Imagine a bike that shifts when you want it to.
SRAM designed the PG-970 Cassette to shift quickly and positively with PowerGlide II technology.
Share your thoughts
Good value, but heavy
This cassette shifts well, but is a bit on the heavy side. I like having the ability to take the cassette apart to deep clean it every so often. This cassette does seem to have good durability and provide years of good use with appropriate maintenance.
What is the difference with cog sizes, can...
What is the difference with cog sizes, can anyone translate it into what one experiences on the trail? thanks...
The basic idea is that the smaller the number translates to how fast you can pedal the bike down a hill, and the bigger the number translates into how easy it will be to grind up a hill.
The fewer teeth there are on the smallest cog, the longer it'll take you to pedal out of your gears. For example, running a 36t front chainring with a 11t smallest cog in the rear will basically make it so you won't spin out as fast as with a 12t rear cog. In other words, you'll be able to pedal your bike to a higher top speed because for every one revolution of your cranks with an 11t rear cog, your wheel will revolve 3.27 times (36/11), whereas with a 12t rear, your wheel will revolve 3.0 times (36/12).
The tallest cog - the bigger number - translates into how easy you can make your gear ratio for climbs. For example, say we're running in the small ring in the front, a 24t. If you've got the 11-21 cassette, your biggest gear in the back will be 21t, and your easiest gear ratio will be 1.14. For every revolution of the cranks, your rear wheel will rotate 1.14 times. Thats not an easy gear to climb a steep hill with. If you're running a 11-34t cassette, then that changes to 0.71 (24/34), a much, much easier gear to climb with.
Rebuilding my Touring/commuter bike and...
Rebuilding my Touring/commuter bike and running into some questions. I have the 09 novara randonnee, thats seen a hard 3500 sum-odd miles and is in desperate need of help. I am revamping the drivetrain with a Shimano Ultegra FD-6703 Front Derailleur + Shimano Ultegra RD-6700 Rear Derailleur. My question is what size cassette should I get to attain a 9 speed with a faster ratio than what came on the factory setup (12/28)those being the sm and big cogs. I was thinking of your SRAM PG-970 Cassette (9 Speed). I would also like to get a new top ring. original size having 28 teeth. I would like to get a faster size. ?.
Why not go with a 10spd cassette as you are putting in 10 spd derailleurs? Unless you want to keep the shifters/chain 9spd. Either way, if you want faster you should go with a lower number of teeth in the rear such as 11-something (11 tooth is the smallest you can get). Remember lower teeth on the rear translate to faster wheel spin/faster speed. The top gear range will be best determined by what kind of terrain you are riding. If you ride on flat terrain, go with 11-23 because you don't need the high gears and you have more options in the lower/faster gears. If you have a lot of hills then go with 11-25 or 11-28 as the higher gears will help on the inclines. Your crankset (standard vs compact vs triple) will also help determine how fast you go at a certain cadence. A 53-tooth big front ring will go faster/at a lower cadence than a 50-tooth. Any higher number of rings than 28 is usually used for MTB bikes that go steep uphill on dirt. Then you should get MTB derailleurs/full drivetrain.
Solid, if Heavy, Cassette
I've used the 970, 980, and 990, and they all do the job. They've all got steel teeth and last a long time and shift very well. I love sram cassettes.
For those of us still on 9spd:
If you're not on a budget and don't care about value, get the 990.
If you're on a budget but still want light weight, get the 980.
If you don't care about weight, get the 970.
Other than the weight you really won't notice the difference.