You'll also need to consider the fork offset (based off of the crown steerer).

 

I knew there was something I wasn't considering.

That kills it I'd think -- quite a difference in rake/offsets between the two.

 

Lol, I thought you were doing to get the less offset. That's what I'm working on with a Pike.

 

Bringing this back up from last summer. Thought I'd ask this again since a lot of the new 29er forks are coming with 44mm offset. And that seemed to be the one sticking point here.

So ... any reason this can't be done? Stock offset on the 27.5 is also 44mm

 

Yes this can be done with no issues. I was about convert my Diamonds from 27.5 to 29er by doing a lower leg swap but ended up sticking with the Fox 29 so I could fit the push kit.

 

Hi, sorry to necro an older thread. Do you guys know whether installing a 27.5" upper in a 29" fork is possible, and if so, does it affect travel?

Replacement Rock Shox uppers in the 27.5" size are easily obtainable, but 29" are hard to find.

Thanks!

 

I've been having this same questions lately. The CSU are the same, so are the 29er lowers longer than the 27.5? on the 2021 the airshafts are the same.

 

No issues doing this. Especially with the shorter 29er offsets. I did this conversion for several months before buying a new 29 fork

For Fox, the air shafts are wheel-sized specific. So if it's for a Fox fork you'll need a new air shaft too.

I believe RockShox the air shafts are interchangeable - so a 140mm 27.5 air shaft is equivalent to a 120mm 29 air shaft

 

Anyone know if it would it be possible to put a 2020 Fox 36 27.5 lower leg on a 2006 Fox 36 Talas 26 to "mullet" the bike and just keep the same internals?

The stanchions are the same diameter and distance apart, and I figure because the Talas has adjustable travel you could alter it to accommodate the bigger wheel without having to get a new air spring. I guess my real questions is: would the Talas air spring and dampener connect properly to the ports at the bottom of the new lower leg correctly and might there be anything else I should be concerned with besides the slightly altered geo of the potentially new bike set-up?

Thanks!

 

Thinking about trying this. I'll look up fork specs on my fox 34 and see if airshafts are different. I have a Mojo 4 I'm wanting to make a mullet. I was going to put a 44 offset 130 on it, but then I thought I could keep it a 140 if I can change out the lowers with the 37 offset upper.

 

Hey, did that work? I know with a Mezzer you can just swap the lowers, but you get +7mm offset. I had a 44os 275 so ended up with 51os 29er. If I had the 37os 275 I'd get a 44os 29er. They sell two CSUs, 'long' and 'short'. Is it the same with Fox?

 

Thread dig-alig-dig.

Got some pristine lowers from a set of 35mm Revelations (29") but trashed CSU.

I have found someone selling a set of 27.5" lyriks and was thinking to swap the lyric CSU onto the Revelation lowers.

Is this possible...?

 

No, too long

 

That's what she said.

 

What is too long?

 

The Lyrik's upper tubes are 20mm on the right and 30mm on the left longer than on the Revelation/Pike.

 

Ah righto, so the Revelation lowers will fit in the lyrik CSU (as in, distance between stanchions is the same), but axle-to-crown will be wack and max fork travel would anyone's guess as to what it ends up being.

 

Yes and the left side will bottom out before the right.

 

Yes, the damper leg casting have a higher cast bottom. They wanted to give the airspring a little more room.

 

Awesome thanks.