Freewheel problem

[alonstar]

Hey guys!!
i have a unique foldable bicycle.
my front crank is 50T
i want ti replace the rear freewheel to a smaller one to make it harder to paddle.
(its a single cog with a single speed tensioner.)
i was looking on that 12T cogs but i cant understand, what tool do you use to install them?
adding pic



Does anyone knows what tool do i need? maybe is it just better to get a 14t that has a regular pattern like that?



thanks for the help everyone!!

 

[alonstar]

adding a view of the other side of the first cog

 

[Chalo]

i was looking on that 12T cogs but i cant understand, what tool do you use to install them?
adding pic
View attachment 363909


Does anyone knows what tool do i need? maybe is it just better to get a 14t that has a regular pattern like that?

View attachment 363910

Cheap freewheels like the the one in your first photo often don't have a tool interface. You grease the threads and spin it on by hand, then it tightens when you "paddle" (pedal). To remove it, you punch loose the outer bearing race (ring with two little pinholes in it), take the freewheel apart and unleash squillions of tiny bearing balls, and then wrench off the freewheel core with a pipe wrench or a vise. It's most often a destructive process.

The 14t freewheels in the second photo are made for a different thread size (M30x1), and don't interchange with the ones that you find on hub motors or most other bicycle freewheel threads (1.37"-24). You can find cheap 14t freewheels in the more common thread size, but they also will lack a tool interface.

 

[PaPaSteve]

Hey guys!!
i have a unique foldable bicycle.
my front crank is 50T
i want ti replace the rear freewheel to a smaller one to make it harder to paddle.
(its a single cog with a single speed tensioner.)
i was looking on that 12T cogs but i cant understand, what tool do you use to install them?
adding pic

Does anyone knows what tool do i need? maybe is it just better to get a 14t that has a regular pattern like that?

thanks for the help everyone!!

You'll have much better luck and more possible gear range chage replacing the front chainring even if it means replacing a crank arm too.

 

[alonstar]

t

You'll have much better luck and more possible gear range chage replacing the front chainring even if it means replacing a crank arm too.

thanks for your reply.
Since my bike are quite unique not many shops want to help me with it so i have to get all the tools required for replacing not only for a rear freewheel but for a crank removal as well. and also, if i understand correctly, what you mean is replacing the crank to a larger one with more teeth? this is a bit of a problem for me since my bike are foldable and it will cause issues with the folding mechanism.
my rear hub is an electric hub motor with a thread 35mm. you think i wont be able to find a 12-14T sprocket 34mm?

 

[alonstar]

tha

Cheap freewheels like the the one in your first photo often don't have a tool interface. You grease the threads and spin it on by hand, then it tightens when you "paddle" (pedal). To remove it, you punch loose the outer bearing race (ring with two little pinholes in it), take the freewheel apart and unleash squillions of tiny bearing balls, and then wrench off the freewheel core with a pipe wrench or a vise. It's most often a destructive process.

The 14t freewheels in the second photo are made for a different thread size (M30x1), and don't interchange with the ones they you find on hub motors or most other bicycle freewheel threads (1.37"x24). You can find cheap 14t freewheels in the more common thread size, but they also will lack a tool interface.

thanks a lot for making things clear.
Do you know where can i find 12t freewheels 34mm
to fit my hub motor, that will need the use of a regular freewheel removal tool?
or at least how to search for it/name it?

weird to me that no one needs an e bike that is also a single speed with high speed capabilities.

 

[E-HP]

weird to me that no one needs an e bike that is also a single speed with high speed capabilities.

Why do you think that? The DNZ 7sp freewheel has an 11T small cog. Why go to a single speed 12T if you can get 11T? For most bikes, the chain line will suck anyway. (I didn’t like the DNZ quality. It was showing wear after only a few thousand miles, and the ratcheting mechanism wore out in the end).

There are a lot of options for 12T single speed freewheels, you just need to google it. There are extenders that those cheap freewheels can screw on to, and allow using a regular wrench to remove, and ISO threaded BMX freewheels (also uses a regular wrench), the latter probably being the better choice.

 

[Chalo]

tha

thanks a lot for making things clear.
Do you know where can i find 12t freewheels 34mm
to fit my hub motor, that will need the use of a regular freewheel removal tool?
or at least how to search for it/name it?

There isn't one. Single freewheels for that size thread were only as small as 16t until very recently. 14t and 12t versions affect the chainline versus other sizes, so they aren't directly interchangeable without also changing something else, like axle spacing and wheel dish, or chainring position.

If you want that size freewheel with that size thread, you will accept the kind that doesn't have a tool interface. Or maybe you don't want it that much.

What you're dealing with is a stack of too many constraints: adversely small wheel diameter, unnaturally high speed, unwillingness to use a multi-speed freewheel, unwillingness to use a freewheel that must be disassembled to remove, unwillingness or inability to use a larger chainring, and a desire to pedal along at higher than attainable pedal speed. Let one or more of these constraints go, and you'll be able to satisfy the other criteria.

As for me, I would never consider using a single gear that was too high for me to ride the bike when the motor or battery fails. That's inviting unnecessary problems. I have a bike built on a cruiser frame that uses a "single" gear of 60/16 that allows me to pedal along with the 1200W motor. But in fact it has two sprockets in front and two in the rear, so I can access a 39/19 gear if needed to ride the thing unpowered. And I have had to do that before when the controller failed without warning.

 

[amberwolf]

to fit my hub motor, that will need the use of a regular freewheel removal tool?

Remember, the tool is used only to remove the FW, you don't need one to install it.

So the FW removal tool you need is for whatever is *already on* the wheel.

 

[neptronix]

I'd consider some cheap DNP freewheel with an 11t lower gear instead of this, if you have 135mm dropouts.

 

[PaPaSteve]

Consider . . .
16T freewheel is a common size which,
The whole freewheel assembly is narrow enough that the teeth are above the hub threads.
12T is so small the teeth needs to be on the side of the hub threads meaning the freewheel may be so wide it collides with the frame.
A tool is need for removal of the original.
No tool is required for installation, pedal force tightens in place.
Some 12T freewheels use a Shimano cassette removal tool.
Does this answer your question ?

 

[alonstar]

There isn't one. Single freewheels for that size thread were only as small as 16t until very recently. 14t and 12t versions affect the chainline versus other sizes, so they aren't directly interchangeable without also changing something else, like axle spacing and wheel dish, or chainring position.

If you want that size freewheel with that size thread, you will accept the kind that doesn't have a tool interface. Or maybe you don't want it that much.

What you're dealing with is a stack of too many constraints: adversely small wheel diameter, unnaturally high speed, unwillingness to use a multi-speed freewheel, unwillingness to use a freewheel that must be disassembled to remove, unwillingness or inability to use a larger chainring, and a desire to pedal along at higher than attainable pedal speed. Let one or more of these constraints go, and you'll be able to satisfy the other criteria.

As for me, I would never consider using a single gear that was too high for me to ride the bike when the motor or battery fails. That's inviting unnecessary problems. I have a bike built on a cruiser frame that uses a "single" gear of 60/16 that allows me to pedal along with the 1200W motor. But in fact it has two sprockets in front and two in the rear, so I can access a 39/19 gear if needed to ride the thing unpowered. And I have had to do that before when the controller failed without warning.

Thanks again.
The reason for taking such a low 12t cog is because
my crank is only 50t and changing it is a problem for this bike.
basically, conclusion is - the best option for me are the kind with no tool interface. i hope i will know how to remove it when time comes

 

[alonstar]

Consider . . .
16T freewheel is a common size which,
The whole freewheel assembly is narrow enough that the teeth are above the hub threads.
12T is so small the teeth needs to be on the side of the hub threads meaning the freewheel may be so wide it collides with the frame.
A tool is need for removal of the original.
No tool is required for installation, pedal force tightens in place.
Some 12T freewheels use a Shimano cassette removal tool.
Does this answer your question ?

Hey thanks for replying.
im not sure i understand why smaller freewheels have to be wider to work.
but anyway, the ones in the picture you sent looks really good as i will be able to also remove them without destroying them. could you send me a link?

 

[alonstar]

I'd consider some cheap DNP freewheel with an 11t lower gear instead of this, if you have 135mm dropouts.

thank you for replying
i couldnt find anything like it online, could you link me?

 

[Chalo]

Hey thanks for replying.
im not sure i understand why smaller freewheels have to be wider to work.

Conventional single freewheels have the ratchet mechanism around the outside of the hub threads, and the sprocket teeth outside of that. 14t and 12t single freewheels don't have enough room around the hub threads for the mechanism, so it has to sit outside the threads, and that makes the assembly wider. There's no physical way around it, which is why we didn't see these small freewheels for normal 1.37" hub threads until recently (because moving the sprocket teeth outboard harms chainline and requires relocating other components to match).

This is an example of the 11t high gear freewheels Nep was mentioning:

Amazon.com