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How can I easily tap threads on Bottom bracket

sensi

100 mW
Joined
Jun 4, 2022
Messages
36
Can anyone help me to find a cheap and reliable way to make bottom brockets with threads using any ordinary pipes.
I have managed to make my own frame from scratch. The enduro type frame.
Now I need to be able to make threads.

Any help will be appreciated
 

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Look up bottom bracket taps. There are some on amazon for $100. There are also bottom bracket tapping/threading tools from bike repair tool manufacturers. They are more for cleaning existing threads but you may be able to create new threads with them.

If you made your own bike then I assume you have a welder. Go find a junk bike and cut the Bottom bracket off and weld it into your frame.

Or buy an American to Euro bottom bracket adapter for $11 and weld in place. That way you don't need to form the threads yourself.

 
Can anyone help me to find a cheap and reliable way to make bottom brockets with threads using any ordinary pipes.
I have managed to make my own frame from scratch. The enduro type frame.
Now I need to be able to make threads.

Any help will be appreciated

Bottom bracket taps are expensive and not especially easy to use. It's much easier, faster, cheaper, and more convenient to use pre-machined BB shells (even if you have to use cutting tools to clean the threads and faces afterwards).


If you've already welded in a blank piece of tubing for the BB shell, I think the path of least resistance would be to cut it out and replace with a shell that has threads and faces already.
 
Bottom bracket taps are expensive and not especially easy to use. It's much easier, faster, cheaper, and more convenient to use pre-machined BB shells (even if you have to use cutting tools to clean the threads and faces afterwards).


If you've already welded in a blank piece of tubing for the BB shell, I think the path of least resistance would be to cut it out and replace with a shell that has threads and faces already.
Thank you for your reply. I will take it that way.
 
He could use a press fit bearing set if the BB axle is then long enough for the extra width of the press fit and if the BB inner sleeve is not too damaged from welding and removal of ??
 
Yes
Not to be funny but is this the point where you cut it out and weld in a mid-drive motor ?
, I want to make my own frames from scratch also tapping threading using any pipe available and suitable and weld it.
In our country its not easy to find those pre-threaded shells. So the need to make my own from scratch.

Below is my frame made from scratch, That bike can do 70k/h. Am based in Zambia.
 

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This is my completed frame commuting with it to work everyday, 1000W motor and 3000W controller from Bumble Bee classic bike. Working without heating at all
 
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He could use a press fit bearing set if the BB axle is then long enough for the extra width of the press fit and if the BB inner sleeve is not too damaged from welding and removal of ??
Am actually building frames from scratch not modifying anything
 
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It was meant as a joke about the mid drive as that how everyone is going lately these days with the bafang mid-drive and others. This means running through the gears and the chain and the cassette which wears them out.
I myself am a fan of direct drive rear hub motors as my motor is a mxus 3,000 watt at 4,000 watts.
If you're worried about heating the motor by lugging it get off the bike and put your hand on the motor if it's too hot to use stop and let it cool off.
Yes there are a few frame builders here on ES but it's a very difficult thing to do and I applaud you.
 
It was meant as a joke about the mid drive as that how everyone is going lately these days with the bafang mid-drive and others. This means running through the gears and the chain and the cassette which wears them out.
I myself am a fan of direct drive rear hub motors as my motor is a mxus 3,000 watt at 4,000 watts.
If you're worried about heating the motor by lugging it get off the bike and put your hand on the motor if it's too hot to use stop and let it cool off.
Yes there are a few frame builders here on ES but it's a very difficult thing to do and I applaud you.
Thank you, But on my response meant the usage of 3,000W on 1000W motor not heating despite the controller been more powerful than the motor. and am using a BMS that can give 80A continuous.
 
For a bicycle crank shell the most common thread size around here is a JIS 1.37" X 24 threads. (JIS = Japan Industry Standard)
A pipe thread is very different.
If you switch to a one piece crank the crank tube is not threaded as shown in this picture.



71ZkNX01FOL._AC_SL1500_.jpg
 
For a bicycle crank shell the most common thread size around here is a JIS 1.37" X 24 threads. (JIS = Japan Industry Standard)
A pipe thread is very different.
If you switch to a one piece crank the crank tube is not threaded as shown in this picture.



71ZkNX01FOL._AC_SL1500_.jpg
So This means I still need a shell inside the pipe?
The challenge is buying those shells will be expensive shipping because of weight. Below is the image of the type of shells we have in Zambia. Hard to use for my purpose.

What about this used tool looks to be in good shape and strong. its vintage but I think it can still do the job, is that the same as 1.37" X 24 threads (click here = Vintage Thread Tap) |What do you think? Should I get it?

Is it possible to help me with that document where that picture came from?

Thank you
 

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This is an example of a one piece crank shown with bearing kit :
bmx-mtb-steel-one-piece-crank-bottom-bracket-axle-170mm-arm-length-bb-set-option-option-bb1-7885-p.jpg

This style needs a larger diameter crank tube that is not threaded.
Usually used on lower cost bikes.
Threading tap in your provided link looks worn out to my eye.
Here's a new one for a similar price :

TAP
Hope that helps ...
 
This is an example of a one piece crank shown with bearing kit :
bmx-mtb-steel-one-piece-crank-bottom-bracket-axle-170mm-arm-length-bb-set-option-option-bb1-7885-p.jpg

This style needs a larger diameter crank tube that is not threaded.
Usually used on lower cost bikes.
Threading tap in your provided link looks worn out to my eye.
Here's a new one for a similar price :

TAP
Hope that helps ...
Ok, so using this crank I don't need to thread the tube?
If that's the case, I will try I have seen these in the shop somewhere.

As for the tap I was thinking that new one looks unreliable. Its great that you have recommended it. I will get one set.

Am learning all this from nothing. Therefore, your help is really valued.

Thank you
 
Yes

, I want to make my own frames from scratch also tapping threading using any pipe available and suitable and weld it.
In our country its not easy to find those pre-threaded shells. So the need to make my own from scratch.

Below is my frame made from scratch, That bike can do 70k/h. Am based in Zambia.
Can you just find an old junk bike frame and cut out the bottom bracket shell and weld it into your frame, or do you really want to tap the shell yourself?
 
Can you just find an old junk bike frame and cut out the bottom bracket shell and weld it into your frame, or do you really want to tap the shell yourself?
Am learning and getting into producing custom bikes for sale not just for self use.
We don't have such bikes in Zambia and people are amazed with the one I made and already want me to produce for them.

If I keep learning more and try to understand the geometry sooner, I can make a good living in this.
 
Am learning and getting into producing custom bikes for sale not just for self use.
We don't have such bikes in Zambia and people are amazed with the one I made and already want me to produce for them.

If I keep learning more and try to understand the geometry sooner, I can make a good living in this.
Ah OK, so you'll be an ebike pioneer. If you go for a one piece crank, here's the info from Sheldon Brown's page. Note that they required different pedals than other bikes.
 
Ah OK, so you'll be an ebike pioneer. If you go for a one piece crank, here's the info from Sheldon Brown's page. Note that they required different pedals than other bikes.
Yes, I want to be an ebike pioneer. The idea is making my own frames and buying motors and controllers from China, of which I already have a contact to the manufacturing industry Yuma motors. they are good near QS motors. Thank you very much for your help, it means a lot. I will check the link after my Sabbath.
 
Yes, I want to be an ebike pioneer. The idea is making my own frames and buying motors and controllers from China, of which I already have a contact to the manufacturing industry Yuma motors. they are good near QS motors.
Next time you order motors from China ask the company if they would be willing to source crank shells (bottom brackets) and include in the same shipping box.
This type cooperation is sometimes possible.
 
Tell us about what voltage and amp hour your battery you have on that bike and where do you resource the cells to make batteries. Plus tell us more about your controller the voltage and amperage it needs.
 
Tell us about what voltage and amp hour your battery you have on that bike and where do you resource the cells to make batteries. Plus tell us more about your controller the voltage and amperage it needs.
That one was a learning phase.

CONTROLLER: The controller I bought 50A 72V sinewave, second hand Bumble bee classic.

BATTERY: The battery i made it from Used laptop batteries, tested and picked only between 2.2-2.5AH cells. Checked the discharge rate for each cell to make sure some don't drain fast and selected only those with similar discharge rate.
20S8P battery pack.

BMS: bought a TDT BMS 80A discharge 80A charging direct from Manufacturing in China. I bought two at USD46 (Click Here) 05a31a19958cb236a904fd81fe340d78.jpgBMS Manufacturing industry image attached

MOTOR: I bought ly-48v1000w from eBay bidding at USD100. Surprising this motor has 12 wires inside the coil and it can handle 3000 without even getting warm at 70Kh full throttle. the link here is for a similar motor (Click here) s-l1600 (4).jpgSimilar motor here.

Body made from covers for this (Click Here) Analogue Transmitter. 10997.jpgafter migrating to Digital this was decommissioned at my work place. Therefore, I requested and my boss gave me 2. I have one untouched fully working. If you need just tell me we can talk.

If anyone wants to help me with means of shipping, please let me know. I have problems with shipping cells from China. I did find the good manufacturing to colab but shipping is still the issue.

You are all Amazing in your help, please keep helping me.
 
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