Reasonable to Turn 28.6 @ 858 DT into 856 Double Butted Seat Tube?

[jclay]

I'd like a seat tube with 856 walls but am unaware of any. Is it reasonable to hand ream an 858 DT to make it become 856 wall and a double butted seat tube? If so, is an adjustable reamer suitable or should a different tool be used?

Thanks,
John

[Curt Goodrich]

It’s possible but the outcome probably won’t be worth the effort. The likelihood of leaving a scored surface is great. That can lead to cracking which will occur after some months of use. Buying a new tube would be a prudent purchase and a savings in the long run.

[jclay]

It’s possible but the outcome probably won’t be worth the effort. The likelihood of leaving a scored surface is great. That can lead to cracking which will occur after some months of use. Buying a new tube would be a prudent purchase and a savings in the long run.

Thanks Curt,

It's not that I want to do it, not at all; it's that I want an 856 DB seat tube. I gather that if one can't be found then use something else rather than trying to make one out of 858. Though I'da thought it could be managed if careful, and stopping before the flutes get to the belly section.

I've been informed that Reynolds has an 8/.55 ST so that's a reasonable substitution.