ISP to Standard Seatpost (Wilier)

[YesNdeed]

Does anyone have direct knowledge of cutting off the integrated seat post and inserting a standard post? Specifically on a Cento1, 2010 model year. I've heard of this being possible, but can't find much about it. An old Weenies thread said it's a 31.6 diameter, and I don't have the bike in my possession.

I sold my Cento to a friend who is not very mechanically inclined. It would be a lot easier for him to dial in seat height with a regular post. My gut tells me not to risk going this route, but just looking at all options for him.

[stefthehat]

Sorry not done it on this brand but did it successfully on a Somec I no longer have ,I was confident as I’ve worked with composites all my adult life,maybe if you’re interested I should p.m you .I started typing out the protocol/process and thinking behind each step but it was hugely long ,whilst not possible I could verbally describe the process or physically show it in a workshop situation in approx 5 min ,it requires very few tools but definite discipline in measuring/marking and cutting,there’s a little bit of measuring and planning ahead but the job itself was approx a 10min job,cheers

[prototoast]

1) Remove the seatpost topper and shine a light down the top of the mast, and see if the tube appears to be round and uniform all the way down (or at least as far as you'd stick a seatpost). If the frame was made with an external mold, the inside could look like just about anything.

2) If it looks okay, measure the inside of the seatmast. Is the inner diameter round, and of the dimension that is consistent with a normal seatpost? For example, you could have a 34.9 outer diameter with a 31.6 inner diameter, and it's easy to find a seatpost that fits. On the other hand, if you have a 34.9 outer and a 31.2 inner diameter, it's going to be hard to find a seatpost that works with that.

[StressStrain]

This sounds like it would take a lottery winner's amount of luck to actually work.

I can't imagine a frame would be designed with a seat mast ID and the frame's supporting structure to allow this.

[benb]

Absent some weird design that actually took this into account it seems risky.
The whole point of ISPs originally was the TT/ST/SS junction not needing to be as reinforced as a bike with a seatpost. It was a weight weenie thing first before they started thinking aero.

So it seems like the challenge is:

- Do you have to bond something in there to make it actually accept a seatpost after you cut it up?

- Can the frame actually handle adding a clamp without cracking?

- Is it going to crack riding along since the junction is not designed to take those forces?

Does the Willier ISP suck or something like so many others? 2010 was the era of suck for ISPs AFAICT.