Honda CB750 Sandcast

Who would be interested in getting 11mm mirror stems?

markb · 134 · 29110

markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
Test a small piece of the centerless ground 7/16.
Good idea.  The 7/16 stock is .438" and 11mm is .433" so about .005" would be removed.  I'm hoping that is enough to produce a good finish.  The original stems look like they were made from TGP (turned, ground & polished) stock, not CFS.  There's another reason to use the inch stock.  I can only get the metric TGP stock in 1045 and I can get the inch stock in 1018 (more bendable).
I'm interested.
But are they correct for my vin 737, 1081 and 1256?
From previous discussion on this thread they were found on 1221.  We can only guess on the exact cutoff and it may be that there were VINs before 1221 that didn't come with 11mm stems.  I guess my real answer is I don't know.
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?)


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
Talking about the finish brings up another question.  The original stems were typical Honda finish.  In otherwords there was not much, if any, additional polishing beyond the required fabrication.  There were still machining marks visible on the nuts and grinding marks on the stems.  My plan is to replicate the finishes as close to the original as possble.  That said, I know some of you prefer a little more "bling" than that.  Would anyone want unplated stems and nuts so you could finish them to your liking?  I think I can get the plating done for less than $10 per stem and nut.  I've got some chrome stuff at this particular plater right now and should find out in the next week or two how he does.  Of course if a lot of your prefer unplated, that might increase the cost of the plating slightly for those that want plated.  I'm working on finding someone that can do the brazing and once I do I should be able to give you a pretty good estimate of the costs.     
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?)



Riccardo

  • Sr. Member
  • ****
    • Posts: 362
    • View Profile
I'd like my stem and nut plated...  ;D  prefer as original finish as possible so it matches my orig.11mm stem/nut.

I agree with Steve.
Riccardo
Your Italian friend.
737/940 Restored
1081/1362 Preserved
1256/665 Restored - ex Owner: Chris R.
10253/10315 (K0) Next project
1969 - Kawasaki H1 Mach III low ign cover - Restored
1969 - Kawasaki H1 Mach III high ign cover - Restored
1971 - Kawasaki H1A - Restored
1973 - Kawasaki H1D - Preserved
1973 - Kawasaki Z1 Blackhead - Restored
1971 - Norton Commando SS - Preserved
1978 - Honda CBX - Unmolested Museum Quality
1988 - Honda CB 400SS - Unmolested
1997 - BMW R80 GS Basic - blue frame - Museum Quality
2007 - BMW HP2 Megamoto - blue frame - New





markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I think I’ll call that unanimous.
I have the round stock back from the grinder.  It looks good.  I also dropped off a piece at the bending shop to do a test bend to double-check the bend allowance so I can determine the exact required straight length.  There are formulas for that but even the shop said it would be a good idea to test one.  Once I determine the straight length we can start machining the stems.  I had to by a 14mm hex collet for machining the nuts (no one in town had one).  



« Last Edit: February 28, 2012, 10:56:38 am by markb »
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

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
Thanks, Mark for the update !  

I appreciate the time you're taking and the expense you're going to, to reproduce these stems.  

A part appearing so simple is not so simple to re-produce !


kp

  • Administrator
  • Hero Member
  • *****
    • Posts: 1801
    • View Profile
I  I had to by a 14mm hex collet for machining the nuts (no one in town had one).  


If you Gringos used metric rather than imperial then the town would have been full of 14mm hex collets  ::) Oh! Mark, what is a hex collet   :-[  ;) ;D
Yabba Dabba KP


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
A collet is used on a lathe to hold the bar stock for turning.  It screws into a collet holder that has a lever on it to open or close the collet to clamp onto the material.  It does the same as a chuck but faster and won’t mark up the surface of the bar as much.  They come in round, square, hex and other shapes.


« Last Edit: February 29, 2012, 09:16:20 am by markb »
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?)


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I got my sample with the test bend back.  Looks like I need to increase my cut length by .08” (2mm) to allow for the bend.


An unexpected problem is the tooling mark.  The bender says it will polish out.  The photo makes it look way worse than it is.  I looked at a stock 10mm stem and it looks like it probably had the same mark.  When I pick up my chrome plating (hopefully it will be done soon) I’ll have him look at it.  


When you look at it from the side you can see there is no noticeable distortion.  Once I determine it can be polished out I will get the stems cut and threaded.

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

  • Hero Member
  • *****
    • Posts: 2705
    • View Profile
    • cb750sandcastonly.com
Mark, the bend looks great.  Excellent job !  Do you recall if there was a bend mark on my stem ?  If you want me to look for a bend mark on my stem, let me know.  steve


markb

  • Hero Member
  • *****
    • Posts: 1249
    • View Profile
I don't recall seeing a mark on your stem and as a matter of fact I was going to ask you to check it out.  Like I said, I looked at a 10mm stem and if I look real close it appears that it has the same mark but almost invisible.  I tried to take a picture but it really doesn't show it well.  I talked to my chrome guy yesterday and he says my parts should be done by the end of next week.  We'll see, it has already been a week or two after he said it would be done.  But that's typical I guess.  Anyway he said he would see if it will polish out OK when I pick up my parts.  I might get impatient and bring it to him sooner.
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?)


Joe K

  • Sr. Member
  • ****
    • Posts: 268
    • View Profile
Hello Mark,

Can you please put me down for two stems, if it is not too late?  You are doing a great job!

Joe K.