27.5 Forks - do they exist? - Singletrack World Magazine November 19, 2018

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This topic has 16 replies, 9 voices, and was last updated 5 years ago by DezB.

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27.5 Forks – do they exist?
fotorat
Free Member

Not sure if this has been covered already but after fitting a mudhugger to my new bike which has 27.5 X 2.3 Magic Marys there is hardly any clearance and the mudhugger fills up with mud a rocks and is causing premature wear to my front tire, and on Saturday the front wheel completely jammed solid.

So today I have fitted a 26″ wheel in there which sensible mud clearance

also I measure my old 26″ forks from axel to bridge and to my horror my new 27.5 is the same ie 26.5cm

My 2008 fox 32 RL is 26.5cm as is my 2005 Talas, so is there no such thing as a 27.5 fork? – do they just carry on using 26″ forks?

Maybe I just need bigger lowers to fit 27.5 properly?

Posted 5 years ago

dmorts
Full Member

What are your new 27.5 forks?

My newer 27.5 forks say they will take a 27.5″ wheel with up to 2.8″ tyre. My older set of 27.5 forks have much less clearance

Some Manitou forks have the same lowers for 26 and 27.5. For the larger wheel size you just adjust internally to stop the crown hitting the tyre if it bottoms out

Posted 5 years ago

mikewsmith
Free Member

Sounds like you have a 26″ fork there!!

Are you sure on the measurements being in cm there?

Posted 5 years ago

dmorts
Full Member

Sounds like you have a 26″ fork there!!

Also could be that!

Posted 5 years ago

fotorat
Free Member

its on my 2016 Cannondale Moterra LT1- FOX Factory 36 FLOAT FIT4, 160mm, 3-Pos-adj, 15QRx110mm, Kashima Coat

But like I said the distance from axle to brige is 26.5cm which is 26er size! so are there only 26er and 29er forks produced?

I thought if I was buying a 27.5 wheeled bike – then it would have had a 27.5 Fork and frame?

https://www.cannondale.com/en/Europe/Bike/ProductDetail?Id=5a819f9c-8bb5-4db1-8135-52be7276043e

Posted 5 years ago

BearBack
Free Member

The 4 digit code on the back of the non drive side will tell you.

Search it in the upgrades page on fox’s web site

Posted 5 years ago

mikewsmith
Free Member

But like I said the distance from axle to brige is 26.5cm which is 26er size! so are there only 26er and 29er forks produced?

No, there are 27.5″ forks produced I’ve had stuff side by side before.

26.5cm =

27.5″ Rim (according to wikipedia https://en.wikipedia.org/wiki/Bicycle_wheel#27.5_inch_/_ISO_584_mm )

Has a 58.4cm diameter or 29.2cm Radius – Axle to Crown for just the rim which is whats confusing me (not got anything to hand ot actually measure here)

On anything else I’ve seen decent clearance on most 36’s for 27.5, on my old 26″ 34’s a 650b wheel would fit just and the same wheels spin clearly in every 650b fork I’ve had.

But if the clearance is the same on the 26″ one something sounds like a factory cock up

Posted 5 years ago

Stevet1
Free Member

fotorat has discovered that 26″ and 27.5″ parts are the same and the industry has been selling 26″ forks, frames and tyres just with the 27.5 printed on the side.

Posted 5 years ago

BearBack
Free Member

https://www.ridefox.com/fox17/help.php?m=bike&id=580

Fox say tire size limit is 27.5×2.5
any tire size greater than 2.35 much be checked with fork crown fully compressed and have a minimum of 6mm tire to crown clearance.

I just measured a 2018 36 27.5 and a 2016 34 27.5 and axle center to underside of arch is 37.5cm
There is a difference between 26 and 27.5 36 lowers as back in 2014/15? we had a guide run a 26″ 36 and he had to run a 2.2 Trail King as the 2.4 wouldn’t clear. The 2.4 cleared fine with the 27.5 lowers.

FWIW a foldable mud hugger barely fits in my 34 27.5plus with 29″ wheels (2.4 baron) and same 30mm rims as you. It makes lots of noise and would probably quickly gum up if we had that kind of mud here

Posted 5 years ago

fotorat
Free Member

Mine is DDRY and if this a 27.5 fork then Im a monkeys uncle…..also does anyone know what those 2 small threads are for on the rear on the Arch – is this for a mud gaurd that doesnt clog?

Posted 5 years ago

mikewsmith
Free Member

Well if you are sure I’d be heading back to the shop with it!

Or at least an email to fox UK to get some numbers to check.

Posted 5 years ago

tomhoward
Full Member

is this for a mud gaurd that doesnt clog?

Yes, but they never got round to making it IIRC. Though, again IIRC, Mojo as was did some but they were about £60

Posted 5 years ago

julians
Free Member

I typed that code (ddry) into the fox website,and it says that fork is a :-

<h1>2018 Factory Series 36 FLOAT 27.5 160 FIT4 3POS ADJ</h1>

https://www.ridefox.com/fox17/help.php?m=bike&ref=findbycode

Posted 5 years ago

mrhoppy
Full Member

Syncros do a guard to fit on those threads.

Posted 5 years ago

bsims
Free Member

@ fotorat- that’s interesting as my 2014 (can’t remember exactly) won’t take a 650b with hr2, ground control 2.3 or xr2 on a 23 mm rim.

cost cutting maybe with less material or to save weight, what do yours weigh?

Posted 5 years ago

fotorat
Free Member

I think all my problems are caused by the mud hugger and the clay that I ride on – the MH would be good if mud didnt stick to it and in some parts of the country that might be the case.

I have orderded the puny syncros bolt on guard (£15 posted Tredz) and If it doesnt cover the rear of the front tire very well I will extend it, hopefully it will be a bit higher than the Mud hugger, so that stones dont get stuck in it.

I never had any issues like this with my lefty bikes, and BTW my 2002 lefty 130 defects less that the Fox 36 under braking! but apart from that the fox is a great fork, even if the lock out is harder to reach than on the old lefty,

The MH is no on a 26er Marin with a 2.2 tyre and it looks a better fit (ie more clearnace)

Cant wait to see how Tight the 2.6 Butcher is in the Foxes

Posted 5 years ago

DezB
Free Member

Ebike!

Posted 5 years ago