Chain master link rivet flare amount?

[dazzler24]

Quick question to the learned many.  How much flare needs to go on a rivet style master link?

I'm in the process of installing a flash new DID chain and have got to the point of flaring the master link pins but have been gripped by doubt and don't want to stuff it up.  I think I need about 0.6mm of flare??  i.e. add ~0.5 - 0.7mm to the untouched rivet head.

Does this sound about right?  All advice greatfully received.

[johnmark101]

When I have installed chains I use a digital caliper to measure the size of the flare.  I read somewhere that 5.3 to 5.8 mm is correct, so that it what I have always used.  Just don't over flare the rivet or it will crack.  I take my time, flare it a little and measure until I reach the desired size.

[Buggy Nate]

There is actually a specified amount dependent on the chain manufacturer/size/type of chain.

Failing finding that information don’t go so far as to crack the pin. If you do you will need to start over.

[Lone Wolf]

I followed this video, bought the calipers and shocked how affordable they were (local hardware stores have them)

Also - before you flare a master link rivet you need to pay close attention to how the side plate is positioned. They don't just "slip on over the pins", there is a degree of friction and they are gently pressed into place with the chain tool.

You make your best guess on how tight to press on the side plate (after apply lube to the pins and inner surfaces, O-rings for that master link).

Then you LOOK at it, with magnify glass and make sure there are no gaps, and the side plate is up against the O-rings like the neighboring links. 

Then you move the links a bit by hand, to see if that master link moves easily, is it too tight and binding. It should bend with some resistance, like it's neighbors. 

If you just throw the side plate on and flare the rivets, you can make a poor fitting side plate "locked in" permanently

One last thing, there are a lot of different chain tools and they all work, but they can be very different from each other. You need to be absolutely certain that the tool's back plate is positioned so that it "captures" the back side of the pin you are flaring. Those tools are also used to "break" a chain by pushing out the pin, and if you aren't watching you could push the pin out of place that you are trying to flare.

The following image is from RK chains

Edited June 14, 2021 by Lone Wolf

[fjrchuck]

Great post Lone Wolf! Thanks for sharing!! 😎

[dazzler24]

Well, many thanks to all who posted here.  Especially Lone Wolf.  That was a pearler with much detailed info!

Anywho, the job is now done and what started as a 30 minute chain oiler installation ballooned into - while I'm here, I'll do some maintenance... maybe also take to opportunity to change the chain...... better do the sprockets as well.... the gear shifter needs to be adjusted..... all these other moving points down here need lubing.... etc.

You know how it goes. 😏

How do these pins look to the critical eye of the forum mechanics?

[Buggy Nate]

Looks good from Australia matey.

[Lone Wolf]

Perfect. Yours look identical to the RK Chain suggested flare photo. (I use DID chain as well).

It really doesn't take a lot of flare to retain the side plate, so the calipers are vital to know when to stop.

Edited June 15, 2021 by Lone Wolf

[dazzler24]

Just now, Lone Wolf said:

Perfect. Yours look identical to the RK Chain suggested flare photo.

It really doesn't take a lot of flare to retain the side plate, so the calipers are vital to know when to stop.

Thanks. Yes, I used a digital vernier and you're right - adjust a little and check - rinse and repeat until done.

Patience is the key.  You can always do a little more but can't undo it once past the specs.

Cheers and thanks for the help.

[micah2074]

I measure the width of the factory plates and riveted heads and make mine the same. I’ve done dozen of chains like this over the decades never had a problem. 

[dazzler24]

1 hour ago, micah2074 said:

I measure the width of the factory plates and riveted heads and make mine the same. I’ve done dozen of chains like this over the decades never had a problem. 

This is pretty much the way I went about it.

Press the master plate on until it matches the others then rivet the pins to be a similar diameter to the existing quad staked ones - as closely as possible on both counts.

[PhotoAl]

Good post, just finished replacing my chain and sprockets.  Did exactly that, measured the width of the plates until the master link was same width.  Much to my chagrin discovered have a clip master link not a rivet type.  Leaving in a week for long trip so not time to get on now so went ahead with the clip which seemed to go on OK - not too easy and not too hard.  

[Slee]

Hi Team

 

I have just put a new chain on and all went well until I flared the pin. The anvil that I put on the backside of the chain must have allowed the pin to move back fractionally. The flare is perfect as is the width of the master link in terms of mm. My only niggle is the pin slightly protrudes on the back of the plate. Have a look at the pics...what do you think?

[Lone Wolf]

21 minutes ago, Slee said:

...the pin slightly protrudes on the back of the plate.

Master links are cheap, gaining the experience is priceless.

Good on you for noticing the issue - some professional shops may have just called it good.

Personally I think that given the forces involved, the side plates will eventually loosen up. Then you will have a very sloppy fitting link. It may be OK until a new link arrives in your mailbox.

Also see my post above. "there are a lot of different chain tools and they all work, but they can be very different from each other. You need to be absolutely certain that the tool's back plate is positioned so that it "captures" the back side of the pin you are flaring. Those tools are also used to "break" a chain by pushing out the pin, and if you aren't watching you could push the pin out of place that you are trying to flare."

Edited November 4, 2023 by Lone Wolf

[Slee]

Thanks Lonewolf...silly question but just clarifying the pin head on the rear of the plate...what does it normally look like as I have nothing to compare to? I'm assuming there should be no visible gap unlike mine?