Mystery Frame Bracket

[cmfalco]

A tab on the frame, ~8" back from the front engine mounting stud, on right side of my1928 Model C Ariel is used for attaching the exhaust pipe. However, there's a mystery tab on the left side, whose shape and location (~6" back) seem inconsistent for attaching the second pipe on a twin-port engine. A friend has the same bracket on the frame of his 1938 Red Hunter, so it must have been useful for something in order for them to have kept it for so long. Can someone tell me the purpose of this mystery tab?

[simon.holyfield]

It's for the second exhaust pipe on a twin-port.

[cmfalco]

It's for the second exhaust pipe on a twin-port.

This photograph of both sides of a twin-port 1930 Ariel show the exhaust mounts are in the same relative location, whereas that mystery bracket on my 1928 Model C and my friend's high-pipe 1938 Red Hunter differ in position by ~1½"–2" from the bracket on the other side.

If it is for mounting the twin-port exhaust pipe, is there also an additional piece for that offset? And, if so, why did they put the bracket where it is, instead of directly across from the one on the right side of the machine?

[Roger Gwynn]

It is for mounting the left ex pipe. There isn't an additional piece of anything but the 'P' clips are different. The 1933 drawing shows the RH brkt 1-1/2" behind the left one and is the same in 1950. The SQ4 has them in the same position

[cmfalco]

the 'P' clips are different.

Thanks for that information. In addition to being in different locations, the shapes of the two lugs are different, which made me question whether it was for mounting the pipe.

[simon.holyfield]

the 'P' clips are different.

Thanks for that information. In addition to being in different locations, the shapes of the two lugs are different, which made me question whether it was for mounting the pipe.

I've noticed that too. There has to be a reason - anyone fancy diving down that particular rabbit hole?

[Roger Gwynn]

I have often wondered why the design of the 2 brackets is different, the later SQs, at least and I think all the ohv ones, use two of the brackets with the sq headed bolt. The left bracket is the same as the pillion footrest bracket but why, I don't know.

[Paul Slootheer]

…and even the very late rigid (mid 50’s) VB bears the same bracket, all together with the swingarm type lug for the side stand. It seems Ariel just could not depart from their inseparable bracket