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PostPosted: Wed Jun 30, 2010 12:37 am 
Dirt Disciple

Joined: Tue Jun 08, 2010 12:19 pm
Posts: 13
Wonder if anyone has access to both Strada and Pista Chainsets or rings so that they can check something for me?

I have a Record 151 Strada Chainset and have been sourcing chainrings partly to replace my completely worn out one. So I have my original 51 and 53. The 51 is ok but the 53 is so worn that the chain just keeps jumping.

So far I have purchased 3 rings all of which were advertised as 151 PCD and were said to be 3/32. One a Williams 44 fits perfectly (thanks JM) and I have now fitted. The other two a Sugino Black stamped S-54 and a Williams AB77 48 Stamped regd no 908786 and with a Capital P on the front do not. Although the inner circle that fits on the spider is the correct size the bolt holes are slightly nearer to the inner circle which means that they will not line up with the mounting holes.

I am just wondering if although both are said to be 151 in fact there is a slight difference between the Pista and Strada chainset mounting and that therefore the two that do not line up are Pista and the Williams that does are in effect Strada. If so does that also make the non fitting rings 1/8 and not 3/32.

Will probably sell them but would prefer to be certain what they were before passing them on to someone else.

So hence my question. Does someone has rings for both sets and can they put one on top of the other and see if the holes are in fact differently placed?

Or of course any other explanation!

many thanks


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PostPosted: Wed Jun 30, 2010 12:40 am 
Dirt Disciple

Joined: Tue Jun 08, 2010 12:19 pm
Posts: 13
Just to add that the two non fitting rings both line up with each other so I seem to have two distinctly different mountings.


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 Post subject: cranks
PostPosted: Wed Jun 30, 2010 9:31 pm 
Old School Grand Master
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Joined: Mon Sep 28, 2009 8:16 pm
Posts: 3273
Location: north wales
GBMax
The measurement c-c chainring bolt holes should be 88.9mm
Which multiplied by 1.7 gives you a 151bcd
I am desperately sourcing a Record strada 151bcd Chainset for my 1963 Falcon San-Remo Restoration
If you are thinking of selling the record strada chainset,please could you give me 1st refusal
This is the only item i need to finish my retoration
Yours faithfuly
Cipo ( Malc )
Contact 07899937939
Thank you


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PostPosted: Wed Jun 30, 2010 11:19 pm 
Dirt Disciple

Joined: Tue Jun 08, 2010 12:19 pm
Posts: 13
Ok so I have just measured them. As they were sold as 151 and appeared so near to fitting I didn't think to do the obvious thing and measure them.

Looking at it now I recon the holes are 84/85mm which would make them both 144. Can't account for the seller of the Sugino's mistake but I can probably understand it in the case of the Williams one. According to the guide on the classiclightweights web site Williams Alloy 151 PCD rings are stamped regd 908786 which is what this is marked.

Sorry Cipo (Malc) looks like I do not have any spares 151 bcd and the usable ones that I have are needed on my ride.

I do however now find myself with an unneeded 144 bcd 48 and 54 so just need to decide if they are really 1/8 or 3/32. Maybe I should look out for a crankset for them


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PostPosted: Thu Jul 01, 2010 1:08 am 
Old School Grand Master
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Joined: Wed Feb 20, 2008 12:21 pm
Posts: 5785
Location: Lost in Translation
When Campag went from 151 to 144mm bcd they simply took 151mm ring blanks, and drilled the holes 3.5mm closer to the inner diameter. That means that, as you discovered, the rings will sit on either spider, but the bolt holes won't line up.

This gives you a quick visual check that lets you identify the bolt circle of old Campag (and compatible) rings at a glance. The bolt holes of a 144mm ring nearly touch the inner diameter of the ring, while the 151mm versions have a fair bit of metal inboard of the hole.

The left-hand ring in this picture is a 151mm bcd. The right is 144:

Image


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PostPosted: Fri Jul 02, 2010 12:11 am 
Dirt Disciple

Joined: Tue Jun 08, 2010 12:19 pm
Posts: 13
Thanks for that. Was beginning to think that was the case and was starting to see the visible difference. Think it also shows there is a lot of confussion out there and items inacurately described.

Take this current listing on ebay for instance, listed as 151 but looking at the picture the holes look near the edge and therefore could well be 144.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT


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