How do I upgrade my 8-speed cogset to a 9-speed on my mountain bike?

Question

I've heard that the 8-speed hub can hold a 9 speed cassette as well. Would that mean that all I need to do to changeover my bike to be a 27-speed from a 24-speed is: (1) replace the cassette, (2) replace the chain, (3) replace the shifters??

Seems too simple. What am I missing?

I should add that the rear derailleur I'm currently using is for 8/9 speed (supposedly). Also, I'm happy with my current frame (pretty high end), and can't really afford to go buying a new bike. My motivation for wanting to upgrade is that replacement parts (shifters/cogs/derailleurs, etc..) seem more available in 9 speed these days.

Answer 1

Yes you can you already have the answers except that your going to need to upgrade to a 9 speed derailleur for optimal performance some 8 speed derailleurs can be made to work but its best to just go with the 9 spd derailleur. Reading some of the other answers makes me wonder if any of these guys has actual experience in short if you don't know what your talking about don't answer the question, the cassette body on 8 speed it the same as a 9. The shifters have to be changed the cog set has to be changed and if the chain was new enough it would work but if your replacing the cog set i would go with a new one go with a SRAM chain its worth it.

Answer 2

It is important to understand that you won't be able to go any faster on a 27 gear bike than you can on a 24 gear bike. What the extra gears give you is the ability to transition more smoothly over terrain and speed so you can keep your cadence (pedal rpm) constant- the whole reason behind multiple gears.

Note that I avoided the use of the term "speeds" when talking about this. Speed has nothing to do with the gear ratios on a bike... it is all about the rider. Additionally, you won't be able to use all 27 gears (or your current 24 for that matter) since you should never use the 2 "big sprockets" or 2 "small sprockets" as combinations because of the chain offset and also the length of the chain.

It is true that it is mechanically possible to change from an 8 gear rear to a 9 gear by switching cassette, rear axle (sometimes), rear derailleur, chain, frame spacing (maybe), shifters, and possibly the chainrings (front sprockets) but at this point unless you have a good cache of parts already you could likely buy a new bike for less money.

Should you decide to go ahead and try this anyway, be absolutely certain that the new shifters are compatible with your rear derailleur, that your rear derailleur can be used as for a 9, and that the narrower chain is compatible with your chainrings. I think the Shimano and SRAM websites have the tech information for that, but if you have components other than those it is a tricky situation unless you physically check compatibility.

Good Luck!

Answer 3

I don't know if you need to replace the rear hub, but I think that probably you're okay with that. You would need to replace the rear deraileur, shifters, chain and cassette. Probably not worth it.

But you know something? You're probably better running 8 speed vs 9 speed. The 8 speed chain is stronger, you have less chances of ghost shifting.

If you want to improve your shifting performance, make sure that your deraileurs are well adjusted and tuned in right. Maybe search for a cassette that has 32 or 34 tooth rather than 28 or 30 to make it easier on the climbs.

Answer 4

Also remember that the stronger you get, the easier it will be to use the gears you have. I have an 8 speed rear cog. It kills at the beginning of the season when I'm weak and can't keep my speed up. Now that I've been biking hard for 3 months the extra cog wouldn't help that much.

You have to ask yourself if it is worth a couple hundred dollars to upgrade your bike.

For me the answer was to keep using what I have for a couple more years and replace with a high end bike when parts start to fail.

Another option would be to stick with 8 gears, but replace the cassettes or chainrings to get more favorable gear ratios.

Answer 5

Your analysis is too simple. Unless you're really attached to your bike, consider getting a new one. You 'can' replace an 8-gear cassette with a 9-gear, but you'll have to change the chain (which you've already noted) and the rear derailleur. It'd be easier to buy a newly built rear wheel assembly, but you'd still have to change the derailleur and chain. Unless the shifters are indexed, you shouldn't have to replace them. But you might as well if you're changing out the cassette.

Again, you might consider just getting a new bike.

Answer 6

Well I'm not going to get involved in an argument other than to say what you want to do can be done and it's not as simple as everyone makes it sound.
Two things thing you have to determine before you even start, one is my hub-set I'm using now compatible with a 9 speed cassette and I'm betting the answer is probably no. two is my bike frame compatible with a 9 speed hub-set and cassette again I'm betting most likely not.

So unless your bike is a steel frame or you just don't like your bike I wouldn't even consider stretching the frame because Aluminum and Carbon don't stretch well, infact they crack, been there, done that.

Seen to many people try to turn something they have into something else they wish they had and all it does is cost them a ton of money, Just buy another bike and save yourself the trouble.

Answer 7

I accept as true with the different posts that this possibly isn't worth doing, yet i prefer to characteristic a pair factors. a million) If that's a greater moderen bike with 7 cogs, that's unquestionably decrease end; however the physique spacing might enable for 9-velocity. The rear hub won't, despite the fact that if. 2) If it extremely is an older bike with 7-velocity, it possibly has narrower hub spacing interior the rear, meaning a 9-velocity hub won't honestly greater healthful. A metallic physique can likely be changed to settle for the wider hub, yet a save ought to try this, as there's a hazard of throwing the physique out of alignment attempting this one at domicile. 3) In the two case, no person pronounced that the chainrings ought to additionally be replaced. A 9-velocity chain is narrower than a 6- to eight-velocity chain, and could self-destruct below load if used on non-9-velocity chainrings. it ought to seem to artwork on assembly, yet will finally fail (have faith me!). So...it ought to be a competent thought to save for a 7-velocity cassette/freewheel with a numerically extreme greatest cog, as that's what's going to make a distinction in mountain climbing. 34-the tooth is in lots of cases the main important you will locate on a 9-velocity cassette, and 32-the tooth is in lots of cases the main important on those with fewer gears - makes a distinction, despite the fact that if it extremely is not any night-and-day.

Answer 8

Get a new bike. Yours is probably engineered for the set-up you have on it. Ask at a GOOD bikeshop.

Answer 9

it's just that simple!! don't know why some of the answers are so long winded