Instruction: Given a question and the related document, predict if the question is answerable based on the information provided in the document. Output only yes or no.

Input:
Question: is this for a 9-speed or an 8-speed cassette?
Document: Good shifters. I used this on my 7 speed Shimano casette. It does a good job. Although this is an 8 speed shifter, it works pretty smooth on my 7 speed casette.I have some small complaints:1. I wish Shimano could add some grease along with the cable in there package. I had to buy grease seperately.2. There is no installation guide. I had to use my intution and videos on youtube to install the shifters.3.
Enjoy!Update 9/17/2010Had these STi shifters on for about a week. They've been awesome and well worth the money. I also upgraded to a 9 spd chain which is slightly thinner and shifts flawlessly and without rubbing like I had with my 7spd chain. I originally had a 7spd freewheel but upgraded to 8spd to be compatible with a combo lever like these. One thing I didn't know is that a 7spd and 8spd are indexed the same, just one more gear for the 8th cog.
The fashion in road bicycles is to go with nine, ten, and even eleven speed rear cassettes. Why? I cannot fathom how this is necessary. I can tell you my fifty one year old legs do not have eleven speeds in them! Also, I believe that the thinner chains these cassettes require are fragile.This is to say nothing of the cost of such components.
compared to down tube shifters, the sis brake-shifter sets are nice and easy to use when riding fast or hard. They are a bit trickier to keep in tune (until you get them right), but they are a great invention. It is a excellent upgrade for the older 14/16/20 speed drive bike. After the shifters the next thing I would upgrade is to buy a great chain.If you don't have them, the price is dropping and that makes them very affordable.
I got these in hopes of being able to upgrade my 1989 trek 1200 from downtube to STI. It worked! The shifting is very smooth and the components are top notch.The only thing that this kit didn't include was adapters to hold the cables in place once the downtube shifters were removed, luckily its possible to just drill a hole in the old shifters and run a cable through there.All in all this is a great set of STI shifters and will work with ancient derailleurs and 7 speed cassettes.
But even with those two aspects, they are not worth over twice the price over these STi shifters. Keep in mind, the 22/2300 series shimano stuff is pretty much the previous years Sora group. So, if you're like me and are upgrading from tube shifters and seperate brake levers, these are so worth it! Just keep in mind if you have anything less than an 8 spd freewheel/casset, these will not work. Also, your rear cogs need to be compatible with SIS indexing.
now about the brake line? buy some jag wire to compliment these and your have a big improvement over the braking performance.
it is located on the side of the shifter hood and is operated via thumb, which can prove problematic whilst in the drops.
haven't use them yet but these look like there going to be very durable. these are my first set of sit shifters. they feel heavy compare to the drop bar i bought to pair these up with. but for the price you can't really argue these kinds of things.the good thing about these it feels like the brake lever won't bend over when you put allot of braking power into it like the other junky ones that came with my bike, (plastic maybe).
amazing and come very good come i like it a lot is a good product i will buy another soon
Answer: yes