Front gear / chainset incompatability (?)

jdm33 said:

I just fitted a new chainset to my hybrid (2000 Specialized Crossroads Elite) and now find that the front gear won't shift down to the smallest cog, even with no tension in the wire and with the low adjustment screw fully out. It feels as though the new chainset's rings are somehow closer to the frame than the old one. Does that sound possible?

The front gear is Shimano Nexave; the chainset is a cheap MTB, fixed ring job (but with the same size rings as the old one - 28/38/48). I can't find a part marking on the old chainset - it's whatever came with the bike, and has a Specialized 'S' on it.

Any suggestions on how to fix this?

Is there any way to add a spacer between the crank arm and the bottom bracket?

Would a new gear be likely to fix it? How do I identify one which wouldn't have this problem?

TIA,
Jon

From your wording I assume you replaced the entire crank set, not just the chainrings. If this is true it is quite possible that the chainrings are too close to the frame for the front derailleur to work properly.

Cranksets are designed to work with specific length bottom brackets, if you use the wrong size BB the chainrings will be , either too close or too far from the frame, causing a bad chainline and resulting bad shifting.

The paperwork that came with the new parts should list the proper length BB.