Removing 1 to 2 mm from steerer tube
#1
Resident PIA
Thread Starter
Join Date: Jul 2004
Location: City of Oaks, NC
Posts: 889
Bikes: Gunnar Roadie, Look 765 Optimum, Spesh Aethos
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked 377 Times
in
200 Posts
Removing 1 to 2 mm from steerer tube
If you wanted to remove 1 to 2mm from a carbon fiber steerer tube how would you do it?
Would you bevel the edges down to where you wanted to end up?
.
Would you bevel the edges down to where you wanted to end up?
.
__________________
--
Shad
I knew where I was when I wrote this
I don't know where I am now...
05 Gunnar Roadie Chorus/Record
67'er
--
Shad
I knew where I was when I wrote this
I don't know where I am now...
05 Gunnar Roadie Chorus/Record
67'er
#4
Expired Member
Join Date: Jun 2007
Location: TN
Posts: 11,891
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 3797 Post(s)
Liked 5,795 Times
in
2,929 Posts
It doesn't need to be particularly true. Longer lengths are usually cut with a hacksaw, not precise.
#5
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,167
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4239 Post(s)
Liked 3,973 Times
in
2,363 Posts
Since the top of a threadless steerer doesn't need to be particularly square with the axis a simple and quick "eyeball" approach is all that's needed. One trick is to wrap a bit of masking tape around the steerer and use the upper edge as a visual guide while grinding away. Remove the tape and deburr by hand with fine emery cloth. Andy
__________________
AndrewRStewart
AndrewRStewart
#6
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,055
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 141 Post(s)
Tagged: 1 Thread(s)
Quoted: 5971 Post(s)
Liked 2,878 Times
in
1,602 Posts
As noted by others, it doesn't have to be perfect because nothing ever rests on the top and relies on it for squareness, nor is it ever seen.
However, if you're finicky, throw a hose clamp around it as a reference guide, and trim down with a file, or cut down with a hacksaw. While a bevel isn't necessary, I bevel all cuts out of habit.
However, if you're finicky, throw a hose clamp around it as a reference guide, and trim down with a file, or cut down with a hacksaw. While a bevel isn't necessary, I bevel all cuts out of habit.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Likes For FBinNY:
#7
Senior Member
Join Date: Aug 2009
Posts: 1,889
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 525 Post(s)
Liked 692 Times
in
405 Posts
We have a dedicated miter saw with a crazy fine blade and a jig to hold the fork (or seatpost) cause time is money, but a sacrificial hose clamp or old stem and a disk sander (hand held or otherwise) works well too. This is another "i gotta shoot the s***t with the mechanic for a bit" scenario, otherwise folks ***** about the rate per minute on the service. I usually tell em to get a coffee or such, and "it should be ready" when they get back...
#8
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,055
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 141 Post(s)
Tagged: 1 Thread(s)
Quoted: 5971 Post(s)
Liked 2,878 Times
in
1,602 Posts
One hint for those using a hacksaw to cut CF steerers.
One of the general rules of using saws counts double with CF, namely, Let the saw do the work. People have a tendency bear down when sawing, which is fine on wood, kind of OK with steel or other metals, but a definite NoNo with CF. You want a sharp blade, and want to let it do the work. Bearing down causes it to bite too hard and tear rather than make a smooth cut.
Same with a file, light but firm pressure, not force.
One of the general rules of using saws counts double with CF, namely, Let the saw do the work. People have a tendency bear down when sawing, which is fine on wood, kind of OK with steel or other metals, but a definite NoNo with CF. You want a sharp blade, and want to let it do the work. Bearing down causes it to bite too hard and tear rather than make a smooth cut.
Same with a file, light but firm pressure, not force.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Last edited by FBinNY; 05-13-24 at 03:32 PM.
Likes For FBinNY:
#9
Resident PIA
Thread Starter
Join Date: Jul 2004
Location: City of Oaks, NC
Posts: 889
Bikes: Gunnar Roadie, Look 765 Optimum, Spesh Aethos
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked 377 Times
in
200 Posts
As noted by others, it doesn't have to be perfect because nothing ever rests on the top and relies on it for squareness, nor is it ever seen.
However, if you're finicky, throw a hose clamp around it as a reference guide, and trim down with a file, or cut down with a hacksaw. While a bevel isn't necessary, I bevel all cuts out of habit.
However, if you're finicky, throw a hose clamp around it as a reference guide, and trim down with a file, or cut down with a hacksaw. While a bevel isn't necessary, I bevel all cuts out of habit.
__________________
--
Shad
I knew where I was when I wrote this
I don't know where I am now...
05 Gunnar Roadie Chorus/Record
67'er
--
Shad
I knew where I was when I wrote this
I don't know where I am now...
05 Gunnar Roadie Chorus/Record
67'er
#10
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,867
Bikes: Trek FX 2, Cannondale Synapse x2, Cannondale CAAD4, Santa Cruz Stigmata 3
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 2068 Post(s)
Liked 1,561 Times
in
1,082 Posts
I would just add a 2 mm spacer, but maybe I am too risk-adverse when it comes to non-reversible changes.
Likes For SoSmellyAir:
#11
Senior Member
Join Date: Apr 2011
Posts: 7,366
Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4595 Post(s)
Liked 1,749 Times
in
1,146 Posts
Don't grind it. That will damage the matrix. Use a diamond saw or a well worn metal hack saw.
#12
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,055
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 141 Post(s)
Tagged: 1 Thread(s)
Quoted: 5971 Post(s)
Liked 2,878 Times
in
1,602 Posts
For that amount, I wouldn't bother either. However the OP asked how can I, not should I.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Likes For FBinNY:
#13
Senior Member
Join Date: Jul 2007
Location: South shore, L.I., NY
Posts: 7,036
Bikes: Flyxii FR322, Cannondale Topstone, Miyata City Liner, Specialized Chisel, Specialized Epic Evo
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 3335 Post(s)
Liked 2,182 Times
in
1,239 Posts
Likes For Steve B.:
#14
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,167
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4239 Post(s)
Liked 3,973 Times
in
2,363 Posts
The amount wanted to be removed (the reason and some of our opinions are unknown) is pretty much the cutting width of a common metal hack saw blade and much less than those carbide glued to a wire ones. So in this specific case I sort of suggested using a bench grinder or belt sander. The key, as I learned it by doing, is a fast cutting speed and a maximum grit count (fine cutting) stone/belt. The feed should be pretty slow and I have held the steerer's end against the grinder so the cutting force is tangential and the fibers support each other better. The usual time to do this is after cutting down the factory length to fit a bike and one does want to deliver the bike with a close to square and smooth top of steerer, so only minor removal is done. But taking off another mm or so should be no big deal if one doesn't use a hand held sawing tool. Andy
__________________
AndrewRStewart
AndrewRStewart
#15
Senior Member
Join Date: Apr 2016
Posts: 1,419
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 564 Post(s)
Liked 504 Times
in
383 Posts
#16
Resident PIA
Thread Starter
Join Date: Jul 2004
Location: City of Oaks, NC
Posts: 889
Bikes: Gunnar Roadie, Look 765 Optimum, Spesh Aethos
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked 377 Times
in
200 Posts
The amount wanted to be removed (the reason and some of our opinions are unknown) is pretty much the cutting width of a common metal hack saw blade and much less than those carbide glued to a wire ones. So in this specific case I sort of suggested using a bench grinder or belt sander. The key, as I learned it by doing, is a fast cutting speed and a maximum grit count (fine cutting) stone/belt. The feed should be pretty slow and I have held the steerer's end against the grinder so the cutting force is tangential and the fibers support each other better. The usual time to do this is after cutting down the factory length to fit a bike and one does want to deliver the bike with a close to square and smooth top of steerer, so only minor removal is done. But taking off another mm or so should be no big deal if one doesn't use a hand held sawing tool. Andy
.
__________________
--
Shad
I knew where I was when I wrote this
I don't know where I am now...
05 Gunnar Roadie Chorus/Record
67'er
--
Shad
I knew where I was when I wrote this
I don't know where I am now...
05 Gunnar Roadie Chorus/Record
67'er