ES2 rear chain adjusters

Previously George Phillips wrote:

The threads on the rear chain adjusters on my '55 ES2 are a bit iffy but I can't seem to find a replacement set. I'm thinking of buying a set of taps/dies and re-threading them down a size. Does anyone know the size/TPI/and thread type (Whitworth/BSF etc) of the standard unit? Many thanks for any help. George

Type Chain Adjusters into the search box ( top Left) and there is an interesting "thread" in there about sizes of thread for these. Similar machines but clearly more than one solution.

Cheers

Jon

It's an odd size something like 7/32 BSF or BScY (I'll try to find the tap I bought)...My original nuts were rounded off (ouch) so I used a common size nut with a smaller thread hole and tapped this to make four perfectly fitting nuts that you cannot buy anywhere it seems (spent ages looking) ...You suggest you might re-cut the thread on the screw but this will leave it very thin too thin in my opinion. So best to try new fitting nuts or at least make them as I did.

Les

I am describing here the situation I had on my 1957 Dominator a few months ago.

I dealt with CPC Engineering near Redruth by email when I had a problem with my own chain adjusters. They produce a stock adjuster which is 1/4 UNF (28 TPI) which was not the size on my own machine.

I had to drill both of mine out because they had broken off and I tapped them out to 1/4 BSF (26 TPI) and they made me a pair to suit and did a lovely job of it for about £15.00 and I was extremely satisfied.

Hi Richard the type on the early bikes is like this photo:....I have a feeling that your adjusters were the single screw type?:

Previously les_howard wrote:

Hi Richard the type on the early bikes is like this photo:....I have a feeling that your adjusters were the single screw type?:

Yes of course. Very different. Quite agricultural in fact.

What ...the older ones or newer type? (in agricultural terms)

The older type are better in my opinion. I've had the newer screw in ones bend under load whereas a screw/bolt under tension is very strong and secure and they are easier to adjust as its easier to get at....and... it's easier to tighten the large spindle nut as it isn't rubbing on the screw adjuster and wearing off the finish.

Les

Previously les_howard wrote:

What ...the older ones or newer type? (in agricultural terms)

The older type are better in my opinion. I've had the newer screw in ones bend under load whereas a screw/bolt under tension is very strong and secure and they are easier to adjust as its easier to get at....and... it's easier to tighten the large spindle nut as it isn't rubbing on the screw adjuster and wearing off the finish.

Les

That's what I meant by agricultural Not only stronger but look like they have been forged by a blacksmith.

I have a original 1955 19S and the rear chain adjuster is similar to Les Howards photo and the threads is 5/16 bscy.

Svein.

The parts list I have for my '61 Model 50 says that the part number is: E3229

An interchange I found says that the thread form is: 1/4-26 CEI

I wouldn't think that Norton made any changes to this part between '55' and '61

Mike

Previously svein_marken wrote:

I have a original 1955 19S and the rear chain adjuster is similar to Les Howards photo and the threads is 5/16 bscy.

Svein.

Partnr:

Rear chain adjuster complete H12/483

Rear chain adjuster bolt only H12/666 5/16"bscy

Rear chain adjuster bolt nut E3223

Rear chain adjuster fork end cap H12/668

This is from Norton Spares Part List for 1955 ES2 19 Spring Frame.

George

These adjusters are the same as f/b manx and they may be had from

Andy Molnar product code 18255 at GBP 40.00

Regards

Arne

George

These adjusters are the same as f/b manx and they may be had from

Andy Molnar product code 18255 at GBP 40.00

Regards

Arne

George,

My 1955 ES2 has the lollipop shape adjusters and the thread is 5/16 bscy. The smaller locking nuts can be bought from autojumbles from some of the nuts and bolts stallholders, you have to look carefully to find them.

As these adjusters are very difficult to find I got my brother to make me a pair for my other 1955 ES2 project. I've tried attaching a photo, so hope it joins this text!

Regards, Philip

George

Eh well....99% sure...

I would contact Mr. Molnar and ask him, if they do not fit I'm sure

they can be returned.

Regards

Arne

Thread size is 9/32 BSF...not 5/16...well in my case they are and they are are unadulterated or un-modified original parts....bet you find 5/16th too big...............you might find 5/16" sort of fits but then loses its grip which might be why you think the thread has worn....

PS: Anyway.....these are so easy to make from scratch...including the end plate....One fat washer..... one sawn off bolt....a piece of mild steel bent and drilled.....and a dead easy braze together of bolt and washer....I wouldn't entertain the extortionate price of buying ready made ones....but each to their own.........

Indeed....Stick with 5/16 BScY if you do make some new ones.

If you do....I would file a flat on the bolt that is welded to the the big washer so it sits better on it. Also note that the bolt does not have to have to be welded to the edge of this washer, it lies at the back all the way up to the central hole and does not get in the way when tightened as it lies snugly in the cut out or slot in the swinging arm that takes the spindle.

SIDE POINT: As far as finishing....well you could get them chromed or better still, bright zinc plated. Then again if you get them welded carefully the original zinc finish wont be affected or damaged too much anyway.

For a quick protecting finish on any fresh raw metal you can use a "Galvanising spray"....NOTE: This is NOT a grey spray paint, it is a zinc solution that chemically BONDS to the raw metal supposedly as strongly as proper galvanising! I have used it and it is pretty good...can be bought from SCREWFIX and other places....very cheaply.

Les