What's the OD of a steerer tube? ID of threadless bars?

keons5

Collin Snoek
Is the OD of a steerer tube 1.120 or 1.125. Yes the 5 thousands of an inch matter!

ID of threadless bars is 1.120 or 1.125?

Thanks
 

demo

Member
keons5 said:
Is the OD[outer diameter] of a steerer tube 1.120 or 1.125. Yes the 5 thousands of an inch matter!

ID[inner diameter] of threadless bars is 1.120 or 1.125?

Thanks

a fork tube has an OD of 1.125 so the ID of the BARS in 1.125. the OD of the bars can be either 1.25 for chromoly, or 1.375 for aluminum.
 

keons5

Collin Snoek
In the how to make bars thread I found this:
1.12" Inner Diameter, 0.065" wall - Steer Tube

So then a 1.120 steerer tube is correct? I machined all my steerer tubes to 1.120


Edit: Math to back my theory up. 1.25OD - .065 - .065= 1.120ID
 

keons5

Collin Snoek
I have tried to place a 1.125OD steerer tube into my 1.120 bars and it did not go, so I have been machining all steerer tubes to 1.120. Is that good?
 

Michael Rankin

Super Moderator
keons5 said:
I have tried to place a 1.125OD steerer tube into my 1.120 bars and it did not go, so I have been machining all steerer tubes to 1.120. Is that good?
well of course it wouldnt fit. you were trying to fit a steertube into bars that were smaller than the steer tube. but yea if you machine the steertube down to 1.120, then you should be just fine.
 

saltwater

Member
If you do some reasearch it you clear yup alot of questions.
With tubing generaly its measured from the outside in with piping its the other way around, so this means you can't (or hardly) get an exact 1.250 OD and 1.125 ID tubing/piping
Generally the most commin Chromoly tubing with a ID close of 1.125 is 1.250 OD tubing with a 0.058 WT or 0.065 WT.
With a 0.058 its mostly use for sliding a tube inside that tube although there is a clearance of 0.004
You can use 0.065 WTto make bars although its 0.005 to thick as long as you have a slit that is a lil long the pipe will stretch and it will fit snug

LOCK THREAD.
JonDogg said:
bars arent threaded, js

stock bars are/were
After clamping ur stock bars on to your threaded forks it leaves an impression.
 

GoGzS

Bronze member
Mike Rankin said:
keons5 said:
I have tried to place a 1.125OD steerer tube into my 1.120 bars and it did not go, so I have been machining all steerer tubes to 1.120. Is that good?
well of course it wouldnt fit. you were trying to fit a steertube into bars that were smaller than the steer tube. but yea if you machine the steertube down to 1.120, then you should be just fine.

A headset is made for 1 1/8" a.k.a. 1.125...
Machining your fork tube to 1.120 will make you have 0.005 free space betweehn the headset and fork = wobble...

That's the theory part...in real..it will be fine...enjoy...
 
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