Virgin LSR Build

[Koncretekid]

For BUB/AMA Modified class (M), do not extend your wheelbase more than 10%. If you change the rake, it can also effect how much you can extend your swingarm.  The rule reads as follows:"Effective 2013: Maximum total wheelbase shall not exceed factory OEM dimensions by more than +10%."
Tom

[Paulzbike]

I have been off the site for a while but the build is still in progress. I have scrapped the idea of using the stock sportster front end and have acquired a 90's GSXR front end. I have purchased a doner swing arm to do the extension. I have found lots of info on the swingarm extension.

Any ideas on adapting the gsxr front end to the sporty neck.

Paul

[racer]

Looked at the GSXR Swing arm and mono shock....?

Build looks great....  Lucky Son and a Lucky Dad....

Good Luck and Have Fun....

I have been off the site for a while but the build is still in progress. I have scrapped the idea of using the stock sportster front end and have acquired a 90's GSXR front end. I have purchased a doner swing arm to do the extension. I have found lots of info on the swingarm extension.

Any ideas on adapting the gsxr front end to the sporty neck.

Paul

[saltwheels262]

Any ideas on adapting the gsxr front end to the sporty neck.

a solid stem would be okay. pressed, threaded or welded to your lower tree. OD to fit your bearing cups. enuff length to thread a nut above your top triple tree.

pM me if you like.

franey

[Stainless1]

Before going overboard, you should have them off and do a side by side.... MC2032 on this site put a GSXR front on his sportster with minor work on the stem IRRC.  PM him and ask the question, he will fill you in on the details.

[panic]

Read my comments here:
http://victorylibrary.com/brit/chassis-2a.htm

[JimL]

Just in case, take a look at my mistake on swing arm length for M class.  Near bottom of this page.

http://www.landracing.com/forum/index.php/topic,10559.30.html

Your chain adjustment range will affect things, and so will lowering and changing swing arm angle.

Regards, JimL

[saltwheels262]

Before going overboard, you should have them off and do a side by side.... MC2032 on this site put a GSXR front on his sportster with minor work on the stem IRRC.  PM him and ask the question, he will fill you in on the details.

that's a good idea.

the way it was posted made me think it needed a new stem.

franey

[mc2032]

stock stem ('93 gsxr 750). went to the local bearing store, looked in the timken cross reference for '88 sportster and '93 gsxr and got as close as possible.  kept the stock HD races and found timken bearings that would fit the stem o.d. had to turn the stem a few thousanths for the lower and had to make a small shim for the upper.  biggest obstacle was finding a working lighter to fire up the propane torch to heat the lower triple to press out the stem.  DO NOT try to beat it out with a "one pound hammer" (see Bob Steele or John Gonutskie for definition), all it does is make noise.  a little heat and about three pumps on the 20 ton press and presto.   neck on the sportster is apprx. the same height as the metric bike (probably an industry standard? more likely the metrics copied HD?) so the whole front end just dropped on like it was made for it.  you may want to use the 3/4 inch controls from the donor cycle or fab shim stock to adapt the 1 inchers stock from harley.