Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-11-07, 04:39 PM   #1
andrefulci
Amish Warrior
Thread Starter
 
andrefulci's Avatar
 
Join Date: Jun 2007
Location: Norcal
Bikes: '05 Santa Cruz Chameleon, '06 Voodoo Erzulie SS, '87 Schwinn LeTour Fixie
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
100mm Reba Team shrank to 80mm ???

I recently purchased a RockShox Reba Team fork. I believe it's a 2007, and it was new in the box. The travel was set at 100mm when I installed it. After the first ride, I can clearly see my travel has shrunk to 80mm! I have a pic of the bike before the first ride, and the difference is obvious. What the??? The fork seems to function fine, but this is confusing me...

This fork came with a loose negative air stem core, which caused me some headaches. Now this happens. I'm quickly losing confidence in RockShox...
andrefulci is offline   Reply With Quote
Old 11-11-07, 05:12 PM   #2
Trekbikedude
Bicycle Rider & Mechanic
 
Trekbikedude's Avatar
 
Join Date: Dec 2004
Location: Delaware
Bikes: Superlight, Dragon Team, Eclipse, Om Flyer
Posts: 686
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like it's leaking air.

I'd have it checked out at the lbs, or send it to sram.
Trekbikedude is offline   Reply With Quote
Old 11-11-07, 05:32 PM   #3
andrefulci
Amish Warrior
Thread Starter
 
andrefulci's Avatar
 
Join Date: Jun 2007
Location: Norcal
Bikes: '05 Santa Cruz Chameleon, '06 Voodoo Erzulie SS, '87 Schwinn LeTour Fixie
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I checked the air pressure and it's the same as it was before the ride. It doesn't appear to have lost air.
andrefulci is offline   Reply With Quote
Old 11-11-07, 06:42 PM   #4
Svr
Senior Member
 
Svr's Avatar
 
Join Date: Dec 2005
Location: Atlanta, GA
Bikes:
Posts: 1,223
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like the air in the positive air chamber is seeping in to the negative chamber. You could remove the positive air cap and see if the proper amount of oil is in there.

If this oil is missing, adding the right amount will probably solve your problem.

How many rides/hours are on this fork?
Svr is offline   Reply With Quote
Old 11-11-07, 08:17 PM   #5
andrefulci
Amish Warrior
Thread Starter
 
andrefulci's Avatar
 
Join Date: Jun 2007
Location: Norcal
Bikes: '05 Santa Cruz Chameleon, '06 Voodoo Erzulie SS, '87 Schwinn LeTour Fixie
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Only one ride, about 3 hours. I wonder though, if air from the positive chamber is leaking into the negative chamber, wouldn't I be able to determine that from the pressure reading on my shock pump? Both chambers show the same lbs. as before the ride. If it's the problem you suggest, wouldn't the negative chamber show an increase in pressure and vice versa? Maybe there's an explanation for that as well?

Now I'm thinking it's possible the shock was originally set for 80mm, but needed to settle? The shop I bought it from had it listed as 100mm, but maybe they know not. I've read that new shocks need to "settle." Not sure though. I'm befuddled~

I'll check the oil level though, per your diagnosis. Thanks~

Last edited by andrefulci; 11-11-07 at 08:25 PM.
andrefulci is offline   Reply With Quote
Old 11-11-07, 09:08 PM   #6
well biked 
biked well
 
well biked's Avatar
 
Join Date: Jul 2005
Bikes:
Posts: 7,065
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by andrefulci View Post
I'm quickly losing confidence in RockShox...
I lost confidence in them when they came out with the SID several years ago, most overpriced piece of junk I've ever seen.

But back to the point, I would suggest you put a zip tie around one of the stanchions, near the dust seal, and then after a hard ride measure how far the zip tie has moved from the dust seal. That will show how much travel you're actually using.

Another thought, since you say the fork seems to be visibly different than it was before: is this a fork that has adjustable travel? If so, maybe you've decreased the travel without realizing it-

Last edited by well biked; 11-11-07 at 09:27 PM.
well biked is offline   Reply With Quote
Old 11-11-07, 10:03 PM   #7
Svr
Senior Member
 
Svr's Avatar
 
Join Date: Dec 2005
Location: Atlanta, GA
Bikes:
Posts: 1,223
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by andrefulci View Post
Only one ride, about 3 hours. I wonder though, if air from the positive chamber is leaking into the negative chamber, wouldn't I be able to determine that from the pressure reading on my shock pump? Both chambers show the same lbs. as before the ride. If it's the problem you suggest, wouldn't the negative chamber show an increase in pressure and vice versa? Maybe there's an explanation for that as well?
Not necessarily.

If the seal is bad (or the oil is missing) the pressure between the positive and negative will equalize. Because the negative chamber has a relatively small volume when the fork is topped out, the pressure reading will drop quite a bit as the air pump is connected as air must fill it for the gauge to read.

Still, have your fork checked out. It's still under warranty.
Svr is offline   Reply With Quote
Old 11-11-07, 10:49 PM   #8
andrefulci
Amish Warrior
Thread Starter
 
andrefulci's Avatar
 
Join Date: Jun 2007
Location: Norcal
Bikes: '05 Santa Cruz Chameleon, '06 Voodoo Erzulie SS, '87 Schwinn LeTour Fixie
Posts: 35
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
For Well Biked - It's not a U-Turn, so that's not the case. Thanks anyway. I have a 2005 coil U-Turn Pike on my other bike and it's worked amazingly well despite the abuse I've put it through, so I figured I could trust the Reba. Now I'm wondering if I should've bought a Fox Talas.

Thanks Svr. I'm riding tomorrow so we'll see if it gets any worse. I hate to send it off so quickly after just finishing the build, but if that's what it comes down to... so be it.

Anyone know an LBS in Sacramento that's an authorized RockShox service center? Their website's no help.
andrefulci is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:42 PM.