30 teeth sprocket for 8 speed Campag cassettes

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fausto99
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby fausto99 » 5 May 2019, 4:03pm

Have Campag MTB (Centaur) cassettes/freehubs got the same splines as Campag road components?

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fausto99
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby fausto99 » 5 May 2019, 4:16pm

Following on from MickF's thread about headset spanners, I'm inclined to investigate laser or water-jet cutting of sprockets. I imagine I could get quite a few cut for the price of an IRD freewheel.

Has anyone looked at this? What grade of steel would be best for a 30t rear sprocket?

drossall
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby drossall » 5 May 2019, 4:20pm

Gattonero wrote:There used to be an official Campagnolo kit of spacers ("kit-003") with 7 blue metal spacers made right for this purpose, but is very difficult to find now.

But presumably someone who is replacing a worn 8-speed cassette (which is what I assumed mattsccm was doing) could just steal its spacers?

I've looked into this a fair bit. I've got 8-speed Athena gear that I was running with a 7-speed freewheel (same spacing of course). I've now got some 9-speed wheels, so a respaced cassette is my current plan. But I got the frame resprayed some considerable time back, and the rebuild is still on my to-do list :oops:

So I'm a bit of an armchair expert, rather than a seasoned pro, at this.

Brucey
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby Brucey » 5 May 2019, 4:53pm

8s sprockets are slightly thicker than 10s ones, so 8s spacers are not a perfect match if you intend to build an 8s spaced cassette using 10s sprockets. Campag 9s ones are an inbetween size.

The numbers I have written down are

8s 1.85mm
9s 1.75mm
10s 1.7mm

but there may be variations.

cheers
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drossall
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby drossall » 5 May 2019, 5:25pm

Yes agreed, that's why I suggested starting with a 9s cassette instead of a 10s one. If anyone knows where we can get actual 8s sprockets... (but then they wouldn't fit 9s splines, I think).

Presumably a proper 8/9s spacer kit would allow for this, whereas stealing 8s spacers doesn't? But I believe that it's pretty close?

Brucey
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby Brucey » 5 May 2019, 6:05pm

8s sprockets fit 9s splines but if the freewheel body is aluminium and the lockring isn't tight, the splines wear.


If you use 8s spacers with 9s sprockets you can make it 'perfect' by adding a 0.1mm shim with every spacer.

cheers
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mattsccm
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby mattsccm » 5 May 2019, 9:59pm

Ii have two 8 speed cassettes but only 10 speed wheels.
Never realised that 8 speed Ergos could be converted, most wisdom suggests otherwise.
Any idea what part is needed?

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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby Brucey » 5 May 2019, 10:28pm

mattsccm wrote:Ii have two 8 speed cassettes but only 10 speed wheels.
Never realised that 8 speed Ergos could be converted, most wisdom suggests otherwise.
Any idea what part is needed?



you will have to look in the campag spares pdfs to see the part numbers but IIRC when they changed to 10s there were spare parts available to make most 'pointy hooded' ergos work with

- 8s
- 'old' 9s
- 'new' 9s
- 10s

as I mentioned earlier getting hold of these spare parts is no longer easy, but they are out there if you look hard enough; anyone who has done a conversion in the past will have a spare part left over that you might want; for example (somewhere) I have spare 'new' 9s part that may see use again at some point.

cheers
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mattsccm
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby mattsccm » 5 May 2019, 11:25pm

I knew that new 9 could be done but not the older stuff. That would be good.

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fausto99
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby fausto99 » 6 May 2019, 11:03am

fausto99 wrote:Following on from MickF's thread about headset spanners, I'm inclined to investigate laser or water-jet cutting of sprockets. I imagine I could get quite a few cut for the price of an IRD freewheel.

Has anyone looked at this? What grade of steel would be best for a 30t rear sprocket?

Bump
Would any steel do as long as it's case hardened?

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Gattonero
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby Gattonero » 7 May 2019, 9:47am

Sounds like a lot of faff to me!
IMO, a lot easier to just replace the front chainset with a lower-geared one, so to use the current stock of cassettes with 28t sprocket?
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...

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Mick F
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby Mick F » 7 May 2019, 9:54am

fausto99 wrote:What grade of steel would be best for a 30t rear sprocket?
Does it have to be steel?
Many chainwheels have less than 30t and they are alu.

Difficult bit would be the splines of course, but maybe they could be bolted or riveted to the adjacent sprockets.
Mick F. Cornwall

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fausto99
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby fausto99 » 8 May 2019, 9:28am

Mick F wrote:Does it have to be steel? Many chainwheels have less than 30t and they are alu.

Difficult bit would be the splines of course, but maybe they could be bolted or riveted to the adjacent sprockets.


Don't forget that chainwheels are bolted on with big fixings. The dog-spline(?) contact on a freehub is much smaller area and higher pressure. I think al alloy would deform under pedalling pressure.

I've done the bolt thing on my Moulton Safari. I added a 6th sprocket onto a 5 speed Regina freewheel, locked it solid and added it to the SA AW hub with a threaded driver. Works very well.

I will investigate if splines could be laser or water jet cut economically.

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fausto99
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby fausto99 » 8 May 2019, 9:32am

Gattonero wrote:Sounds like a lot of faff to me!
IMO, a lot easier to just replace the front chainset with a lower-geared one, so to use the current stock of cassettes with 28t sprocket?


One man's faff is another man's hobby in retirement :P . It keeps me off the streets :lol: :lol: :lol:
Besides, I like my Shimano 105 hollowtech triple and BB. When it wears out I'll reconsider.

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Mick F
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Re: 30 teeth sprocket for 8 speed Campag cassettes

Postby Mick F » 8 May 2019, 9:54am

Gattonero wrote: .......a lot easier to just replace the front chainset with a lower-geared one, so to use the current stock of cassettes with 28t sprocket?
This is a possibility of course, but not necessarily the best way for any individual bike.
It all depends on which other chainwheels you have and if a smaller one could even be fitted.

I think I'm correct in saying that there are some cassettes with the big cogs are alu.
Mick F. Cornwall