kyledr

Hi,

I have some mechanical ability, but am wondering how difficult it is to use a die to thread a fork, because I want to buy a fork that's too long and won't have any/enough threading once cut down. Also how hard is it to cut a fork down? It'd probably cost me like $20 or $30 to get it done, so I was thinking I'd just use the local public shop where it costs $10/hr to work and use their tools. This would require I do it myself though, and I just want to know if this is something a newbie can do. I read that it's a moderately difficult job, but I'm just looking for some more practical tips. Also, does it damage the headset when you cut the steerer down since you cut against it sort of?

Thanks,

Kyle

capwater

Don't do it.

BikeWise1

We charge about $40-50 to do this to a steel steerer. It is a huge PITA! It takes a large amount of physical effort, a very expensive tool, and a fair amount of time-and as an added bonus, if you screw it up, it's time for a new fork! I don't understand your concern about the headset. The fork is nowhere near the headset during the procedure. IOW, the fork is off the bike in a jig.

If you really want this done, find a shop with experience, and pay them what they ask. This is not a time to bargain-hunt.

TheSlav

+1 to the 'pain in the ass'

i also looked into doing this lately while building up a dumpster fixie and i ended up just converting to an old threadless fork/headset i had laying around instead. if you really want to rethread though i would recommend taking it to a machine shop or some place that would do it more often than a bike shop would. bike shops dont do this much nowadays and are probably out of practice and its not an easy thing to do.

Stacey

+1!!!

I tried it at a shop which told me, "Yeah, we have a threading die around here somewhere." Not only did they botch the thread job, but messed up the fork crown royaly too.

kyledr

Bikewise1, I'm talking about when cutting off the fork to be the correct length for the headset. Blegh, finding the right fork is a pain. Barnett's manual only says it'd take under an hour... in fact I think it said about 30 mins.

TheSlav

cutting the fork is easy, hacksaw with a sharp blade and a saw guide should get you there...rethreading it is the horrible part.

also if you go through with this you will probably want to extend the threads down to where you need them and then cut the fork to the right size. continuing threads is way easier than starting new threads from scratch.

BikeWise1

That's a good estimate....if all goes well....for a mechanic who does it often....which is very uncommon. We do one or two a year! And it usually takes more than one mechanic. You need an assistant to brace the fork. It takes a lot of force, and someone has to hold the fork blade blades to keep it from rotating in the jig...

Cutting the steerer is the easy part, but it is better to do this after the fork is threaded. You should have some idea of where the threads need to end-shorter threaded section is better and stronger. Once the threads are cut, thread on the adjustable cone or cup, then add the spacers if any. Use a caliper and measure the inside of the locknut and make sure you cut the steerer about 2 mm shorter than your measurements indicate once it's all added up. Better to be a little long than too short.

San Rensho 

I agree, continuing threads is not that bad at all.

If the shop has the die, go for it. Technique is pretty easy, use lots of cutting oil, go about 1/2 turn, back off a quarter turn, repeat endlessly. Use compressed air to blow it clean frequently as you go. Some elbow grease required, but 3-4 on a scale of 1-10 as far as mechanical difficulty goes.

bluehair

Rensho is correct. I did this to a hard to find 1" suspension fork for my Klein tourer, and it worked well. The hard part is taking it easy. Use lots of oil. Take a 1/4 turn forward then back up, then a 1/4 turn forward. Don't take off too much at a time as you will cut your threads right off. If you have a long distance to thread, that may be a problem as the diameter and thickness may vary as you go toward the fork, but threading an inch or so should be fine. Good luck.

roadfix

Well, I guess I was lucky. I had a very nice threaded fork which was way too long so I had my LBS extend the threads further down an additional 2 inches or so on the steel steerer. They charged me $10. Then I chopped the steered tube down to size, myself.

BikeWise1

It's a whole 'nuther ball game if threads already exist. Super easy to add more. It's the threading a plain steerer that's a royal PITA!

kyledr

Sweet. I will contact the bike shop and see if they're cool with me doing this myself. One more question... is it even possible to cut a fork Italian thread anymore? I can't find such a die on Park's site, and the shop I'm referring to uses their tools. I know the difference is minute, like 5 degrees on the pitch (right?), but I read that you shouldn't go back and fourth between Italian and English thread, and some day I may want to go back to the original fork. Is it OK to just ignore this or am I asking for messing up the threads?

Lurker1999

Where are you located? I had a guy that's reasonably near here thread a fork for me that also was too long. All it really took was a good stand, preferably someone to hold the fork clamped in the stand, and then the threading tool, cutting die and some patience.. Then you just need a cutting guide and hacksaw and you're all set. The guy did it for me in about 15 minutes.

kyledr

I'm in Minneapolis

roadfix

Yes, I understand that. I thought the OP's steerer was threaded, and like me, was simply looking to add more threading.

tellyho

My solution would be to convert to threadless. A new headset and stem may very well be cheaper than getting this done, and no chance of screwing it up.

masi61

"
Stuff comes up on ebay periodically if you search under "VAR" or "Park Tool" or "Campagnolo" or "Bicycle Research". Old bike shops close down all the time and unload their inventory, something like an Italian thread 1" fork die is going to be rare, but not unheard of to track one down in the wild. BTW: Park Tool makes steerer tube cutting gauges for threaded or unthreaded forks for about $30 which are realily available. Using one of these would assure a square cut on the steerer tube and the threaded version has the added feature of acting as a thread chaser to remove burrs as you remove it so that the freshly cut end allows the headset adjustable cup to thread on easily.

Old Breadbutt

thanks for the info in this thread. I found an old steel fork on the street that needs to be cut and threaded to fit a frame I have that needs a fork... my LBS want's $40-50 and the fork isn't worth anywhere near that. I'm gonna go buy a die tomorrow and give this a shot. if I ruin the fork, no great loss. if I get it right, I'll be able to throw it on a Cinelli frame that came with an under sized fork...

Dan Burkhart 

Adding new threads to an existing thread is not a bad job, but as others have said, lots of cutting fluid, advance 1/4 turn, back 1/2 to break and clear the chips. Another thing to consider when doing this job is that the tube you are threading is relatively thin material and heats up quickly. This causes expansion which can cause new threads to be cut deeper than ideal. I like to do this job when I have something else on the go. This way, I can cut one revolution of the die at a time and then go work at something else for 10 minutes. This prevents too much heat being generated and results in much cleaner, more consistent threads.
Dan Burkhart
www.boomerbicycle.ca

operator

I dunno. $40-$50 will get you an entirely new fork. One with correct everything. I picked up surplus columbus steel forks at my LBS for $20.

Retro Grouch 

$40-50 isn't going to be nearly enough money to buy that die that you'll probably only use once.

HillRider

Boy, is RG right. The die alone costs $30 - $200 and the die stock (handle) will add at least another $100.

Look here for details: https://www.biketoolsetc.com/index.cgi

To summarize: If the fork you have is already threaded and you just want to extend the threads further down AND you can find a shop with the proper die that knows how to use it, the job is not too bad. Cutting the fork to length is quite simple after the threading is complete.

If the fork is not already threaded do not even think of trying to thread it from scratch.

Retro Grouch 

How much too long is it?

Before I agreed to let a shop extend the threads on my fork I'd want to ask how many they've done. My experience has been that the more confident they are about doing it the fewer they've actually done. If you need more than a couple of threads added I'd be wanting at least $50.00 to do the job. If it doesn't already have threads that I can start on I'm simply not touching it.

oilman_15106

First of all if you have the correct tools, threading a fork is not difficult. I am amazed at all the comments telling you not to do it. However if you check out Park Tools site the die and tool is like $200 so is it worth it to do it yourself? Extending the current threads and then cutting is much easier as stated. 1 inch is 24 threads per inch, pretty sure, and you can not find a die even at places like Grangers.

Second, since your in a big city there may be a shop that lets you do your own work. We have one in Pittsburgh and I even cut and threaded a 1 1/8 inch fork for a project. Short of that, find a shop that still works on older bikes. They most likely will know what they are doing and have the proper tools. Good luck.

I have done this 4 times and it is not difficult.