Ironhead Steering stem too short for tapered bearings, convert to balls?

[tiderider]

Originally Posted by DR DICK

2:40 mark
https://youtu.be/h4pmMNrDAZU

Thanks Joe, got my new fork boots so I figure it's time to check this entire front end while it's coming apart.

[73HEAD]

Originally Posted by Ferrous Head

OK.

The 1 inch stems can be used in the Sportster frame. There are conversion kits to do this.

You can actually use any of the the 7/8ths stems with the frames and the fork legs but the ones with a -52 casting number have a different trail. Most will have a -62A casting number.

But now you will have skinny little fork legs and a krappy front brake.

I "improved" the front brake on my 62 but all that happened was that the fork legs twisted if I braked too hard and I was still stopping 15 foot past that stop sign.

If it's just a show bike that won't matter to you. Just buy suitable Timkens and cups.

thank FH, appreciate your input.

[73HEAD]

Originally Posted by DR DICK

To use a 71-72 FX front end on a 73 sportster:

you need the correct trees.
top: 47539-59 or-62 or -62a or 62b used 59-72 xl xlh xlch & 71-72 fx.
71-72 fx and xl used the -62b top tree.

bottom tree can be
45702-57
45702-57a
45702-57b
45702-67
45703-71

transplanting the 73 xl stem into the 72 fx lower tree will allow use of your existing parts.

the 1" fx stem is not only too large in diameter for the superior xl ball bearing setup but the stem is also too long.

i know this is alot of part numbers'
---------------------------------------------------------------
simplified:
top tree
59-72 all sportster, 71-72 fx.


bottom tree:
57-72 xl, xlh, xlch.

[73HEAD]

Originally Posted by DR DICK

To use a 71-72 FX front end on a 73 sportster:

you need the correct trees.
top: 47539-59 or-62 or -62a or 62b used 59-72 xl xlh xlch & 71-72 fx.
71-72 fx and xl used the -62b top tree.

bottom tree can be
45702-57
45702-57a
45702-57b
45702-67
45703-71

transplanting the 73 xl stem into the 72 fx lower tree will allow use of your existing parts.

the 1" fx stem is not only too large in diameter for the superior xl ball bearing setup but the stem is also too long.

i know this is alot of part numbers'
---------------------------------------------------------------
simplified:
top tree
59-72 all sportster, 71-72 fx.


bottom tree:
57-72 xl, xlh, xlch.

thankyou doc

[Ferrous Head]

You can install almost any forks you want to in a Sportster frame.

You just might have to be prepared to do a little fabrication work.

Here are Ceriani 35mm GPR forks in my P3 Solo. All that was required was making a bew stem and purchasing a Timken Conversion Kit. The kit was about $90 and the stem was around $80.

But these forks are a major upgrade from the spindly HD forks. The tubes are not only a larger diameter but the tubes themselves have thicker walls. And they have external compression and rebound damping.

I used them as they are eligible under our racing rules (made prior to 1963). If I could use 50mm upside down Ohlins, they would be on there.

[73HEAD]

thankyou muchly for taking the time to assist me with my enquiries. you can always be relied upon to give accurate easy to digest answers. for this i am greatful. i have decided to go with the 4570752a bottom tree and transplant my stem from the 73xlh onto the mentioned trees. that seems to be the easiest, most practical way to remedy the deal. that way i know everything will marry up. im very excited to see what it all looks like and how it rides. the hamburger drum brake i reckon is a work of art. very handsome pice of macinery indeed. id like to thank everyone who took the time to chime in. when ive got it all together i will post a few picks. this old machine of mine sure is costing s few pennies, but well worth it. theres not to many ironhead getting round the streets and its a good buzz to feel the interest people show. thanks again