Flexible joins on oil pipes.

[Triton Thrasher]

For reliability, the rigid metal section should be no more than a stub that you fix the flexible hose onto

see where your coming from TT but I'm thinking that due to the very small holes that the rocker feed studs have in them and the not so great oil pressure that leads to them would a long run of rubber not (that will be to some degree expandable) loose pressure.

This is the great thing about this forum, random queries lead to lots of info that is of benefit to many of us

It could have an effect, who knows!

A narrow I.D. pipe might get oil up to the rockers sooner after starting too, but I don't know if it matters.

[Topdad]

I've been using braided fuel line for my rocker feed , clips at each end, for the last 4 yrs , no problems with the line but had  more than my fair share of leaks from the connectors at  the rocker box.

[BSA_54A10]

The biggest problem is too much oil in the head.
It is quite happy with 5/8 of SFA oil at almost no pressure.

[chaterlea25]

Hi All,
Earlier there was mention of using a flaring tool on copper oil lines, not a good idea on old bikes in my opinion
There were and are  good reason why there were brass ends soldered to the copper pipes at the connections
This greatly increases the reliability of the joint

in industry, copper sheathed pyro electrical cables and 1/4'' copper pneumatic control lines had vibration loops adjacent to their connections to machinery.
This was to stop the copper breaking at the compression gland.

Another reason why this is and was done is to provide extra "spare " cable/pipe
when for instance motors are removed for overhaul or replaced with a similar but different terminal box one
the cable can be re terminated  without rewiring or adding another joint. 
Pyro almost always failed at the joints or terminations,
that extra loop would have been welcome a lot of times when I was repairing faults at work

Cheers
John