Long Seat-Tube for ISP

[Lovetoclimb]

My friend who is starting his frame-building business is going to make one of his first road bikes for me. Because I am difficult and stubborn I have requested he build me an ISP road bike, using light tubing for a climbing oriented machine (I dream of racing over Cols one day . . . )

Unfortunately with a saddle to BB measurement of 85cm I am in need of a very long steel tube to work for my ISP seat-tube. The longest we can find in Columbus tubing is 63cm and True Temper has only 75cm.

- Does anyone have experience in sourcing long tubes for tall guys like myself?

- Or have builders out there successfully welded a "ST extension" to mimic one long tube for an ISP?

I have seen several ISP bikes in existence but never taken the time to measure and see if us tall guys are left dreaming of days without saddle-post slippage. :confused:

[EricEstlund]

Don't do it.

ISP's on steel frames are not as simple as just running a longer seat tube. As one of his first frames I would recommend he not jump into this- especially if he's unsure of how to do it.

[Brian Smith]

My friend who is starting his frame-building business is going to make one of his first road bikes for me. Because I am difficult and stubborn I have requested he build me an ISP road bike, using light tubing for a climbing oriented machine (I dream of racing over Cols one day . . . )

Unfortunately with a saddle to BB measurement of 85cm I am in need of a very long steel tube to work for my ISP seat-tube. The longest we can find in Columbus tubing is 63cm and True Temper has only 75cm.

- Does anyone have experience in sourcing long tubes for tall guys like myself?

- Or have builders out there successfully welded a "ST extension" to mimic one long tube for an ISP?

I have seen several ISP bikes in existence but never taken the time to measure and see if us tall guys are left dreaming of days without saddle-post slippage. :confused:

I'm confused.
Does your friend think that due to your height, a bike without an extended seat tube will suffer from seatpost slippage?
My own experience is that there are a great many bikes for riders whose saddle to BB measurement exceed 85cm without slippage and without extended seat tubes.

As an aside, before Serotta made most of its own tubing, using welded-on seat tube extensions was a common occurrence for tall frames, despite the weight penalty, and they worked fine. All of these were for seatposts used inside the seat tube, too.

[Lovetoclimb]

Hey Brian,

Clarification on the ISP

I personally have experienced many issues with seatpost slippage, and as such want an ISP to eliminate the problem from my future.
I also find them to be very aesthetically pleasing, and for the smaller market of custom metal bikes I think it really sets them off as unique.

Thanks for the Serotta tip. I have asked him if he has contacted any other builders for advice, but apparently that is uncouth to do . . . seems like a brotherly group to me . . . not like his small Cincinnati based start-up will suddenly sweep the market with ISP bikes!

[vqdriver]

If you have to have an ISP get it from another builder.

[dekindy]

I asked Dave Kirk about this at NAHBS because I saw a steel frame with an ISP. If I remember correctly he said that it was unnecessary weight for no advantage and did not recommend it.