Recently picked up a 98 SA50 that's very ugly cosmetically but quite beautiful mechanically. Belonged to the daughter of a real "wheeler-dealer" and was her college ride. Has ~3,500 miles and runs smoooooothly. Haven't checked top speed with GPS but the speedo rides above 35 mph on the flats with no wind with just me aboard. Keeps up with traffic quite well here in the city so long as I stay on the correct routes and avoid the roads where typical speeds are the "limit plus 10". Take-off is decent (quicker than the average car being driven casually) and is all I expect from a 50cc automatic. Acceleration is linear from stop to top speed, whatever that speed actually is doesn't matter much to me really but it does get there without lugging or noticeably over-revving.
Here's a shot of her coming home in the van: (note the phonebooks piled about)
Now here's a shot of what I mean by hardworking:
That's a load of 40 phone books, 9 on the front rack (I bolted on a random wire rack from the thrift store, works GREAT) and 31 on the back (typical milkcrate on white wire-frame shelf) totalling about 50 lbs total, to which I add my 210 lb self. Here's the front rack, bolted right on to the stock front cover retaining nuts using some padded p-clamps (aka aviation line clamps, etc) and you get a shot of the horrible paint job.
This bike is mostly just gonna be an around town ride, back and forth to work and school, maybe 10 miles a day max but over the summer I'm delivering phonebooks locally (still in that 10 mile radius) as a side job. I ride responsibly and don't lug the old girl up steep driveways when loaded heavily and I'm mindful of the extra weight when it comes to stopping distances, brake fade, etc. I treat her nice with good oil (Motul Scooter Expert) and keep her tires aired up and let her warm up and cool off before and after her chores.
I've spent the current budget getting her home and fixing some of the PO's stupid mistakes (HEAVY lawn mower battery hacked-in under the seat, zip-tied broken handlebar cover, etc) and making the headlight upgrade to a 2001 spec unit instead of replacing the costly sealed-beam as originally equipped (low beam was burned out when I bought her). The originally purple plastics have been spray-bombed black (by PO, not me). The handlebar cover is cracked and broken and zip-ties hold it on which causes terrible headlight alignment. A replacement has been ordered and I used the part-number for a 2001/1992 model so it'll already be nice and black.
Future plans might include a couple mods toward increased top speed, nothing crazy but turning 35 into 45 would be real nice for the occasional evasive maneuver or when running late to class, etc. My thoughts are, in order: 90/90-10 rear tire for increased diameter, 9:1 gears for lower rpm at higher speeds, and a different variator with lighter rollers (7.5 gram to start or whatever works out best eventually) to offset the loss of gear reduction and probably a different center spring to match the lighter rollers. I'm open to suggestions on all of the above. I'm curious what difference just the tire would make in top speed? Might be worthwhile to upgrade that sooner than later and keep the current 3.00 for when the front wears out.
I'm pretty knowledgeable of machines and engines, rpm, gearing, etc but haven't uncovered useful information on this machine other than it's gears are ~12:1. What's the stock redline? What RPM should a stock machine turn at 35 mph? What spread of ratios are available from the stock CVT? Would 9.8:1 gears be a better compromise considering I cannot afford to burn up a clutch moving the load but would like to move a bit quicker when unloaded? What's the top speed with 9.8:1?
Thanks in advance for any and all constructive assistance! Look forward to hearing from you!
THANKS for the input!!!