Hi, I am about to fix a threaded pedal crank, but I am not sure what size helicoils to order. The pedal thread is 14 mm, and I see you can buy 14 mm helicoils. What I am not sure about, is if that 14 mm measurement is the inside of the helicoil, or the outside. If anyone can point me inthe right direction, that would be fantstic, thanks.
How do you measure a helicoil?
- Thread starter Colino
- Start date
Page may contain affiliate links. Please see terms for details.
Domus
Guru
- Location
- Sunny Radcliffe
The thread you need is the insert you buy. The external thread is a unique thread for which you will need the tap as supplied by Heli-Coil. Amazon sell various kits, not all are genuine Heli-Coils which is a trade name.
gbb
Legendary Member
- Location
- Peterborough
You also need to consider the thread pitch and whether the damaged side is left or right hand thread.
Standard 14mm bolts are 2.0mm pitch...i don't know if pedal threads are 2.0 mm or maybe less.
A helicoil kit will come with the appropriate oversized tap.
Standard 14mm bolts are 2.0mm pitch...i don't know if pedal threads are 2.0 mm or maybe less.
A helicoil kit will come with the appropriate oversized tap.
tamiya
Well-Known Member
- Location
- AU, MY, SG
Sheldon sez
Yellow Saddle
Guru
- Location
- Loch side.
A helicoil kit will cost you more than the crank. You'll have to buy two taps - one left hand, one right hand. Then one drill bit and of course helicoils, which don't sell singly.
A German bicycle tool company sells a tool that uses threaded inserts rather than coils. Works much better and is much more robust. I just can't think of the name now - Icsus?? Naah, not that. Anyway, I still have such a tool somewhere, not sure if I have inserts for both sides.
A German bicycle tool company sells a tool that uses threaded inserts rather than coils. Works much better and is much more robust. I just can't think of the name now - Icsus?? Naah, not that. Anyway, I still have such a tool somewhere, not sure if I have inserts for both sides.
Yellow Saddle
Guru
- Location
- Loch side.
No, another company. On the tip of my tongue, but the Unior tool you show is exactly that. The one that I had in mind has a separate reamer, but this is a neat solution.
Graeme_FK
Veteran
- Location
- Wherever there are sick bicycles
I don't want to come over all bicycle trade here but ...
If you are asking this question, are you sure that you know enough about what you are doing, to do it?
There are a number of helicoil or helicoil-esque kits, from Unior and Cyclus for instance (they are the two most widely used) but to do a good job, you also really need a pillar drill and a way to check that you are drilling and tapping dead square to the BB axle. If you don't, you will end up with a pedal that sits "off" square which will feel very odd to ride (like a bent pedal spindle) and if it's a long way out, and you ride a lot, you are headed for knee problems.
This kind of job is best left to a workshop that really knows what they are doing ... and no, I am not punting for business (although we would be happy to help, of course!)
If you are asking this question, are you sure that you know enough about what you are doing, to do it?
There are a number of helicoil or helicoil-esque kits, from Unior and Cyclus for instance (they are the two most widely used) but to do a good job, you also really need a pillar drill and a way to check that you are drilling and tapping dead square to the BB axle. If you don't, you will end up with a pedal that sits "off" square which will feel very odd to ride (like a bent pedal spindle) and if it's a long way out, and you ride a lot, you are headed for knee problems.
This kind of job is best left to a workshop that really knows what they are doing ... and no, I am not punting for business (although we would be happy to help, of course!)
Yellow Saddle
Guru
- Location
- Loch side.
It is Cyclus. See, I told you it starts with an "I" like in Iclus. Cyclus, Iclus.....
Anyway, this is the set I have somewhere.
https://www.internet-bikes.com/en/12315-cyclus-repair-set-crank-and-pedal/
I even have a few inserts left, not sure if they are left or right side though.
Thanks for the replies. I would take it to a bike shop, but I can't get the crank arm off as much as I try, and I don't want to completely trash the cotter pin. I live in Paris, and this sort of repair has not landed here as yet, it's a bit much for the French. Good points about making sure it is square, and as far do I know enough, time will tell I guess, thanks.
