Trek 520 - Shimano 105 compatibility

[hbcomb1]

I'm in the process of building a Trek 520 frame and would prefer to minimize expenses by using spare parts from about the house. In short, I have a 9 speed Shimano 105 group with a double (39-53) crank and 105 hubs on 700cc rims.

Previous threads indicate that I can get around the 135mm rear spacing with washers. But now the bigger issue...

The first problem I've encountered is that the large chainring of the double crank hits the chainstay. Obviously, something has to give, but I'm not sure what.

I know that the new Trek 520's come set up with a 105 triple, but I don't know if the geometry on my older frame is the same as a new frame. In short, I am looking for an answer as to whether a triple crankset will pose the same problems with the chainstay. In addition, I am a little concerned about chain lines with a triple.

Any help would be greatly appreciated.

[daveornee]

I'm in the process of building a Trek 520 frame and would prefer to minimize expenses by using spare parts from about the house. In short, I have a 9 speed Shimano 105 group with a double (39-53) crank and 105 hubs on 700cc rims.

Previous threads indicate that I can get around the 135mm rear spacing with washers. But now the bigger issue...

The first problem I've encountered is that the large chainring of the double crank hits the chainstay. Obviously, something has to give, but I'm not sure what.

I know that the new Trek 520's come set up with a 105 triple, but I don't know if the geometry on my older frame is the same as a new frame. In short, I am looking for an answer as to whether a triple crankset will pose the same problems with the chainstay. In addition, I am a little concerned about chain lines with a triple.

Any help would be greatly appreciated.

What length and Model Bottom bracket are you using?

What year Trek 520 are you using?

[boudreaux]

I'm in the process of building a Trek 520 frame and would prefer to minimize expenses by using spare parts from about the house. In short, I have a 9 speed Shimano 105 group with a double (39-53) crank and 105 hubs on 700cc rims.

Previous threads indicate that I can get around the 135mm rear spacing with washers. But now the bigger issue...

The first problem I've encountered is that the large chainring of the double crank hits the chainstay. Obviously, something has to give, but I'm not sure what.

I know that the new Trek 520's come set up with a 105 triple, but I don't know if the geometry on my older frame is the same as a new frame. In short, I am looking for an answer as to whether a triple crankset will pose the same problems with the chainstay. In addition, I am a little concerned about chain lines with a triple.

Any help would be greatly appreciated.If you are using the 109.5 octalink BB,and have chainring /chainstay interference,you could shim the BB by 2 or 3 mm if that would fix it ,otherwise use an xtr 112.5 or 116BB or a 118.5 for the road triple crankset. You could always monkey around with an old square taper crank and box of BBs till you found one that worked. A 105 octalink triple will move the big ring out about 5mm.What's to be concerned about with chainlines and a triple?

[hbcomb1]

The issue arose when I tried a double crankset with a 109.5 bottom bracket. These came off another bike, and I just wanted to try them out. My proposal is to use a 118.5 with a triple.

As for the year...the frame is approximately 4-6 years old.

Thanks.

[boudreaux]

The issue arose when I tried a double crankset with a 109.5 bottom bracket. These came off another bike, and I just wanted to try them out. My proposal is to use a 118.5 with a triple.

As for the year...the frame is approximately 4-6 years old.

Thanks.
1999 520 used a 105 triple.