DerFrischmaker

This is probably a very dumb question but what is the difference between 7,8,9,10 speed systems? I know there are some compatibility differences but what I really want to know is the technical explanation for what it means for something to be 7,8,9, or 10 speed. Examples, a 7 speed derailer versus a 10 speed derailer...etc. Can someone give me a brief tutorial or a link to a tutorial? Also, any advice on how to identify a part as being 7,8,9, or 10 speed would be appreciated. Many thanks.

sydney

The speeds are how many cassette( or freewheel) cogs there are. Speeds are not in the RD.It's a marketing term.The shifter speed(cable pull/click) speed has to match the cassette speed, and the cassette cog spacing. Campy and shimano cog spacing is not the same for given speeds(other than campy 8 is the same 5mm as shimano 7). The RD throw ratio also has to be compatible with the given shifter.Campy and shimano RD are not compatible with each others shifter.....As for what speed something is, either you know or you use model # backup. Current indexing has been around since 1985 and covers so much ground and compatibility issues that Sheldon Brown has not even written the book. There were 'speeds' before 85, but then stuff was friction,and most everything worked with everything else.

Applehead57

Extra note. It doesn't really matter how many speeds (rear sprockets) you have, it is the gearing you have available. Most rear cassettes have about the same smallest gear (11 or 12 teeth) and about the same largest gear (about 25 teeth), it's just how many in-between gears they have between them. Having lots of gears (10 speed) lets you shift with smaller jumps between each gear, not a crisis, but smaller is better. As the speeds have grown from 5 to 7 and now up to 10, the components have gotten skinnier, i.e. so that they can stuff more stuff in about the same space. Even the chain is skinnier.
This discussion easily can consume a case of good beer, but don't worry, having 8, 9, 0r 10 speeds isn't that important. You won't necessarily go faster with more speeds, just get yourself a quality bike and then just go riding.

DerFrischmaker

Thanks. I already do a lot of riding, I'm just trying to become a better mechanic. The technology behind the various "speeds" is something I have been baffled by because there doesn't seem to be very good literature out there about this. These explanations are very helpful.

Berodesign

There are people complaining about shifting problems when they have a old FD and a modern narrow chain, i.e. 9 speed chain. This is due to the wider cage of the older FD's. Not an issue in a friction-system though.

The spacing between the front rings can be a issue if you have a new FD. For example 6 speed double crank with a 9 speed FD. But it should be basically a throw ratio problem, so it is covered, just that noone usually thinks in terms of throw ratio on a FD, only on RD's.

SJK

The difference is 3sp, 2sp, and 1sp.

srf

IMHO the major difference is the tolerances get finer each time. This usually effects each component of the drivetrain (thinner spacers, chains, cogs, etc).

dannyg1 

Unchecked for accuracy, so fact check before employing any of the info I'm imparting.... I've read that:

In the mid eighties, as indexing systems were coming into being, rear stay frame spacing was 120-125mm. 6 speed freewheels were the standard and anything more would cause bad dishing problems for the rear wheel build. The new standard frame spacing was upped to 130mm and all was fine to an 8 speed. With the more current introduction of 9 and 10 speed cassettes, 135mm has become the standard.

Please, anyone with more knowledge, correct at will.

DG1

53-11_alltheway

In addition to what has already been mentioned.


7 spd uses 126mm rear drop out spacing. 8/9/10 speed uses 130mm drop out out spacing.

Brian

Or 135mm spacing.

Retro Grouch 

8, 9, and 10 speeds put progressively more cogs into the same amount of space on the rear wheel. To make this work the chain has been made progressively more narrow and the shifters have to be designed to match the cog spaceing of the cassette.

sydney

There was a 7 speed 128 spacing as well as 126 and some 7 speed hubs were even 130.

sydney

130 is the current 8/9/10 road spacing,and 1135 is MTB spacing..there were also 6 speed cassettes....GEEzzzzzzzzze folks why not keep piling more misinformation onto this one...eh?

Brian

Er, yeah. Like 1135 is MTB spacing?

jeff williams

geez..and I thought my 140 MTB spacing was big.

Raiyn

Why? When you can do it for us, why should we?
Only picking, you left yourself wide open.

Brian

1135 may be ok Raiyn. If you're running a 31x10.5x15 All Terrain...

Raiyn

Imagine the rolling resistance and the chainline on that sucker.

sydney

Ever hear of a typo or crack induced twich...eh braintrust?

Brian

From you Sydney? Yeah, I can believe it.

Raiyn

Never nosepicker. You hold everyone to such a high standard that you must be omnipotent and infallible yourself. Turnabout is fair play after all.


At least the rest of us can admit when we're wrong