Tap and Die...

[inreb]

some taper prolly like 4 threads at the bottom.

OK, that's not bad.....

For the drill press idea to work properly you need to satisfy that your piece is bang on square and parallel. Can't use a torpedo level unless the drill press is level. Once that's set how would you crank a tap that size without a T handle? Not dissing previous poster, just wondering.

What are you trying to mount there?

[kellen]

Got a drill press kellenator?

no, sorry.

I don't know about the drill press but he does have a two person shower he can sit in.

eeeeek

[Freestyle72]

OK, that's not bad.....

For the drill press idea to work properly you need to satisfy that your piece is bang on square and parallel. Can't use a torpedo level unless the drill press is level. Once that's set how would you crank a tap that size without a T handle? Not dissing previous poster, just wondering.

What are you trying to mount there?

[ChrisR]

I may try to find someone with a drill press.

If you're going to try to find somebody with the right tool, you want to find someone with a lathe.

[Freestyle72]

If you're going to try to find somebody with the right tool, you want to find someone with a lathe.

Drill presses are more common and I just need to get started in the right direction with the tap after that I just need my hands lol.

[inreb]

I was wondering what you're trying to mount there.

I'll just take a gamble here because I haven't got a clue but have you ever seen how bark busters are mounted to aluminum handle bars at the bar end. If I'm way off please ignore.

They a 1/2" internally threaded affair, 2pcs. diagonaly cut. When you tighten the bolt these pieces slide on the diagonals pressing outward against the inside of the handlebar. Very tight.

If this is not helpfull, again, please ignore. I wish I was there to help you, I love hands on......

[Brian P]

If I'm seeing what I think I'm seeing, the right way to do this would have been to mount the stem in the chuck of a lathe prior to having pressed it into the triple clamp, and mount the tap in the tailstock. That way you absolutely know it is going in square.

What are you attaching to the top of the stem? Most bikes either have a through hole in the stem (all the way top to bottom) or a closed stem nut that covers this hole but threads on from the outside of the stem, not the inside, or a decorative cover over an external stem nut.

[frekeyguy]

If I'm seeing what I think I'm seeing, the right way to do this would have been to mount the stem in the chuck of a lathe prior to having pressed it into the triple clamp, and mount the tap in the tailstock. That way you absolutely know it is going in square.

What are you attaching to the top of the stem? Most bikes either have a through hole in the stem (all the way top to bottom) or a closed stem nut that covers this hole but threads on from the outside of the stem, not the inside, or a decorative cover over an external stem nut.

maybe a gps mount?

[Freestyle72]

The deed is done. I am kind of ****** I spent $50 on drill bit and tap when I could have taken it to my machinist. He did it for $10. And I gave him $5 more because quite frankly I think the work/time he spent is worth more than $10.

It's done and it's very slick though. I now have an adjustable length stem.



And I am debating on leaving a little bit of thread at the top for a GPS mount...

[inreb]

Finally the big mystery has been revealed. OK, I thought you were trying to mount something.
Your application definately calls for a bang on job. Good thing you didn't come by yesterday.

[Freestyle72]

Ya... now you can see why I was being so anal about how straight I wanted it.

[ChrisR]

I thought you were afraid you would get lost due to the error introduced by having your gps mounted crookedly

[inreb]

So, where does one buy titanium threaded rod?

[Freestyle72]

LOL... it's $124 for a length of it off this site

http://buy.titanium.com/cco_catalog/...Threaded%20Rod

I used SS rod though.

[inreb]

LOL... it's $124 for a length of it off this site

http://buy.titanium.com/cco_catalog/...Threaded%20Rod

I used SS rod though.

Actually, that's a usefull link

Can you describe how the machinist did that. Any and all info is good.

Buddy wants to put a YZ250 fork on KLR650. Hey, you never know.....

[Freestyle72]

We used a lathe. centred it on a lathe tapped the thread. And then used a saw to cut off the extra bit of the stem.

Basically I had a custom bearing made to fit the top bearing surface of the GSXR stem into my FZR (there are many bearing combos that u may find stock on other bikes, the FZR to GSXR just happened to be just about the only bearing size you can't find standard).

So the GSXR stem was already almost 17/32" wide. I ran the drill bit through each side to make sure it was that wide it only shaved a very small amount (probably less than .5mm from each side).

After that he stuck it on a lathe and ran the tap through until it was straight. Then pulled it off the lathe and finished by hand.

I am using nuts to lock the parts in place and may have a welder tack the nuts in place later for extra peace of mind. Even though some people have ran the set up without nuts in the middle before.

[Freestyle72]

Actually, that's a usefull link

Can you describe how the machinist did that. Any and all info is good.

Buddy wants to put a YZ250 fork on KLR650. Hey, you never know.....

YZ250 (1974-1987)
Upper: 25 x 47 x 15
Lower: 30 x 55 x 17

KLR650 (1987-1997)
Upper: 25 x 47 x 15
Lower: 28 x 52 x 16.5

So to use the YZ250 stuff you use the same top bearing. But for the lower bearing you need to use a 30X52X17 bearing.

so according to this link the KZ650 uses that size bearing. So you can use the bearing from that bike.
http://forums.kz650.info/index.php?topic=1045.0
If the stem length (and location of bearing areas is the same between the two bikes it's a bolt on affair with the correct bearings). If the stem length is not the same you can then thread the original parts of the stem as I did to achieve the desired stem length.

[Freestyle72]

Now the YZ250 and the KLR650 have the same thickness steering stem it would be easier to press the KLR650 steering stem out. And the YZ250 steering stem out. And then put the KLR stem into the YZ triples. And then you just use the stock KLR bearings.

The reason I couldn't press the FZR stem into the GSXR triple is because it is smaller and would have needed to be sleeved. And I am not sure I trust a sleeve to all the forces a steering head is subjected to.

[inreb]

I am using nuts to lock the parts in place and may have a welder tack the nuts in place later for extra peace of mind. Even though some people have ran the set up without nuts in the middle before.

Another option is to drill and tap into the flat of the nut for a set screw. Or use a bit of red loctite.

Wow, thanks for all that other info. Funny, the YZ front end is supposed to be off a late '80's model yet to be deterimined.

OK, looks like everything's on track.

[Brian P]

Hmmmm ... I'm not sure I like this.

The stock stem rod/tube is essentially the same diameter as the inside diameter of the bearing in order for the stem to be as stiff as possible in bending. I think your threaded rod is substantially smaller in diameter and it has a stress riser at the bottom of every thread. Remember that the stiffness in bending of a circular cross section goes up with the 4th power of diameter, e.g. half the diameter means 1/16 the bending stiffness ... and 80% of the diameter means 41% of the stiffness. A tube that has a hole up the middle that is 80% of its outside diameter is stiffer than the rod that would fit up the middle of that tube ...