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Giant TCR ONCE 2001 & Triple Drive Train(3 posts)

Giant TCR ONCE 2001 & Triple Drive TrainProspectus
Jan 22, 2002 3:29 PM
According to the Giant website, the TCR ONCE 2001 frame is incompatible with a triple because "Most TCR frames have too short chain stays and the seat tube is too large".
I tried putting this to the test and I found that the triple derailleur knocks into the seat tube before shifting on to the innermost chainring.

However, I'm only using a 112.5mm bottom bracket. Do you think a longer bottom bracket might be the answer or am I chasing a lost cause? Anyone have any experience with the above frame?

Thanks in advance.
Hmmmmm.nee Spoke Wrench
Jan 22, 2002 5:10 PM
My QBP catalogue lists the recommended spindle length for a Tiagra or Sora triple to be 113mm, the Sugino road triple is 118mm.

What kind of crank are you using? If it's a Sugino, a wider BB might well be the answer. If it's a Shimano, you might just be trading inability to shift into the granny for inability to shift onto the big ring. The short chain stays will augment any chain line issues you may create.

While I enjoy wrestling with this kind of problem, if it were my bike, I think I'd take the advice of the frame maker and build it up as a double. This is the kind of project that you can sink a bunch of money into trying various combinations of parts and still not get satisfactory performance.
Perhaps that's why there is a TCR TripleProspectus
Jan 22, 2002 11:59 PM
Without doing my research I plonked down for an Ultegra triple - wasn't helped by my LBS not knowing about the above incompatibility issue.

The current problem lies with the derailleur knocking into the seat tube when attempting to shift into granny. That's why I thought a longer BB would work.

Question is, what do I do now with the triple crank apart from building up another bike? Aargh...

Just keeping my options open for later in the year when I attempt the Pyrenees and the Alps.