2.8 plus size vs 27.5 regular tires

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This topic has 6 replies, 5 voices, and was last updated 7 years ago by panzerjager.

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2.8 plus size vs 27.5 regular tires
dirksdiggler
Free Member

Has anyone compared the difference between 2.8 plus and “normal 27.5” tires?
I had read and assumed that 27.5 plus was close to 29″ overall diameter and figured that all plus bikes would be 29″ cross compatible… however comparing my 2.4 Conti mk2s to 2.8 Nobby Nics shows only a few mm of difference, whereas a 29″ Conti 2.4 is much larger.
So, all these slack short travel plus bikes could run regular tires and be closer to their plus sized designed bb height than by running 29 instead?
Running a regular 27.5 2.4 conti wheel in my plus bike would only drop the BB height by 2mm. The 29″ 2.4 more like a 15mm increase in bb height.
Is this just because I’m comparing plus tires to high volume contis or am I missing something?

Posted 7 years ago

whitestone
Free Member

Even comparing within wheel sizes, different tyres come up as different sizes. I’ve seen a 26″ tyre come up about 2mm short of a 27.5 tyre. There’s a nominal 40mm between 650b and 29er tyres, I’ve a set of B+ tyres, one is 8mm shorter than a 29er tyre, the other is 15mm shorter.

It was/is just luck that a 29er could run most B+ wheel/tyre combos, whether it works the other way round …

Posted 7 years ago

scotroutes
Full Member

however comparing my 2.4 Conti mk2s to 2.8 Nobby Nics shows only a few mm of difference,

about 0.4″ by any chance?

Posted 7 years ago

Fresh Goods Friday 700 - The censored edition

PimpmasterJazz
Free Member

about 0.4″ by any chance?

Crazy talk!

Posted 7 years ago

TheGhost
Free Member

I was running 2.8 nobby nics on my Sonder Transmitter but have switched to 2.4 27.5 high rollers. There is only 10mm difference in width and the heights of my wheels when stood together with one of each tire on were within 10-15 mm.

I think a new 2.4-2.6 trail bike standard will begin soon. 2.5 Wide trails are already out there and 2.6 are on the way. Basically 2.8 and above is a bit too slow with lots of drag, 2.6 will be the sweet spot in 12 months time is my guess. Lol.

Posted 7 years ago

PimpmasterJazz
Free Member

I think a new 2.4-2.6 trail bike standard will begin soon. 2.5 Wide trails are already out there and 2.6 are on the way. Basically 2.8 and above is a bit too slow with lots of drag, 2.6 will be the sweet spot in 12 months time is my guess. Lol.

Spesh are already doing several of their tyres in 2.6″ and 3″, possibly for that reason and probably because a 2.6″ tyre will squeeze into most frames.

Saying that, I have been pleasantly surprised riding 2.8″ and 3″ tyres as to how well they roll.

Posted 7 years ago

panzerjager
Free Member

FWIW, This is the reason the new Mojo 3 & new rear triangle for the HD3 make the 27″ in to a 27+ for the very reasons you just gave.
According to their tests, 27+ tyres run at lower pressures are virtually identical to regular 27″ tyres at relatively higher pressures.
I think the 29er to 27+ is more about the additional clearance further back in the chainstays/seatstays to allow for the extra width.

Posted 7 years ago