"Teething Issues"- How Many Teeth?

[The Mighty Volt]

Hi folks.

One issue that I really don't know anything at all about would be the issue of teeth- on the front single speed chainset and the rear freewheel.

I believe that certain teeth require a certain chain but I also have come to understand that there is a certain ratio between the two which must be observed.

How many teeth should my chainset/chaincrank have and how many teeth therefore should my rear freewheel have?

Oh- and does anyone know what free-wheel will fit onto the X5304?

Many thanks.

 

[Ypedal]

With an X5, the largest front chainring you can find, and the smallest rear available is 16t..

Freewheels are standard and the X5 will take shimano or compatible thread pattern, nothing special about it. a single speed is all you need.. as long as you don't run out of battery power ! lol.

The thickness of the teeth in relation to the chain can matter, very high count rear cassettes tend to use very thin profile chains, but you don't need to worry about that..

 

[MadRhino]

I have a 9 11/34t freewheel on a 5304, in a 150mm swingarm. The 11t freewheels can be found at ebike.ca. I have a nice 7 11/34 set too, that they sold me for 28$ if my memory is good. The chain width has to match your freewheel set, meaning wide chains won't fit nice a 9 freewheel and derailer won't like it.

 

[The Mighty Volt]

With an X5, the largest front chainring you can find, and the smallest rear available is 16t..

Freewheels are standard and the X5 will take shimano or compatible thread pattern, nothing special about it. a single speed is all you need.. as long as you don't run out of battery power ! lol.

The thickness of the teeth in relation to the chain can matter, very high count rear cassettes tend to use very thin profile chains, but you don't need to worry about that..

Many thanks Ypedal.

What happens if the front ring is say, 44 teeth, and the rear is 16, just for arguments sake?

Is there any real importance in the ratios?

Thanks again.

 

[The Mighty Volt]

I have a 9 11/34t freewheel on a 5304, in a 150mm swingarm. The 11t freewheels can be found at ebike.ca. I have a nice 7 11/34 set too, that they sold me for 28$ if my memory is good. The chain width has to match your freewheel set, meaning wide chains won't fit nice a 9 freewheel and derailer won't like it.

So you are running 34t to 11t, correct?

I won't be using a Derailleur, just a chain tensioner.

Thanks!

 

[Zoot Katz]

. . .
What happens if the front ring is say, 44 teeth, and the rear is 16, just for arguments sake?

Is there any real importance in the ratios?

Thanks again.

Gears with fewer teeth wear faster.
The 44/16 gears would give you ~75.1 gear inches that works out to 17 mph at 80 rpm
A 53/11 combination would yield 29.3 mph at 80 rpm
Plug some real numbers into Sheldon Brown's gear calculator.

 

[The Mighty Volt]

Thanks for that Zoot.

So there is a relationship in the ratio of the teeth and your cycling experience?

I wanted to avoid a 1:1 ratio, as it is for all practical purposes, useless.

I like the idea of a parasitic-drag workout and also the idea of working with the battery.

Thanks for the link.

 

[MadRhino]

I have a 9 11/34t freewheel on a 5304, in a 150mm swingarm. The 11t freewheels can be found at ebike.ca. I have a nice 7 11/34 set too, that they sold me for 28$ if my memory is good. The chain width has to match your freewheel set, meaning wide chains won't fit nice a 9 freewheel and derailer won't like it.

So you are running 34t to 11t, correct?

I won't be using a Derailleur, just a chain tensioner.

Thanks!

Yes and no

I can run 34 to 11t, cause my chainring is a single 34t on a DH bike
Rear freewheel has 9 gears, ranging from 11t to 34t

Planning to replace the crankset with a Shlumpf HSD 34t, that will give 85T chainring equivalent!
85 to 11t will drive about 50mph at 80rpm, letting me pedal almost the full speed of my motor.

 

[The Mighty Volt]

I'll be using a single speed freewheel at the rear. Like a BMX freewheel. I am aware that there is a parasitic drag so I was hoping to get a single speed crank at the front a good few times the size of the rear freewheel, so as I get a good ratio.

 

[spinningmagnets]

What is your wheel diameter, 26"? Also what is the top-speed of your e-bike system?

Once those are known, get the smallest rear-sprocket you can find, and if you want to contribute to the power of your system by pedaling when the motor is at its max speed, the size of the large front chainring (tooth-count) can then be determined...

 

[dogman dan]

What is it you want to do? Pedal along helping the bike on the flat? At what speed? Pedaling just on the hills? At what speed?

I find the typical 44 front 14 rear good for pedaling along on the flat at 20 mph. By 25 mph you are cartoon pedaling. To help up a hill, it depends on how steep. but I rarely need to shift down more than to the 16 tooth gear in the back to go up 6%. that allows good pedaling about 15 mph.

On my racing bike, I can assist by pedaling at up to 35 mph. That bike has 14 rear, and 56 front.

Once a bike breaks down, or runs the battery dry, then I find myself in a gear ratio that goes about 6-8 mph.

 

[FMB42]

Here's a link to "Sheldon Brown's Bicycle Gear Calculator" that might be of interest:

http://www.sheldonbrown.com/gears/

BTW, I normally use a 38-14 (= ~ 2.71 ratio) on the 18 speed "hybrid" MTB that I use for mild (i.e. smooth and level) off road riding conditions (I rarely find the need to use any other gear range on this 450w 36v geared hub ebike).

 

[The Mighty Volt]

What is your wheel diameter, 26"? Also what is the top-speed of your e-bike system?

Once those are known, get the smallest rear-sprocket you can find, and if you want to contribute to the power of your system by pedaling when the motor is at its max speed, the size of the large front chainring (tooth-count) can then be determined...

Hi spinningmagnets- I am as of yet undecided on the wheel size, probably 26", but still toying with the idea of a 24" wheel, if I can arrange something for a rear disc brake.

Top speed? Well, 24s is 79volts nominal, so in the 5304 and with a hardtail, no rear suspension, I wouldn't be looking to be going any faster than 40mph.

Principally my aim here is to have a sufficiently adequate ratio, freewheel:chainset so that when I pedaled it had a noticeable effect, and provided some workout for the legs, saved battery capacity, and contributed to the "bike" aspect of "electric bike".

Thanks.

 

[The Mighty Volt]

What is it you want to do? Pedal along helping the bike on the flat? At what speed? Pedaling just on the hills? At what speed?

I find the typical 44 front 14 rear good for pedaling along on the flat at 20 mph. By 25 mph you are cartoon pedaling. To help up a hill, it depends on how steep. but I rarely need to shift down more than to the 16 tooth gear in the back to go up 6%. that allows good pedaling about 15 mph.

On my racing bike, I can assist by pedaling at up to 35 mph. That bike has 14 rear, and 56 front.

Once a bike breaks down, or runs the battery dry, then I find myself in a gear ratio that goes about 6-8 mph.

Hi......Do you know "greasypants" build? He took a 3 speed chain-set/chain-crank and cut off the two biggest rings, leaving him with the smallest ring. He then installed a BMX style free-wheel on the X5 itself. He then finished with a chain-tensioner to complete the job, having cut and re-bored the cranks to make them shorter.

This means the bike is still legally a bicycle, but for all practical purposes, it has zero pedaling application. Any pedaling motion would be short, artificial, and involve ridiculous repetitions and revolutions just to get the X5 to turn.

I just want whatever set up allows me to, at low speeds, cruising, play some role in propelling the bike under my own power.....up severe hills, it will be full-throttle. I don't have that 20Ah battery for nothing :lol: :lol:

In the simplest possible terms, when I cycle, at low to moderate speeds, I do want to feel that I am playing some part in turning the wheel and propelling the bike. Obviously at high speeds, I will just be holding on and letting the motor do its thing.

 

[dogman dan]

Then a good ratio might be the classic MTB gearing. 14 rear, and 44 front. Or 48 front for pedaling 25 mph, up to 30 mph max. Easy to find stuff, easy to fit to your bike. On the better MTB cranksets, you can unbolt any of the front sprockets you don't want, leaving just the 44 tooth one for instance. That's how my buddy at the used bike shop creates fixies that he can sell better to students out of mtb's.

 

[The Mighty Volt]

Then a good ratio might be the classic MTB gearing. 14 rear, and 44 front. Or 48 front for pedaling 25 mph, up to 30 mph max. Easy to find stuff, easy to fit to your bike. On the better MTB cranksets, you can unbolt any of the front sprockets you don't want, leaving just the 44 tooth one for instance. That's how my buddy at the used bike shop creates fixies that he can sell better to students out of mtb's.

Cheers dogman.

Unfortunately the POS chainset I took off my Raleigh Chinhook is, as we discussed earlier in a different thread, welded and riveted in such a fashion as the only wheel I could get off it would be the smallest one, which has some worn teeth anyways.

14:44....I will read up on it. Thanks.

At least this part of the job is relatively inexpensive.