27.5+ = 29?

Mica

Likes Dirt
Curious to hear others thoughts on this as I haven't seen much talk on it but is the new 27.5+ movement just the full circle of the bike industry moving back to 29 just under a different name. Yes 27.5+ is a wider tyre, larger contact patch/traction, more cushion etc but in the end aren't we still looking at a 29 wheel and all its supposed flaws when we consider the external diameter?

So to really get the flames going does that mean 29 is best (as if there is any real answer to that question, but it is fun to ask)?
 

Dozer

Heavy machinery.
Staff member
I've assumed a similar idea; 27.5+ is the same rolling patch as a 29" tyre albeit wider. The thing that I think of most is the tyre roll that a plus tyre will attract and that bothers me to think that these tyres would be terrible on anything requiring some stability. Surely the tyre would have to be built heavier to limit the tyre roll? Would a lighter tyre be a totally pointless exercise? Above all else; do we need a plus tyre range?
I've not ridden a plus bike and cannot see any real benefit to it on top of what we already have. Riding bikes is all about having fun though and these could be a fun option for a new bike buyer. I can't imagine a rider of the punter level would feel any great benefit to this tyre size but an advanced rider that brings it to the limit might notice some huge differences.
 

mitchy_

Llama calmer
I've assumed a similar idea; 27.5+ is the same rolling patch as a 29" tyre albeit wider. The thing that I think of most is the tyre roll that a plus tyre will attract and that bothers me to think that these tyres would be terrible on anything requiring some stability. Surely the tyre would have to be built heavier to limit the tyre roll? Would a lighter tyre be a totally pointless exercise? Above all else; do we need a plus tyre range?
I've not ridden a plus bike and cannot see any real benefit to it on top of what we already have. Riding bikes is all about having fun though and these could be a fun option for a new bike buyer. I can't imagine a rider of the punter level would feel any great benefit to this tyre size but an advanced rider that brings it to the limit might notice some huge differences.
My 29x2.5" Minion is one hell of a fat tyre. I can't imagine needing much more width than that offers.

But to answer your question; yes 29" is the best, it's a bigger number.
 

Duane

Likes Bikes and Dirt
A 27.5 wide rim built on boost hubs with asymmetric spoke holes would be heaps stiffer wheel than anything you could build in a 29er, makes a difference to us Clydesdales.
Not that I'm interested in the +size fad, but wheel stiffness would certainly be one advantage even in a standard build. I don't think whippet sized riders would need it though as they don't suffer the flex issues as much.
 

The Duckmeister

Has a juicy midrange
Curious to hear others thoughts on this as I haven't seen much talk on it but is the new 27.5+ movement just the full circle of the bike industry moving back to 29 just under a different name. Yes 27.5+ is a wider tyre, larger contact patch/traction, more cushion etc but in the end aren't we still looking at a 29 wheel and all its supposed flaws when we consider the external diameter?

So to really get the flames going does that mean 29 is best (as if there is any real answer to that question, but it is fun to ask)?
Yes a bit, but not really. Sure the overall tyre diameter is similar, but as Duane touched on, the 27.5 is a smaller wheel, so inherently stiffer. Add in Boost hubs, which are intended to be part of the + package and the wheels get even stiffer thanks to the wider flanges & spoke brace angle. Yeah there'd be some more squirm in the tyres from the extra volume, but I'd hazard a guess that it's less than the stiffness gain in the wheels.
 

creaky

XMAS Plumper
A 27.5 wide rim built on boost hubs with asymmetric spoke holes would be heaps stiffer wheel than anything you could build in a 29er, makes a difference to us Clydesdales.
Not that I'm interested in the +size fad, but wheel stiffness would certainly be one advantage even in a standard build. I don't think whippet sized riders would need it though as they don't suffer the flex issues as much.
Pointless having a stiffer wheel build if you're just going to run a sloppy joe tyre on it at 25psi though ...
 

mitchy_

Llama calmer
Yes a bit, but not really. Sure the overall tyre diameter is similar, but as Duane touched on, the 27.5 is a smaller wheel, so inherently stiffer. Add in Boost hubs, which are intended to be part of the + package and the wheels get even stiffer thanks to the wider flanges & spoke brace angle. Yeah there'd be some more squirm in the tyres from the extra volume, but I'd hazard a guess that it's less than the stiffness gain in the wheels.
I would have thought it would be the opposite way? Surely a larger tyre is going to flex much more than a small increase in wheel stiffness.
 

The Duckmeister

Has a juicy midrange
Quite the contrary... The increase in wheel stiffness is actually pretty massive. Secondly the flex in the tyre is concentrated around the contact area, where the wheel flexes over a lot more of its area, so overall the 27.5+ is still going to be a stiffer package.
 

PINT of Stella. mate!

Many, many Scotches
Curious to hear others thoughts on this as I haven't seen much talk on it but is the new 27.5+ movement just the full circle of the bike industry moving back to 29 just under a different name. Yes 27.5+ is a wider tyre, larger contact patch/traction, more cushion etc but in the end aren't we still looking at a 29 wheel and all its supposed flaws when we consider the external diameter?
Yeah, so you might as well f*** both sizes off and go back to 26" as it's looking to be the future!

http://www.singletracks.com/blog/mt...-27-5-to-26-conversions-are-gaining-momentum/
 

Nambra

Definitely should have gone to specsavers
Just wait for 29+ bikes to come along...

I reckon Duane and Ducky have nailed it though; 29" diameter with 27.5" stiffness, and with big fat grippy tyres, it's more like a super playful dual suspension fat bike!

I read this review of the Scott Genius Plus on FlowMB a little while back and another 'benefit' is the ability to run 27.5+ wheels and 29" wheels on the bike (laced to boost hubs of course). Certainly provides for some interesting options...

Somewhere in all this marketing someone must have asked "how do we cash in on the fat but wealthy middle aged man" market - big tyres will make for a more comfortable ride for the anorexically challenged...
 

Duane

Likes Bikes and Dirt
Plus these 27+ tires with stiff wheels are the perfect platform for the 'e-bikes we all want.... :behindsofa:
 
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