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PostPosted: Tue May 10, 2016 1:17 pm 
Retro Guru

Joined: Wed Dec 10, 2008 9:19 am
Posts: 2230
Location: Sheffield, top city
LukeFRC wrote:
I'll check but think I've got a 52 from my old bike that will work - thinking I can probably use the chain rings from the old bike and run 52-38-30 ?
I need to look at the condition of the 30 and 50 on there currently the 40 is shot.
smallest you can get for Campag 135BCD is 39 tooth, so no 38 I'm afraid. Don't get confused with Shimano fit 130BCD spiders, they are different pattern rings.

Quote:
On them they are labeled "50-40" and "40-30" - what does that mean is that something about how it shifts or something?
that's how the chainset came set up. You don't have to stick with that, you can separate the rings and fit anything that fits the spider.


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PostPosted: Tue May 10, 2016 7:05 pm 
Dirt Disciple

Joined: Thu Mar 07, 2013 6:49 pm
Posts: 61
Location: Leeds
39 tooth - I think I remembered it wrong!

Anyway - I strongly believe that any internet forum is better with photos - and cos I'm relying on you for advice... here we go...

The triple - the middle chain ring is almost all worn away at places
Image
Image
Image
the double
Image
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Image

so I could stick the 39 tooth on there as a direct replacement for the 40 tooth. But quick question - the 39 tooth doesn't have the rivets in it like the 40 tooth. Infact it looks like a really really differently made chainring.
I'm guessing i've got bits from two different series from different times?


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PostPosted: Tue May 10, 2016 7:06 pm 
Dirt Disciple

Joined: Thu Mar 07, 2013 6:49 pm
Posts: 61
Location: Leeds
sorry they aren't cleaner!


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 Post subject: Re:
PostPosted: Tue May 10, 2016 8:53 pm 
Retro Guru
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Joined: Sat May 21, 2011 7:42 am
Posts: 314
Location: Glasgow (ish)
The rivest are changing ramps, designed to pick the chain up quicker and easier. You wouldn't have them on the inside of a double because nothing to change up from, but they would be present on a triple to pick up chain from inner ring... I'd never realised that before! So while the BCD etc is the same between the outer two of triple, and std chainset, a true triple ring will have ramps on the middle.


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 Post subject: Re:
PostPosted: Wed May 11, 2016 1:58 am 
Old School Hero
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Joined: Thu Aug 20, 2015 3:55 am
Posts: 201
Location: Murrieta California
Racing T crank with TA Vento 9/10 speed rings 49, 39, 28, tooth and TA self extracting crank bolts. Cost effective and available, shifts nice with the Racing T front mech.

Image

: Mike


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PostPosted: Wed May 11, 2016 10:49 am 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8757
Location: New Forest, UK
Without the ramps you will probably get away with the chain shifting fine, especially as Campag shifters of that ear have the micro-indexing instead of the Shimano-style true indexing. You might have to overshift a little. We all survived in the past without shifter ramps etc.

The Veloce and Racing T crank forgings are identical.


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 Post subject: Re: Re:
PostPosted: Wed May 11, 2016 9:35 pm 
Dirt Disciple

Joined: Thu Mar 07, 2013 6:49 pm
Posts: 61
Location: Leeds
Blackbike wrote:
Racing T crank with TA Vento 9/10 speed rings 49, 39, 28, tooth and TA self extracting crank bolts. Cost effective and available, shifts nice with the Racing T front mech.

Image

: Mike



Mike that's so helpful! You don't know how reassuring just having someone say "I use these TA vent chainrings" is - looking at the bizarre mix of TA stuff you see online...

Was fixed on using my old chainrings and having 52/39/30 - essentially the same setup as my old bike but with the added comfort of the granny ring.
I accidentally made a 99p bid on eBay at lunchtime and just won a TA vento 42T middle ring .... which means I now have a bit more choice....

52/39/30
52/42/30
50/39/30
or 50/42/30

anyone got any advice which would make most sense? - live in reasonably hilly Yorkshire and my body prefers spinning to standing up on the pedals.


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PostPosted: Thu May 12, 2016 8:02 am 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8757
Location: New Forest, UK
Generally front shifting works a little better if the difference in chainring tooth count is smaller between middle and big compared to middle and small. On that basis 52/39/30 is probably going to be most problematic (but Campag micro-indexing shifters help a lot!)

Personally I find 42 a bit big for climbing, but that depends on your rear cassette. I prefer to set it all up as a double + bailout. For that I'd go with 50/39/30.


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PostPosted: Thu May 12, 2016 6:43 pm 
Retro Guru
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Joined: Sat May 21, 2011 7:42 am
Posts: 314
Location: Glasgow (ish)
50 is too slow downhill. Why waste all that effort getting up by not ripping down the other side like a maniac? :-)


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PostPosted: Thu May 12, 2016 6:46 pm 
Old School Hero
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Joined: Sat Mar 16, 2013 12:14 pm
Posts: 204
Location: Durham/Northumberland border
+1 for Mike's choice of TA rings. I've quietly amassed a small battalion of these from eBay over the last few years for use on Campag chainsets with a 135 bcd like yours. They come up frequently, are beautifully made, can often be found reasonably priced and come in a huge variety of sizes.

HW


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