How often do you bottom out your forks?

Just curious about this. As i bought some new fox 140's about 5 weeks ago which were a massive step up on my old xc forks. Anyway they're set up relatively plushly & i've been riding them quite hard since i've got them. Out of curiosity i've been keeping an eye on the line showing how much they've bottomed out on the ride at the end of every ride. Anyway so far i've only managed to get about 120-125mm down on them. Which has left me wondering how often do most folks bottom out on their travel? And should i maybe run them even a smidgeon softer/plusher?

Once or twice a ride.

same as jambo, anyless and you are either not riding right, or have got way too much travel

If you have decent jumps or compressions you should be bottoming out a good few times.

No point in having travel and not setting the forks up correctly to make use of it.

Somewhere like Ae i will use full travel 5 or more times not including the big drop offs at the end of Omega Man (130mm Revelations).

The loading on your arms will soon tell you if you are using all the travel.

Once a lap at Kirroughtree on Saturday. Once or twice on an average ride would be normal. If its an easier ride then you probably won't bottom them out and likewise if its a harder than normal ride then you would probably bottom them out more.

Never really. I used to bottom my old ones out all the time but since I got more travel I don't think I have. I hate soft forks and also hate the feeling of them bottoming out, so I set em up harder than recommended to avoid this.

Once ever, when I accidentally jumped something and landed on the fork – 130mm and all the way to the crown.

All the time, but mine are crap.:)

do you mean:

A) THUNK!! – bugger me. my wrists just shattered.

B) oh, look, judging by the zip-tie i put round the stanchion for just this purpose, i think i used just about my full stated travel.

answers:

A) hardly ever – usually a sign that something's wrong

B) sometimes once a ride, sometimes every descent, sometimes several times during a descent. depends how hard i'm riding.

on the big boingy bike at least once a ride for full travel, on the 29er less often as I prefer a stiffer frontage with some emergency squish for when I **** it up 😀

you don't want to leave a ziptie on the forks, you'll scratch the stanchions over time. A nice soft rubber O ring is much more fork friendly

bump for the day shift

It's a fine balance between getting as much travel as possible and having them too soft causing them to use too much travel when braking riding down steep stuff reducing the head angle and making the bike feel a bit twitchy.

I'm on the border between two spring rates on my vanilla 140mm forks for xc and general riding around the softer spring is fine and will use virtually all it's travel bottoming once or twice a ride on big hits and on some of my more sketchy landing 😕

The heavier weight spring works well for more dh riding if I'm doing runs of Cwmcarn downhill track for example, and only bottoms on really heavy front end landings where if I'd been running the softer spring I'd probably have crashed. The sensitivity on the forks isn't as good either on small bumps.

You don't mention which model of Fox forks they are the rlc's have have compression adjustment so you could use that to adjust the feel while running lower pressures.

The best way is to set the fork pressures/spring rates up using the sag and adjust the other feature afterwards, have a look at the link below for some pointers, if you have any further questions drop me a mail or call me at the workshop, Simon

http://www.locotuning.co.uk/tech-info.html

They're Float 140Rl's. I haven't played around with the sag too much though they're set up at the correct presure for my weight. Anyways like i said i'm getting around 125mm out of them almost every ride. Which is 90% of the travel so i'm not overly worried as i'm not sure i'd like to be running them any plusher than they are at present. I'm just curious to see what the norm is more than anything else.

sounds ok, you could always just drop 5psi at a time to see how they feel.

I'm on the border between two spring rates on my vanilla 140mm forks for xc and general riding around the softer spring is fine and will use virtually all it's travel bottoming once or twice a ride on big hits and on some of my more sketchy landing

Identical to me. I like them as they are though, with a couple of turns of preload added they're just spot on. 🙂

I haven't played around with the sag too much though they're set up at the correct presure for my weight

If you've not checked the sag, you have no idea if they are set up properly for your weight. 🙂 Given air pressure guides can, and usually are, be way out. There's waaaaaay tooo many variables for them to be very accurate (Weight distribution basically – LOTS of things affect it)

Go check the sag. Start at about 25% and go from there, but stick between 20% & 30% as a rule of thumb.

Go on: Now! What you waitin' for? Shoo! Get on with it!

🙂

twice a ride

I'm running the softer spring with full preload Peter. There's a small gap in the spring rate between that and the heavier spring run with no preload, really minimal but I'm a fussy bugger when it come to suspension 😉

I thought it was bad to bottom out your forks? maybe I need less PSI in mine then!

Not necessarily bottom them out hard, as in clunk just use all their travel, there are bottom out rubbers at the bottom of the lowers to protect the bottom of the fork stantions, but these will not protect them if you are repeatdly bottoming the forks heavily.

Air forks NEVER give all their stated travel. The manufacturers lie through their teeth – unless they are Pace in which case you get a little more than the stated travel.

The internals probably have 140mm of movement when they're dismantled, but the air chamber would have to go to zero size to get that, which is clearly impossible.

My Fox 140s gave about 125mm travel, so you're doing ok. My Revs give similar, and I once had some Manitou Minutes which only gave 100mm when all the air was let out and they were jumped on.

Air forks NEVER give all their stated travel

Oh by fek yes they do mate! 🙂 You should hear the noise Rebas make when you bottom them out! It doesn't happen often, but when it does, you know about it! 🙂

I'm talking seals ALL THE WAY to the crown!

EDIT
I bottomed my forks out when we were out the other night actually, just once, off that drop on Fenceline. But they're Vanillas, so that's a bit beside the point… 🙂

My Revs would have to be far too soft in normal riding to allow the seals to get to the crown. Likewise my Marzocchi 66s – long battle with them trying to get full travel. The air ones mind, not the coil ones which gave full travel easily – like you say 🙂

my solo-air lyriks often give me 160mm

and guess how much travel i get from my 140mm solo-air recons?

go on, have a guess…

molgrips – Member

Air forks NEVER give all their stated travel. The manufacturers lie through their teeth – unless they are Pace in which case you get a little more than the stated travel.

Rubbish – all mine do – set up properly.

I aim to set forks so that they use all the travel once per ride in normal riding. We have bottomed the z1s on the tandem hard with a clang once but use all the travel on a run round GT red

Fox 32 air forks are notorious for not using all their travel when the sag is set in a normal range.

My own 100mm Fox's have never bottomed out. I have to run much more sag on them than I did on my Reba's to get decent travel and reduce harshness. The downside of this is that they tend to dive more on the brakes.

It can be due to too much Float fluid in the air chamber and there is also a diy solution involving shortening one of the internals but there is no way I'm taking a hacksaw to them.

I think getting them Pushed is supposed to solve it.

A few times each ride (and they're air forks)

I never bottom mine out, to my knowledge. To set them soft enough that they do, they'd dive loads under braking and on steep descents.

Sounds like they're too linear then Kit…

i got some cheap marz 55's on the bottlerocket. i havent bottomed them out yet at herts shore which suprised me

I always put a little extra oil in my marzocchi's, then its very difficult to bottom them out. Otherwise they make a horrible clunk when they go.

My Revs would have to be far too soft in normal riding to allow the seals to get to the crown

In normal riding I'd say you should be getting up to 5-8mm from full travel. After that you're into bumpstop territory! In all the time (4 years) I had my Rebas I truly bottomed them out twice, the first time wheelying through a ditch at speed, which was bigger than anticipated, I slammed flat into the opposite bank. WHUMPHHH! That did it! 🙂

depends on the riding. When doing DH i sometimes bottom them out, rarely when doing xc. I'm too lazy to mess around with spring rates. Scareyest thing is getting repeated bottomouts over large braking bumps (8" deep) on a steep, fast dh run. Just have to hold on and hope they finish..