Changing stem on full carbon. Advice?
02-25-04, 12:39 PM
#1
Senior Member
Thread Starter
Join Date: Nov 2003
Location: New London, NC (near Charlotte)
Posts: 277
Bikes: Bianchi (road), Cannondale R3000,Trek (mtb)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Changing stem on full carbon. Advice?
I'm about to change the stem on my Cannondale R3000, which requires removing and later re-installing the bolt in the top of the steerer tube. I've been told to use caution re-installing the bolt since the steerer tube is carbon fiber. Any advice would be appreciated.
__________________
04 Cannondale R3000, Dura-Ace 10, Ksyrium SL
03 Cannondale Ironman 5000, Dura-Ace 9, Cane Creek Aros
86 Bianchi lugged steel with full carbon (Bianchi!) fork
03 Trek MTB
04 Cannondale R3000, Dura-Ace 10, Ksyrium SL
03 Cannondale Ironman 5000, Dura-Ace 9, Cane Creek Aros
86 Bianchi lugged steel with full carbon (Bianchi!) fork
03 Trek MTB
02-25-04, 01:08 PM
#2
Senior Member
Join Date: Nov 2003
Location: Natick MA
Posts: 148
Bikes: Specialized P2, Cove G Spot
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
when you are putting the steerer tube bolt back in, make sure the screw is alligned with the starfingle (the star shaped piece inside the tube of your front fork). Otherwise you may bend the starfingle out of shape and therefore unable to be used. trust me, without the right tool these things are a pain in the a** to replace.
02-25-04, 01:10 PM
#3
Senior Member
Join Date: Apr 2003
Location: Pasadena, CA
Posts: 3,162
Bikes: Litespeed Firenze / GT Avalanche
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
The bolt at the top is what snugs the bearings up. It is not something that you really crank down on. The bolt on the stem itself are the ones that cause the stem to grab the steerer. they need to be nice and snug, but not gorilla tight. I am sure someone here can give you the torque spec if you have a torque wrench.
When you put the stem back on leave the stem bolts loose. Tighten the top cap down lightly. Then tighten the stem bolts. Check the adjustment by locking the front brakes and pushing the bike back and forward. If you feel movement, loosen the stem bolts, tighten the top cap 1/6 - 1/4 of a turn, tighten the stem bolts again. Test again. It may take a few tries.
When you put the stem back on leave the stem bolts loose. Tighten the top cap down lightly. Then tighten the stem bolts. Check the adjustment by locking the front brakes and pushing the bike back and forward. If you feel movement, loosen the stem bolts, tighten the top cap 1/6 - 1/4 of a turn, tighten the stem bolts again. Test again. It may take a few tries.
02-25-04, 01:18 PM
#4
hello
If your steerer is carbon, it may not have that dreaded star-fangled nut....but something a little gentler designed for carbon tubes. In any event, you should proceed with caution any time you're clamping or tightening anything onto carbon fiber.
George
George
Last edited by roadfix; 02-25-04 at 02:10 PM.
02-25-04, 02:25 PM
#6
DEADBEEF
Join Date: Aug 2002
Location: Catching his breath alongside a road near Seattle, WA USA
Posts: 12,234
Bikes: 1999 K2 OzM, 2001 Aegis Aro Svelte
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 6 Times
in
4 Posts
I would personally avoid a star-fangled nut on a carbon steerer. Instead, consider using a compression assembly like the following:
Also, be careful about the new stem's clamp slot and check with your fork's manufacturer to see if the stem is compatible. Some clamp designs put a stress riser in the steerer. You basically want a clamp where the slot is in line with a radial of the steerer and the bolt is perpendicular to the radial from the center of the steerer.
Also, be careful about the new stem's clamp slot and check with your fork's manufacturer to see if the stem is compatible. Some clamp designs put a stress riser in the steerer. You basically want a clamp where the slot is in line with a radial of the steerer and the bolt is perpendicular to the radial from the center of the steerer.
__________________
1999 K2 OzM
2001 Aegis Aro Svelte
"Be liberal in what you accept, and conservative in what you send." -- Jon Postel, RFC1122
1999 K2 OzM
2001 Aegis Aro Svelte"Be liberal in what you accept, and conservative in what you send." -- Jon Postel, RFC1122
02-25-04, 08:58 PM
#7
Senior Member
Join Date: Jan 2004
Location: Richmond, VA
Posts: 160
Bikes: Pinarello, Gunnar, Ventana, CoMotion, Opera, Colnago
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Cannondale recommends a star nut for its new all carbon forks. I was surprised, but the Cannondale rep confirmed it. I'm guessing that it saves 75 grams, and that may be reason enough for them to use it.
02-27-04, 11:47 AM
#8
El Inglés
Join Date: Dec 2003
Location: Benidorm , Alicante , ESPAÑA
Posts: 465
Bikes: road ( Mendiz ) & mtb (crap )
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by Phil from VA
Cannondale recommends a star nut for its new all carbon forks. I was surprised, but the Cannondale rep confirmed it. I'm guessing that it saves 75 grams, and that may be reason enough for them to use it.
