Hey team - new to the forum and am looking for guidance on options to replace SRT600 grip shifters.
I have a 96-97 model Diamondback Ascent EX with STX (3 speed front) and Deore LX (8 speed rear) and the rubber on the existing grip shifts has perished after 30 years.
I want to stay with grip shifters as opposed to trigger and I prefer to have the cable exit under my brake levers.
Google is indicating revo shift shifters should do the job but can I use my existing cabling?
Any other grip shift options worth considering?
thanks in advance
Adrian

SRAM brand MRX 3x8 will work for you.
they come with fresh shift cables installed at the factory.
search: SRAM MRX 3x8.

as to the cable housings, i'd strongly advise building/using fresh ones now, instead of having trouble later.
re-using cables and housing is a not a good choice, especially when the shifters are having trouble already, eh?
plus, re-inserting frayed cables is usually a mission to total frustration.

i still ride my DB Ascent from time to time.

this might be the perfect time to step up to Trigger shifters, btw...
Search on ebay: Shimano Altus SL-M315 Rapidfire+ 2x7/ 2x8/ 3x7 / 3x8 Speed Trigger Shifter
then select 3x8 and front & rear.. under $30, with cables already installed.

MRX and Centera are the new shifters from Sram that will work. The Centera is slightly nicer quality, but both of them don't have a click that is as satisfying as the SRT600. I'd consider finding new rubber for your existing shifters, or finding another pair of SRT600 or SRT800 shifters to be better ideas.

I would go with a nice thumb shifter from Microshift and maybe get a new chain and cassette and run 9 speed (without the need to change other parts) and you will be set. I think GripShift back in the 80s and early 90s was cool and the SRAM story is pretty neat and inspiring but when you have great shifters like modern trigger shifters or proper thumb shifters (not the cheap tourney garbage) there is no way I would want to keep GripShift having a shifter that I can accidentally move while simply gripping the grips. is not ideal.

thanks for the feedback Maddog, my existing cables are around 5yrs old as they were replaced when I added riser bars.
Interesting thing with my frame is the cable housing for the derailleurs and rear brake terminates near the start of the top tube of the frame and the inner cables run across the top of the frame within thin plastic tubing before re-entering the cable housing at the back of the top tube of the frame.
Not sure if this will cause issues with using trigger shifters if different diameter inner cables are used.

the cables for shifters are basically, always the same diameter, 1.2mm
brake cables are all about 1.5mm now...

a scant few variances exist, but none of them will apply to your needs.