ColinL

Prior to the past two months, my experience with jumps and drops was all on a BMX bike. I've been jumping everything in sight on my FS MTB now and I don't actually feel anything odd, but I take note of my travel indicators after a ride, and compare that to my fork & shock settings and how I thought the bike handled.

I have a new 2012 Fox Float 32 120mm RLC fork and a very old, but still quite functional, Fox Float R AVA shock which I would guess is around the age of the frame (2004).

what could happen from bottoming out?
- blowing the fork or shock? (just seals or can the damper cartridge be harmed?)
- bending a wheel?
- breaking the frame? nah... I don't jump anything huge, it's Kansas.

I can dial in some more low speed compression in the fork and decrease the AVA on the shock without increasing the air pressure in either of them. To me, this is a good thing since the air pressure determines sag and small bump compliance. I guess I'd be interested in tuning to avoid bottoming out if I still have good performance on the rest of the trail. Because, really, these jumps are totally optional. But they're *fun*.

Thoughts?

ColinL

Oh, and besides not actually feeling it when I bottom out, so far there are no signs of issues with the bike at all. No oil weeping past the seals in the fork or shock, no wheels out of true, etc. My riding weight is 178 pounds with a camelbak full of water and a few tools.

I've also heard that if your suspension is properly adjusted you should use all your travel one or two times on a trail. I'm sure there's a difference between 'just' using all the travel and bottoming harshly...

ColinL

Nothing? No opinions or thoughts at all?

Dannihilator

Could bend the internals on the fork, and get the rear shock stuck down. Not entirely likely though.

Lexi01

I used to use a hybrid on some local trails.

It had a 62mm front suspension with a little manual switch to lock/unlock the fork. After a pretty rough ride one day (involving a shed load of bottoming out - not easy to avoid when you're over 220 with a 62mm susp) I got home and noticed that the little switch was gone...

I'm assuming the abuse it took just popped it right off.

So - I'm not saying this could happen to you as Im assuming you're using a "propper" mtb...but it illustrates the stresses that bottoming out can inflict on the fork.

mystolenbikes

If you are bottoming out your suspension you don't have it tuned right the begin with. Even if don't damage the bike whatever you said about small bump compliance or having the slow compression adjusted all went out the window. Tune your suspension properly and you'll enjoy your bike a whole lot more. Plus your components will last much longer too.

scrublover

If you're not feeling any actual harsh bottom out, then fuggedaboutit. So long as you feel the travel is doing its job otherwise, not feeling too harsh on other stuff, not wallowing otherwise, no worries.

If it's feeling harsh, then you:

1. ride smoother
2. more air pressure
3. more compression damping
4. as you say, play with the AVA volume
5. some combo of the above

I'd personally go for 1 and 4, and again, not wory about it unless you find yourself harshly bottoming.

Thor29

Bottoming out is totally fine. It is really dumb to tune your suspension to prevent bottoming out - that would mean that your suspension is set way too stiff. When it bottoms out your bike effectively becomes "rigid", just like the bikes us old timers used to ride in the old days (and some people still do). That will not hurt the bike or the suspension unless you are hitting really, really hard. If you hit things that hard you will know because you will bend rims, break handlebars, stems, and possibly your own body. Suspension is designed with bottoming in mind because there are bumps much larger than the longest travel forks.

ColinL

Good feedback, thanks everyone! I think I need to stop mid-ride between the optional jumps and find out how much travel I'm using on the rest of the trail. Also there's a jump right at the start, actually beside the trail, where I can do so tweaking and see if I can tune the suspension to not bottom and then back see how it rides the trail with that setting.

And no... this isn't like bottoming out a Suntour or RST hydraulic coil, I wouldn't think. It feels very plush when landing, and I've harshly bottomed out a dirtbike before. (Actually it was an enduro being ridden on a MX course.) So I know what that feels and sounds like.

mystolenbikes

Lol those are some if the worst advices I've ever seen. Proper tuning of your suspension is one of the best things you can do for your bike. It'll affect your entire riding experience. From climbing to going downhill to jumping to braking. Bro tune your suspension properly and watch your bike transform itself.

ColinL

I don't think anyone disagrees that tuning is important. You are the only one advocating to tune so that the suspension never bottoms out. That would produce a pretty stiff ride if your trails include jumps and drops. If you don't have any drops or jumps, it's quite easy to tune softer and still not bottom out.

And I do realize that I should have multiple tuning setups.

ncfisherman

If you're not using all your travel occasionally, then your suspension is not set up properly. There is a big difference between using all your travel and harshly bottoming out the fork/shock. As long as you're not hitting the wall, you're good.

mystolenbikes

Lol I hope you are kiddign. If you are not you need to quit riding full suspension bikes asap and stop giving bad advice too.

Read Thor29's post. If you are bottoming out I don't care how soft you think you are bottoming out. If you are, you way passed your bike's suspension travel. This is why you set 25-35% sag on your suspension.
So you are saying if I take out 5-10 psi out of my tires and I feel my rims hit the rocks and roots softly as I'm coming down the mountain I should be ok?

That example goes for the suspension. Let me repeat myself again...IF YOU ARE BOTTOMING OUT YOUR SUSPENSION IS SET UP WRONG! Period.

ColinL

Thor29 doesn't agree with you, so what are you expecting me to learn from re-reading it again?

You cannot 'way pass' your suspension travel. There's an end to the travel and obviously you can't ever exceed that travel.

The end of the travel in a decent fork or shock has an elastomer bumper. I think we established that hitting it hard is bad. Hitting it gently is *using* all the travel.

The purpose of sag is so that when you hit a hole or anything lower than where the wheel is now (like the downside of a series of bumps) the wheel will travel, and to ensure you have the correct spring tension (whether air spring or coil) for the suspension to operate as expected.

Now please, go troll somewhere else.

Thor29

If you set up your suspension per the manufacturer's instructions at 25-35% sag, and you never bottom out, then that can only mean one thing - you are really, really slow. And you definitely do not jump or go off drop-offs. The only way that a fast rider or jumper can set suspension so that it doesn't bottom out is to put in so much air pressure that there is almost no sag at all. (Keep in mind that I am only talking about air sprung forks and shocks, for coil sprung suspension you would have to replace the coil to decrease your chances of bottoming out).

If you are not slow, then maybe you bottom out and don't realize it. My Fox forks bottom very smoothly and you really don't feel it. But I am guessing that you are, in fact, really slow.

ColinL

I'm pretty sure that sort of abusive nonsense is not encouraged at BikeForums.

making

I am locking this for now until we have a chance to take a look.