80 XS11 Midnight Special chop/rebuild log

[Nightengale]

what about standard

160/80-16.... that's the upper limit for the Special rim width, and leaves about .050" clearance to the swingarm if everything is fitted just right...

I'll be posting this mod once I get further along assembling this bike.

about how big do you think i could do on a standard rim

[crazy steve]

Absolute maximum tire width is 6.15".... not even a touch more. So that's the main thing you need to look at if trying a bigger tire with a modified arm. The other thing to consider is rim width; the Special 16" wheel is 3" wide, the standard 17' is only 2.5" wide and there's a much poorer selection of tires available in 17" sizes that can be used on a rim that narrow. I spent quite a bit of time looking at this (tire sizes, tire widths) before deciding that the 160/80-16 was the best choice...

[3Phase]

I suspect the shaft failure that Scott had was caused by this, as from what he says he likes to 'load 'er up' and may have run enough miles with the suspension compressed more than normal to do that.

Nah, the drive shaft was bad when I bought the bike and it failed because the original owner was a big ol' Cuban who rode it up and down a canyon for twenty years going to work and back.

It's a very steep grade and on some of the corners the front tire is almost rubbing the paint off of the rear license plate so going up the canyon makes the bike squat and grunt a little bit as it works up and out of the corners.

Go too fast or slip it too much espresso and the bike bottoms out hard and stays there through the corner. This is double-plus-un-good because something has to give so the drive shaft splines bend and oval out when the input pinion is twisted so hard that it bows and makes the coupler rub and bind against the final drive housing.

If you're going to make a hardtail, mind the weight and the angle of the drive shaft and try to stick to straight roads and bar hopping.