Gear ratios

[Contaminated Haggis]

Does anyone know the biggest number in sprocket teeth one can jump regarding gear ratios? Currently on any shimano or campy cassette that I have seen, the biggest jump from 1 sprocket to another is 2 teeth.

 

 

 

For example in an 11-25 ten speed Campy cassette, you would get the following sprockets: 11, 12, 13, 14, 15, 16, 17, 19, 21, 23. The 11 sprocket to the 16 are individual sprockets divided by spacers (except for the 11 and 12), and the 17 / 19 and 21 / 23 are riveted together. If say the 17 / 19 started slipping, could one swap it out with say a 17 / 18 instead? This would obviously make the jump from the 21 sprocket to the 18 sprocket 3 teeth instead of the standard 2 teeth.

 

 

 

My concern here is damaging the cassette, chain and or rear dr.

[Contaminated Haggis]

Anybody ??

[mapep]

hey dougaroony, also waiting in anticipation to your querie

[VincentBikes]

I have tried once to build an 11-25 shimano set from an orriginal 11-23 and did the same thing in replacing the last three ie: 19-21-23 with a 21-23-25 and adding in a 19 to give a 11-12-13-14-15-17-19-21-23-25 but this did not work out as I kept having problems with the upchange where between two specific gears it simply never changed smooth. My final conclusion was after studying the cluster block is that the hyperglide is manufactured and machined with the chain movement to be precise when moving from the one gear to the next and if you take a gear out you actually mess with that timing and simply don't get it right.

[Johan Bornman]

Felty is right. Sprockets are designed to work with specific leading and trailing sprockets and won't shift well if you mix and match.

 

On Campagnolo they have three different classes of sprockets A, B and C. You can mix within the classes and will then be gauranteed a good shift. If you mix outside classes, say A with C, you won't get a good shift. However, I find the shift OK. Just don't shift under power.

 

It is not so much the number of teeth that you jump but the position of the ramps with respect to one another.

[Contaminated Haggis]

Aah, so that's what that little A on each of the sprockets is for then.

 

 

 

Thanks for the info guys, I saw that mine all have the A type so yesterday I decided to give it a go and slapped the new config together. Obviously I had no idea what the A meant then but it seemed to work ok on my ride.