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What size allen key?
Posted: August 13th, 2021, 5:13 am
by fried_rice
I'm trying to replace the small wheels from the seat as they are slightly bent which is resulting in too much seat movement.
The bolt which attaches them is just spinning so I need to lock with an Allen key. Issue is I have a 4mm and 5mm key but 4 is too small and five is too big. I can only assume a 4.5 will work (which are not that common. I guess they other option is it could be an imperial measurement. Can someone please confirm the required size key?
Thanks
Re: What size allen key?
Posted: August 13th, 2021, 5:36 am
by Citroen
https://www.concept2.com/files/pdf/us/i ... cement.pdf
That says you need 3/16" (5mm) or 5/32" (4mm) hex wrench but doesn't say which size is used for which task.
Re: What size allen key?
Posted: August 13th, 2021, 6:34 am
by fried_rice
Thanks- I guess they have been stripped by previous attempts to remove
Re: What size allen key?
Posted: December 29th, 2022, 10:40 pm
by mc900ft
Just ran into the same problem.
Despite what the instructions say, the correct answer is a 4.5mm allen key.
We have 5 metric allen key sets at home and one imperial. None of the 4 or 5mm keys fit, nor did similar size imperial ones.
Had to make a trip to the hardware store for a 4.5mm key (that was only available as part of a set of 25
)
Fits perfectly...
Re: What size allen key?
Posted: December 30th, 2022, 8:47 am
by Willy.VdW
Perhaps, since it is a US made machine, the correct size is 11/64 which translates to 4.4mm?
Re: What size allen key?
Posted: December 30th, 2022, 3:33 pm
by Carl Watts
Every screw and part on the C2 is imperial, you need a set of imperial Allen keys and spanners etc to work on these. The threads on all the screws is imperial as well so you need things like a 3/16 UNC tap to clean up threads in the frame.
About the only metric thing on the whole rower is 17mm bearings used to support the flywheel.
Re: What size allen key?
Posted: December 30th, 2022, 7:41 pm
by Carl Watts
The Allen key you need is probably 3/16 so that's just not a metric size at 4.75mm.
The metric ones will either be to big or to small.
Re: What size allen key?
Posted: December 31st, 2022, 3:28 am
by mc900ft
The problem is the instructions on the c2 site quote both imperial (3/16" and 5/32") or the metric equivalents (5mm and 4mm) needed to do the job. Metric keys will work fine - the tolerances are close enough. 4.5mm is close enough to 3/16" to work
https://www.concept2.com/files/pdf/us/i ... cement.pdf
The 4mm for removing the rear leg is fine but the metric equivalent 5mm quoted for the bottom roller is
wrong. You can't fit a 5mm hex in a 3/16' hole. Most metric sets skip straight from 4 to 5mm too. 4.5mm is not a commonly used metric size and hard to find.
So an imperial set is the easy way to go for sure. But the instruction sheet could do with a correction.
Re: What size allen key?
Posted: December 31st, 2022, 11:04 am
by Tsnor
mc900ft wrote: ↑December 31st, 2022, 3:28 am
The problem is the instructions on the c2 site quote both imperial (3/16" and 5/32") or the metric equivalents (5mm and 4mm) needed to do the job. Metric keys will work fine - the tolerances are close enough. 4.5mm is close enough to 3/16" to work
https://www.concept2.com/files/pdf/us/i ... cement.pdf
The 4mm for removing the rear leg is fine but the metric equivalent 5mm quoted for the bottom roller is
wrong. You can't fit a 5mm hex in a 3/16' hole. Most metric sets skip straight from 4 to 5mm too. 4.5mm is not a commonly used metric size and hard to find.
So an imperial set is the easy way to go for sure. But the instruction sheet could do with a correction.
Could you drop a note to concept2 at
info@concept2.com
They are very responsive, but don't monitor the forums. Your wording change might save someone ordering parts and tools some trouble.
Re: What size allen key?
Posted: December 31st, 2022, 4:29 pm
by mc900ft
good idea.
Done
Re: What size allen key?
Posted: December 31st, 2022, 5:32 pm
by Carl Watts
A good tool shop will sell a single Allen key and they are pretty cheap, even the good ones like Bondhus which is what we used to sell when I worked in a tool shop. Just buy the right tools and look after them they last a lifetime.