Sprocket/freewheel ratios.

I've noticed on some of the sprocket/freewheels laying around the garage,
there's some variation in the sizes of the biggest sprockets.

So I'm wondering what jargon do I need to know when I need to order one?

Thanks.

On Monday, September 21, 2015 at 7:36:53 PM UTC+2, Ian Field wrote:
I've noticed on some of the sprocket/freewheels laying around the garage,
there's some variation in the sizes of the biggest sprockets.

So I'm wondering what jargon do I need to know when I need to order one?

Thanks.

Number of teeth.

Loi

WITH a few exceptions, the chain links are the same across the board...see SHELDON BROWN HARRIS 'chains'

so the COGS at 36 teeth are the same size

can freewheel cogs be bought ? in steel ? if you see a cog or sprocket check if the material is ALLOY. Alloy is aluminum suitable for 100 milers not 500 milers.

Not an expert but no I haven't come across any steel single cogs or sprockets.

what you do need with a freewheel is a Wheels Mfg freewheel axle.

On 9/21/2015 12:37 PM, Ian Field wrote:
I've noticed on some of the sprocket/freewheels laying
around the garage, there's some variation in the sizes of
the biggest sprockets.

So I'm wondering what jargon do I need to know when I need
to order one?

Thanks.

gear ratio calculator he
http://www.bikecalc.com/gear_ratios

Some gear changers are quite limited in their capacity while
many modern SGS type changers can span a 36t rear.

Depending on which rear changer do you have and how low a
gear you plan, may need new changer. It's good practice to
replace chain when changing driven sprockets. Whether you
install a new one or try to use the old one, ensure your
chain is long enough:
http://www.yellowjersey.org/CHNLENGT.JPG

Wrap the largest front and rear, add 2 or 3 rivets. That's
your length. Then pass the chain through your changers and
join it.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Monday, September 21, 2015 at 12:36:53 PM UTC-5, Ian Field wrote:
I've noticed on some of the sprocket/freewheels laying around the garage,
there's some variation in the sizes of the biggest sprockets.

So I'm wondering what jargon do I need to know when I need to order one?

Thanks.

If it was a cassette, the total number of cogs to go on it. That determines the width of the cog and the chain.

http://www.sheldonbrown.com/gloss_ch.html
*1/8" (0.125", 3.18 mm) chain is used on most single-speed bicycles, and bicycles with internal gearing.
*3/32" (0.094", 2.30 mm) chain is used on derailer equipped bicycles that have more than 3 cogs at the rear.
*Even somewhat narrower chain, typically .090" or 2.29 mm between the inner plates, is used for derailer-equipped bicycles with 10 or more sprockets at the rear.

"Lou Holtman" wrote in message
...
On Monday, September 21, 2015 at 7:36:53 PM UTC+2, Ian Field wrote:
I've noticed on some of the sprocket/freewheels laying around the garage,
there's some variation in the sizes of the biggest sprockets.

So I'm wondering what jargon do I need to know when I need to order one?

Thanks.

Number of teeth.

The answer I was hoping for; was that I order a wide ratio
freewheel/sprocket, or a close ratio one.

The last one I bought has a smaller bottom gear sprocket than some I've
seen, so not ideal for the hilly terrain where I live.

Since the hills are sometimes downhill, I don't want to sacrifice top gear
ratio by ending up with a bigger than necessary top gear sprocket.

On Tue, 22 Sep 2015 17:05:44 +0100, "Ian Field"
wrote:


"Lou Holtman" wrote in message
...
On Monday, September 21, 2015 at 7:36:53 PM UTC+2, Ian Field wrote:
I've noticed on some of the sprocket/freewheels laying around the garage,
there's some variation in the sizes of the biggest sprockets.

So I'm wondering what jargon do I need to know when I need to order one?

Thanks.

Number of teeth.

The answer I was hoping for; was that I order a wide ratio
freewheel/sprocket, or a close ratio one.

The last one I bought has a smaller bottom gear sprocket than some I've
seen, so not ideal for the hilly terrain where I live.

Since the hills are sometimes downhill, I don't want to sacrifice top gear
ratio by ending up with a bigger than necessary top gear sprocket.

Do you mean "freewheel" or "freehub"? If the later than I believe that
most shops use Number of cogs and high and low cog teeth number, as in
"9 speed, 11-25"
--
cheers,

John B.

On Tuesday, September 22, 2015 at 3:25:55 PM UTC+1, Mike A Schwab wrote:

*1/8" (0.125", 3.18 mm) chain is used on ... bicycles with internal gearing.

Perhaps true once, though that must have been well before my time. On modern internal hub gearboxes (IGH) 3/32" chain is pretty common. Rohloff, for instance, while admitting that 1/8" chain will fit, warns against its use, and recommends 3/32" chains. Shimano's Nexus/Alfine, probably the most common IGH on millions of bicycles, can use either 1/8" or 3/32" chain and is often seen with the latter. In cases where the IGH is not run as a single speed but has cogs either at the front or the back, it is usually essential to fit a 3/32" chain as the 1/8" commonly doesn't have enough lateral space to shift cleanly. Upmarket bicycles fitted with Rolloff, Shimano and other IGH not intended for downhillers and mudpluggers are virtually always fitted with 3/32" chains to permit a close-fitting chain guard to be fitted. (As a generalization, the common Hebie Chainglider doesn't fit anything bigger than 3/32" chain.)

*3/32" (0.094", 2.30 mm) chain is used on derailer equipped bicycles that have more than 3 cogs at the rear.

And on many internal hub bikes.

The socalled "8-speed" 3/32" chains from the best makers, especially KMC, are a gold standard of durability and all-round economy.

Andre Jute
Generalizations are not a skipping stone, they're a tripping rope

On Wednesday, September 23, 2015 at 11:16:45 AM UTC+1, Andre Jute wrote:
On Tuesday, September 22, 2015 at 3:25:55 PM UTC+1, Mike A Schwab wrote:

*1/8" (0.125", 3.18 mm) chain is used on ... bicycles with internal gearing.

Perhaps true once, though that must have been well before my time. On modern internal hub gearboxes (IGH) 3/32" chain is pretty common. Rohloff, for instance, while admitting that 1/8" chain will fit, warns against its use, and recommends 3/32" chains. Shimano's Nexus/Alfine, probably the most common IGH on millions of bicycles, can use either 1/8" or 3/32" chain and is often seen with the latter. In cases where the IGH is not run as a single speed but has cogs either at the front or the back, it is usually essential to fit a 3/32"

Duh. Of course I mean "In cases where the IGH is not run as a single speed but has ***multiple*** cogs either at the front or the back, it is usually essential to fit a 3/32"

chain as the 1/8" commonly doesn't have enough lateral space to shift cleanly. Upmarket bicycles fitted with Rolloff, Shimano and other IGH not intended for downhillers and mudpluggers are virtually always fitted with 3/32" chains to permit a close-fitting chain guard to be fitted. (As a generalization, the common Hebie Chainglider doesn't fit anything bigger than 3/32" chain.)

*3/32" (0.094", 2.30 mm) chain is used on derailer equipped bicycles that have more than 3 cogs at the rear.

And on many internal hub bikes.

The socalled "8-speed" 3/32" chains from the best makers, especially KMC, are a gold standard of durability and all-round economy.

Andre Jute
Generalizations are not a skipping stone, they're a tripping rope

On 9/23/2015 5:16 AM, Andre Jute wrote:
On Tuesday, September 22, 2015 at 3:25:55 PM UTC+1, Mike A Schwab wrote:

*1/8" (0.125", 3.18 mm) chain is used on ... bicycles with internal gearing.

Perhaps true once, though that must have been well before my time. On modern internal hub gearboxes (IGH) 3/32" chain is pretty common. Rohloff, for instance, while admitting that 1/8" chain will fit, warns against its use, and recommends 3/32" chains. Shimano's Nexus/Alfine, probably the most common IGH on millions of bicycles, can use either 1/8" or 3/32" chain and is often seen with the latter. In cases where the IGH is not run as a single speed but has cogs either at the front or the back, it is usually essential to fit a 3/32" chain as the 1/8" commonly doesn't have enough lateral space to shift cleanly. Upmarket bicycles fitted with Rolloff, Shimano and other IGH not intended for downhillers and mudpluggers are virtually always fitted with 3/32" chains to permit a close-fitting chain guard to be fitted. (As a generalization, the common Hebie Chainglider doesn't fit anything bigger than 3/32" chain.)

*3/32" (0.094", 2.30 mm) chain is used on derailer equipped bicycles that have more than 3 cogs at the rear.

And on many internal hub bikes.

The socalled "8-speed" 3/32" chains from the best makers, especially KMC, are a gold standard of durability and all-round economy.

Andre Jute
Generalizations are not a skipping stone, they're a tripping rope


One might easily find full roller chain in 1/8" at a
moderate price but 3/32" chain generally wears much faster
due to the prevalent interrupted sideplate design.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971