etherhuffer 

I have a Sugino compact triple with a Tiagra front derailleur. I am using STR shifters, the Shimano unit for small handed people. I can't get a decent shift into the big ring. I have tried adjusting the cable, checked the stops, even the alignment of the cage. Not working. What am I missing? Wrong derailler for my set up? It's an 8 speed set up. Dang.

HillRider

Can the derailleur swing out far enough to make the shift, even with the high limit screw backed out all the way? Perhaps your crank spindle is too long and places the crank too far outboard.

joejack951

Can you more accurately describe the problem? What constitutes a decent shift into the big ring to you? Are you getting derailler cage rub when in the big ring?

etherhuffer 

Dang, good point. The screw is indeed all the way out.

etherhuffer 

With a good push the chain goes against the ring but won't go up. Now, that is with the middle and small ring set up. When I try to bias it towards the big ring, it sometimes goes but with effort.

etherhuffer 

So I checked the bottom bracket, I am using a 107 bracket and Sugino suggested 113, so I should have enough throw length.

operator

Which tiagra front derailleur do you have? And what the heck is an STR shifter? XTR is a flatbar shifter. STI requires a flatbar specific derailleur.

badamsjr

Double check that you have not much slack in the cable when shifted to to the small ring. I had a similar problem, and had slack---so was unable to get enough pull to go onto the big ring. After taking out the slack, it worked.

etherhuffer 

It was Shimano's STI for people with small hands. I think its Ultegra level. STR 600 or 700 I think.

joejack951

That would be ST-R600 or ST-R700.

joejack951

You need more cable tension. Once you add more cable tension you'll also need to adjust the high stop screw to keep the chain from shifting off the big ring. Read up at www.parktool.com and start over from the beginning. A little extra time spent getting things totally right from the beginning will save you a lot of aggravation and time later.

etherhuffer 

I am going to check that as well. Although, I really have a lot of resistance on the last upshift already.

joejack951

Make sure you have the correct stop screw backed out. If you are concerned about the resistance, disconnect the cable and try moving the derailler by hand. Can you get the outer cage well past the big chainring? If so, the resistance you are feeling is simply the front derailler's return spring. You may want to check that your cable is routed correctly through the bottom bracket cable guide and that your derailler housing and ferrules are in good shape.

etherhuffer 

Everything is brand new, and all the cable routing good as this is a new build I did. But I will disconnect the cable and see.