why would it even be considered that running at 80 would damage the motor?

 

Not IMO. At 75 the drop in RPM is the equivalent of slowing down about 2 mph. Now, if you were to change the complete gear set, primary & secondary, to that of a 1200, your talking about a 500+ RPM difference at 75.

 

how much would that cost?

 

I don't know where you got that chart Charley but I have a gearing calculator that indicates the 883 with a 28T front sprocket at 3,600RPM in 5th gear is going 67.2mph and a swap to the 29T will move it up to 69.6mph and the 30T will move it up to 72mph at that same 3,600rpm. The chart puts the bike at 64mph while going 3,600 in 5th. The final changes from 2.42 on the 28T to 2.34 on the 29T and 2.26 using the international 30T. The 1 tooth change in the front is worth almost 4 teeth on the rear and on my 1200 the 29T swap to the 28T was worth roughly 350rpm observed on the tach read out at 60mph. Granted the 1200 is running a primary of 1.5:1 whereas the 883 is 1.67:1. I saw this chart for a 1200 and could never get it to match up with the tach on the bike. I checked the tach at 70mph today and it was heads up at 3.300rpm. The calculator I am using says it should be 71mph at 3,300 so I figure an error factor of roughly 1.5% is close enough. If the drop in rpm were only 138rpm people wouldn't be making the change to the 29T as it would be useless to them and this simply isn't the case as some folks I know have made the swap and done pretty good when going to the big bore kit without changing to the 1200 primary.

 

When my Sporty was a stock 883 cruised at 80 nicely would do 100+ but the vibration and strain on it was not good ..

 

Ive been over 120 mph on my sportster and my buddy has an 883 and he's just fine ripping down the highway with me....He's never bitched about bad vibrations or anything like that, but it does stop accelerating at like 105 lol.

I think its funny every time HD cuts a fender and paints parts black on a sportster, people act like its a whole new bike and specify it as such...(Ex: Nightster and new Nighty Light)

 

60 mph cruiser great for faster rips where desired. Here is my take on favorite bikes:

Town scoot: Yamaha 250 40mph
Burb commuter: Suzuki 40 single 50mph
Best standard: 883 Sportster 60mph
Super slab eater: Road King 70mph

No bike is best of everything. The little Yamaha will do 80, but not with me on it. Nothing is more fun up to 50 than a thumper, but then it's out of breath. Sportster is THE standard, but that doesn't make it a great scooter or a superslab boat. Enjoy the ride.

 

I know it's a little 'OT', but those little thumpers are great fun for running around in nasty stuff.

Good friend of mine has a Suzuki DR650 that I've ridden many times. It will do an honest 100 MPH, and is perfectly happy cruising at 70 to 75 all day long.

Guy more of less gave me a slightly modified Honda XL250S a few months ago which pulls about 28 or so horsepower at a 'wet weight' of only 275 pounds. Damn little thing will pull a wheelie in 1st, 2nd, and 3rd, and I've had it up to an indicated 80 MPH before I came to my senses. It's more happy cruising in the 60 MPH range, and it's great fun for using on the dirt/gravel/mud roads around here.

Nothing beats a good Harley for highway cruisng, but those little lightweight thumpers have a good power to weight ratio and are just plain fun. Besides that, no chrome on them to worry about getting dirty. Just hose them off every once in a while and they are happy.

 

I hit on my 2010 Iron883 185km/h with no vibrations,can't check max acceleration - radar ahead!
Installed SE exhaust system and Screamin' EagleŽ Street Legal "Heavy Breather".

 

Max cruise speed would depend mostly on what the speed limit is.