1970 Harley Davidson Sportster C-Section Rims

IMPORTANT TIRE INFORMATION / 1970 SPORTSTER

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

1970 Harley Davidson Sportster C-Section Rims

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.

Original Goodyear Tires and Replacement Cheng Shin Tires
Description Tom's Toys Front Tire Tom's Toys Rear Tire
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 ?

Recommended Tire Pressure Table
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

Ride safe... and no flats...

Sportster Page