Frog bike crank removal

[confusedcyclist]

Hey folks. I bought my 4 year old a Frog bike. They don't make them in her favourite colour, so I'm attempting a respray. The frame which I bought used has a few scuffs and is in need of a full service anyway, so I've stripped it down, except for the cranks which I can't figure how to remove.

Here are some images. How the heck do I get these off? They are unlike any cranks I have worked on before.


View: https://imgur.com/a/206wxLs

 

[confusedcyclist]

Yes, the insides are threaded, looks to be the way to go. Thanks!

 

[Cycleops]

Also be available on the high street from Halfords, Decathlon etc and LBS. Standard square taper crank. Make sure you screw it it in all the way before tightening the extraction bolt.

 

[Legs]

Haha, this is about the only type of crank that I DO know how to remove!

 

[Ajax Bay]

I would take care over the quality of the tool bought. Random e Bay ones can be made of cheese.
Also take care when threading in - hand tight is fine. If crank stuck, just give it more welly, with a spanner rather than the allen key option.

 

[confusedcyclist]

Turns out I had a crank puller tool already, just that I had forgotten about it.

EDIT: Posted a follow-up question but worked out that my puller tool is too big for my particular spindle. So ordering another.

 

[confusedcyclist]

Haha, this is about the only type of crank that I DO know how to remove!

None of my road bikes or touring bikes have had these kinds of cranks.

 

[C R]

Turns out I had a crank puller tool already, just that I had forgotten about it.

EDIT: Posted a follow-up question but worked out that my puller tool is too big for my particular spindle. So ordering another.

Most likely the extraction bolt is going into the bolt hole in the spindle, you will need to block that hole somehow so that the extraction bolt has something to push against, or buy some self extracting square taper bb bolts like these, and you won't need a tool.

 

[Ajax Bay]

worked out that my puller tool is too big for my particular spindle.

Very surprised. Thread diameter and pitch for square taper cranks are very standard, and have been for 40+ years.
Unscrew the bolt till flush before trying to thread the tool in.

 

[confusedcyclist]

This is the tool I have:

View: https://imgur.com/XM1pczK


and hopefully you can see where it is gouging the inside of the crank.

View: https://imgur.com/C7pJDau


The foot on this crank pulling tool is nearly 15mm wide at it's widest. I could be wrong, but it looks like this is snagging on the inside of the crank surface before hitting the spindle, which is why I'm getting no movement. Is it possible that my crank puller dimensions are only suitable for ISIS/Octalink? I think that was the standard required for my other bike you see!

 

[confusedcyclist]

Most likely the extraction bolt is going into the bolt hole in the spindle, you will need to block that hole somehow so that the extraction bolt has something to push against, or buy some self extracting square taper bb bolts like these, and you won't need a tool.

I don't think it's getting that far actually, see the second picture in my last post.

I have contacted Frog bikes for an explaination of their crank removal process as I'm a bit flummoxed. Maybe I'll wait before wasting £10 on ebay!

 

[Big John]

If I'm not mistaken you should find the end of that tool has a magnetic 'cap' specifically for octalink type bottom brackets. Remove the magnetic cap to reveal the end that you'll need to remove that crank arm. It's a bog standard square taper BB. If in doubt YouTube probably has at least a hundred videos of how to remove a square taper crank arm.

 

[confusedcyclist]

If I'm not mistaken you should find the end of that tool has a magnetic 'cap' specifically for octalink type bottom brackets. Remove the magnetic cap to reveal the end that you'll need to remove that crank arm. It's a bog standard square taper BB. If in doubt YouTube probably has at least a hundred videos of how to remove a square taper crank arm.

Well the top came off, but I had to really muscle it and it won't go back on. But it did the trick, success!

Thanks all for input, saved me money on bike shop fees yet again.

 

[confusedcyclist]

And now I know why they call them 'square taper'! My daughter will be chuffed when it's done and the end is in sight

 

[Cycleops]

This is the tool I have:

View: https://imgur.com/XM1pczK


and hopefully you can see where it is gouging the inside of the crank.

View: https://imgur.com/C7pJDau


The foot on this crank pulling tool is nearly 15mm wide at it's widest. I could be wrong, but it looks like this is snagging on the inside of the crank surface before hitting the spindle, which is why I'm getting no movement. Is it possible that my crank puller dimensions are only suitable for ISIS/Octalink? I think that was the standard required for my other bike you see!

I think you've found the problem. The foot on my Decathlon tool is 10mm.