front end conversion

[saltcaveminer]

In order to install a 1980 Sportster front end on to a 1970 Sportster do I need to replace the neck cups?Any thoughts?

[Ohio HD]

https://www2.vtwinmfg.com/fork-neck-cup-conversion-kit.html

[saltcaveminer]

Thanks for the reply but my question is are the necks the same size or do I need to change something to make it work.

[Ohio HD]

No the stem in the front end is not the same. That's why I posted the link to the conversion parts.

These also work.


Vulcan

[saltcaveminer]

Ok got it! Thanks for the reply

[kd]

Can't you use the 1970 lower tree?  You can use the original brgs then.  IIRC I used an early FX lower tree and post to mount an early XLCR dual disc front end on my early shovel head frame.  It worked great.

[Ohio HD]

'57 to '72 Sportsters use a 1.312" fork tube. '73 to '86 uses 35mm (1.378") fork tubes.

Late forks won't fit early trees, hence the conversion kits. 

[kd]

Ahhhh.  I used a 77 XLCR front end and I don't really remember what year FX lower tree so there you go.  :nix

[Ohio HD]

'73 to '83 FX used 35mm tubes. All Big Twins used Timken bearings at the tree.

'52 to '77 Sportsters used ball bearings at the tree.

[kd]

Yup, and that's why it worked.  We did a few like that. Mine was the only XLCR conversion in the bunch. The IIRC Timkin  07100 brg set (same as the swing-arm). It was a long time ago.

[bobrk1]

If you're  doing  an upgrade  I'd  change  cups  and  bearings while  you  have  it  apart  just  for  piece  of  mind .