Honda CB750 Sandcast

Rear Flange Finish

Wayne · 24 · 8021

Wayne

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Are there 2 sandcasts truly alike top to bottom? (apart from VIN)

i would suggest, perhaps the later vin LH horn bikes.  Would think alot of the RH horn bikes are the same.

I was thinking right down to the nitty gritty detail Steve, like date stamps and stamps such as these. What are the chances that 2 bikes got components all dated the same, stamped the same, same range of parts if there was a production change and so on. It COULD be a bit mind boggling when you get right down to it no?
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vnz00

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Mark, those marks on your drive flange are from the chain having jumped off the sprocket at some point. Usually down to a stretched drive chain, and a careless owner who didn't adjust it soon enough.  It acts as a saw once the chain has jumped off and you try to ride off again.

Regards, Steven


kp

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I think you are right Mr Swan, the early bikes are a bit hit and miss with component parts, whereas as the VIN numbers increased there seems much less in the way of surprises. My 248 has 2 scalloped exhaust spigots and 2 early standard Spigots. I couldn't see the original owner changing 2 of these so I have assumed there was a change afoot with this particular component at about this time
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Steve Swan

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Agreed Wayne, no two alike.

As fare as the sprocket carrier stampings on #97, if the "5" "18" were May 18, then #97 would not have received that part until at least that date.  Given 97 was very likely assembled not long after the completed assembly of #1, kind of hard to imagine the rest of 97 sat around until mid-May wiating for assembly.

The "C" is another confunding stamping.. ?

"5" "18" is from vin 1553.....  :-[   OOPS.... misread.  my bad. this stamping does make sense for being May 18.  

I'd agree w/ Steven V on those marks.  They do look like they were made in a rotational line; as Steven suggests, from a jumped chain.  Lucky the cases were not broken...  :o


Riccardo

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Mark,

regarding the print date my tought is an alfhanumeric classification:

C=March
12-the day of the month.

In this way the date seems to macth with your early vin, as Steve says.

About damage on the flange, i think at external factor (chain?) because the damage is also on the fins, i do not think at poor sandcasting.
« Last Edit: January 06, 2013, 12:51:17 pm by riccardo »
Riccardo
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markb

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regarding the print date my tought is an alfhanumeric classification:
C=March
12-the day of the month.
That is a plausible theory.  Anyone else have numbers?

 
Your flange from 1553 looks as bad as mine!
Actually it is better than 97 was.  The thinnest part of the edge is .140” (3.5mm) so it will clean up nice.


Wayne, sorry again for hijacking your thread.  Thank you all for the great feedback.  I agree that it has to be chain damage.  I’m not sure it can be removed and still look decent.  So now I have a tough decision to make.  Try to clean up the flange from 97 or use the one from 1553.  It would sure be nice to see what numbers were on a flange from oh, let’s say like the 2xx range.

Makes me want to pull the rear wheel off 232...
It makes us want you to pull it off too.  ;)
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


Wayne

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Hijack away Mark. That flange from 1553 will clean up no problem. I wish 576's was anywhere near that good. :(
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markb

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Well I bet you can all guess what I decided to do.  Try to save the flange for 97.  I took some sandpaper to the worst area and it took a while but it will clean up.  One down and three to go.  Just not today.

Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


Steve Swan

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Good one !  "It makes us want you to pull it off too." 

Bravisimo, Riccardo !  "C" = 3 = March.

Hmm...  Mark, now you've dared me....  Ha !   l'd have to do some major moving to get to 232 to remove the rear wheel.