Question about early type (fat) exhaust clamps

[markb]

I'm looking at the picture of the clamps on the following link and I trying to figure out where the clamps are shaved to clear the fins on the head.  
http://www.cb750sandcastonly.com/support23.htm
I've got a set of clamps that are definately fat but when I compare them I can't see any difference.  Are all fat clamps shaved?  What am I missing?
Thanks,
Mark

[Wayne]

I had to look closely as well Mark. Here's what I think the area is we are talking about. If that's the case, the flanges were mixed up on 576. Must have been done when the PO installed the Jardine Headers. Image on the right shows the ground and polished off fins compared to the flange on the left.

[Steve Swan]

Yes, that red boxed in area is the shaved area on the #2 & 3 fins.  The fixing bolt of the 2/3 clamps doesn't sit horizontal; is angled in approximately the 10/4 o'clock position.

[markb]

Thanks Wayne.  I will look again now that I know where to look.  For some reason I had the idea it was in the area where the screw is so I was concentrating in the wrong area.  Pretty obvious to me now.  So technically all four clamps are different even though there are only two different part numbers?

[Steve Swan]

Yes, technically; all 4 are different, despite #'s 1/2 having their own pn and #'s 3/4 having their own pn.  (Another one of those early sandcast details!)  1 & 2 are LH.  3 &4 are RH.  #'s 2 & 3 have the fins champfered.

If my memory of observation serves me correctly, "I think" the back side of the fins on the early clamp have more of a 'taller' radius, which strikes the cyl.head fins in the 2/3 cyl.head fin area, hence requiring the champfer on the 2/3 clamp's fins.

If my memory serves me correctly, "I think" the radius on later clamp's fins does not arc quite as high as the early fins and does not strike the cyl.head fins. 

[markb]

I remember seeing these from Yamiya a while back.
http://www.yamiya750.com/index.php?main_page=product_info&cPath=35_88&products_id=696
They also talk about the shaved clamps but it's a little hard to tell in their photo too.  The set even comes with the radiused flanges (or franges   ) for about $840.  I'm glad I have a set.  It should be a lot less than that to have them rechromed.

[Steve Swan]

Wish i had kept those radiused 'franges' i got Yamiya...  I sold mine, as all evidence seemed to support, at least at the time, 232 would not have had radiused flanges fitted at the factory.  

Certainly seems the radiused flanges were used on some of the early prod.bikes, we just don't know what vins.  

KP's 248 has 2 radiused and two not radiused flanges appearing to never have been removed after leaving the assembly line.  To the best of my knowledge, KP's 248 is the only prod.sandcast we've found having these flanges.  

Andy Dixon's 175 does not have radiused flanges.

[markb]

KP's 248 has 2 radiused and two not radiused flanges appearing to never have been removed after leaving the assembly line.  To the best of my knowledge, KP's 248 is the only prod.sandcast we've found having these flanges. 

KP's is the only one with two and two or the only one with radiused flanges?  My #97 has radiused flanges.

[Steve Swan]

Good to know 97 has radiused franges.

[cb7504]

My newest acquisition vin# 151 has the radius type exhaust spigots (4).

[markb]

I guess I never replied about my clamps.  I checked them and they definately were shaved.  For just a second I was thinking that maybe they hadn't started doing it on the earliest ones.  Thanks for all the feedback.