Maxima Racing Oils - Fork Oil. Most vintage Honda's don't have a spec for which weight fork oil to use, since there wasn't fork oil back then. Most manuals recommend engine oil or ATF for the forks, but today there is Fork Oil that's specifically designed for forks, so we recommend taking advantage of that fact! Odds are the fork oil in your bike is decades old, so if you're replacing the fork seals or doing general maintenance, now is a great time to replace the fork oil.
10W - 15W is what's most commonly used in the Honda CB550's and CB750's. However, please do some research to find out what might be the best weight for you, maybe try 2 different weights and compare them to see what works for your preference. Always replace the fork oil in both forks at the same time, that way you know they have the same amount of fork oil and the same type of fork oil.
Maxima Fork Oils are formulated from the highest quality base oils and advanced additives to prevent foaming, seal hardening, oxidation and stiction. Lubricinol provides for very low sliding friction and protects internal components from wear. Temperature stable viscosity provides for constant fork action and terrain compliance for the front wheel. For all front suspension systems, both standard and cartridge.
Sold Individually. 1 Liter (33.8 FL. OZ.) Choose the weight you'd like from the drop down menu, we have 5, 10, 15 and 20 weight oil.
Additional Technical Data from Maxima.
Some Honda Specs: (Double these specs when doing both forks)
CB400F - Dry Fork Assembly - 160 - 165 cc (5.4 - 5.6 oz.) - After Draining: 145 150 cc (4.9 - 5.1 oz.)
CB550K/F 1974 - 1977 - Dry - 150 155 cc (5.1 - 5.3 oz.) - After Draining: 145 - 150 cc (4.9 - 5.1 oz.)
CB750K 1969 - 1972 - Dry - 7.5 - 7.8 oz - After Draining: 6.9 - 7.1 oz
CB750K 1973 - 1976 - Dry - 5.3 - 5.4 oz - After Draining: 4.6 - 4.7 oz