The Heavy Hitter 300M Chromoly Upgraded 12MM E Ride Jackshaft Bolt is a heat-treated 300M chromoly replacement for the 12 mm jackshaft bolt on the E Ride Pro-SS 3.0, Pro-SS 4.0 and Pro-SR and on 2026 and newer Pro-S, Pro-SS and 2.0 bikes. Made by Heavy Hitter and sold here at GritShift, it weighs 0.4 lb with its flange nut.
Specs verified September 2026 against the live GritShift product page.
Specifications
| Material | Turned 300M chromoly steel, heat-treated for durability and hardness |
|---|---|
| Bolt size | 12 mm |
| Weight | 0.4 lb |
| Hardware | Flange nut included |
| Failure mode | Bends rather than snapping under extreme load |
| Tools | 6 mm Allen and 14 mm hex for the nut |
| Installation | Plug and play with the stock swingarm |
What bikes does the Heavy Hitter 300M 12 mm jackshaft bolt fit?
- E Ride Pro-SS 3.0 (all years)
- E Ride Pro-SS 4.0 (all years)
- E Ride Pro-SR (all years)
- E Ride Pro-S, 2026 to current
- E Ride Pro-SS and 2.0, 2026 to current
2026 E Ride Pro-S and Pro-SS 2.0 models switched to a 12 mm jackshaft bolt. Check that your bike is not still on the older 10 mm hardware before ordering; the 10 mm bikes take the Heavy Hitter 4340 Chromoly Upgraded 10MM E Ride Jackshaft Bolt.
Why 300M chromoly instead of titanium or Grade 12.9?
Heavy Hitter tested titanium and Grade 12.9 bolts for the jackshaft and rejected both: their metal composition makes them brittle, so they snap instead of bend and leave a rider stranded on the trail. 300M chromoly, turned and heat-treated, is stronger than the OEM hardware and fails by bending, which keeps the bike rolling home. Heavy Hitter describes it as the best plug-and-play option for a stock swingarm.
Can a jackshaft bolt fix chain derailment on an E Ride?
Only partly. Riders who send it hard will likely bend any bolt on the market and may unknowingly bend the swingarm too; repeated chain derailment without hitting anything is the sign of swingarm flex. The 300M bolt is the strongest drop-in for the stock swingarm. For the ultimate fix Heavy Hitter points to its billet swingarm: see the Rogue 2.5 Inch Extended E Ride Billet Swingarm or the Rogue Stock Length E Ride Billet Swingarm.
How do I install the 12 mm jackshaft bolt?
It is a direct swap for the OEM bolt in the stock swingarm. You need a 6 mm Allen for the bolt head and a 14 mm hex for the flange nut that comes in the package. Heavy Hitter does not publish a torque figure for this bolt on the product page, so torque it to the value in your E Ride service documentation.
Where can I buy the Heavy Hitter 300M Chromoly Upgraded 12MM E Ride Jackshaft Bolt?
Right here. We sell the Heavy Hitter 300M Chromoly Upgraded 12MM E Ride Jackshaft Bolt at GritShift. Browse every Heavy Hitter part we carry in our Heavy Hitter collection.
