Bicycle Mechanics - DIY Bottom Bracket Tool

So I'm trying to make a BB tool. Anyone know the pitch and the diameter of a crank bolt?

what you mean by BB tool?

Crank Puller?
http://upload.wikimedia.org/wikibooks/en/thumb/4/4d/Crank_puller.jpg/200px-Crank_puller.jpg
Lockring tool?
http://www.benscycle.net/bmz_cache/1/11409981f4f1aec3a563c66caf2f90b5.image.150x112.JPG

buy one........unless your hobby is tool building instead of bikes. You'll spend more $$ in time than it's worth.

Are you referring to cup and cone style bottom brackets? Sheldon made a fixed cup removal tool. Otherwise, it's easier (and cheaper) to just buy the correct wrench, etc.

http://sheldonbrown.com/tooltips/bbcups.html

Simple question what's the pitch and diameter of a crank bolt. I know what a crank puller is I know how to remove various bottom brackets. If you don't know, I don't need you 2 cents.

why don't you take a crank bolt run it up your nose; maybe then you tell the pitch and diameter.


I don't know what it is lately in this forum; but more and more posters don't have clue about common courtesy or decency. You try to help someone and all they can do is turn into a jerk.

Simple question what's the pitch and diameter of a crank bolt. I know what a crank puller is I know how to remove various bottom brackets. If you don't know, I don't need you 2 cents.

Speaking of cranks... :rolleyes:

measure it yourself.

if you have the skills/resources to make a tool, then you should be able to measure pitch and dia.

Simple question what's the pitch and diameter of a crank bolt. I know what a crank puller is I know how to remove various bottom brackets. If you don't know, I don't need you 2 cents.


Let's start:

Search #1 - Crank Bolt Bicycle (http://www.google.com/search?q=crank+bolt+bicycle&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)

Search #2 - M8 Pitch Diameter (http://www.google.com/search?q=M8+pitch+diameter&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)

Which might lead you to this: http://www.engineersedge.com/hardware/metric-external-thread-sizes1.htm

You should really learn to use the gray matter between the ears.

Let's start:

Search #1 - Crank Bolt Bicycle (http://www.google.com/search?q=crank+bolt+bicycle&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)

Search #2 - M8 Pitch Diameter (http://www.google.com/search?q=M8+pitch+diameter&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)

Which might lead you to this: http://www.engineersedge.com/hardware/metric-external-thread-sizes1.htm

You should really learn to use the gray matter between the ears.

...instead of the nasty stuff on your tongue. :D

Let's start:

Search #1 - Crank Bolt Bicycle (http://www.google.com/search?q=crank+bolt+bicycle&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)

Search #2 - M8 Pitch Diameter (http://www.google.com/search?q=M8+pitch+diameter&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)

Which might lead you to this: http://www.engineersedge.com/hardware/metric-external-thread-sizes1.htm

You should really learn to use the gray matter between the ears.

Can't believe you actually helped him.

Why would someone think WE would know this?

If I wanted to know something this odd I would bother a manufacturer of said tools.

Wait a minute ... Michelle is asking about the crank BOLT, not the inside circumference of the crank arm which is where the BB tool or crank remover would go.

Maybe the idea is a spindle tool to do something with the spindle, since the crank bolt goes into the crank spindle. ???

Je crois que Michelle est une doosh.

Can't believe you actually helped him.

It's more fun to shame then to scold.

the crank bolts arent M8

I tried an M8 bolt in there on Monday...there too coarse a thread.
Might be the same as wheel axles. Which are British standard Cycle thread...shortened to BSCY.

You get bottom bracket tools that screw into the bb axle
One is on order at work. Its £60.
For removing BB cartridges.

the crank bolts arent M8

I tried an M8 bolt in there on Monday...there too coarse a thread.
Might be the same as wheel axles. Which are British standard Cycle thread...shortened to BSCY.

You get bottom bracket tools that screw into the bb axle
One is on order at work. Its £60.
For removing BB cartridges.


The M8 is the standard for traditional square tapered bottom brackets. You don't say what the particular bottom bracket is that you've got.

the crank bolts arent M8

Not standard M8, but they are definitely M8

Not standard M8, but they are definitely M8Well.. there's coarse and fine-thread metric. Typically 8x1.25mm is common. But 8x1.0mm is also a valid metric size as well. Ever try looking for 7mm metric bolts?

Simple question what's the pitch and diameter of a crank bolt. I know what a crank puller is I know how to remove various bottom brackets. If you don't know, I don't need you 2 cents.

My, my don't we have our knickers in a knot? A pitch gauge and a common micrometer would be nice to own wouldn't it?

Simple question what's the pitch and diameter of a crank bolt. I know what a crank puller is I know how to remove various bottom brackets. If you don't know, I don't need you 2 cents.

You are such an incredible tool maker and you can't make a simple measurement yourself?

My two cents? You have no idea what you are doing and can't even take the time to make a simple measurement that any one that has ever held a mike could do in five seconds.

He or she never claimed to be an "incredible tool maker", they just decided to be a little less nice than what we all expect of others here.

It's not worth it to make it more of an issue, this thread is already at three pages, more than half of which is derisive crap we've tried to stop twice by redirecting it to useful information. We've probably already driven them away from contributing anything of value.

Suggestion: Maybe the thread should be locked, and the OP can try asking again, this time a little nicer.

About the original question, I'd agree that the OP would do better to borrow a gauge/mic. and measure a few samples of bolts themselves if our information is not satisfactory.

I think DannoXYZ has the answer.

8mm with thread pitch of 1mm fits.

It is the first time I've looked at BikeForums and I hope it becomes the sort of place where you can ask simple questions without getting lots of sarcastic replies.

7mm bolts:
DannoXYZ, I guess you found http://www.northlandfasteners.com/catalog/MetricBolt_1.htm for a hex head.

In the uk we've got 7mm socket cap bolts in 25 & 45mm but we had to get them from Taiwan.

Are you referring to cup and cone style bottom brackets? Sheldon made a fixed cup removal tool. Otherwise, it's easier (and cheaper) to just buy the correct wrench, etc.

http://sheldonbrown.com/tooltips/bbcups.html
It's even easier to simply leave the fixed cup in place unless it's totally shot.

A little off topic, but someone on a framebuilders listserve asked how to solder cable ends onto bulk cable!

I'm all for DIY, but sometimes its not worth it. You'll end up spending hours trying to solve your problem but then you'll just end up buying the thing anyway.