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keons5

Collin Snoek
Hey guys, I'm working on a new fork, and I'm not sure what wall thickness I want to get. I don't want to sacrifice much strength for weight. I'm going to be using 1020 DOM opposed to the popular 4130N alloy steel. I'm torn between a .065 wall and a .125 wall for the head tube on the fork. Just curious what you guys would go with. I'm leaning towards a .065 because over summer I assisted building a cage at a local track with .125" 1020 DOM. However, most of the forks on here seem to have a .125" wall. Thanks,
 
K

keons5

Collin Snoek
Oh, since I'm probably going to get flamed for not using 4130 alloy steel.... Here's the deal, from what I know normalized 4130 is not worth the greater price unless it will be re-heat treated after welding to stress relieve the joints. Until then there will be no large difference in strength between normalized 4130 and 1020 DOM
 
conordavidson

conordavidson

Member
0.083" will be your best bet. Right inbetween. It'll be light and strong enough. If you have to go between 0.065 and .125, go with 0.125". 0.065" does not cut it nowadays.
 
A

alexiorio

Member
Yeah DOM is fine for forks dude.
It's called a steerer tube, by the way.
For threadless forks, something like 0.083 is optimum, 0.065 is a little weak and 0.125 is a bit overkill.
Threaded forks, for sure go with 0.125.
 
K

keons5

Collin Snoek
I guess I'll go with .125" wall for the fork. What do you guys think about 1020 DOM with a .065" for the bars? Maybe I could go with 1026 DOM for the bars? It's still a cheaper route than 4130.
 
K

keons5

Collin Snoek
Ok here's what I'm thinking:

Steerer Tube: 1-1/8 OD x .125 wall x .875 ID
Bars Steer Column: 1-1/4 OD x .095 wall x 1.060 ID

Both materials are 1020 DOM. It'll be tight but I'll be able to work with it. I can probably just wet sand that much off. If not, I can just take it to the shop and take it off on the lathe.
 
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alexiorio

Member
Crossbar and steerer tube are good. 0.95 will be pretty heavy for a steer column, and 1.060 ID will not fit on regular forks.
 
M

me1

Member
keons5 said:
Ok here's what I'm thinking:

Steerer Tube: 1-1/8 OD x .125 wall x .875 ID
Bars Steer Column: 1-1/4 OD x .095 wall x 1.060 ID

Both materials are 1020 DOM. It'll be tight but I'll be able to work with it. I can probably just wet sand that much off. If not, I can just take it to the shop and take it off on the lathe.
Click to expand...
ID for the steer column is going to have to be 1 1/8 if you want it to be compatible without the SCS.
 
K

keons5

Collin Snoek
1.06 is only .06" smaller than the OD of the steerer tube. I'll be able to work with that.... Let me know your thoughts, specifically on whether .095 wall on the steer column is too heavy
 
A

alexiorio

Member
keons5 said:
1.06 is only .06" smaller than the OD of the steerer tube. I'll be able to work with that.... Let me know your thoughts, specifically on whether .095 wall on the steer column is too heavy
Click to expand...
I'm telling you it is dude.
0.065 works fine, the crossbar is what needs to be thicker.
A 0.095 wall Crossbar would be PERFECT.
 
K

keons5

Collin Snoek
Ok, I know you are a firm believe of .065" doing the job, but for some reason I'm still doubting. I think .065" will do it, but I don't want to end up breaking these. I guess at this point I'll just order .065" and build new ones if I snap them. Anyone else have an opinion?

Btw, I'm rather ridiculously tall and will have rather tall bars
 
A

alexiorio

Member
keons5 said:
Ok, I know you are a firm believe of .065" doing the job, but for some reason I'm still doubting. I think .065" will do it, but I don't want to end up breaking these. I guess at this point I'll just order .065" and build new ones if I snap them. Anyone else have an opinion?

Btw, I'm rather ridiculously tall and will have rather tall bars
Click to expand...
Well then get a thicker wall, but you have to get 1 1/8" ID for bars.
Can you find 1 1/8" ID with 0.083 wall? That'd be bangin.
 
K

keons5

Collin Snoek
Alex Iorio said:
Well then get a thicker wall, but you have to get 1 1/8" ID for bars.
Can you find 1 1/8" ID with 0.083 wall? That'd be bangin.
Click to expand...

I do not need a 1.125" ID for the steerer column. I have access to a lathe and I can take 1.06" ID out to 1.12" ID very easily. This shouldn't affect a decision on which thickness wall I should buy. I'm hittin the sack, I'll check this tomorrow. Thanks for all of the replies, I appreciate it.

EDIT: Wow, I'm a retard. In order to get the .095" wall to fit around the fork, I will need to take it down to a .065" wall, so the weakest part of the bars will then be .065". Basically, if I went thicker, I would just be adding extra weight and little or no strength. .065" wall it is.
 
C

coryM

Member
If you bore it out make sure to taper down to the origional ID it so it dont crack. Unless you think .095 is thick enough to handle it. Id deffinetly go thinner than .095 no matter how tall thats just overkill for steel.
 
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