Franz and Grubb Engine
Triumph 650 750 Main Bearings
Regular price
$56.95
Shipping calculated at checkout.
Genuine English made bearings are the best choice for any Triumph rebuild. All of our bearings are in sealed factory packaging and should not be removed until ready for installation. For applications please see below.
Bearings are graded by numbers to designate the internal clearance.
Ball bearings generally are supplied in C3 condition, but roller bearings are supplied in CN (normal), C2 (less than normal), and C3 (more than normal) clearances.
Main bearings used by year and model
| engine | Timing side | Drive side |
| 500 to 1954 | 70-1592 | 70-1591 |
| 650 to 1954 | 70-1592 | 70-1591 |
| 500 1955-57 | 70-1591 | 70-1591 |
| 650 1955-62 | 70-1591 | 70-1591 |
| 650 1963-65 | 70-1591 | 70-1591 |
| 650 1966-71 | 70-1591 | 70-2879 |
| 650 1972-73 | 70-3835 (metric) | 70-2879 |
| 750 1973-76 | 70-3835 (metric) | 70-2879 |
| 750 1977-80 | 70-3835 (metric) | 70-2879 C2 |
Triumph Main bearing sizes
70-1591 ball bearing (RHP MJ1 1/8JC3)
70-1591 ball bearing (Hepolite MJ1 1/8C3)
70-1592 ball bearing (RHP MJ1JC3)
70-2897 roller bearing (RHP MRJA1 1/8JCN)
70-2897 roller bearing (Hepolite MRJA1 1/8C3)
(70-2897 also interchanges BSA 68-0625)
70-3835 ball bearing (metric) 6306C3
(70-3835 also same as 60-4167)
70-2879 C2 roller bearing (RHP MRJA1 1/8JC2)
For any other bearing requirements please contact the shop.
