Crank-arm Dustcap Problem

David said:

Went to pull the old crankset (Sugino or SR-made square taper "retro"😉
and the dustcap was stuck. Soaked it with WD40, as I have done before,
came back a few minutes later, and tore it apart when I twisted the
screwdriver. I think the good ol' WD40 softened the plastic instead of
loosening the threads...

Any expert suggestions on getting the rest of the plastic out of the
threads so I can use the puller?

Thanks.

Those plastic dust caps were always stripping their threads and leaving
debris in the crankarm. I'd scrape the threads out with something sharp
and pointy. You really only have to get the first couple threads clean-
once the remover is started, it'll clean out the rest of the threads
just fine. That's assuming, of course, that the threads in the crankarm
were in good shape in the first place.

Jeff

David said:

Went to pull the old crankset (Sugino or SR-made square taper "retro"😉
and the dustcap was stuck. Soaked it with WD40, as I have done before,
came back a few minutes later, and tore it apart when I twisted the
screwdriver. I think the good ol' WD40 softened the plastic instead of
loosening the threads...

Any expert suggestions on getting the rest of the plastic out of the
threads so I can use the puller?

Thanks.

Dig it out with a dental tool or a thin screw driver and then remember
to not use these things again. On a properly installed crank, no need
to have the 'dust caps' to hold the crank on if the bolt loosens.

David said:

Went to pull the old crankset (Sugino or SR-made square taper "retro"😉
and the dustcap was stuck. Soaked it with WD40, as I have done before,
came back a few minutes later, and tore it apart when I twisted the
screwdriver. I think the good ol' WD40 softened the plastic instead of
loosening the threads...
Any expert suggestions on getting the rest of the plastic out of the
threads so I can use the puller?

We use a pointy spoke.

We also have a crank puller with slots cut in it (disc
grinder) to clear oxidized/dirty threads but for plastic
dust cap detritus, a pointy spoke is all you need. Handy
tool for clearing glass/debris from tire cuts, too.

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

swab with linseed oil