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 Post subject: Merckx - Campagnolo 8sp
PostPosted: Mon Jul 19, 2010 2:51 pm 
Dirt Disciple

Joined: Mon Jul 19, 2010 1:30 pm
Posts: 10
Rightly or wrongly! I decided to seek retro Campag Chorus 8sp parts for my Merckx Corsa Extra frame rebuilding from scratch.

In order to get up and riding quickly, I was hoping to get new wheels but then learned the Campag 8 cassettes don't fit on newer Campag hubs.

I'm attracted to the idea of a cassette spacer conversion kit for a Shimano 8sp cassette. US firm WHEELS MANUFACTURING INC do them. That way I would have the choice of new wheels with Shimano hubs and perhaps a new cassette would be easier to find. (with correct spacers there's still 0.1mm difference in sprocket width Campag/Shimano)

Anyone know where to get these spacer kits in the uk? Is this a daft idea? Or any other suggestions greatly received.

many thanks

Jon - noob in many ways and new forum member.


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 Post subject:
PostPosted: Mon Jul 19, 2010 3:21 pm 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8222
Location: New Forest, UK
The easiest way to do it is to buy a 9 speed cassette, dismantle it and re-use the 8 speed spacers off the old cassette.

Old 8 speed will fit onto a 9s hub body, but as 9s went to Alu. The 8s cassette will chew its way into the 9s freehub, hence the deeper splines on 9s.


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 Post subject:
PostPosted: Mon Jul 19, 2010 7:44 pm 
Retro Guru

Joined: Mon Feb 01, 2010 8:57 pm
Posts: 774
Campagnolo do a 9 to 8 spacer kit - try Mercian Cycles or if they can't help, try Highpath Engineering


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 Post subject:
PostPosted: Tue Jul 20, 2010 1:55 pm 
Dirt Disciple

Joined: Mon Jul 19, 2010 1:30 pm
Posts: 10
Thanks for the tips hamster/monty, much appreciated.

So is it reasonable to get factory Ambrosio Evolution wheels with Campag hub and a stock Veloce 9sp 13-28 cassette. Lose the 28t sprocket for 13-25 (I live in the hills) and make it fit using the correct spacers? Would a Chorus short/long cage mech be ok with this?

Or they also do a Veloce 13/26 cassette, so I could go 13-23 (losing 26 sprocket) but I'd guess this would make for a tough climbing ratio. I was planning on 53/39 chainrings.

thanks again

Jon


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 Post subject:
PostPosted: Tue Jul 20, 2010 4:25 pm 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8222
Location: New Forest, UK
It depends a lot on where you ride - I can do round the Isle of Wight with a lowest of 39/23, which has some nasty short climbs and some long steep ones.

For most mortals a 34T compact chainset makes life much more pleasant, and I usually ride with a triple and 26T inner as a bailout gear with a 12-23 cassette.

However, long cage Campag rear mechs are not so easy to find (Racing T).

You can get away with a 12-23 and 30-39-48T triple with a short cage mech - it worked OK for me, although it's a bit noisy in the little-used big-big combo.


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 Post subject:
PostPosted: Tue Jul 20, 2010 9:23 pm 
Dirt Disciple

Joined: Mon Jul 19, 2010 1:30 pm
Posts: 10
Sorry to say, I'm faced with a grinding 18% outside my door. Nevertheless I'm just hoping that it will shift and run nicely with this Franken-Cassette thing I'm planning to do!


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 Post subject:
PostPosted: Wed Jul 21, 2010 10:17 am 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8222
Location: New Forest, UK
Oh well, you'll soon get string enough to bully it up the hill :shock:


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 Post subject:
PostPosted: Thu Jul 22, 2010 5:45 am 
Gold Trader
Gold Trader

Joined: Mon Apr 20, 2009 9:13 pm
Posts: 714
Location: Venice, CA
I've wrestled with using different hubs on Campy 8 speed.....

BEST suggestion I can make is to get a Campy 8 speed hub and Campy 8 speed cassette, simple and works great.

You may find that the Campy Chorus 8 speed rear derailleur is rarer than the Campy Record 8 rear derailleur - so don't be surprised if this is the case.

I also use Campy Record cranks (1994ish and 111mm Campy bott bracket)

I've been riding this setup for almost 10 years and it works awesome...it's not necessarily a "cheap" setup but not terribly expensive either.

Side note (I might be wrong on this) I don't think the 8 and 9 speed spacers are the same width.


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 Post subject:
PostPosted: Thu Jul 22, 2010 10:02 am 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8222
Location: New Forest, UK
The cog pitch is different for 8 and 9 speed. So you have to reuse the 8 speed spacers if building a cassette using 9 speed cogs.

The big difference with Campag stuff is that it lasts and lasts, unlike Shimano.


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 Post subject:
PostPosted: Thu Jul 22, 2010 12:38 pm 
Dirt Disciple

Joined: Mon Jul 19, 2010 1:30 pm
Posts: 10
Just been through this analysis myself. The 8sp shift sprocket to sprocket is 5mm. 9sp sprockets are 1.75mm thick so you need 3.25mm spacers to make a 9sp sprocket correct for 8sp. But you'll also need 1.25mm of packing spacers behind the cassette to make up the length on the hub body (38mm).

It's encouraging that the standard 8sp spacers work ok, it seems the spacing must be well within limits.

So I'm getting a campag 9sp 13-26 cassette, losing the 16 sprocket and changing spacers.

I have an early 90s Chorus crankset. On the front chainrings, I'm in two minds whether to go for the standard 53/39 or see if I can find suitable rings for a 50/36 compact. It's looking like it will be 53/39 because I can't find compact chainrings within budget.

Also, does anyone know if Athena/Chorus/Record/Mirage 8sp mechs are all compatible with 8sp chorus ergo levers?

Also, Merckx Corsa Extra has an Italian threaded BB. Is the spindle length critical to get the chainline right?

Again thanks for the advice
Jon


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