Lectric XP - Correct Threading Die

[Skywagon]

I have a replacement front fork on order (P35) style with suspension for my XP. These have an unthreaded steering stem. I can’t locate a machinist willing to thread the 1 1/8” (28.6mm) after cutting the tube to the correct length. I will have to purchase the correct die to do the threading such that I can use the standard XP parts to complete the job.
My question: What is the correct size “die” needed to match the standard factory upper steering parts..?
Thanks for the information….
Skywagon

 

[lectricG]

I have a replacement front fork on order (P35) style with suspension for my XP. These have an unthreaded steering stem. I can’t locate a machinist willing to thread the 1 1/8” (28.6mm) after cutting the tube to the correct length. I will have to purchase the correct die to do the threading such that I can use the standard XP parts to complete the job.
My question: What is the correct size “die” needed to match the standard factory upper steering parts..?
Thanks for the information….
Skywagon

Try taking your old fork to the local hardware store and try metric nuts until you find correct size I'm sure it's a fine thread

 

[m@Robertson]

Try taking your old fork to the local hardware store and try metric nuts until you find correct size I'm sure it's a fine thread

Good luck finding a metric nut that fits a 28.6mm steering tube in a hardware store. On a normal fork, the base where the crown race goes bulges out to 30mm. Thats why you can drop the crown race down the steerer and then have to bash it on the last bit of the way.

 

[Johny Rocket]

I have a replacement front fork on order (P35) style with suspension for my XP. These have an unthreaded steering stem. I can’t locate a machinist willing to thread the 1 1/8” (28.6mm) after cutting the tube to the correct length. I will have to purchase the correct die to do the threading such that I can use the standard XP parts to complete the job.
My question: What is the correct size “die” needed to match the standard factory upper steering parts..?
Thanks for the information….
Skywagon

Don't you have a local bike shop to take the old and new fork to? Probably charge less than the cost of the die....

 

[Skywagon]

Good luck finding a metric nut that fits a 28.6mm steering tube in a hardware store. On a normal fork, the base where the crown race goes bulges out to 30mm. Thats why you can drop the crown race down the steerer and then have to bash it on the last bit of the way.

Thanks for the “bulge” tip at the steerer base. I’ll check if that is still the case for the replacement fork when it arrives.

 

[Skywagon]

Concerning these XP replacement, P35 style suspension forks.
Does anyone know how the steering stem is attached to the fork piece..? if it happened to be using a pin (hidden under the paint), then it could be driven out, releasing the steerer tube. Now you have something that could easily chucked in a lathe and now a simple matter to cut the thread needed…
Skywagon

 

[Skywagon]

Try taking your old fork to the local hardware store and try metric nuts until you find correct size I'm sure it's a fine thread

Thanks….pretty sure they would not carry a nut that size. A nut is not going to help cutting a new thread unless highly modified and costly..

 

[Skywagon]

Try taking your old fork to the local hardware store and try metric nuts until you find correct size I'm sure it's a fine thread

Thanks….pretty sure they would not a carry nut that size. A nut is not going to help cutting a new thread unless highly modified and costly

 

[Marcela]

That might be something to do on a lathe. Once you find the correct die.

 

[MWRider]

You can find a cheap die, but could not guarantee results. Stem tube needs to be about 1/8” wall thickness. Could be done on a lathe, single pointing the threads, between centers after making an appliance to hold the fork end.

 

[Johny Rocket]

I have a replacement front fork on order (P35) style with suspension for my XP. These have an unthreaded steering stem. I can’t locate a machinist willing to thread the 1 1/8” (28.6mm) after cutting the tube to the correct length. I will have to purchase the correct die to do the threading such that I can use the standard XP parts to complete the job.
My question: What is the correct size “die” needed to match the standard factory upper steering parts..?
Thanks for the information….
Skywagon

Here is the link for Park Tool cutting dies if you want to do it yourself. Scroll down the page for choices in both 1" and 1 1/8". https://www.parktool.com/en-us/category/frame-fork

 

[Marcela]

Or use the die, put it in a socket, put an extension on the socket so you can eyeball the assy and keep it in line with the tube, use cutting oil or some lubricant, and go at it! Good luck and be careful. Getting it started straight is the trick and how much thread there is to cut may effect the outcome

 

[MWRider]

SB9 thread chart. I would guesstimate $100 from a Good machinist to have it done. Depth of thread would only be about .020” per side with 26 TPI.

 

[Marcela]

I'd find a bike shop that has the tools. I see Park Tool has the die for $290 and the rest of the stuff to do it with probably. Park tool might have a list of places that could do it or they may be able to.

 

[Skywagon]

Or use the die, put it in a socket, put an extension on the socket so you can eyeball the assy and keep it in line with the tube, use cutting oil or some lubricant, and go at it! Good luck and be careful. Getting it started straight is the trick and how much thread there is to cut may effect the outcome

Thanks for Tip details….

 

[Skywagon]

Or use the die, put it in a socket, put an extension on the socket so you can eyeball the assy and keep it in line with the tube, use cutting oil or some lubricant, and go at it! Good luck and be careful. Getting it started straight is the trick and how much thread there is to cut may effect the outcome

Thanks for Tip details….

SB9 thread chart. I would guesstimate $100 from a Good machinist to have it done. Depth of thread would only be about .020” per side with 26 TPI.

Thanks for your reply and details . . .

 

[Skywagon]

I'd find a bike shop that has the tools. I see Park Tool has the die for $290 and the rest of the stuff to do it with probably. Park tool might have a list of places that could do it or they may be able to.

Thanks, I think we have one bike shop in town…. I’ll check with them..

 

[Skywagon]

“Final word”on this conversion to a suspension fork.
Conclusion first…. Not sure I would recommend the task as I laid it out.
Details….
* Fork delivered after a 4+ week wait
* Die for steering tube also from Aliexpress arrived….cost $30
* No one said they could or would thread the steering tube because of its awkward shape
* My threading solution used the threaded original XP fork, the new unthreaded fork and a carefully selected wrench “long” socket.
I found a long socket that fit into both forks after a few wraps with painters tape on each end resulting in a tight fit in each.
Next I threaded the new die onto the old XP fork tube.
Then I shoved the “socket” using half its length into the tube.
Next I attached the new fork by inserting its tube onto the remaining half socket.
Now I have both forks back to back aligned via the long socket.
This paints an interesting picture…!
Next I carefully loaded the old fork into a vise as I needed both hands free to do the step of threading the new fork. I didn’t have a die holder large enough for this die so I used a large adjustable water pump pliers.
With one hand I kept the two tubes jammed together on the socket and with the other I rotated the die up to the junction of the tubes. Adding threading oil and the pliers I cranked the die off the old and it got started on the new tube. Moving slowly and backing often to clear threading chips the operation went perfectly.
* Now hard part…..
* I assembled the new fork on the bike with greased bearings, etc. and top XP retainers. All great so far…
* Last step should have been grabbing the handlebar assembly and sliding the steering mast into the new tube..
* IT DID NOT FIT…?
* It turns out that the new tubes wall thickest is about 0.060” greater than the factory tube which is less than 1/8” and thus larger in ID….,!!
* Story end….. I spent a long time honing out the new fork tube to increase ID using a hone for a brake cylinder..
* When it finally all went together it was perfect using all the original XP steering parts….but not sure I’d ever attempt again

 

[gromike]

Epic bike story from the mechanical side of things. Great that you got it all together without disaster.

 

[Marcela]

Thought it was a no go when the dia was different. Good for your resourcefulness. Another reason to keep the tools, never sell the tools!