Special Goodyear tires and rims are supplied as original equipment on standard 1970 Sportster (high ground clearance) models. The tires are identified on the tire sidewall as follows:
Front - 3.75 x 19 Sport Rib
Rear - 4.25 x 18 All Traction
These tires must be used exclusively for replacement on these rims. This type rim has a special tapered bead seat with a safety hump as shown in sketch below. Standard tires such as Goodyear 3.50 x 18, 4.00 x 18 or 3.25/3.50 x 19 sizes will not fit correctly and will result in unsafe operation if installed for any reason.
Correct inner tubes for use with tires are identified as follows:
Front - 3.25 x 18, 3.50 x 19
Rear - 4.00 x 18, 4.50 x 19
New "C-Section" rims can be positively identified after tire is removed from rim by the following part numbers stamped in rim.
Type of Rims | Position | Part Number | Size |
---|---|---|---|
Steel Rims | Front | 43003-70 | 19 x 2.50C |
Rear | 43004-70 | 18 x 2.50C | |
Aluminum Rims | Front | 43010-70 | 2.50C - 19 |
Rear | 43008-70 | 2.50C - 18 |
See the Harley Davidson Service Bulletin No. 597 from September 16, 1969.
Description | Original Front | Repl Front | Original Rear | Repl Rear |
---|---|---|---|---|
Manufacture | Goodyear | Cheng Shin | Goodyear | Cheng Shin |
Size | MM90-19 | 3.25/85H19 | 4.25-18 | 4.25/4.60H18 |
Tread Design | Sport Rib | C-199 | All Traction | C-199 |
Type | Tube | Tube | Tube | Tube |
Ply | 4 | 4 | 4 | 6 |
Cords | Polyester | Nylon | Rayon | Nylon |
Overall Width in inches | 3 13/16 | 3 1/4 | 4.50 | 4 5/8 |
Load Range | B | B | ? | C |
Profile | Low | Low | ? | High |
Max Load | 475 | 470 | ? | 740 |
Load ? | . | 54H | . | 65H |
Max pressure | 32 | 40 | ? | 40 |
Made in | ? | Twian | U.S.A. | Twian |
Serial numbers | MH61 MTA201 | . | MH6E MPA103 | . |
Circumference (with 11,000 miles) |
? | 80 1/8 | 83.25" | 81.5 |
Diameter (with 11,000 miles) |
? | . | 26.50" | . |
Recommended Tire Pressure | 18 | ? | 30 | ? |
Increase for each 50 lbs. over 150 lbs. |
+1 | ? | +2 | ? |
Total Weight of rider and passenger | Front | Rear |
---|---|---|
150 lbs. | 18 | 30 |
200 lbs. | 19 | 32 |
250 lbs. | 20 | 34 |
300 lbs. | 21 | 36 |
350 lbs. | 22 | 38 |
400 lbs. | 23 | 40 |