[perrowtodd]

I don't know if anybody can help, but any ways I have a 2000 model mongoose DX 3.5 which originally came set up with a front chain line of 50.0mm I have been riding this set up for 2 and half years now with continually problems, these included the chain dropping from the middle ring down and poor shifting.
Any ways I have finally decided to upgrade the cranks and would like to know if it is possible to change to a 47.5mm chainline or would this cause shifting problems with the front derailleur, or would clearance between the crank arms and chain stays be an issue.

If it helps the seat tube has an outside diameter of 34.9 and I am upgrading to a 2003 Shimano XT crankset and ES71 Bottom bracket.

 

[NRSracer]

Originally posted by perrowtodd
I don't know if anybody can help, but any ways I have a 2000 model mongoose DX 3.5 which originally came set up with a front chain line of 50.0mm I have been riding this set up for 2 and half years now with continually problems, these included the chain dropping from the middle ring down and poor shifting.
Any ways I have finally decided to upgrade the cranks and would like to know if it is possible to change to a 47.5mm chainline or would this cause shifting problems with the front derailleur, or would clearance between the crank arms and chain stays be an issue.

If it helps the seat tube has an outside diameter of 34.9 and I am upgrading to a 2003 Shimano XT crankset and ES71 Bottom bracket.

The poor shifts on the mongoose may have simply been caused by poor derailleur tuning. 2.5 mm can be a big difference, however the front derailleur may be able to account for that with the set screws. What Derailleur and Crankset are you running now?

 

[perrowtodd]

current crankset- Suntour XR180
Current Front der- Shimano Alivio