Helicoiling

I've got an (expensive) ahead stem with stripped threads in the steerer clamp. I believe it can be
repaired (and even made better than new) with helicoil inserts*.

1) What type of place would be best to do the job: bike shop, motorcycle shop, car shop? I'm
thinking they do this sort of thing more with motors than bicycles so they might be more
reliable and cheaper?

2) Any recommendations for places in the London area that could help?

3) Is it worth DIYing? Someone from another forum kindly gave me full instructions but is it a
reasonable job someone who's never done anything like this before?

* For those unfamiliar with these things, see: http://www.hillcliff-tools.com/helicoil.html

Thanks ~PB

 

In a brief moment of lucidity Pete Biggs scribbled:

> I've got an (expensive) ahead stem with stripped threads in the steerer clamp. I believe it can be
> repaired (and even made better than new) with helicoil inserts*.
>
> 1) What type of place would be best to do the job: bike shop, motorcycle shop, car shop? I'm
> thinking they do this sort of thing more with motors than bicycles so they might be more
> reliable and cheaper?

It's a relatively simple operation, provided you have the corect sized drills and the tang tool ..
so almost anywhere that says they can and will do helicoiling *should* be OK. It's a standard
engineering 'repair' and isn't a big deal really.

> 2) Any recommendations for places in the London area that could help?

Sorry, I live in Nottingham ..

> 3) Is it worth DIYing? Someone from another forum kindly gave me full instructions but is it a
> reasonable job someone who's never done anything like this before?

Yeah, dead easy and relatively easy for a novice. Read the instructions, read 'em again, then make
sure you have all the bits, understand what you're doing and go at a pace to suit. It would take an
experienced fitter maybe ten minutes, inexperienced about 1/2 an hour ..

> * For those unfamiliar with these things, see: http://www.hillcliff-tools.com/helicoil.html
>
> Thanks ~PB

--

My house is FOR SALE ... http://tinyurl.com/69r0

 

"Pete Biggs" <pLime{remove_fruit}@biggs.tc> wrote in message
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>
> 3) Is it worth DIYing?

As a one-off probably not. This is because you not only need the threaded inserts but also the
special tap, insertion tool and perhaps odd size drill. These are usually purchased as a kit
initially, >£20 without discount, and then inserts bought on their own for re-stocking.

>Someone from another forum kindly gave me full instructions but is it a reasonable job someone
>who's never done anything like this before?

The actual job is a doddle (providing there is sufficient meat around the enlarged hole) and I don't
imagine you'd find it demanding. You could always do a trial on an old bit of alli.

Pete

 

Peter B wrote:
> The actual job is a doddle (providing there is sufficient meat around the enlarged hole)

That's a point. How much is required? The holes are only 2mm away from the edge on one side, and
about 3 to 4mm the other. The material is aluminium.

Thanks for the info.

~PB

 

"Pete Biggs" <pLime{remove_fruit}@biggs.tc> wrote in message
news:[email protected]...
> Peter B wrote:
> > The actual job is a doddle (providing there is sufficient meat around the enlarged hole)
>
> That's a point. How much is required? The holes are only 2mm away from the edge on one side, and
> about 3 to 4mm the other. The material is aluminium.

You might be better off tapping to the next size and using a larger bolt. Look at imperial if
current size is metric, or vice-versa.

Would be cheaper for the diy-er, for sure.

 

"jt" <[email protected]> wrote in message
news:[email protected]...
>
> "Pete Biggs" <pLime{remove_fruit}@biggs.tc> wrote in message

> > That's a point. How much is required? The holes are only 2mm away from the edge on one side, and
> > about 3 to 4mm the other. The material is aluminium.

Dunno Pete, it's a judgement call for you to make.
>
> You might be better off tapping to the next size and using a larger bolt. Look at imperial if
> current size is metric, or vice-versa.

This is an idea that can work providing there is clearance for the bigger screws head. An original
M4 (quite possibly the size in the headset) will tap out to M5 and in fact 5mm is the tapping drill
size for an M6 thread should you need to make that jump (unlikely).

Tapping to a bigger size won't be as strong as a helicoil though.

Pete