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Eye Bolt Huntmaster Gearbox

Posted: Mon Sep 16, 2019 3:42 pm
by graylee
Hi all,
Been going over my Cyclone which is new to me so trying to check if a few things are as they are supposed to be.

There is a nut which sits in a u-shaped lug on the frame, and is on a bolt that appears to go to the back of the gearbox, at the top.

I assume it adjusts something?
Anyway, it is loose. In fact you can swing it up out of the lug. Is this correct? What does it adjust and should it be done up tight?

I think it might be called the eye bolt??

I will attach a photo if I can.

Thanks for any help.

Re: Eye Bolt Huntmaster Gearbox

Posted: Mon Sep 16, 2019 3:43 pm
by graylee
IMG_2419.JPG
Picture of the Nut

Re: Eye Bolt Huntmaster Gearbox

Posted: Mon Sep 16, 2019 4:57 pm
by graylee
Looking through other sources it is for clutch adjustment. But should it be loose enough to just lift out of the frame lug? I guess that is what I need to know.

Re: Eye Bolt Huntmaster Gearbox

Posted: Mon Sep 16, 2019 5:17 pm
by Mick D
Hi

That nut and eye bolt assembly moves the gearbox fore and aft to adjust the tension of the primary chain, make sure the secondary chain is slack during and adjusted after the primary is set.

Before adjusting the primary chain you need to slacken the gearbox to plate attachments in order that the gearbox is free to move. Once the chain tension is set and the gearbox attachments are torqued the eye bolt assembly has no function to perform, just nip it up in the tighten direction.

Regards Mick

Re: Eye Bolt Huntmaster Gearbox

Posted: Mon Sep 16, 2019 5:31 pm
by graylee
Hi Mick,
Thanks again! I'll just tighten it up to stop it bouncing around!
Lee

Re: Eye Bolt Huntmaster Gearbox

Posted: Thu Sep 19, 2019 9:19 am
by roger.fellows
Lee, I don't know whether you've understood Mick's post.

If that nut is loose you should check the tension of both primary and secondary chains. You could be heading for serious damage and personal danger if not.

I'm sorry, I've no idea how familiar you are with Ariels, perhaps you could get help from somebody if you are unsure about this. The nut needs to be set so that it bears the right way to maintain tensions. I can't remember which way that is without referring to somebody who knows.

Can you give us a rough idea of your location - don't be too specific?

Re: Eye Bolt Huntmaster Gearbox

Posted: Thu Sep 19, 2019 9:45 am
by Mick D
Hi Roger / Lee

As I said, once the primary chain tension is set and the gearbox mounting studs tightened the adjuster has no function, the torque on the mounting studs maintains the position of the gearbox and therefore primary chain adjustment. Nipping the eye bolt nut in the tighten direction safeguards the gearbox position in that it cannot move forward in the, (unlikely), event of a loss of torque on the mounts resulting in a slack primary chain.

Regards Mick

Re: Eye Bolt Huntmaster Gearbox

Posted: Thu Sep 19, 2019 1:44 pm
by jj.palmer
The eye bolt and its adjusting nut act as a "adjustable mechanical stop" (as opposed to a friction stop) similar to the ones that are fitted either side of the rear wheel, all three are essential to ensuring that both drive chains maintain their correct tension.

It is therefore important that the eye bolt adjusting nut does not move out of the "U" shaped bracket, otherwise as stated, it may not only result in a slack intermediate chain but also an over tight rear chain.

I would advice that you lock the eye bolt adjusting nut into the "U" shaped bracket by some method, even a piece of wire would suffice. (I always make a locking bracket held in position by a screw.)

Hope this helps.

John P.

Re: Eye Bolt Huntmaster Gearbox

Posted: Thu Sep 19, 2019 2:06 pm
by graylee
Hi,
Thanks guys for the input.
I don't really know anything about old British bikes. The oldest bike I had before this was from 1981.
I am on the Suffolk/Cambridgeshire/Norfolk border.
The bike currently runs very well so I can only assume all is good at the moment, regarding the chain tensions.

As I tighten the nut to stop it being loose it works it's way out of the U-bracket, so I think I do need some way to keep it in there. I will put a bit of wire over the bolt as suggested temporarily.
I appreciate any advice and help.
Regards
Lee

Re: Eye Bolt Huntmaster Gearbox

Posted: Thu Sep 19, 2019 2:27 pm
by Mick D
graylee wrote:As I tighten the nut to stop it being loose it works it's way out of the U-bracket,


Hi Lee

Yes mine does the same, I just nip it up with a ring spanner whilst applying downward pressure - it doesn't need to be tight, just nipped to remove any slack.

Regards Mick