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Air Fork vs Coil

canadmos

canadmos

Cake Tease
May 29, 2011
20,437
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Canaderp
I've been riding a Fox 36 Van for the last 6 or so years. I have no complaints about this thing and it is still in great shape.

But I have been seriously pondering moving over to a Fox 36 Float, to lose a little weight off the bike and to have a little bit more control over the sag/spring rate as compared to the limited spring options in the Van.

What should I expect from an air fork, in particular the Fox 36 Float? I have not ridden on one before, so I have no clue.

The maintenance on this one has been pretty stellar, too. I pretty much change the oil twice a year and I've only had to replace the seals twice. And only one bladder malfunction... Will the Float require a lot more service?

Are there any particular Float years to avoid because of problems?

This is the fork I currently run...Its the Van R.
 
dan-o

dan-o

Turbo Monkey
Jun 30, 2004
6,499
2,805
15/16 Float 36 is awesome.
I've owned them all and this is far and away best generation and only one to buy.
 
djjohnr

djjohnr

Turbo Monkey
Apr 21, 2002
3,012
1,704
Northern California
I just installed a '15 36 Float RC2. It actually has less stiction then my '07 36 Van with '09 damper did. Only one ride on it so far so I can't comment on much more yet, but so far so good.
 
Sandwich

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,061
5,970
borcester rhymes
really like my 36 for its range of tuning, stiffness, small bump, and composure through the rough stuff. great fork.

coil vs. air is not as big a problem on modern forks with good negative spring setups and non-dh temperature problems.
 
Udi

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
The Float spring unit will *never* be as good as the coil, it's just physics. You have more sliding surfaces and seals, air preload effects, and negative air spring effects (in the 2015 model) adding to stiction and nonlinearity. In my experience though, the biggest advantage of the coil spring is consistency. It feels the same every day in most states of disservice, whereas the air springs always seem to degrade over their service intervals - often a psychological battle of "is it actually worse?" until service day when the answer is a resounding "yes it was".

That said, they've worked hard to make the 2015 36 good (bigger bushing clearances, new oil, low friction damper sealhead, decent air spring), so if you literally drop your Van and pick up the new one, you'll probably be happy. The damper is probably the biggest upgrade over the old variety, and you'll notice a solid increase in compression range as well as more reliability - it's pretty hard to blow up an invert FIT-RC2 damper.

I wouldn't get pre-2015 models of Float unless you've tried one set up for yourself and are happy - the older ones use a coil negative spring which *is* actually superior *if* you happen to match the exact single pressure value that matches the negative spring, but otherwise it either sits into its travel or tops out. The 2015 addresses this by going back to an auto-eq air negative.

The ultimate solution is (and always will be) dropping a coil rod and spring into the latest chassis - and unless you've done this it's not an apples-to-apples comparison, but that's not something everyone has the luxury of doing.
 
4130biker

4130biker

PM me about Tantrum Cycles!
May 24, 2007
3,884
449
Udi said:
...that's not something everyone has the luxury of doing.
Click to expand...
Have you, or anyone else converted a modern 36 or Pike to coil?
Are there options out there that are achievable with readily available parts?
Sounds like it could be pretty awesome...

I suppose you'd have to fully commit with the potential of scratching up the inside of the stanchion.
 
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djjohnr

djjohnr

Turbo Monkey
Apr 21, 2002
3,012
1,704
Northern California
One thing about the newer chassis - it doesn't feel as stiff. My last 36 was 160mm while I'm running this one at 180mm so it's not exactly apples to apples, but I have a feeling if I lowered this one it still wouldn't be as stiff as the '07 I had.

Udi said:
The ultimate solution is (and always will be) dropping a coil rod and spring into the latest chassis - and unless you've done this it's not an apples-to-apples comparison, but that's not something everyone has the luxury of doing.
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I'm surprised a company like Push/Vorsprung/TFTuned haven't brought a coil conversion kit to market yet.
 
HAB

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
djjohnr said:
One thing about the newer chassis - it doesn't feel as stiff. My last 36 was 160mm while I'm running this one at 180mm so it's not exactly apples to apples, but I have a feeling if I lowered this one it still wouldn't be as stiff as the '07 I had.
Click to expand...
I don't agree with this at all.
 
djjohnr

djjohnr

Turbo Monkey
Apr 21, 2002
3,012
1,704
Northern California
You'll find the same comment in a few reviews. An '07 36 Float weighs 5.05 lbs, a 15 is 4.38 lbs. It's not a noodle, but going through the same rock garden it wasn't quite as stiff.
 
jackalope

jackalope

Mental acuity - 1%
Jan 9, 2004
7,605
5,914
in a single wide, cooking meth...
In full disclosure, this is coming from someone who's only detected the dreaded fork noodlyness in RS Indy SLs, longer travel Fox 32s and a Zoch Shiver, but my understanding is the new 36 lowers, tapered steerer, clamping mechanism and crown design makes it stiffer than the older models like your '07. I had an '06 Van 36, and it was a helluva good fork for the time, but I picked it up a few weekends ago and I think it weighs more than my frame does now. But again, I can't tell the difference between my old 36, '13 Float 36, 55 CR, or new Pike in terms of stiffness - in any direction. I can say the '13 Float 36 had the worst damper and air spring (by far), but the chassis was more than adequate IMO.
 
kickstand

kickstand

Turbo Monkey
Sep 18, 2009
3,441
392
Fenton, MI
djjohnr said:
You'll find the same comment in a few reviews. An '07 36 Float weighs 5.05 lbs, a 15 is 4.38 lbs. It's not a noodle, but going through the same rock garden it wasn't quite as stiff.
Click to expand...
Would be interesting to weigh to the two empty chassis side by side, as I could see the coil spring taking up a fair chunk of that .7 lbs. I'd also bet the old fork isn't stiffer.
 
djjohnr

djjohnr

Turbo Monkey
Apr 21, 2002
3,012
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Northern California
That's a float vs a float. My Van was heavier then 5.05 lbs. It felt considerably stiffer then the '15 I rode yesterday. Granted, that's 180 to 160, but still. Fox did a lot to stiffen up the chassis, but that was likely necessary to counteract how much weight they dropped.
 
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Udi

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
For those claiming the new fork is stiffer, have you laterally and torsionally loaded the new vs. old chassis with a fixed mass/force and measured deflection? This stuff isn't actually hard to test, a German magazine did exactly this when 15mm came out.

I haven't myself so I'm reluctant to comment, but given how this stuff works, I'd say djjohnr is more likely to be correct. The alloys haven't changed substantially, so less weight = less material, and given that neither stanchion diameter not external dimensions have changed substantially, it's very likely that the old 36 is stiffer. It's basic moment of inertia stuff. Of course with that said, the new 36 is still going to be stiffer than all its competition while saving a lot of weight, so it's a win/win for most people.

kickstand said:
Would be interesting to weigh to the two empty chassis side by side, as I could see the coil spring taking up a fair chunk of that .7 lbs. I'd also bet the old fork isn't stiffer.
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You don't need to, Fox provide most of this data for both the new 36 and new 40, it's brilliant. If you know the weight of the old one, you can work out exactly how much weight you'd add by running the new chassis with old coil spring assembly. Hint: most of the weight savings are in the chassis, so you can build a very light coil fork provided you can find the correct rod length.





4130biker said:
Have you, or anyone else converted a modern 36 or Pike to coil? Are there options out there that are achievable with readily available parts? Sounds like it could be pretty awesome...
Click to expand...
I did that exact conversion on a new 40 and the results are exactly what you'd expect: ~2850g complete fork weight (down from 3120g) with all the benefits of a coil spring. Feels way better than the Float (I started with a stock Float, so rode it back to back).

Will do the same with a 36 soon, but right now my 36 is a van/kash/RC2/160. I definitely prefer it as a coil, and obviously the functionality won't change with the new chassis - just the weight.
 
HAB

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
Udi said:
For those claiming the new fork is stiffer, have you laterally and torsionally loaded the new vs. old chassis with a fixed mass/force and measured deflection? This stuff isn't actually hard to test, a German magazine did exactly this when 15mm came out.

I haven't myself so I'm reluctant to comment, but given how this stuff works, I'd say djjohnr is more likely to be correct. The alloys haven't changed substantially, so less weight = less material, and given that neither stanchion diameter not external dimensions have changed substantially, it's very likely that the old 36 is stiffer. It's basic moment of inertia stuff. Of course with that said, the new 36 is still going to be stiffer than all its competition while saving a lot of weight, so it's a win/win for most people.
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I haven't. I mostly agree with what you're saying about the materials not changing much, and less material likely meaning less stiffness, though the placement of that material does matter a lot. Better optimization could potentially drop weight without impacting stiffness much.

The difference that I think you're not accounting for is the steerer. IIRC they didn't offer a tapered steerer until 2008, and my 2015 has one. That's a (relatively) recent bike industry standard "innovation" that actually does make an appreciable difference.
 
djjohnr

djjohnr

Turbo Monkey
Apr 21, 2002
3,012
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Northern California
HAB said:
The difference that I think you're not accounting for is the steerer. IIRC they didn't offer a tapered steerer until 2008, and my 2015 has one. That's a (relatively) recent bike industry standard "innovation" that actually does make an appreciable difference.
Click to expand...
That was my rational for why I thought stiffness would be a wash when I ordered it. If I had to guess it's the lighter crown and uppers that I'm feeling. Whatever, I LIKE the fork. It's definitely not a noodle, it has good mid-stroke support and the small bump absorption is fantastic. I'll probably replace the Mattoc on my trail bike with one as well.
 
W

wood booger

Monkey
Jul 16, 2008
668
72
the land of cheap beer
Dampers between air/coil forks are different (like Float vs Van).
If you just drop a spring in an air fork, it will tend to blow through the end of the travel and bottom a lot. or you will end up running a very stiff spring. But they do feel smooooove.
Don't know how a coil Pike would fare...

Air forks are so bomber these days, and uber sensitive, and adjustable, I don't think coil has much advantage.
And air you can actually fine tune with a little pump....

I have been on a '15 Fox 36 for the past year+ and have run it at 160 and 170mm. It can easily adjust from 160-180mm by pulling the air spring side apart.
By far and away the best fork I have ever owned, saves my ass and makes me smile almost every ride. I drop the lowers every few months, no damper service yet.
 
Udi

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
HAB said:
The difference that I think you're not accounting for is the steerer. IIRC they didn't offer a tapered steerer until 2008, and my 2015 has one. That's a (relatively) recent bike industry standard "innovation" that actually does make an appreciable difference.
Click to expand...
I was, you could get the taper steerer on plenty of the previous generation models, so I meant under an apples-apples comparison (taper vs. taper) - but yeah fair call for the OP's case. I must say though I'd be curious to see actual deflection data for a taper steerer vs. straight steerer in an otherwise identical fork. I have both CSU units for my 36 (taper and straight) and swapping between them I can't really notice much difference.

I do remember on the Totem you could 'feel' a difference between taper and standard - but I think that was mostly audible thanks to the horrible creaking.

I wish there was more data released on all this stuff, but semantics aside, no complaints on what they did with the new 36 - sweet axle design to keep everyone happy and the rest carefully optimised.
 
HAB

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
Udi said:
I was, you could get the taper steerer on plenty of the previous generation models, so I meant under an apples-apples comparison (taper vs. taper) - but yeah fair call for the OP's case. I must say though I'd be curious to see actual deflection data for a taper steerer vs. straight steerer in an otherwise identical fork. I have both CSU units for my 36 (taper and straight) and swapping between them I can't really notice much difference.

I do remember on the Totem you could 'feel' a difference between taper and standard - but I think that was mostly audible thanks to the horrible creaking.
Click to expand...
I haven't ridden an otherwise identical fork back to back in a while, so I don't have any real anecdotal thoughts either. I'd love to see some data too. One thing that just occurred to me is that I've only ridden my 2015 with Enve wheels, so maybe some of the stiffness improvement that I'm attributing to the fork should be chalked up to the wheels. I can say pretty conclusively that I think it's markedly stiffer than a Pike or Mattoc (both of which I've ridden extensively with the same couple of pairs of Enve wheels, on the same couple of bikes).

Udi said:
I wish there was more data released on all this stuff, but semantics aside, no complaints on what they did with the new 36 - sweet axle design to keep everyone happy and the rest carefully optimised.
Click to expand...
Yup. More hard data would be great, but it's definitely a really good fork.
 
big-ted

big-ted

Danced with A, attacked by C, fired by D.
Sep 27, 2005
1,400
47
Vancouver, BC
My old 2006 36 Van RC2 with straight 1 1/8 steerer was noticeably stiffer fore-aft than my new, tapered Pike, FWIW. Less difference in torsion, but the difference in fore-aft stiffness was definitely there.
 
Sandro

Sandro

Terrified of Cucumbers
Nov 12, 2006
3,224
2,537
The old world
canadmos

canadmos

Cake Tease
May 29, 2011
20,437
19,446
Canaderp
It is sometimes :D

Please note: US Fox dealers are prohibited from shipping Fox Shocks out of the US.
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The Canadian dollar sucks way too much right now to buy anything new from down there anyways. There are tons of 27.5 forks on PinkBike :(
 
jstuhlman

jstuhlman

bagpipe wanker
Dec 3, 2009
16,676
13,021
Cackalacka du Nord
i run a 2015 27.5 float 170 on my bike with a 26" wheel. the axle to crown and other numbers are actually very, very close to those of my old 160 float 36. it really adds to the unrideability of my bike. oh, and #futureproofed.
 
Flo33

Flo33

Turbo Monkey
Mar 3, 2015
2,065
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Styria
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