Differences between 850 frames

I have 2 frames for 850 Commando and would like to better understand the significance of the differences. I have reviewed this thread:


and have an idea of the various distinguishing elements but I am not clear on their significance.

Frame #1 has the stamp on the right side of the headstock: 850 F 1 019xx. It also has 06-4140 stamped on the left side tank/coil mounting bracket, and F-8/73 stamped on the left side Z-plate mounting bracket.

Frame #2 has no marking on right side of the headstock but has 00106 stamped on the left side of the headstock, and 06-4140 stamped on the left side tank/coil mounting bracket.

The diameter of the main backbone tube of frame #1 2.25" (57.15mm).
The diameter of the main backbone tube of frame #2 is 60mm.
Both were measured horizontally at the headstock.

The two frames also have different rear loop gusset plates that the top rear shocks mount into. Both are larger than the earlier gusset plates.


Frame #1 gusset Frame #2 gusset

The gusset on Frame #1 looks like the one that AN supplies (06-4282). The one on Frame #2 is slightly larger, so probably gives more support.

I know it is difficult with Commandos, but it would be nice to know what models these might be from and the significance of some of the markings and other differences. I've read that Commando frames were originally built by Reynolds, but later some of the production was done in Italy. Does that fit into this puzzle?

Any help will be appreciated.

Different gusset could be Italian vs UK. I think frame numbers started in 1974, the stamping on the right side.the frames all have a 06- type part number, i think on the left. There are more knowledgeable folks here.

NickZ said:

The diameter of the main backbone tube of frame #1 2.25" (57.15mm).

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Probably a Reynolds frame check if the smaller tubes are 1 inch diameter.

NickZ said:

The diameter of the main backbone tube of frame #2 is 60mm.

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Probably a Verlicci frame check if the smaller tubes are 25mm.

NickZ said:

Frame #2 has no marking on right side of the headstock but has 00106

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Iv'e always thought that was an Italian batch code mark but I could be wrong about that.

NickZ said:

The two frames also have different rear loop gusset plates that the top rear shocks mount into.

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I don't think Iv'e seen that second style of gusset plate before.

wildbill56 said:

I think frame numbers started in 1974

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I think it actually started on Mk1.
Unfortunately I can no longer post the link to the dynodave page where the first entry is;
That F number should possibly be F10108#.

L.A.B. said:

Probably a Reynolds frame check if the smaller tubes are 1 inch diameter.



Probably a Verlicci frame check if the smaller tubes are 25mm.

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The smaller tubes for both frames are very close to 1" diameter. Frame #1 diameters are right a1 1.0" and the diameters of Frame #2 are just under that at around 0.99" which is just above 25mm.

L.A.B. said:

Unfortunately I can no longer post the link to the dynodave page where the first entry is;

​

302591

Apr-73

#850#F 00108#

W

That F number should possibly be F10108#.

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Thanks for the info LAB.
Frame #1 stamping is #850#F1019xx# but it had no number plate attached. It came with parts including 850 engine with crankcase stamped 3080xx. That doesn't necessarily mean they came from the factory together, but might have.