The FS Drop Test
 

[Closed] The FS Drop Test

 jfeb
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I've heard people say (including Tim Flooks on his suspension-setup video) that you should be able to lift the rear wheel of your FS bike off the ground and when you drop it, it shouldn't bounce. When I do this to my, still fairly new and therefore possibly not properly bedded in, Blur 4X it bounces two or three times before stopping, much like my hard tail would.

Is this "drop test" a real measure of if your rear suspension is set up right? I can't imagine running the shock soft enough to stop my rear wheel bouncing when dropped.


 
Posted : 14/04/2009 10:16 pm
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I can't see it being right.

An FS correctly set up for a 9 stone whippet is going need much firmer spring/pressure than for a 20 stone clydesdale.


 
Posted : 14/04/2009 10:19 pm
 momo
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mingsta - Member

I can't see it being right.

An FS correctly set up for a 9 stone whippet is going need much firmer spring/pressure than for a 20 stone clydesdale.

er...think you might have got that the wrong way round


 
Posted : 14/04/2009 10:20 pm
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Try dropping the bike with you and all your kit on it. That's probably a better test.... it won't bounce back quite so quickly 🙂


 
Posted : 14/04/2009 10:22 pm
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I'd go with what TF says over some random bloke on an internet forum any day 😉


 
Posted : 14/04/2009 10:23 pm
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As far as I know that holds true, I have mates whose full sussers manage it however mine has always bounced around like a pogo stick!


 
Posted : 14/04/2009 10:23 pm
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its all about rebound balance. not enough to pitch you off (i.e. your bike is a bit pogo stick) and not slow enough to pack down. the wheel test worked for me - 9.5 stone when i rode FS.
it has nothing to do with sag which is weight dependant,


 
Posted : 14/04/2009 10:26 pm
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Slow your rebound a little to pass the drop test.


 
Posted : 14/04/2009 10:27 pm
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From what i have seen, most bikes with a coil shock on the rear will not bounce, and most with an air shock do...

I think it is just a bit of stiction in the air shock that mean that there is not enough give to stop the bike from bouncing on its tyres.

DH tyres do a lot to stop a bike from bouncing too.


 
Posted : 14/04/2009 10:32 pm
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stop dropping and start riding! 🙂


 
Posted : 14/04/2009 10:34 pm
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It also depends on what riding you are doing. I do use the drop test and it works well, but that is on an 8 1/2 inch travel DH bike with 40's on the front that does 10 ft drops and big jumps. My Specialized Pitch isn't set up to be quite so forgiving for big hits as It doesn't do big drops and jumps very often and I want to avoid pedal bob that I don't have to worry about on the DH bike as I don't pedal it on the flats.
So, softer/slower rebound for a DH bike (drop test soft) and slightly firmer/ faster rebound for other disciplines.
Hope that helps


 
Posted : 14/04/2009 10:35 pm
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Seems to work fine with no bounce here, but that's with 6.5" travel, lots of sag (as normal), a coil shock and DH tyres 🙂


 
Posted : 14/04/2009 10:39 pm
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my marin quake doesn't bounce with a dhx air shock


 
Posted : 14/04/2009 10:47 pm
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Yes, the drop test is real. Definitely tried and tested on bigger bikes.


 
Posted : 14/04/2009 11:00 pm
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Definitely use it for bigger bikes, wouldn't think of setting up my Epic that way though!


 
Posted : 14/04/2009 11:06 pm
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my st10 used to stick to the floor like glue .... my heckler probably woulda done a backflip if i tried that !


 
Posted : 14/04/2009 11:16 pm
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Tim Flooks is supposed to be the guru but it seems a very odd way of testing them to me - an unladen bike will behave very differently to one with the rider aboard. testing it like that you are only going to be using a tiny part of the sus travel and the tyres are going to have a big effect.


 
Posted : 14/04/2009 11:17 pm
 Epic
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Drop test is a good 'guide' to getting the damping settings correct, but personal preference on the trail also means alot.

Both my current Scott Octane DH rig and Scott Spark XC rig are set up to pass the 'drop test' and feel good on the trail. But, I've had prevoius full suss XC rigs that packed down on rougher descents if I set the damping to pass the drop test, so I then ran less rebound damping and they rode better on the trail. But 'failed' the drop test.

Trial and error is the best way to set up your bike. What feels good for YOU and your riding style/rider weight/favourite terrain, is always best. Not what I, a forum, or Tim Flooks tells you!


 
Posted : 14/04/2009 11:18 pm
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TJ You seem to be thinking it's some sort of part of the set up process or definitive test - it's not. It's just a trait that most well set up dh bikes share.


 
Posted : 14/04/2009 11:21 pm
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My Demo 8 and 224 didn't bounce. My commencal does. Even my Azonic with a short stroke coil shock did


 
Posted : 14/04/2009 11:25 pm
 GW
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it's a DH bike test!

don't most of you lycra beardy weirdos ride your suspension so it doesn't actually work anyway?


 
Posted : 14/04/2009 11:40 pm
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Oh?
I thought the drop test was 6 foot to flat.
🙄


 
Posted : 15/04/2009 1:22 am
 mboy
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it's a DH bike test!

don't most of you lycra beardy weirdos ride your suspension so it doesn't actually work anyway?

LOL, made me chuckle

It is indeed for long travel, coil sprung, DH bikes this test. And it is of course only an indicator. An 80mm travel superlight XC bike with rock hard 1.9" tyres is going to bounce all over the place still. A DH bike with 2.5" super tacky's should definitely not pogo when dropped.

Whether beardy and weird or not, from what I see of most FS bikes out on the trail, I very much agree with GW here. Seeing bikes get less than half their available travel, rebound either way too fast or way too slow, is all too common. I know that the couple of 2nd hand FS bikes I have bought were setup totally to pot, to the point of being unridable to me (ridiculously slow fork rebound and zero rear shock rebound on the one bike). Personal preference does play a part, but a shock has rebound damping for a reason!


 
Posted : 15/04/2009 2:23 am
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my bikes do this. Am I GNAR?


 
Posted : 15/04/2009 7:56 am
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aye, my norco grabs the ground doing the bounce test. 6" travel, dhx air shock.


 
Posted : 15/04/2009 8:55 am
 Olly
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3rded (ish) for being a DH bike trait, if i set my trance up like that i would race through the travel far to quickly with me on it.
much easier to achieve on a 50lb DH bike with 9" of travel to wallow around in


 
Posted : 15/04/2009 9:03 am
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I've seen it done in Biketreks. Spesh Demo 8, IIRC. Coil both ends....


 
Posted : 15/04/2009 9:11 am
 Del
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for most bikes this will be a test for a FS that is set up 'safely'. ie the rebound is set slow enough to err on the side of packing down to pass the test, therefore as the bike takes successive hits, the angles will get slacker, and the bike will become more stable ( at least until you run out of travel! ). get it to the point where it passes the test, then for general riding speed up the rebound a little, IMO.
front should be set up the other way around for the same reasons - the rebound should be a little on the quick side, as the last thing you want is for the front to pack down.


 
Posted : 15/04/2009 9:11 am
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Mine's fine - air shock, only 4" travel but set up pretty squishy. Bearings rattle like a bag o' spanners though - must get to the lbs 😉


 
Posted : 15/04/2009 9:38 am
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My hardtail bounces when I do the drop test, should I be worried?


 
Posted : 15/04/2009 9:48 am
 juan
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The drop test here is to lift your bike up to 1 m (3 foot 😉 ) and drop it. Shouldn't bounce either.
But it's just a hint on how the bike should be set up 😉


 
Posted : 15/04/2009 9:52 am
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How can you properly appreciate a nice fast downhill if you have suspension?

You may as well ride on the road 🙂


 
Posted : 15/04/2009 9:55 am
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My properly set up NRS bounces all over the show with the drop test 🙂 My old coyote didnt though, that had a lovely ground-mushing feel that absorbed all sorts, including loads of energy from my legs 🙂


 
Posted : 15/04/2009 10:08 am
 juan
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My properly set up NRS bounces all over the show with the drop test

You have to thanks the F1 arm chair engineer for that... "Let's get rid of bobing with FS bike shall we... Yes lets run on with no SAG"

Stoopidest thing ever


 
Posted : 15/04/2009 10:10 am
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Not stoopid when you ride one though juan. Just becuase it isn't a 9" travel machine with 3" tyres oozing GNAR ...


 
Posted : 15/04/2009 10:37 am
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I reckon i can get my steel hardtail to pass this test. 2.35 tyres with about 15psi should be about right. Does that make it properly "sorted" or does it make this one of the most generalised generalisation i have ever read about. I could get a £99 tescos special to pass that test and it would still ride like a bag of poo


 
Posted : 15/04/2009 10:47 am
 juan
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anotherdeadhero I don't have a 9" DH FS with 3" tyres 😉 but I still use sag in my rear and from suspension


 
Posted : 15/04/2009 10:49 am
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😉 I think thats becuase your suspension design is designed to use sag ... whereas the NRS isn't ...


 
Posted : 15/04/2009 11:11 am
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NRS rides like a dream with no sag imo.Just like a h/tail with a bit of plush suspension when you need it most....


 
Posted : 15/04/2009 1:09 pm
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TheLittlestHobo
I reckon i can get my steel hardtail to pass this test. 2.35 tyres with about 15psi should be about right. Does that make it properly "sorted" or does it make this one of the most generalised generalisation i have ever read about. I could get a £99 tescos special to pass that test and it would still ride like a bag of poo

I think you've missed the point here. But I encourage you to post a video of you doing the above.


 
Posted : 15/04/2009 1:18 pm
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TJ (and others) , the test accounts for different rider weights as you set the sag first then the rebound. So the heavier rider has a harder shock, so runs more rebound to stop it bouncing back up again........

It works, but then again i run all my bikes under sprung and under damped (i.e. fast in both strokes) by most peoples standards.


 
Posted : 15/04/2009 1:21 pm
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I normally use my RAD-o-meter to see if my suspension is set up right.


 
Posted : 15/04/2009 1:27 pm
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I thought there was only one setting to a RAD-o-meter, MAX!


 
Posted : 15/04/2009 1:48 pm