Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Flexible Handlebar Mtg

Hi

I have just come across a Triumph service bulletin concerning the above.
It calls for an additional 12mm O ring to be inserted adjacent to the spherical washers H1529, but does not give a cross section for the O ring.
Any recommendations?

Dave

H1580/97-1580 (rubber washer not an O-ring) is approximately 1/4".

https://www.feked.com/triumph-bsa-handlebar-p-clamp-rubber-buffer-washer-500-650-750cc-models.html

L.A.B, wrong part Mate. This is the service update showing the addition of a 12mm O ring.

I gave it a try with the thickest O ring I could find and it made no difference. Mine are now solid mounted and Ive noticed no additional vibration just a better feeling bike.

What is the Triumph Service Bulletin number?
The only Triumph service bulletin I'm aware of pertaining to the flexible mount was the addition of the cup, steady rubber and distance piece, below (Service Bulletin No.306/ USA #1-70) :



Perhaps it's someone's idea of a modification they've added to the drawing (especially as it's a metric O-ring size) below unless you have further information on the service bulletin number.

It looks like an addition. The typeface is different. Might be a good idea though? I've never had problems with the rubber mounted handlebars on any Triumph I've owned, as long as all the components are as they should be and assembled in the right order.

Link to Terry McDonalds site where I pinched it from
https://triumphbonneville120.co.uk/rubber-mounted-handlebar-modification.php

Ok, thanks. As there were no T140s in "1970" and says "O-ring modification added 2018" then it's not a genuine factory service bulletin.

i have a 72. i hate tbe wobbly bars.

i take all that crap out, add flat washers, and torque em diwn until it doesnt wiggle anymore

Hadn’t noticed the T140 bit. I assumed the 2018 was when it was added to the site. Seems odd and somewhat pointless to fake a 50 year old service bulletin.

It does seem odd that whoever created the page didn't want to take credit themselves for the O ring idea if they thought it was such a good one. But it is clearly a non-Meriden addendum, presumably by the person who posted the page on the 'net.

Looks like it was a T150 service bulletin originally with some alterations: