Will Dura Ace 7700 9 speed DT shifters work with 8 speed ?

[Beans]

I found some Dura Ace 7700 9 Speed downtube shifters for sale at a very good price, cheaper than the 8 speed version I actually need.

My bike has dura ace FD and Shimano 600 RD, 8 speed basic shimano cassette (I think sora/tiagra).

I know shimano MTB shifters are sometimes made dual compatible, so you ignore the extra click and such when using a smaller cassette. Is it the same case for road shifters, and these particular ones?

Thanks.

 

[one-eyed_jim]

7700 shifters are compatible with an 8-speed cassette if used in conjunction with a 7400-series derailleur.

Shimano used a unique derailleur geometry for their 7400-series Dura Ace derailleurs that required less cable pull per shift than all their other models. When 9-speed cassettes appeared, they harmonized derailleur geometry across their range. But 7700 (9-speed DA) shifters pull the same amount of cable per click as 7402 (8-speed DA).

So, you can use 7700 shifters with your 600 rear derailleur to index a 9-speed cassette, or buy the 7700 shifters and a 7402 rear derailleur to index an 8-speed cassette. Or you can friction shift your current rear mech and cassette with just about any levers.

Here's Sheldon's summary:

http://sheldonbrown.com/dura-ace.html