What size allen key?

[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

[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.

[fried_rice]

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.

Thanks- I guess they have been stripped by previous attempts to remove

[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...

[Willy.VdW]

Perhaps, since it is a US made machine, the correct size is 11/64 which translates to 4.4mm?

[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.

[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.

[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.

[Tsnor]

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.

[mc900ft]

good idea.

Done

[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.