Ariel Owners Motorcycle Club

I have just bought a vh500 with twin port iron head. The exhaust clamps at the cylinder head are both broken. They are sealed well enough, but on close inspection both clamps are broken, presumably over tightened and just sit in the right place doing nothing.

Before I measure the pipe diameter and buy replacements on eBay - is there any thing I should watch for. For example is there a correct torque setting to allow for thermal expansion? Is this a common thing?

Is there a preferred seller of these - or are the eBay ones OK?

To answer the obvious - Why not just leave them? I plan on changing to high level pipes (that I already have) purely for aesthetics.


Thanks in advance for any input.

Roughly what year is it? To clamp effectively they'd have to be CNC'd from steel. Some clamps have no fins. Nev

The "clamps" are often made of malleable cast iron or aluminum and act more like cooling rings - they don't have enough strength to bend the headpipe and hold it there. I've broken both types. And run with a broken one for years. My recollection is the twin port head has 1 3/4" OD pipes that are the same as Triumph twins and that some of the Triumph clamps are steel. There should be no difference in the OD of the high and low pipes so your broken "cooling rings" should also fit on the high level pipes too.

The "Black Ariels" and the W/NG never ran finned clamps. Mostly a styling thing. Nev

According to the dragonfly website they should be 1.75", but they are not in stock. But there are some on eBay advertised as Triumph at 1.75 inch. Measuring suggests the OD of the pipe is a smidge larger than 1.75 inch.

I can't answer what year the head is.... reg document says 1946, engine number says 1958, but chromed external push rods says the top of the engine is older than the bottom.

But the point made above that they are more style than function.... I am tempted just to leave them as is, and when I swap the pipes, see how secure the pipes are with no clamping force.

I think Nev's comment was about the fins being more style than function, not the clamps themselves.

SG

Simon.Gardiner wrote: Sat Jun 07, 2025 12:43 am I think Nev's comment was about the fins being more style than function, not the clamps themselves.

SG

But who would make cast alloy as a 'flexible' clamp....? We're the original ones mild steel?

This is the original non-finned clamp that was on my 1946 SQ4. Some very good replicas of these are available:

Those stainless clamps are pretty enough. I'll get a set of them ordered up.
Being in Scotland, I am not sure the cooling of the head is as important and some other places, so hopefully if won't miss the fins.

Or I may go with these:
https://www.feked.com/exhaust-finned-ma ... n_id=26352

Those stainless clamps are pretty enough.

The plain ones pictured above are chrome plated steel (as per originals) not stainless. Triumph finned clamps also look quite good on an iron head. Important, however, do not overtighten the clamp - you risk damaging the lug on the head. Pete