Lower headset 1.5 -> 1.8" conversion

[JAMAN]

Did a mistake and bought a fork with 1.8" steerer tube. Trek Rail takes 1.5" steerer tube inside. I couldn´t find conversion cups in market so I designed and builded conversion cup myself. This lifts front 13mm but hey, it works! Here are the results:

 

[bart594]

Nice!
Can you share stl/step file? I bought fork with 1.8" steerer tube too
I was not aware that we have one more "standard"....

 

[Opteron13]

Yep, Jama. ,

Could you help us with some files please

 

[JAMAN]

PM me and I’ll send you the cat file

 

[Sirax]

Hello @JAMAN
I do not have 10 posts yet to PM. Can you please PM me the files as well? I would very much appreciate it! Thanks

 

[Bernardo Brazil]

Same here @JAMAN @Sirax
Congrats on the idea @JAMAN ! nice solution!
Please share the files with me too.
I will have to make one for myself here in Brazil.
Thank you very much!

 

[Opteron13]

thank you very much

 

[Munch90]

i have gone and done the same thing and this seems like my only soloution right now any chance i could get the CAD file also i would rerally appreciate it

 

[Michelna]

Did the same mistake, bought a 1.8 for a trek.
@JAMAN how is your converter performing, any extra stresses on the headtube weld?
Would it be possible to share the cad?

 

[JAMAN]

Sure, I'll send the CAD in private message.

I used blue locktight when I assembled the conversion cup. It sticked well to the original cup. Mainly I go for rocky, technical downhill enduro tracks, so I think I've had tested this conversion cup pretty well. So far everything is perfect, no problems with the frame. And this 1.8" steerer tube gives extra stability!

 

[Bongo]

Hi I really need something like this does anybody know if you can purchase such thing please

 

[hayden]

H

Did a mistake and bought a fork with 1.8" steerer tube. Trek Rail takes 1.5" steerer tube inside. I couldn´t find conversion cups in market so I designed and builded conversion cup myself. This lifts front 13mm but hey, it works!

Would I be able to get the files as I have done the same thing and does this work on Marin frames

 

[DylanJM]

I thought Rails (pre gen 5 at least) came with the oversize 1.8 headtubes? Why would you need an adapter?

 

[stringerfury]

hi. can you send me stl?

 

[silo]

This is what I need for my CEF55 build.
JAMAN, would you consider dropping one of these in an envelope and ship it to Norway?
If you can't do that I would be really happy with the file as well.

 

[USELESS6191]

Did a mistake and bought a fork with 1.8" steerer tube. Trek Rail takes 1.5" steerer tube inside. I couldn´t find conversion cups in market so I designed and builded conversion cup myself. This lifts front 13mm but hey, it works! Here are the results:

View attachment 139026View attachment 139027View attachment 139028View attachment 139029View attachment 139030View attachment 139031

Hey i think I made the same mistake as you did which is buy a fork that has a 1.8 steerer on it, then I heard that you have a adapter, would you please help a feller out

 

[longpete]

Anyone made this adaptor and willing to sell me one?

 

[pip1983]

Sure, I'll send the CAD in private message.

I used blue locktight when I assembled the conversion cup. It sticked well to the original cup. Mainly I go for rocky, technical downhill enduro tracks, so I think I've had tested this conversion cup pretty well. So far everything is perfect, no problems with the frame. And this 1.8" steerer tube gives extra stability!

Hi do you still have the CAD file for this please. I have recently bought some zebs but bought the 1.8 and not the 1.5. Thanks Phil

 

[Waynemarlow]

Hi do you still have the CAD file for this please. I have recently bought some zebs but bought the 1.8 and not the 1.5. Thanks Phil

Wouldn't it be easier to go the other way and adapt the 1 1/8" bottom section of the fork to 1 1/2" with one of these.

They are widely available on the likes of EBay or from your local bike shop ?

 

[cozzy]

Wouldn't it be easier to go the other way and adapt the 1 1/8" bottom section of the fork to 1 1/2" with one of these.

View attachment 164499

They are widely available on the likes of EBay or from your local bike shop ?

1.8 isnt 1 1/8

 

[RustyIron]

1.8 isnt 1 1/8

Well if you drive it in with a leather mallet, it might fit.

 

[Waynemarlow]

Whoops error on my part, 1.8” though is not 11/8”

 

[Opteron13]

Aloha you all out there, after 4 years of riding my PUNK with 59 HT ( with 160 mm fork ) and 180 Yari /160 mm suspension I have decided to upgrade my fork to a Zeb Ultimate 180 mm but I didn't pay attention to the fork diameter steer tube .
Zo, bought it on high discount, and tried to put it on bike...and.....the steerer diameter is 1.8 inch tapered, new one for E-MTB , and my bike of course that accepts only 1.5 tapered. Zo, who's got a friend that his dad has and knows to operate a lathe ? I , MYSELF ,.
So, bought an Acros IS60 for bearing and crown race, measured frame internal dimension and for external adpater bearing and crown race are the reference.
Fit it today perfect , will test it thus weeeknd at The Mother - Bikepark Winterberg

Details:
Fork 180 mm Zeb Ultimate 44 offset
Adapter material Steel Is Real MTB height 15 mm
= 195 mm "suspension" zo HT 57 degrees if the frame was built for 160 mm ?

Thank you dearly Marino Bike Marino Bike , Dragos Coarfa Dragos Coarfa , Tudor Coarfa Tudor Coarfa , Rcz Bike Shop Rcz Bike Shop and not the last Jaman from emtbforums for reference CAD files.
Wahhhh ❤

 

[nickf]

Wouldn't it be easier to go the other way and adapt the 1 1/8" bottom section of the fork to 1 1/2" with one of these.

View attachment 164499

They are widely available on the likes of EBay or from your local bike shop ?

Although this wouldn't be any use if it was indeed a 1 1/8" to 1 1/2" converter, it is actually a 1.8" to 1.5" converter so should do the job!

FSA Trek 1.8" to 1.5" Headset Reducer Crown

 

[Peque]

Did a mistake and bought a fork with 1.8" steerer tube. Trek Rail takes 1.5" steerer tube inside. I couldn´t find conversion cups in market so I designed and builded conversion cup myself. This lifts front 13mm but hey, it works! Here are the results:

View attachment 139026View attachment 139027View attachment 139028View attachment 139029View attachment 139030View attachment 139031

Hi! I have the same issue, could you help me with the file? Thank you very much, and nice work!

 

[Opteron13]

Hi! I have the same issue, could you help me with the file? Thank you very much, and nice work!

 

[Peque]

Thank you very much! Would you be willing to make and sell me one?

 

[Opteron13]

Thank you very much! Would you be willing to make and sell me one?

Oh, this is just a plan for Jamal's bike...for reference only.
Every bike is different and should be custom made.
With your frame and this sketch you could find in you own town somebody that has a lathe. For him it will be simple but you need also Acros headset for bearing and lower crown.
First make your calculations because it will be not cheap. In my case a friend made it in 15 min for free zo just yhe Acros headset price only.....

 

[Peque]

Thank you, you are right, might need some adjustments

 

[Peque]

Oh, this is just a plan for Jamal's bike...for reference only.
Every bike is different and should be custom made.
With your frame and this sketch you could find in you own town somebody that has a lathe. For him it will be simple but you need also Acros headset for bearing and lower crown.
First make your calculations because it will be not cheap. In my case a friend made it in 15 min for free zo just yhe Acros headset price only.....

If you used IS60 bottom cup, shouldn't this measurement be 60mm?