Originally Posted by
retroroadie
A few things to check out: 1) Not all Gripshifts are Shimano compatible; you didn't mention which model you had;
BITD all original Gripshift was Shimano compatible, also, the OP said they had Sachs shifters, these were different to Gripshift, these were 100% Shimano compatiable, used them myself. It was only after the SRAM brand was introduced that SRAM designed a range which was incompatible with Shimano.
Originally Posted by
retroroadie
2) Even if the Gripshift is Shimano compatible, the shifting will be poor when paired with a Shimano rear D using the linear spring (not enough return force);
Wasn't a problem BITD, it all worked together fine.
Originally Posted by
retroroadie
3) And a gummed out or kinked or rusted cable may not help matters, either. Luck.
The cable is most likely the issue, from memory Sachs shifters didn't have the same issues with gumming up as Gripshift, and didn't require special lube