I have seen this happen on some carbon frames, Alan frames and hyperthinwall steel frames like accel tubing, or 753 or 853 pipes. Some frame makers do not reccomend using the ISC-1 in their frames for this reason. And a seatpost that you find at a swap meet or in the back of a shop is a LOT cheaper than an $80.00 tool that is invariably a special order form your LBS, or the mail order places. The ISC-1 is a good tool for certain frames- mostly low end, and certain applications, like a bench mount Park tool claw where the reach is too short and you do not have enough room to pedal the bike w/o getting it tangled up with all the stuff under the bench. I'm just not gonna use it on any of my bikes.
home of the guerrillas
> I have the shop quality single-arm Park repair stand, which is about 20
> years old or so, and I see that the new ones now have an additional height
> adjustment that brings them up to 62". At that height, clamping to the
> seatpost lends a more comfortable work height. I'm not challenging your
> statement Tom, but it's hard for me to see how the ISC-1 could damage a
> frame. It does not expand at the seat lug, so shouldn't affect clamping of
> the seatpost, and the multiple plastic wedges seem to grip the inside of the
> tube very well with minimal clamping force. I suppose if a gorilla really
> reefed on it, they might do some damage, but a modicum of attention should
> avoid any problems.
> Steve Barner, Bolton, Vermont
> ----- Original Message -----
> From: "Tom Martin" <firstname.lastname@example.org>
> To: <email@example.com>; <firstname.lastname@example.org>
> Sent: Thursday, June 12, 2003 12:15 PM
> Subject: Re: [CR]Holding a vintage bike in a repair stand
> > List:
> > I would not recommend the internal seat tube clamp (ISC-1). I have seen
> > seat tubes expanded out so much on some frames that the original post no
> > longer clamps in the frame. It's better to use a cheapo alloy post as a
> > dummy in the frame and then clamp it to the repair stand.
> > Park tool now has extensions for all their stands so you don't have to
> > over if you are a giant. The park clamps are bombproof and easily
> > and are in use in every last bike shop in the US- some for 30 years and
> > more. I like the Ultimates too, they have a broader range of adjustment
> > a good and simple clamp. They are just not vintage enough for me I
> > guess......
> > Tom Martin
> > Oakland CA
> > No on topic bikes (yet), but I do have on topic tools and stands