with the cascade link to run a mullet setup that would be able to keep the geo the same of the 29er setup, would it be worth the investment or is it all in my head?
To me - having the two different wheels shows that Mountain Bike is essentially clueless on how to sustain itself, except for XC.
If you're speaking about step downs, long doubles, drops, etc. built for mountain bikes I don't believe anything will make a bigger difference than riding more and getting used to moving your body and bike around in the air. The best way to get comfortable with the relatively small amount of control you have in the air is by riding jumps of all sorts of shapes and sizes; experimenting with the different speeds and the different techniques required to land them smooth and in control.
A new wheel size is not going to make much of a difference in comparison to the creative practicing of jumps, going fast one run, slow the other, nose high, nose low, whipping left and whipping right, turning your head mid-air, taking off a hand, using the rear brake to bring the front end down, landing into corners, taking off from out of a corner, etc. There is a whole ton of practice that can be done that's "free" before looking to change wheelsize. My favorite things are jumping into/out of a corner and going progressively slower until I can no longer clear the gap (this one gets exciting as you will have to keep the front down to gain the extra few feet and it's easy to OTB after a hard bunnyhop while attempting this and not quite clearing the gap)
Short version:
There is very little benefit to taking a 29er frame and going to a mullet setup.
Long version:
As recently as 2 weekends ago I tore up my 29er rear tyre in 3 places in 2 runs at Isola 2000, rather than fix it again, i swapped over to my e-bike rear wheel.
29er wheel: DT swiss e1900 (with 36t ratchet), 30mm wide, + Michelin wild something tyre 2.35 wide.
27.5 wheel: Commencal built wheel with spank rim+ 35mm wide, nukeproff ARD foam, michelin E-Wild 2.6
Bike Capra 29 in low.
Note that yes, my 27.5 setup is heavier than the 29er one, which is one issue with my comparison. There was literally no difference in ride feel, probably due to the weight and tyre size counteracting any substantial changes.
Hypothesis:
Mulleting a 27.5 frame might make a difference, as you are changing both the fork and wheel upfront, potentially (unless you decrease your travel quite a bit) giving you slacker head angle and higher stack (both good), yet you still benefit from the shorter chainstays on the 27.5 rear.
Conclusion:
Ride more, think less.
Mulletting a 27,5 can have advantages for sure, putting the BB a little higher from the rear wheel and lower from the front wheel = better integration "in" the bike AND easier to manual. And head angle slacker. Maybe too slack, because a 29" wheel is about 45mm more in diameter than a 27,5", so just changing wheel it makes the head angle about 1° slacker. Plus at same travel a 29" fork is 20mm longer. So An other degree slacker. Not to mention the seat angle follows the same rule.
But to answer the first question : nope, I don't think a mullet bike set up itself would make hitting jumps easier. But you'll hit jumps easier on a bike you are comfortable with, and if you are more confident on a mullet bike so yes, it would make hitting jumps easier.
Generally speaking: In my experience the difference in diameter between good tyre options for 29 and 27.5 is closer to 2cm.
So changing a 275er to mullet: the number affecting the axle is simply the radius (so 1cm higher), and the stack + BB are affected by the radius of the wheel + fork A2C*sin(angle), but let's massively simplify and use the wheel diameter = 2cm.
So without changing travel upfront: Axle goes up 1 cm, stack 2cm, BB (roughly 1/3 of stack increase) 2/3cm == 7mm (which is quite a lot), and your head angle will slacken at least 1degree.
This is why most people would reduce travel on the fork 1cm, to roughly halve those numbers: still get the high axle benefit in full, and a reasonable stack + head angle bump in the right direction, BB increase of 3mm can be compensated with shock tune (less sag, more progression)
Changing just the rear on a 29er to mullet: Rear axle goes down 1cm (not sure any benefit to this), BB goes down 2/3 so again roughly 7mm (again this is a lot), stack virtually unchanged 2-3mm, head angle very minorly impacted.
So if you have an older 27.5 bike and you want to give it a bit of a new life, the change could work well (I'm considering it), especially to get a fairly slacker head angle and improved grip from the bigger tyre up front.
But if you have a 29er frame, other than increased rock strikes the change will not be too dramatic (ony exception I can think of is unless a high BB is what you are trying to resolve, e.g. 1st gen enduro 29 could benefit from this)
But in the end we agree on the use of mulletting a bike.
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