Oldham couplers

[ScottishBadger]

Hi folks, anyone know of a UK source for oversize couplers? Thanks.

[jnnngs]

They are made by Bert at sixcenter.NL (Netherlands), dont think there is a UK distributor that stocks them.

[CBX-tras]

Be careful. You don't want them too tight.

They're intended to move and act as a universal joint.

If they're so tight that they can't move at all, this will cause excessive wear elsewhere on the camshaft towers/caps where there aren't any bearings.

[Larry Zimmer]

Big AMEN there, JR.

[jnnngs]

Be careful. You don't want them too tight.

They're intended to move and act as a universal joint.

If they're so tight that they can't move at all, this will cause excessive wear elsewhere on the camshaft towers/caps where there aren't any bearings.

They are a very slight interference fit - so tap in rather than slide in. They still flex / act as a universal joint and never had any issues.

[CBX-tras]

If the aftermarket/oversize ones that you buy, require that you freeze them for installation, they are too tight.

But, don't let me stop you, there are people here, that will be happy to sell you a new cylinder head.

[daves79x]

I’ve frozen every set I’ve installed, not sure I really needed to, never had any issues. They too, wear in quite quickly and will just fall out after a few hundred miles. I completely understand the theory that they cannot be too tight, but there are many hundreds, if not thousands of bikes running around out there that say it’s not a problem.

Dave

[wessi]

Mmmh, i visited Bert in Heinlo and bought the oversized couplers at his desk. He mentioned, they have to be filed to fit, what i did with a diamond file. Very carefully to keep flanks parallel, removed alternating 1/100 per side.I madem them to slide in under some hand-pressure, now it´s quiet, noise is gone.
The aftermarket couplers are from very hard steel / hardened. Compared with my OEM couplers (20000 Km, ticking noise when engine was cold), they were 5/100 mm thicker and definetely would not go into the slots of the cam at room temperature. I would be scared to heat cams / cool coupler, as this would be a very harsh press-fit, and would avoid any movement to elemiate slag between cam-halves.
I agree to CBX-tras, there will be wear somwhere else at the cylinder head, most likely at cam bearings.
Also agree with Bert from Six-Center, the couplers, he sells, have to be fitted.