HELP with derailleur upgrade question

Asked by: Tasha Davis

Can you upgrade just the rear derailleur?

Compatible sprockets change



Each rear derailleur product has its own “minimum number of teeth” and “maximum number of teeth” for the corresponding sprocket, so upgrading the rear derailleur may change the numbers here.

How do I know what derailleur I need?

If you are replacing an existing derailleur on a bike, simply count the number of cogs on your cassette and you’re good to go. If your drivetrain’s speed is an unknown quantity, you can count the number of steps that your shifter runs through and add ‘one’ to determine the number of gears your drivetrain has.

Will any derailleur fit my bike?

No, bike derailleurs are not universal. A derailleur that works with one bike may not work with another bike based on factors such as the cage length. Check the difference between the smallest and largest cogs and also the chainring size to determine the derailleur compatibility.

What does total capacity mean for rear derailleur?

Rear derailleur Total capacity



It is the maximum amount of chain slack a derailleur can take up or let out, expressed in a number of sprocket teeth. Exceed the total capacity, and your chain will likely be too long or too short for some combinations of gears.

Do I need a new derailleur if I get a bigger cassette?

Derailleur Adjustments



When putting a big cassette, the derailleur jockey wheel it may not be able to be under that big cogs, therefore the shift can’t be made. For that, it requires to use a specific rear derailleur compatible with these big ratios and this can be expensive upgrade.

Can you use a 12 speed derailleur on 11 speed cassette?

So there you go folks, there is no difference in indexing spacing between 11 and 12 speed, the difference is all at the derailleur end. So you can’t use a 12 speed derailleur on an 11 speed setup or vice versa but you can you an xtr 12/11 speed shifter on an 11 speed drivetrain.

Do all derailleurs fit all hangers?

There are thousands derailleur hanger types (designs) on the market. Every frame manufacturer could have different sos hanger design for each model of frame and different sos hanger for same frame but manufactured on different year.

What is the difference between a medium and long cage derailleur?

Quote from video: And it houses these two jockey wheels on a short caged derailleur like this one the jockey wheels will be quite close together and then a longer cage one they'll be much further apart.

Can you use any derailleur?

A derailleur for your mountain bike should match the specifications on the original derailleur. That is, while it doesn’t need to be the same model of derailleur, it does need to be the same brand, in almost every case. It also needs to match the number of gears, or have more intended.

Do shifters and derailleurs have to match?

If all the parts are new, then ignore all that stuff. The shifters and derailleurs need to match. Front: Sram and Shimano work with eachother on the front derailleur.

How do I tell what Shimano derailleur I have?

Quote from video: So they have part numbers to show the difference. This is a front derailleur. Sometimes are hard to find usually I think it's on this plate. But I don't see one on this one it is kind of a older.

Can I use a 7 speed derailleur on an 8 speed cassette?

yes it will work.

Which cassette ratio is best for climbing?

For hill climbing and mountainous terrain, we recommend a road cassette such as the 11-32T SRAM Red 22 XG1190 11 Speed Cassette (A2), or the 11-34T Shimano Ultegra R8000 11 Speed Cassette.

What gear ratio is best for climbing?

The best mountain bike gear ratio for climbing is 46 to 49 on a chainring and 16 to 18 on a cassette. For more diverse rides, mountain bike gears of ratios 46/17 to 42/17 are what work for flatter terrain or occasional hills. However, with that being said, the perfect ratio usually depends on the terrain you’re riding.

What does an 11 32 cassette mean on a bike?

Quote from video:

How do I know which Shimano rear derailleur?

Shimano stamps the rear derailleur model number on the underside/lower plate of the parallelogram.

Can I use a 7 speed derailleur on an 8 speed cassette?

yes it will work.

Can I use a 9 speed derailleur on a 7 speed cassette?

Can I use a 9-speed derailleur on a 7-speed cassette? The answer is yes because the rear shift ratio of 9-speed and 7-speed derailleurs is the same if you stay within the same brand.

Will a 9 speed derailleur work on a 10-speed cassette?

MORGAN @ SRAM: For the rear, no. The cable pull is different for the 10-speed rear derailleurs and the 9-speed rear derailleurs won’t line up properly with the cogs when used with a 10-speed shifter and cassette.

Can you use a 11-speed rear derailleur on a 10 speed cassette?

Can An 11-speed Derailleur Work With a 10-speed Cassette and Shifter? Condensed Answer: Shimano’s 11-speed derailleurs have a different rear shift ratio than 10-speed derailleurs and are therefore not compatible with 10-speed indexed shifters.

Can I use 10 speed rd to 9 speed cogs?

Condensed Answer: 10-speed Shimano and SRAM MTB derailleurs have a different rear shift ratio than 9-speed derailleurs and cannot be effectively combined with a 9-speed shifter and cassette.