My wife's touring bike has a 7 speed freewheel, 11 to 26 but she wants to have a larger big sprocket, up to possibly a 32. How do I know whether the rear mech will be able to cope with the increse in size? It is a Campag set up, and one web site I looked at said that Campag rear mechs have a small, medium or large cage, but with no indication of how to determine this. The mech isn't marked in any way that I can see. Any help would be welcome!
Rear mech capacity
- Thread starter RIPVFR
- Start date
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Ajax Bay
Guru
- Location
- East Devon
"My wife's touring bike has a 7 speed freewheel, 11 to 26" - going to guess this is a cassette as a freewheel couldn't have an 11t small sprocket.
Need to know the number of teeth on the largest and smallest chainrings and the model of the rear derailleur. Also measure (in mm) the distance between the axes of the jockey wheels.
Need to know the number of teeth on the largest and smallest chainrings and the model of the rear derailleur. Also measure (in mm) the distance between the axes of the jockey wheels.
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Cycleops
Legendary Member
- Location
- Accra, Ghana
If you want to go up to a 32t you might have to change to a cassette which would involve a new hub.
If you could provide a pic of the mech it would help identify if it could manage the larger sprocket. If not you could probably fit a wolf tooth gear extender.
to the forum.
If you could provide a pic of the mech it would help identify if it could manage the larger sprocket. If not you could probably fit a wolf tooth gear extender.
to the forum.
T4tomo
Legendary Member
There are the odd exception with the new 11s potenza range, but Campag pretty much famously stop at 29T for maximum cassette size (the different cage lengths deal with triple front chainrings etc.
So the short answer without knowing the models etc is a 11-29 or12-19 cassette in 7 spd flavour will lilkely fit, but beyond that you're looking at needing a wolf tooth link to drop the derailleur down a bit.
when getting a new cassette you need to check what freehub you have got as something in the back of my mind tells me cassette spacing was pretty much similar the between brands so you might have shimano cassette splines or campag. people ,mixed and matched as they did with friction shifting, as it didnt really matter.
So the short answer without knowing the models etc is a 11-29 or12-19 cassette in 7 spd flavour will lilkely fit, but beyond that you're looking at needing a wolf tooth link to drop the derailleur down a bit.
when getting a new cassette you need to check what freehub you have got as something in the back of my mind tells me cassette spacing was pretty much similar the between brands so you might have shimano cassette splines or campag. people ,mixed and matched as they did with friction shifting, as it didnt really matter.
Thanks for the interest folks. And yes it is a freewheel, but 13 to 26, not 11 as I first posted, sorry! The triple chainrings are 24, 36, 50. I think if she will limited to going to 29 then she says she will be happy. I have attached a picture of the Campag rear mech, well used but still going strong. The distance between the jockey wheels is 65mm. I have attached a picture of the rear mech for interest's sake.
Smokin Joe
Squire
- Location
- Bare headed cyclist, Smoker
fossyant
Ride It Like You Stole It!
- Location
- South Manchester
IME Campag stuff doesn't wear out, it just keeps going.
Shimano, on the other hand...
Wash your mouth out, 3 bikes with 30 year old kit
Reynard
Guru
- Location
- Cambridgeshire, UK
If you can't go up at the back, then why not come down a couple of teeth on the front instead?
Sheldon Brown's website has a gear calculator thingy, so you can work out the equivalent. And then, Spa Cycles can furnish triples or individual chainrings in all sorts of sizes.
Sheldon Brown's website has a gear calculator thingy, so you can work out the equivalent. And then, Spa Cycles can furnish triples or individual chainrings in all sorts of sizes.
I have looked the simpler option which is to go down at the front, so that may be the way ahead. I have tried Spa cycles and that was what they suggested.
The bike has indexed down tube shifters, which have resulted in some different reactions from people when on our tours! Some younger people have never seen them before, and older folk look at them with nostalgia. I have replaced the down tube shifters on my ancient touring bike with a more modern set up, and I think my wife will finally enter the 21st century and go that way once we have sorted out the gearing.
Thanks again to you all for your interest.
The bike has indexed down tube shifters, which have resulted in some different reactions from people when on our tours! Some younger people have never seen them before, and older folk look at them with nostalgia. I have replaced the down tube shifters on my ancient touring bike with a more modern set up, and I think my wife will finally enter the 21st century and go that way once we have sorted out the gearing.
Thanks again to you all for your interest.
Cycleops
Legendary Member
- Location
- Accra, Ghana
If she's really serious about entering the modern age she might like to replace the freewheel with a cassette too.
Maybe not just for the above either. The freewheel leaves a large length of axle unsupported which can lead to breakage especially if the bike is carrying a load as it will be in this case. I've experienced this a few times on bikes I've had to repair. Then of course you can go with a wider gear range cassette.
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That would mean a new rear wheel, or at least a new hub and the wheel rebuilt. Her bike is pretty old now (hand built for her back in the early nineties) and has survived over twenty touring trips since then, so fingers crossed it will keep going! We travel pretty light to be honest, no camping involved, but credit card touring so her panniers aren't particularly heavy.
