Bike Combination Lock

General cycling advice ( NOT technical ! )
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Mick F
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Bike Combination Lock

Post by Mick F »

A very good mate has this lock.
It's hardly used and hasn't been used for a couple of years or more.
He can't remember the combination! :lol: :lol:

He's tried picking random numbers and numbers that mean something to him, but nothing worked.
He knows I'm fairly adept at stuff so asked me to try.
IMG_1533 copy.jpg
TBH, I had no idea how I was going to do this, save beginning at 0000 and going right through until it opened.
I soon got bored with that idea.

So, I turned to my computer, and Googled, and YouTube came up.
This one for instance, but there are more.
https://www.youtube.com/watch?v=q0KytPxjmo0
No matter how hard I pulled ........... and I pulled VERY hard indeed ........... there was no feel to the individual numbers. All was silky smooth.
I didn't want to resort to an engineering solution as I didn't want to damage it.

So, my question is, how do I decode it?
Mick F. Cornwall
Jdsk
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Re: Bike Combination Lock

Post by Jdsk »

Mick F wrote: 22 Oct 2022, 10:23am ...
No matter how hard I pulled ........... and I pulled VERY hard indeed ........... there was no feel to the individual numbers. All was silky smooth.
...
I recommend putting some angle on it as you pull.

Jonathan
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Mick F
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Re: Bike Combination Lock

Post by Mick F »

Tried it.
Nowt I've tried has worked, and I've spent a good hour or more.

I could have spent the time going through the individual numbers. Maybe - optimistically - it could start with a 1!
Mick F. Cornwall
slowster
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Re: Bike Combination Lock

Post by slowster »

Mick F wrote: 22 Oct 2022, 10:23am there was no feel to the individual numbers
Did you try every number one at a time on all four wheels? I suspect that manufacturing tolerances will be such that you are likely to be able to detect an open gate on only one particular wheel to begin with. You will not be able to feel the open gates with the other three wheels, because that first wheel is the one with the closest tolerance/tightest fit and so prevents the bar of the lock moving far enough to feel the presence of an open gate on the other wheels.

Also, I think putting in a lot of effort each time when you pull the lock will be counter-productive, because that will probably make it harder to detect the slight difference in feel when you align a wheel with a gate. It should be possible to detect an open gate with minimal pulling force.
fastpedaller
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Re: Bike Combination Lock

Post by fastpedaller »

Reminds me of many years ago when a clubmate revealed to me how it's done. We were in the Cafe, he was about to leave early so I said " I'll give you the combination so you can unlock my bike from yours". He said "No problem I've already done it" :lol:
Good luck with your efforts!
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simonineaston
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Re: Bike Combination Lock

Post by simonineaston »

tbh 10,000 attempts won't take too long if you sit down and watch a couple of borign old movies while you're at it... the YT videos make it look easy. :roll:
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
rareposter
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Re: Bike Combination Lock

Post by rareposter »

Mick F wrote: 22 Oct 2022, 10:23am So, my question is, how do I decode it?
Come to an agreement with your mate - you do 0000 up to 4999, he does 5000 up to 9999.
Have a big family get together, allocate each family member a batch of 1000.
Bin it and buy a new lock.
Have it as a task to do over the next couple of weeks, 1000 per night while you're watching a film or something.
Or (and this is my favourite option) give it back to him and tell him it's his problem!
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geomannie
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Re: Bike Combination Lock

Post by geomannie »

Maybe one of these videos will help?
https://m.youtube.com/results?sp=mAEA&s ... ombination
geomannie
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simonineaston
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Re: Bike Combination Lock

Post by simonineaston »

He's tried picking random numbers and numbers that mean something to him, but nothing worked.
I recall installing a key safe, when my poor old ma started getting a bit dotty. Of course the unit comes with a code you can't change, but I figured I could make it the same as a code I could change so I matched the key safe to my debit card pin.
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
Jdsk
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Re: Bike Combination Lock

Post by Jdsk »

simonineaston wrote: 22 Oct 2022, 12:19pm...
Of course the unit comes with a code you can't change, but I figured I could make it the same as a code I could change so I matched the key safe to my debit card pin.
I recommend Feynman's description of opening other people's safes during the Manhattan Project:
https://www.cs.virginia.edu/cs588/safecracker.pdf

Jonathan
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Mick F
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Re: Bike Combination Lock

Post by Mick F »

geomannie wrote: 22 Oct 2022, 12:00pm Maybe one of these videos will help?
https://m.youtube.com/results?sp=mAEA&s ... ombination
Thanks, but none of it seems to work.
No matter how I pull, there isn't any "feel" to any numbers - from either end.

Maybe I need stronger hands and arms! Maybe it's a young man's sport and I'm too old!
Mick F. Cornwall
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Mick F
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Re: Bike Combination Lock

Post by Mick F »

Hang on a sec, I think I have an idea.

Back soon.
Mick F. Cornwall
Mike Sales
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Re: Bike Combination Lock

Post by Mike Sales »

Mick F wrote: 22 Oct 2022, 1:16pm
Thanks, but none of it seems to work.
No matter how I pull, there isn't any "feel" to any numbers - from either end.

Maybe I need stronger hands and arms! Maybe it's a young man's sport and I'm too old!
[/quote]

Maybe a little lubrication might help the "feel". Or have you tried that?
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
simonhill
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Re: Bike Combination Lock

Post by simonhill »

A set of small bolt croppers will do it.
thirdcrank
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Re: Bike Combination Lock

Post by thirdcrank »

I'd have thought this was right up your street, in the sense of ticking off completed parts of a task.

Make some sort of a chart to log progress, consider setting a daily target, then tick off combinations eliminated as they are achieved.

(It's how I've done this, but much less methodically.)
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