Honda CB750 Sandcast

Who would be interested in getting 11mm mirror stems?

markb · 134 · 34156

markb

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From a previous thread it looks like at least some VINs up to 302 had one or two 11mm stem mirrors.  #97 didn’t have any when I got it but it’s likely it had them too.  It’s one of the last parts I need for the restoration.  This has to be up there as one of the rarest sandcast parts.  So I have been looking into getting a batch made.

It’s more than just a larger diameter stem.  The bend is at a different spot and at a different angle.  The thread is still 10mm but the nut is slightly different too.  The mirror part appears to be the same and can be remounted from a 10mm stem onto an 11mm stem.  The stem is the same for RH and LH, the mirror is just mounted opposite.

The hard part is the clip that the mirror mounts to.  I am currently trying to find a shop to make that part.  It looks like the clip was formed and then the radius and hole punched after.  I know shops that can do it but they won’t bother with the limited quantity.  I think I can do the rest (except plating) at my shop.  I’m not looking to make money, just cover my expenses.

Part of my challenge is I don’t actually have one but I’ve been talking with Steve Swan and he has provided dimensions for me to work from.  I plan on sending him a prototype to make sure it matches exactly.

At this point I have no idea on the price.  The more we make the less expensive they will be.  Assuming we can get them made for a (somewhat) reasonable price, who’s interested?  Once I get a count that will help me determine if this is feasible.

By the way, does anyone have 11mm stems on VINs later than 302?
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

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Thank you, Steve.  That will be a huge help and save a lot of time and trouble.
Mark
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?)


kmb69

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allandry

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markb

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Including me we're up to at least 13.  That's a good start.  Anyone else?
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?)


vince ciotti

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Rddmm2

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I'll jump in too and take a set - but i have a much later sandcast
Rob Waddell



mrhonda2u

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 When i found #1221 in a time capsule sense 1985 and owned by this closed dealer in a storage trailer. This bike had 11 mm mirrors. These mirrors where used on 67-68  bigger bore on and off road bikes. One would think they were made 11mm for stength and may have been reduced to 10mm to lighten the bike. But here is one more fact is in have seen #1226 and this bike is untouched right down too the #28 carb caps and smoth oil filter housing. owned by the original owner. And he states this bike came with those mirrors like a K1. This may have been the a point when Honda was changing the mirrors over.


markb

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Very interesting information!   8) In that case VINs up to 1221 may be correct with 11mm stems.  Rob, what is your VIN?  I would think it's likely that there wasn't an exact cutoff.  Rather the inventory of 11mm stems eventually had 10mm stems added to it and the 11's were eventually used up.  That would explain why some bikes were fitted with one of each.  Just what the assemblers happened to grab.
Also if they were used on other bikes it may mean that there are more available out there than we think.  The strength part makes sense but the weight savings with 10mm stems would be negligible I think.  But maybe 10mm material was more common, certainly a hair cheaper and maybe would bend easier or better.  Who knows why it was changed.  Thanks for the input.
Up to 19 now.
« Last Edit: October 29, 2011, 10:17:11 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

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10vs11, i'd go with 11mm is what mirror mfgr had in stock.  larger diameter stem would probably decrease vibration blurring, assuming the 11mm was used on twins. that's the theory behind bar end weights at least.  who knows.  some of this stuff is like trying to guess the number of angels that would fit on the head of a pin