Mine's geared to do about 125 redlined in 4th. The old Ironhead motor isn't very happy over 5000 rpm (100 mph), though - the vibration gets prohibitive over that speed, so I don't know if it will really pull redline in top gear. I'd like to ride it many more years without a catastrophic failure, so I don't want to flog it too much. Acceleration from 70 to 95 (or so) is impressive for an old bike like this, and the high gearing I put on it gives it a real sweet spot cruising at 65 to about 80 mph. The fairing helps calm things down at high speed, too...

 

That's why I never understood the appeal of the "fat" sportsters. I thought the idea was to be stripped down and light. A sportster should outperform a dyna given similar modifications. But it seems like all the Harley's are getting perpetually fatter... an Ironhead sportster is significantly lighter than anything that's come out recently. And then after the rubber-mount in 2004 (I think) sportsters became like mini-dynas.

 

And so you should,,Big speed Is only for the Track Or completly empty Interstates or Hiways with NO side roads.
My 2 or 3 times over 100 was On the Interstate,,perfect pavement,,perfect conditions,,NO other vehicles anywhere In front of me,
And I could see all the road I would need for a safe stop.

I only go there because I'm amazed at how smooth my Roadster is at those speeds,, Once I got the fork brace and Qtr fairing I had to try.
BTW guys I can do this comfortably sitting up right. That Fairing really smooths the air flow out.

The Thing I can't figure out Is the engine, Its a rubber mount an efi,,,, The vibes that do come through are nothing,,But
what confuses me Is they start about 3,700 rpm and vanish about 4,200 rpm,,I turn 3,500 at 75.

 

115 was all that I had on my completely stock 2012 Sportster 48. Me weighing 300+ pounds probably didn't help the top end though.

 

I just realized that I accidently bumped a 2 yr old thread. Sorry guys!

 

i have done about 100 i could have pushed more but why...? It is not a top speed chasing bike plus the wind is nasty as **** at that speed. 65 is where mine likes to be.