Hitchcocks Forum

Hi from Australia. My 2013 Classic Chrome Bullet 500 has been a gently vibrating delight but in the last few thousand miles the vibes have become steadily worse to the point where what was a pleasure is now a pain.

The bike has done about 16,000 miles total and has had no issues. It has always been professionally serviced by the book. This problem with excessive vibrations started about 3,000 miles ago.

It used to run happily up to 70mph with a particularly sweet spot between 50 - 60. Now its rough all the way through the rev range and buzzes roughly on the over run when I shut the throttle at anything above 50mph.

The bike has generally got smoother and sweeter with the miles so this turn around has me and the dealer, an experienced RE man, mystified.

I couldn't find any chassis probs with frame/mounts or head steady, nor could the servicing dealer who twice checked over the bike. They also popped off the side covers and confirmed no run-out on the crank, nice tight clutch unit and so on. There's never been anything nasty appearing in the oil.

Before the motor is pulled out and dismantled has anyone had a similar experience and can offer any advice?

Much appreciated, Trevor

I'd be wanting to have another good look at the engine mounts.



I'd also thoroughly check the chain and sprockets for tight spots, hooking and broken mounting bolts, also sprocket carrier bearing. Especially if it's more speed than rev related. Coming off the throttle makes the chain tension move from the top run to the bottom run.

WOrth going over it with an engineers stethescope or sounding rod to see if you can localise any funny noises. A large screwdriver with a round-ended handle makes a passable sounding rod. Press the handle to your ear and press the end of the screwdriver to the various parts of the engine.



Of course, this won't show you any chassis related problems but should help localise engine related vibes.

Hi guys-------- Do those models have a balancing shaft at all and if so is it gear or chain driven ?? ----- just a bit of lateral thinking there...LoL !!

Assuming the bike is a C5 it could be a frame breakage or crack; whilst this is not common it's also not unknown. It seems to affect the C5 only for some reason. No, it doesn't have a balance shaft.

Loose or broken/fractured top motor mount is the common cause...

As Tim says, check the headsteady from the cylinder head to the frame. I once had mine vibrate loose gradually and it turned the bike into a pneumatic drill. Re tightening the nut made a huge difference.

Ah, just seen you said you've already checked it!

I've also had an intrusive vibration set in through the handlebars when a motor moved in a frame without anything breaking (not an enfield mind you). I loosened the engine mounts, jacked up under the engine then re-tightened them. The slight movement in the engine changed the frequency of the vibe and stopped the handlebar problem. That said, your vibration sounds more severe than that.

Hi TvR Did you manage to find out why your 2013 Classic Chrome Bullet 500 was vibrating so bad.