Topic: Speedo / Tach Crimp rings

[Ace Blackwell]

I've asked this before in other topics with out much feed back.  Figured I'd make the question it's own topic.   I'm putting my gauges back together.  Got a nice set of plates from Marcel at 750faces.com.  Did an awesome job.  I didn't get new rings. Thanks to the suggestions here I was able to get them off without much damage.  So I painted the black housings and now try to get them back together.  Lot like herding cats.  So before I keep on until i've scratched the paint all up, I was wondering if there is a trick to it?  A specific tool to be used?  Up to this point I've tried various pliers, side cutters, and channel locks with out much success.  I've steered away from a impact approach like beating on it with a flat head screw driver, mainly for fear of missing and hitting gauge.   Plus I can't figure out a good support for underside of the ring.   

I'll figure it out at some point but again, I was hoping there was a trick or technique that has already been proven.

Thanks

[RAFster122s]

A few have cut a wooden gauge holder that allows them to slowly work the flange giving support for the ring with a tight enough fit to not worry with the front face of the crimp ring being held tightly to the instrument body.

Just like you removed it slowly bringing up the ring's crimped area a little at a time, if you slowly work it back down you will not stretch the ring causing problems the closer it approaches to closing it up...

Does Marcel use a delrin plastic ring to help close it up?

David

[micol]

I have used a section of PVC pipe with some tape around the edge to hold the gauge while putting the gauge back together. Worked well with no scratches.

[Ace Blackwell]

Good idea micol.  I'll give it a shot. 

RAF122S Thanks for the warning on working the ring.   I don't know if Marcel uses a delrin ring.   I'm sure he has a set up specific to reworking gauges.  I didn't of asking, assuming his setup wouldn't be something I could duplicate cheaply.   Maybe an incorrect assumption looking back.

Thanks again,

[el pachuco]

I also cut a short section of 4" PVC pipe to hold the upper section secure and protect the painted finish. I hot glued the PVC pipe to a small piece of plywood and used a 12" pistol grip speed clamp to squeeze the upper and lower sections tightly together. For the crimping task I have found that a short 1/4" ratchet extension and a light hammer work pretty good

[Don R]

 I made  a stand from oak, the gauge fits snug to hold the ring while I re-crimp the back side. So far I've only done one. I can't find the pictures, must have deleted them.

[Ace Blackwell]

Will try the 4" pipe thing.  I have the rings back on the assembly with the previously crimped half on the paint half.  Will tap using 1/4" extension on then bare metal half of the asm.   I'll keep you posted.  Thanks.

[tlbranth]

Read this for ideas: https://ngwclub.com/forum/viewtopic.php?t=41376

I thing one helpful idea from this writeup is to screw the 2 halves together before getting the ring in place.

[Ace Blackwell]

Well I got them back together.  The 4" diameter PVC pipe was ideal.  One thing to consider.  I was uncharacteristic in that I took my black housing to Lowes with me (normally I don't think ahead).  If you get the 4" pipe as I would strongly recommend, remember use the thin wall sewer pipe. the thicker wall PVC pipe will not have a large enough ID to allow the casings to fit.  The thin wall however fit mine like a glove.  They came in 10- foot sections for about $10.  I found a piece that was damage and got it for $4. 

Now having said that, remember the not thinking ahead I mentioned?  I crimped my speedo and tach back together tonight and forgot to wipe down the inside of the glass.  I mean it still looks pretty good but does have some light dusting.  I've tried blowing into the holes in back and tried vacuum but no good.  Does any one else have any ideas?  I may try compressed air or contact cleaner.  I'm a little afraid of leaving residue on the glass. 

Thanks

[evanphi]

Take them back apart. You won't clean them well enough otherwise.

Ask me how I know.......

[Dunk]

Hole saw through a 2x12 to support the gauge. I crimped with a small punch got 4 spots 90* apart then another 4 halfway between those then worked around the perimeter. It was a pain, no way around that I'd imagine, but that's the method that worked for me.

[Ace Blackwell]

Thanks Dunk I’ll see what I have available. Meanwhile the pipe worked well but a vise might have helped keep compression on the seal while crimping . As it stood I used a couple of knee pads so not to bend cable connect and basically sit on the part /pipe assembly while crimping. I used a flat head screw driver and tapped with hammer to get the ring rolled over. Then took the suggestion to finish crimp with a 1/4in extension and tapped the ringto flatten the roll over to casing.  Going to be disappointing to take it back apart.

Evanphi, I was hoping for some magic technique but am slowly resolving myself to the fact they have to come back apart. Will give me a chance to add the lithium grease I forgot as well. Was so tunnel visioned on getting them back together after months off sitting I didn’t think past that.  That’ll learn me.
Thx

[evanphi]

Evanphi, I was hoping for some magic technique but am slowly resolving myself to the fact they have to come back apart. Will give me a chance to add the lithium grease I forgot as well. Was so tunnel visioned on getting them back together after months off sitting I didn’t think past that.  That’ll learn me.
Thx

Yeah I was excited to put mine back together too, noticed a HUGE smudge on my glass... off it comes!

[MetroRedneck]

If you're not opposed to the look, you can also cut the ring, flatten and bend the cut ends, then bolt the rings on.

[pjlogue]

The gage restoration and dealing with the rings was probably one of the longest and most difficult parts of restoring my bike.  I ended up getting a length of 4" steel schedule 40 pipe and cutting it in half.  One piece I used as a backing piece.  That piece was turned in my lathe so the ends of the pipe were 90 deg to the length and smooth.  I slit the pipe length wise and the kerf of the cut was enough to use a band clamp to reduce the diameter just a little.  The other section of pipe I turned in my lathe to facet one end so the edge was curved so as the crimp ring was pressed on the end of the pipe it would be forced to bend over the flange of the bottom half of the gage backing.  I then used a shop press to squeeze it all together carefully.  It worked pretty good except one of the gages the pipe wanted to move off center.  If I did it over I think I would get another section of pipe to go around the upper and lower pipes to keep them aligned when in the press. 

The crimp rings where they are supposed to be bent over seem to be a bit short.  It would be nice if the rings were a tiny bit taller and we had some way to get new gaskets for the glass faceplate and the inner shroud on the upper half of the gage.  That would make the gages rainproof.  (not water tight because of the back plate holes)

-P.

[Ace Blackwell]

pj my rolling around on the garage floor trying to keep compression while tapping with a hammer sounds mid evil compared to your setup lol. I was able to get a good crimp but I’m sure the visible side will show the dents and scratches. Maybe some day I’ll order new rings so I don’t have to reuse what I have. Also look up CB750faces.com. They have seals, glass, black housings etc.

Metro, I’ve heard that some years/models actually use the screw on type rings. Would be a lot easier I think. I imagine you would still need to compress the seal.

Currently I’ve got them back a part. Have grandson over tonight so I’ll probably CLEAN THE INSIDES and get them back together Later this week

[Ace Blackwell]

Well here is the follow up on the Speed/Tach assembly.  As previously mentioned I had the two,  together using the 4" pipe, screwdriver, and 1/4" extension.  I took the halves back apart once i realized I hadn't cleaned the glass before assembly.   I cleaned the glass and wiped the face plates.  I blew into the housings. Unfortunately I don't have compressed air yet.  I still had issues with white plastic looking dust in the tach after I got it crimped again.  I couldn't figure out where it came from.  Long story short on the 3rd try, I wiped the silver housing, wiped the face plate, then very lightly steel wool the face plate edge.  I steel wooled the 4" pipe edge.  Finally I taped the holes in the back of the the silver housing before starting the crimping process again.   3rd time charm (twice for speedo).  I still don't know where the white plastic (looking) debris came from but it's not there now.

I've put them all back together.  There are some imperfections.  Only the face plates are new.  The rest of the parts are either steel wool chrome or painted.  They still have pitting and a battle scar dent from when the bike was stolen in the 80s.  I may replace the components some day but I'm cool with it being original parts even if the age shows through.  I would like to replace the foam, but at $30 for the set I can get an OEM mirror for that price so I opted to wait. 

Oh and yes I realize I had the chrome casings switch at the time of the picture (note the light bulb holes) and the rubber bushing for the speedo trip set hadn't been install.  It has been corrected since then. 8-)
   

[el pachuco]

they turned out very nice. well worth the effort.