Chain Sizes

[fitek]

Did a quick search and didn't see a discussion on this...

What are the different chain sizes in use?

When looking for sprockets on the scooter sites and mcmaster-carr, I see various no. sprockets and chains. The scooter sites have no.25 and no.35. I've seen it mentioned that no.35 are used on go-karts.

What is used on bicycles? I know different sizes are used, but I've heard them described as 3/8", etc. Do these map to no.'d chains?

 

[Miles]

Here are the most common chains in order of increasing pitch length:

6mm

#25 (1/4") - 1/4" wide - Mini Scooters etc.

8mm - 10mm wide

#219 Reduced pitch Go Kart chain

#35 (3/8") - 3/8" wide - Go Kart chain

Bicycle chain (1/2") - width varies.

 

[safe]

Racing Go Karts put out anywhere from 10-20 hp and seem able to get by with the #35 chains, so you don't need anything more than that as far as strength. The bicycle chain was invented so long ago that the material advances have made them so strong that you could probably pull 50 hp before thay actually broke unless you had done something silly like used a chainbreaker tool improperly on it. (I wouldn't trust it past about 10-20 hp though)

The #25 chain are where you get into risky areas. I'm using the #25 chain and pulling about 1.3 hp and not having any problems. I would be skeptical that the #25 chain could handle more than about 5 hp before breaking... if even that.

The #35 also should wear longer and they have the largest selection of sprocket sizes. When it comes to freedom to design the #35 is probably the best. (for a typical 1 hp electric bike)

The bicycle chains are indestructable, but since they are rather big you can't get the radical gear ups or gear downs than the #35 chain can do.

The biggest problem is when you try to integrate a motor that spins at several thousand rpm into your pedal cadence of about 100 rpm. I'll be taking a built in geardown motor of about 9 to 1 then using a small sprocket to a big #35 sprocket just to make all it work.

 

[vanilla ice]

For the scooter motorcycle or big EV use, theres these larger standard sizes-

420, 428, 520, 525, 530 and 630.

The 420 is used on smaller motorcycles and IIRC is compatible with #40 and #41 kart sprockets but has a larger diameter pin than those two chain sizes. But the roller OD is the same. These days the high tech 520 chain is used in applications over 100 horsepower, where the giant 630 used to be used.

 

[Miles]

The bicycle chain was invented so long ago that the material advances have made them so strong that you could probably pull 50 hp before thay actually broke unless you had done something silly like used a chainbreaker tool improperly on it. (I wouldn't trust it past about 10-20 hp though)

The #25 chain are where you get into risky areas. I'm using the #25 chain and pulling about 1.3 hp and not having any problems. I would be skeptical that the #25 chain could handle more than about 5 hp before breaking... if even that.

Safe,

Why are you specifying hp? This makes no sense.....

Trials riders seem to be able to break bicycle chains.

If you weren't so didactic, people would be a bit more forgiving....

 

[safe]

Why are you specifying hp? This makes no sense.....

Trials riders seem to be able to break bicycle chains.

Trials riders tend to use really low gearing and the surging "peak" power can be huge. Horsepower is a continuous measurement. So we're talking about conflicting measurements. I'm assuming that anyone who is talking about chains (other than the pedal power transferring chain) is thinking about how to connect the motor to the drivetrain. In this regard horsepower is the right thing to talk about.

This is similiar to the internally geared rear hub issue...

The peak power that a rear hub can handle might be a certain amount, but that means that the cyclical power that pedaling produces needs to be divided in half or more to assure that the peaks don't cause breakage. Let me say that again... you want to be sure that your pedal "peaks" are less than your hub's "peak" limit... which is well below the continuous power output. Got that? Hmmmmm...

Can we agree:

Cyclical loads need to account for higher peak loads.

Continuous loads (like a motor) are easier to specify.

 

[Miles]

Why are you specifying hp? This makes no sense.....

Trials riders seem to be able to break bicycle chains.

Trials riders tend to use really low gearing and the surging "peak" power can be huge. Horsepower is a continuous measurement. So we're talking about conflicting measurements. I'm assuming that anyone who is talking about chains (other than the pedal power transferring chain) is thinking about how to connect the motor to the drivetrain. In this regard horsepower is the right thing to talk about.

This is similiar to the internally geared rear hub issue...

The peak power that a rear hub can handle might be a certain amount, but that means that the cyclical power that pedaling produces needs to be divided in half or more to assure that the peaks don't cause breakage. Let me say that again... you want to be sure that your pedal "peaks" are less than your hub's "peak" limit... which is well below the continuous power output. Got that? Hmmmmm...

Can we agree:

Cyclical loads need to account for higher peak loads.

Continuous loads (like a motor) are easier to specify.

You seemed to be confused between power and torque?

You have to use torque when rating a rear hub, for instance, not power.

Where did you get that illustration from? Anyway, it's not that relevant.

 

[ott]

The thing I learn from this is that bicycle chain is stronger than #35... But don't people that hook up eteks with bicycle chains snap them often? (This could be worse from using a too small drive sprocket I guess).

 

[TylerDurden]

Meh.... just use two of whatever ya got.

 

[vanilla ice]

I think given the limits of its relatively large size, bicycle chain <b>can</b> be extremely strong, but because the manufacturers know they generally see low torque use, they save money by not using the best materials or build processes. Which makes sense as its not needed.

 

[Miles]

Meh.... just use two of whatever ya got.

 

[safe]

You seemed to be confused between power and torque?

You have to use torque when rating a rear hub, for instance, not power.

Where did you get that illustration from? Anyway, it's not that relevant.

Rohloff

http://www.rohloff.de/en/technical/speedhub/efficiency/index.html

You are correct... torque is the final test of the hub and the chain. However, unless you want to get down into the nitty gritty of doing that (which I do on my own spreadsheets just to be certain) then if you assume normal gearing then you can get a ballpark estimate using horsepower.

Gearing is very important... generally speaking the lower the gearing the more stress you place on the components.

Power = Torque * Rpm

...so everyone can just keep this in mind when doing your calculations.

 

[Miles]

And the wheel is part of the "gearing", too - so wheel size will affect the torque going through a hub gear, for instance. That's another plus for smaller wheels

 

[Beagle123]

If you want an explanation of chains try this:

http://www.gizmology.net/sprockets.htm

It uses weight as the measurement for the strength of chains. That's the correct way to measure.

I'm using a nickel plated #35 chain that appears to be much stronger than a bicycle chain. I think that the quality of the materials makes a difference. #25 chain looks like chain for a toy bike to me, but scooters commonly use it with no problems.

It will be beneficial to use chains with a smaller pitch (like #35) for electric motor applications because we have to use tiny front sprockets to get gear reduction. So, if you're planning on using a 9-14 tooth front sprocket, you should consider using #35 or #219 chain because bicycle chain will be too big.

 

[safe]

http://www.gizmology.net/sprockets.htm

Chain No.
Pitch Roller
Diameter Roller
Width
Sprocket thickness
Working Load

#25 --- 1/4" --- 0.130" --- 1/8" --- 0.110" --- 140 lbs
#35 --- 3/8" --- 0.200" --- 3/16" --- 0.168" --- 480 lbs
#40 --- 1/2" --- 5/16" --- 5/16" --- 0.284" --- 810 lbs

And I liked the formulas:

Maximum Pitch = (900 ÷ rpm ) 2/3

Pitch Diameter = P ÷ sin (180° ÷ N)

Outside Diameter = P × (0.6 + cot ( 180° ÷ N) )

Sprocket thickness = 0.93 × Roller Width - 0.006"

By this formula and with my geardown motors I could use a very large chain if I wanted... like up to a 1" pitch. (not that I'd want to)

It's also interesting that the bicycle chain is not really a true #40 size, but something that is a lot thinner. The bicycle widths look mislabeled though because 1/8" is wider than 3/32" (think 4/32") but both of these sizes are less than the 5/16" size of the standard #40. So 5/16" is like 10/32" which is THREE TIMES WIDER than a derailler bicycle chain.

It would have been easier to use metric values...

 

[iberkt]

It would have been easier to use metric values...

Yeah but if you went metric you would loose all of us hard headed Americans who haven't figured out how (and really don't want to learn how) to convert in. to mm :lol: :lol: :lol:

 

[Beagle123]

The whole labeling system is wrong. They should use something like this:

1/2 X 1/4

or

10mm X 20mm

But what do I know. I'm an american. Don't disagree, or I'll get my gun.