Alpinestars stem - what sorcery is this?

[Frankenorange]

Hello

Here is a question for Alpinestars kings and queens. I have recently purchased an old Alpinestars Easton 7005 stem. It is one of those for their own 28.6mm bars. I have seen these advertised as the other end being for a 1 1/8th inch steerer BUT it clearly is not.
It is more like a tad under if not 30mm though i have no vernier at home to be more precise. Am not going near my wokshop for some time so might end up hqving to buy a vernier. The other issue is a regular top cap falls into the stem but that is easier to sort, over a phone, without a vernier.

So; has anyone got dims for me, or maybe a shim and top cap if you have been down this rabbit hole yourself??

Anyhow.....happy xmas all. Stay well and safe and if it all gets too much please pick the phone up before picking up anything else and call a friend, or one of the many helplines. Do not suffer it out. That is a dark road that isnt worth riding!

Edit: a top cap doesn't fall into it if you pick up the right size when you aren't hangry and tired!!

 

[Sundayjumper]

The quill of the stem *IS* 1 1/8", i.e. 28.6mm, but it's *FOR* a 1 1/4" steerer. The 1 1/4" is the outside of the tube, the inside where the stem goes is 1 1/8".

 

[Frankenorange]

Not quill. It is an ahead.

 

[ishaw]

They did do a weird arrangement where the fork was threaded but had an unthreaded section above for an ahead stem. I assumed it was a standard size, I had one but used the frame forks as was, so never questioned it.

 

[Frankenorange]

It is reet peculiar and an @rse!

 

[ishaw]

I think the threaded section on the forks I had was 1 1/4. I think I discovered that a modern headset would fit in the frsme cups (inset style I think is the modern parlance) and I was going to fit some 1 1/8 ahead forks and use a different stem. Didn't get round to that in the end but if memory serves, it seemed possible.

 

[Frankenorange]

Thank you for the replies. Going to have to get a shim machined, or do that myself next year.

It is my own fault as i did ask the seller about the steerer end but he never replied. After some searching i saw a few advertised as being for a 1 1/8th steerer so i took the gamble without a reply from him. Should have asked here first!

I kind of get why they made the bars fatter but lord knows why they didn't just weld a section of the same tube onto the steerer end. Oh well!!

 

[Sundayjumper]

Chances are it's a multiple of fractions of inches - although if it's 1 3/16" (= 30.2mm) which is halfway between 1 1/8" and 1 1/4" then you're SOL finding anything off the shelf unfortunately.

 

[Frankenorange]

Yeah i think i will be turning up a shim, or getting made.

Bodge option for bike fitting purposes could be finding an aluminium seatpost shim that has more or less the required wall thickness, splitting it, then re-shaping it and it will be good enough for a turbo, at least.

Edit: could this be the answer?

Thorn Seat Post Shim

Suitable for use with some Thorn tandems. - Internal Diameter = 28.6 mm - Outer Diameter = 29.8 mm - Length = 80 mm

www.sjscycles.co.uk

 

[Rampage]

Have you got a picture of it?