Suspension - Am I getting enough Travel?

Sorting out your thrunge brackets, fettling your inter-rositers and even stuff about bike parts.
User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Sun Oct 14, 2012 16:12 pm

Hi.

I've got a set of RS Revelation U-turn Dual air's, which go up to 140mm travel. Just went out for a ride, after fitting a zip-tie to the fork leg and found that I'm only getting 95mm travel. I've previously set the pressures to the RS recommended for my weight but does this mean that I need to reduce the pressures yet further, until I get max travel?

I also have a Fox Float RP2 rear shock and I set up the sag with the Fox Sag-Meter and again, it has recommended pressure, however, I am only getting 25mm of travel on the shock (O-ring on the shaft measured)

How much travel should I be getting from the rear shock? Can't find anything on the Fox site.

Any suggestions for the above please?

Thanks

User avatar
supersonic
Lives Here
Posts: 81829
Joined: Fri Nov 25, 2005 11:50 am

Re: Suspension - Am I getting enough Travel?

Postby supersonic » Sun Oct 14, 2012 16:13 pm

Run more sag, ride, see how it goes. Sounds like they are too firm. Recommended pressures are usually too firm.

User avatar
nicklouse
Lives Here
Posts: 80713
Joined: Thu Mar 20, 2003 12:14 pm

Re: Suspension - Am I getting enough Travel?

Postby nicklouse » Sun Oct 14, 2012 16:14 pm

Jenny Taylia wrote:Hi.

I've got a set of RS Revelation U-turn Dual air's, which go up to 140mm travel. Just went out for a ride, after fitting a zip-tie to the fork leg and found that I'm only getting 95mm travel. I've previously set the pressures to the RS recommended for my weight but does this mean that I need to reduce the pressures yet further, until I get max travel?

I also have a Fox Float RP2 rear shock and I set up the sag with the Fox Sag-Meter and again, it has recommended pressure, however, I am only getting 25mm of travel on the shock (O-ring on the shaft measured)

How much travel should I be getting from the rear shock? Can't find anything on the Fox site.

Any suggestions for the above please?

Thanks

read the setting up dual air forks in the FAQs. forget what any fork shock maker suggests as that is only a guess. set your sag go ride and tweek as needed.
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown

User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Re: Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Sun Oct 14, 2012 16:26 pm

[/quote]
read the setting up dual air forks in the FAQs. forget what any fork shock maker suggests as that is only a guess. set your sag go ride and tweek as needed.[/quote]

Can't find the MTB FAQ's, only road bike, can you provide a link please?

thanks

User avatar
nicklouse
Lives Here
Posts: 80713
Joined: Thu Mar 20, 2003 12:14 pm

Re: Suspension - Am I getting enough Travel?

Postby nicklouse » Sun Oct 14, 2012 16:27 pm

at the top of the tech forum

viewforum.php?f=10004
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."

Parktools :?:SheldonBrown

User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Re: Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Mon Oct 15, 2012 10:36 am

Well, just read Supersonic's very informative FAQ on setting up the forks. Mine are 2009 so I don't know if they count as "Old" or "New" regarding the setting up (but I've tried both methods) but after an hour of fiddling :roll:
I find that the only way to maintain 140mm of travel and to have 35mm of sag (25%) is to have 40psi in the Neg and 70psi in the Pos chambers (Set with the rebound damping totally off)

If I match the + & - chamber's psi's, I get only about 120mm or less of travel. Ideally, I'd like 140mm of travel, a slightly softer "Start" to the travel (By having 10% more in the -ve chamber, as per the FAQ)

If I boost the +ve to 130psi and the -ve to 130psi, I don't get enough sag and it all seems way too firm. Tried many combinations inbetween too.

I must be doing something wrong but can't figure out what. I'm 100kg and the RS sticker says 170psi upwards for my weight. Where are RS getting their 170psi figures from? it would be like a fixed fork at that!

HELP please :(

User avatar
bails87
Posts: 13051
Joined: Thu Mar 12, 2009 22:26 pm
Contact:

Re: Suspension - Am I getting enough Travel?

Postby bails87 » Mon Oct 15, 2012 11:07 am

What are you doing to check the travel? Just bouncing on the forks?

Just set the sag while in the attack position (standing on pedals, weight forwards) and tweak from there.
MTB/CX

"As I said last time, it won't happen again."

User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Re: Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Mon Oct 15, 2012 12:26 pm

bails87 wrote:What are you doing to check the travel? Just bouncing on the forks?

Just set the sag while in the attack position (standing on pedals, weight forwards) and tweak from there.



No, not "Just bouncing on the forks" :roll: doing as RS suggest and sitting on the bike in normal riding position, with all my gear on, climbing off and measuring the distance from the zip-tie to the seal :D

The position you suggest would give a "False" reading as downhills, where the forks work most, you're leaning back, weight over the back wheel, surely? but what do I know? (Hence the questions :D )

User avatar
bails87
Posts: 13051
Joined: Thu Mar 12, 2009 22:26 pm
Contact:

Re: Suspension - Am I getting enough Travel?

Postby bails87 » Mon Oct 15, 2012 12:49 pm

That's measuring sag, not travel.


Edit: I clicked edit instead of quote, so rewrote this post....kind of.
Last edited by bails87 on Tue Oct 16, 2012 08:53 am, edited 4 times in total.
MTB/CX

"As I said last time, it won't happen again."


User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Re: Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Tue Oct 16, 2012 08:31 am

I've been measuring the Sag, as stated above, on the bike with my riding gear on. measuring from the displaced zip-tie to the seal, once dismounted.

As for the travel, the forks are U-Turn's, as in the 1st post and have travel amounts stamped on the stansions, which is where I've been quoting the "Travel" amount from. When I've said I can't get 140mm travel, I mean that the seals are settled at the 120mm or less marker, even on full wind-up. I have to have the very low pressures quoted above, to achieve the correct sag and the 140mm travel.

Hope this clarifies and enables a forthcoming solution :wink:

User avatar
bails87
Posts: 13051
Joined: Thu Mar 12, 2009 22:26 pm
Contact:

Re: Suspension - Am I getting enough Travel?

Postby bails87 » Tue Oct 16, 2012 08:54 am

Jenny Taylia wrote:I've been measuring the Sag, as stated above.:


Like this:
Jenny Taylia wrote: doing as RS suggest and sitting on the bike in normal riding position, with all my gear on, climbing off and measuring the distance from the zip-tie to the seal :D

?
Right, that's almost right. But as already said you should be in the 'attack position'.
Jenny Taylia wrote:As for the travel, the forks are U-Turn's, as in the 1st post and have travel amounts stamped on the stansions, which is where I've been quoting the "Travel" amount from. When I've said I can't get 140mm travel, I mean that the seals are settled at the 120mm or less marker, even on full wind-up. I have to have very low pressures to achieve the correct sag and the 140mm travel.

Hope this clarifies and enables a forthcoming solution :wink:


Again, are you measuring it while you're off the bike?

EDIT: How can you have 140mm travel on a 140mm stanchion AND 25% sag at the same time?!

But tbh, ignore the travel. The forks shouldn't be fully extended when you're sitting on the bike btw. If you're riding thorugh a corner and there's a little dip in the ground, the forks extend to keep the wheel on the ground. That's why you have sag, forks don't just compress the absorb impacts, they extend to maintain traction.

The main point is: Set the sag while in the attack position. Then come back and hopefully tell us it's working.

Btw, my point about measuring travel by bouncing the forks wasn't sarcastic. That's how you would measure travel, assuming you could put enough force through the forks to push them down. Otherwise you'd take all the air out and compress them.
MTB/CX

"As I said last time, it won't happen again."

User avatar
The Rookie
Posts: 23071
Joined: Thu Apr 30, 2009 09:29 am

Re: Suspension - Am I getting enough Travel?

Postby The Rookie » Tue Oct 16, 2012 09:21 am

Clearly the forsk are capable of the 140mm idel, so just set the +ve and -ve pressure to get the ride quality you like, numbers are irrelevant as long as you're not bottoming out to often of topping out to often.....

User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Re: Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Tue Oct 16, 2012 10:08 am

Sag is measured as I've stated and the travel is done by reading the stansion marker whilst OFF the bike.

Surely the marker should show 140mm travel, if the u-turn is wound out fully? Then, when I sit on the bike, that gives the sag (Which should be 25% - 30% of the 140mm travel) for those "Dips round corners" etc to prevent the topping-out.

This is where I'm missing something. OFF the bike, with higher pressures - the correct sag gives me only 120mm or less of travel (On the markers).

I get the bit about ignoring the figures and getting the "Ride" I like but my pressures are way less than RS suggest for the optimum travel / ride

User avatar
bails87
Posts: 13051
Joined: Thu Mar 12, 2009 22:26 pm
Contact:

Re: Suspension - Am I getting enough Travel?

Postby bails87 » Tue Oct 16, 2012 11:13 am

Stand on the bike, in the attack position. Set the pressure to give you 25-30% sag in that position.

If you're setting the sag with hardly any weight on the forks then you're going to be running low pressures, which might make the forks sit into their travel a bit when they've only got the weight of the bike on them.

Set the sag in the attack position. Because that's the position you'll be in when you're actually riding the bike and you want the fork to be tracking the ground.
MTB/CX

"As I said last time, it won't happen again."

User avatar
Jenny Taylia
Posts: 224
Joined: Sat Oct 16, 2010 20:24 pm

Re: Suspension - Am I getting enough Travel?

Postby Jenny Taylia » Tue Oct 16, 2012 12:09 pm

bails87 wrote:Stand on the bike, in the attack position. Set the pressure to give you 25-30% sag in that position.

If you're setting the sag with hardly any weight on the forks then you're going to be running low pressures, which might make the forks sit into their travel a bit when they've only got the weight of the bike on them.

Set the sag in the attack position. Because that's the position you'll be in when you're actually riding the bike and you want the fork to be tracking the ground.


Well, we're gonna have to agree to differ on this.

the only time I ever stand up, leaning forwards, is when the forks are locked out and I'm climbing a hill. The most part of my riding is seated (How I've been setting my sag and how SRAM say to do it) and the forks work hardest when I'm standing and leaning back as far as I can, on descents.

Sitting to set the sag is the mid / average position of bike use.

Here's what SRAM say (How I've been doing it) - click the top choice, Dual Air Tuning Guide 2001-2011
http://www.sram.com/service/rockshox/7,107

User avatar
The Northern Monkey
Posts: 19547
Joined: Thu Jun 05, 2008 18:13 pm

Re: Suspension - Am I getting enough Travel?

Postby The Northern Monkey » Tue Oct 16, 2012 12:20 pm

Maybe you aren't riding the bike in a way that needs 140mm travel.. regardless of how you set the fork up. The terrain determins how much travel is required, the fork should be set up as Bails explains above.

If you're sat down all the time, then the likliehood is that you aren't riding anything that warrants 140mm in the 1st place.

User avatar
bails87
Posts: 13051
Joined: Thu Mar 12, 2009 22:26 pm
Contact:

Re: Suspension - Am I getting enough Travel?

Postby bails87 » Tue Oct 16, 2012 12:51 pm

MTB/CX

"As I said last time, it won't happen again."

Plyphon
Posts: 403
Joined: Thu Mar 08, 2012 19:21 pm

Re: Suspension - Am I getting enough Travel?

Postby Plyphon » Tue Oct 16, 2012 13:19 pm

Do you not stand up to sprint?

What about standing up for rock gardens, roots, or faster descents that don't require you to shift your weight back but require you to "attack" the trail?

Even if you ride pure XC you're going to have to stand up at some point.

User avatar
The Rookie
Posts: 23071
Joined: Thu Apr 30, 2009 09:29 am

Re: Suspension - Am I getting enough Travel?

Postby The Rookie » Tue Oct 16, 2012 14:12 pm

Hmm never stand up.....never manual? Rock gardens? Corners? Berms? I'm lost on this......

Regardless, standing up puts more weight on the front, so will inevitably use more travel, as you don't 'Attack' anything then you're not putting enough energy into the fork for it to use it's 140mm.


Return to “MTB Workshop & Tech”

Who is online

Users browsing this forum: No registered users and 2 guests