I'm considering trying to increase clearance between tires and
chainstays on a couple bikes, right behind the bottom bracket. That's
where the clearance is tightest on these frames. The chainstays are
round in cross section. I'd like to dent them on the inside surfaces.

I managed to do this before on one bike, IIRC with a notched block of
wood on the outside, a massive C clamp and perhaps some other bits and
pieces to apply pressure at the right location.

I'm wondering if there's some accepted procedure and/or tool for this
purpose, before I invent my own again. Anybody have experience or
relevant advice?

--
- Frank Krygowski

On 3/4/2022 12:17 PM, Frank Krygowski wrote:
> I'm considering trying to increase clearance between tires
> and chainstays on a couple bikes, right behind the bottom
> bracket. That's where the clearance is tightest on these
> frames. The chainstays are round in cross section. I'd like
> to dent them on the inside surfaces.
>
> I managed to do this before on one bike, IIRC with a notched
> block of wood on the outside, a massive C clamp and perhaps
> some other bits and pieces to apply pressure at the right
> location.
>
> I'm wondering if there's some accepted procedure and/or tool
> for this purpose, before I invent my own again. Anybody have
> experience or relevant advice?
>

There are both presses with shaped forms and also bumps with
shaped forms. The trouble on the inside of chainstays is
that it's not an easy setup as compared with an outside
right chainstay bump for chainring clearance, which is trivial.

p.s. you've just rediscovered Grant Peterson's impetus for
that 584mm wheel obsession.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971