How did you hold the fork legs while drillng from 15mm to 17 mm?

[ct7088]

I have all the parts, now i need to cut the hole. I think only a few have done this but I'm looking for advice. I have a bushing that will allow the use of the 15mm axle but prefer to use the 17mm. I can use a boring bar or an end mill but the forks are so easy to scratch and dent. I'm working on a 85 FJ1100 and intending to swap to a YZF6R wheel along with GSXR rear.

Chris

[rktmanfj]

I have all the parts, now i need to cut the hole. I think only a few have done this but I'm looking for advice. I have a bushing that will allow the use of the 15mm axle but prefer to use the 17mm. I can use a boring bar or an end mill but the forks are so easy to scratch and dent. I'm working on a 85 FJ1100 and intending to swap to a YZF6R wheel along with GSXR rear.

Chris

I sent my stuff to the machine shop to be done, so I didn't have to worry about it.   

You can use a 17mm FZR1000 axle shortened and rethreaded to the length of the FJ axle with the YZF600r r/s spacer and speedo drive.  Then all you should have left to do is backspace the calipers to center them on the rotors. 

[MOTOMYSZOR]

Check this topic first: http://www.fjowners.com/index.php?topic=13479.0

[ct7088]

Check this topic first: http://www.fjowners.com/index.php?topic=13479.0

The LHA bearings are only available in the UK or Europe and are used for some Mercedes alternators. I don't want to be broken down in need of obsolete bearings a few years from now. I may worry to much but I'm not in a hurry. I will just have to make a holding fixture. My 85 already has an axle nut so the one for the YZF axle will look normal to me. Thanks for the replies.

Chris

[TexasDave]

Check this topic first: http://www.fjowners.com/index.php?topic=13479.0

The LHA bearings are only available in the UK or Europe and are used for some Mercedes alternators. I don't want to be broken down in need of obsolete bearings a few years from now. I may worry to much but I'm not in a hurry. I will just have to make a holding fixture. My 85 already has an axle nut so the one for the YZF axle will look normal to me. Thanks for the replies. Chris

I'm sure you could get the LHA bearings here in the U.S. from Mercedes or Audi dealers but they would be expensive. A comparable bearing could be sourced from bearing retailers here for a lot less that would be up to the job and you would not have to drill.  Dave

[Pat Conlon]

A 17mm axle is preferable on our heavy bikes.

[CutterBill]

Drilling the lowers from 15mm to 17mm is an easy job if you have a vertical mill or a heavy drill press.  You mentioned using a boring bar?  Won't work; those are used in a lathe.  An end mill will work as long as it's exactly the right size (not a regrind.)  Like others have said, take it to a machine shop.  I would not even attempt this with a hand drill.  And I'm pretty good with one...   
Bill

[ct7088]

Drilling the lowers from 15mm to 17mm is an easy job if you have a vertical mill or a heavy drill press.  You mentioned using a boring bar?  Won't work; those are used in a lathe.  An end mill will work as long as it's exactly the right size (not a regrind.)  Like others have said, take it to a machine shop.  I would not even attempt this with a hand drill.  And I'm pretty good with one...   
Bill

OK, I will use an end mill. I have access to a vertical mill. Thanks

Chris

[CutterBill]

Chris, do you have a 17mm endmill?  I ask because metric endmills are not common in this country.  Sorry if I'm stating the obvious; just trying to head off another post called "Now what do I do?" 
Bill

[Country Joe]

Chris,
I would recommend holding the fork leg on two v-blocks, clamping the fork leg down with toe clamps and brass or aluminum shim material between your fixturing and fork leg, to minimize scratches. If you are really worried about scratches you can wrap your shims and clamps with a couple layer of masking tape. You can compensate for any misalignment of the existing hole in the fork by using diffent thickness of shims between the v-blocks and fork leg, to insure that the hole you bore is still perpendicular to the internal diameter of the fork leg. If you have access to a vertical mill, hopefully there will be an adjustable boring head around the shop as well. You should be able to get from 15mm to 17mm in 3 passes easily enough, if your fixturing is rigid enough.
Joe

[MOTOMYSZOR]

Check this topic first: http://www.fjowners.com/index.php?topic=13479.0

The LHA bearings are only available in the UK or Europe and are used for some Mercedes alternators. I don't want to be broken down in need of obsolete bearings a few years from now. I may worry to much but I'm not in a hurry. I will just have to make a holding fixture. My 85 already has an axle nut so the one for the YZF axle will look normal to me. Thanks for the replies.

Chris

This option was discovered by someone in Germany long time ago..... Then someone from Poland found it on German FJ forum - also years ago. Then I digged out old topic.....
So until we can exclude human error -  it will be as safe as original bearings.

[CutterBill]

The LHA bearings are only available in the UK or Europe and are used for some Mercedes alternators...

I was curious about this statement so I went to my favorite source for things industrial... McMaster-Carr.  Looks like you can get the 6203 bearings, high precision, double-sealed for about $11 each.
http://www.mcmaster.com/#6203-ball-bearings/=z2wt55
Bill

[ct7088]

The LHA bearings are only available in the UK or Europe and are used for some Mercedes alternators...

I was curious about this statement so I went to my favorite source for things industrial... McMaster-Carr.  Looks like you can get the 6203 bearings, high precision, double-sealed for about $11 each.
http://www.mcmaster.com/#6203-ball-bearings/=z2wt55
Bill

It is obvious that my computer shopping skills are not very good.

Chris

[ct7088]

Chris,
I would recommend holding the fork leg on two v-blocks, clamping the fork leg down with toe clamps and brass or aluminum shim material between your fixturing and fork leg, to minimize scratches. If you are really worried about scratches you can wrap your shims and clamps with a couple layer of masking tape. You can compensate for any misalignment of the existing hole in the fork by using diffent thickness of shims between the v-blocks and fork leg, to insure that the hole you bore is still perpendicular to the internal diameter of the fork leg. If you have access to a vertical mill, hopefully there will be an adjustable boring head around the shop as well. You should be able to get from 15mm to 17mm in 3 passes easily enough, if your fixturing is rigid enough.
Joe

The machinist that used to work for the owner of the vertical mill says that there is a good one there.

Chris

[ct7088]

Chris, do you have a 17mm endmill?  I ask because metric endmills are not common in this country.  Sorry if I'm stating the obvious; just trying to head off another post called "Now what do I do?" 
Bill

MSC has one, they are not available everywhere. I will have one tomorrow. I hope to hold the fork with caliper bolts threaded into a piece of 1" X 2" aluminum 2024T3 bar stock with a second piece carved out to support the end of the tube. Good thing I'm not in a hurry.

Chris