Britbike forum Forums British motorcycles in general British motorcycles in general Concentric and Monobloc - Are cables the same?

I have to replace a Monobloc carb and would like to use a Premier Concentric. Do I have to use different cables? Will my existing Monobloc throttle and choke cables still fit when switching to the Concentric?

Throttle cables are different, inner is different in length. Been there got the T shirt when changing engines with different carbs. No idea on the choke but if you use the parts books look for part number changes.

It goes on further than this, there are variances in throttle bodies too. I bought genuine cables for my oif thunderbolt And pre oif Lightning. Same carbs both with ferule tops.

The correct cable for the thunderbolt (1971) does not work with the earlier style throttle, only the later throttle body as used on oif thunderbolts, rocket 3’s and maybe oif singles.

I got the earlier cable (same number as those I got for the Lightning) to go with the earlier style throttle, and that worked, but wouldn’t work with the later throttle.

So that might be a route out, most modern bought cables are crap so if you have a decent one, it’s worth trying to save it. Can’t remember if monoblock cables are longer or shorter though.
Modern cables aren’t as flexible as the originals and the outer cracks too easily.

Okay, so Plan A is scrapped. I was hoping to simplify things. Any used cables I have on hand are in awful condition. Project 39-1/2 will have a '68 TR6 cyl head, single Premier carb. Plan B, the best thing I can come up with is to buy '68 TR6 cables. That way they would be suitable for a Concentric. The cable might be a bit long (TR6 USA high bars vs. Pr 39-1/2 low euro bars), but hope I can route the cables neatly.

I have a similar issue with the '59 Indian Chief (Royal Enfield 700 twin). I am not restoring, but refurbishing. Bought a Premier Concentric, with initial specs provided by AMAL, to replace an ancient Monobloc. I will need a Concentric cable which will also be for low bars.

Al, buy a few of those universal throttle cables. The ones I get have a ball rather than a barrel on the top end, but have always worked fine. Cut to length and then you only have to solder the little brass bit at the bottom. I've made all my own cables for years, but for throttle or choke I just started doing this. If I did order cables from anyone for anything I'd expect to be disappointed.

Concentric throttle cables need more free play than Monobloc cables because the Monobloc slides pull up from the top of the slide and the Concentric pull up from the bottom of the slide, so you have about an inch of difference right there. And as mentioned there are other variables that will affect the free play needed.