# 8-speed to 9-speed conversion question



## robselina (Nov 1, 2008)

Sorry if this had been covered before. I did a quick search, but maybe I'm not using the best terms since I came up empty handed. 

I have an '03 Giant Rincon with a Shimano Alivio rear derailleur and Acera front derailleur. It has 13-30T 8-speed Shimano cassette. It may also be pertinent to note that I run 22/32/42T front chainrings. 

I want some lower/taller climbing gears. Most of the guys I ride with have a 22T front chainring and a 34T gear on the cassette. 

What would it take to fit an 11-34T cassette on my bike? From what I can tell, 8-speed cassettes only go to a 32T cog. The 9-speed cassettes have the 34T option. 

I know I would need a new chain and 9-speed shifter to work with the 9-speed cassette, but would my existing rear derailleur work? Can I get away with just upgrading the cassette, chain and shifters? Anything else required?

Thanks,

Rob


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## Adirondack Blues (Mar 4, 2004)

robselina said:


> Sorry if this had been covered before. I did a quick search, but maybe I'm not using the best terms since I came up empty handed.
> 
> I have an '03 Giant Rincon with a Shimano Alivio rear derailleur and Acera front derailleur. It has 13-30T 8-speed Shimano cassette. It may also be pertinent to note that I run 22/32/42T front chainrings.
> 
> ...


Your existing rear derailleur should work for 9 speed. The shifter is what limits the cable pull- not the derailleur. Another option for lower gearing would be to replace your front chainring (middle or small) with a smaller one to get a lower gear.

The best solution would be to take all shifters and gears off the bike and convert to singlspeed! Then you'll learn to out climb your buddys for sure!


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## robselina (Nov 1, 2008)

Adirondack Blues said:


> Your existing rear derailleur should work for 9 speed. The shifter is what limits the cable pull- not the derailleur. Another option for lower gearing would be to replace your front chainring (middle or small) with a smaller one to get a lower gear.


Thanks! Wasn't sure if the cogs were thinner on a 9-speed or something like that.



Adirondack Blues said:


> The best solution would be to take all shifters and gears off the bike and convert to singlspeed! Then you'll learn to out climb your buddys for sure!


I'm nowhere near manly enough to punish myself on a single speed. I like gears! :thumbsup:


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## 2WheelMark (Aug 3, 2008)

+1 for the single speed. I will bet a six pack that you like shopping for the latest shiny bike thingy more than you think you need the new gears. I was there once too, then I saw the light, or whatever medefore you wish to insert, SS is the way to go, ouce you learn to climb properly on a SS you can get back on the gears and really fly. 

You 8 speed should be fine unless parts are worn out. but to upgrade to 9 for no reason other than to get a 34, I am positive that I have had 34 in 8 sp, and 7 sp before. Look around Im sure you can find one.


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## ljsmith (Oct 26, 2007)

Doing an 8 to 9 speed conversion can be done 2 ways.

The correct way is to replace the front derailler, cassette, chain, chain rings and the shifters. This can be rather expensive, but it will give better shifting than doing it the other way.

The "other way" is just to buy shifters, chain and a cassette. This will work, but the shifting most likely will be troublesome and hard to tune. 9 speed systems use a thinner chain, so the 8 speed front derailler is not going to shift as well. You can also use the 8 speed chain rings, but the teeth will be a little wider and the chain won't shift off it or on it as smoothly.

In my opinion, if you are going to do it, do it the right way. I would much rather have a sweet shifting 8 speed system than an okay shifting 9 speed system. But you need to ask yourself if the extra gear is worth spending that much? I think in most cases the answer is no. You would be better off getting an 8 speed cassette like this http://www.universalcycles.com/shopping/product_details.php?id=12016&category=42


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## supersonic (May 6, 2004)

Some chainsets used on 8 speed bikes are actually already 9 speed! Quite common now on budget bikes (truvativ just list them as 8/9 speed compatible).

What is the old mech? Check the maximum rear cog size. Some Can't handle the 34t cog. I'd certainly just get the megarange cassette though if compatible.


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## Slimpee (Oct 3, 2007)

I wouldn't screw w/ it 'fi were you. Either get a new bike or learn to climb w/ what you have already.

If you really want lower gear replace the chainring...


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## supersonic (May 6, 2004)

22t is as low as you can go. 22/34 can be very useful - is here at Wharncliffe in the UK, some of the climbs are horrific. Singlespeed around here you have no chance.


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## digitaldelights (Nov 3, 2008)

*The Cost*

The big question is How much do you want to spend?
This will determine the path.


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## rdhood (Jul 30, 2008)

Been there, done that with people telling me what I MUST have to shift.



> Some chainsets used on 8 speed bikes are actually already 9 speed! Quite common now on budget bikes (truvativ just list them as 8/9 speed compatible).
> 
> What is the old mech? Check the maximum rear cog size. Some Can't handle the 34t cog. I'd certainly just get the megarange cassette though if compatible.


+1

Bottom line is change the shifter, cassette. Be prepared to change chain.See how you like it. I'm guessing it will shift perfectly and you will be done. I would bet that the front will still shift perfectly, and that your rear derailleur handles 9 speed just fine.

I sometimes wonder if people who tell you you have to do the whole shebang have actually ever tried parts/pieces. Have they actually ever tried an 8 speed rear derailleur on 9 speed? have they actually ever tried an "8 speed" chain on a 9 speed system or a "9 speed" chain on an "8 speed" crankset?

And folks... the guy asked about 8 speed to 9 speed conversion. Did he say anything about single speed? (NO). Then why make like a parrot and yap single speed at him? It just pollutes the topic.


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## robselina (Nov 1, 2008)

Thanks for the input guys. 

ljsmith: That "megarange" shimano cassette may be the quick route in all this. Thanks for the link! I hadn't had any luck finding a larger cassette to use with my existing drivetrain. That cassette and a new chain is a fairly cheap upgrade. 

I'm debating if making any change makes sense, but wanted to see if I had the details right. For example, I hadn't thought about there being any differences in the front derailleur cage. 

Right now, I get a good work out between my smaller cassette cog options and the fact that this bike is a pig of a hardtail at 37lbs. 

Having not done much with the bike for the last 4 years or so, I started to ride a lot this year. Did a few of the usual changes for fit/use such as a saddle that fits me right, better tires and a shorter stem. The original RST front fork bit the dust rather fast too after the internal friction damper doodad disintegrated. I'm running a Marzocchi XM LO 100mm fork now. Also picked up the usual assortment of trail supplies/tools. 

Anyway, for the most part I'm just enjoying riding, but I do have a techy side that gets into the equipment. I was debating doing piecemeal upgrades as things broke or bugged me and eventually getting a better frame vs. riding it as-is until something big fails and then getting something better. (One of the things lingering in the back of my mind is that I know my hubs had some surface rust and pitting when they were serviced two months ago for example, so I'm not sure how much life they have left in them...)

I'm inclined to think that the 8-speed cassette and chain may make sense when the existing chain wears out (I think it still has a couple hundred miles in it). Probably doesn't make sense to do the 9-speed conversion since that would probably be a slippery slope 

Thanks again for the input. 

Rob


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## supersonic (May 6, 2004)

You will need a nrew 8 speed chain anyway for two reasons: if the old one is worn it will not take very well to the new cassette, and the old one is shorter. If you change into your new 34t cog but are in the 42t chainring, you'll rip the mech off! Always best to measure the chain so it clears the combo, or be very careful shifting (you shouldn't use this combo anyway).


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## donalson (Apr 13, 2004)

19$ but thats a BIG jump between the last 2 gears...
http://www.jensonusa.com/store/product/CS309B00-Shimano+Hg40+8-Speed.aspx


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## Graza (Dec 4, 2008)

Hey. I've worn my 8 speed chain and cassette out. I've been thinking of upgrading to 9 speed. I know wat i need. However i have some questions?
1. Can any 9 speed cassette fit onto my hub body?

2. Can i mix SRAM and Shimano, as i'm price concious? 

3. I've found nicely priced new SRAM X5 shifters, and i already have a Deore rear mech. in good condition, are these compatible?

4. Do i need to replace my front derailluer, which changes a 8 speed chain finely on 9 speed front chainrings

Would much appreciate an answer, Thanks Graham


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## adam728 (Jan 25, 2006)

donalson said:


> 19$ but thats a BIG jump between the last 2 gears...
> http://www.jensonusa.com/store/product/CS309B00-Shimano+Hg40+8-Speed.aspx


I ran that exact cassette for a while on my old Trek when I went to a 1-8 drivetrain. Never had an issue shifting up to the largest cog. I've since switched back to stock because it's now my "around town" bike and I have no need for a 34T cog.

Heck, my girlfriend's first Trek has a 7 speed cassette with a 34.


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## bcaronongan (Nov 8, 2006)

Graza said:


> Hey. I've worn my 8 speed chain and cassette out. I've been thinking of upgrading to 9 speed. I know wat i need. However i have some questions?
> 1. Can any 9 speed cassette fit onto my hub body?
> 
> 2. Can i mix SRAM and Shimano, as i'm price concious?
> ...


1. i'm not 100% sure if hubs are compatible with 8 or 9 speed cassettes
2. you cannot use sram shifters with shimano rear derailleurs using lx, xt, xtr components with x5, x7, x9, x0; i don't know about the lower end stuff if they arecompatible.
3. that combo will not work
4. you do not need to change the front derailleur.


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## robselina (Nov 1, 2008)

FWIW, I wore out the chain, two chain rings and cassette a few months back and ended up just replacing everything with 8-speed replacement parts. I did get a 32T cassette to replace the 30T that was on there, but that's good enough for me on this bike.


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## donalson (Apr 13, 2004)

> 1. Can any 9 speed cassette fit onto my hub body?


yes... as will a 10spd cassette... or a 7spd cassette (but that requires a 4.5mm spacer)



> 2. Can i mix SRAM and Shimano, as i'm price concious?


yes and no... the only non sram/shimano compatable parts are the rear shifter and rear derailleur... if you use a sram specific shifter you must use their rear D (although sram does sell shifters that work with shimano)... if you have a shimano shifter you must use a shimano rear D... up front it doesn't matter... cranks, cassettes, and chains are all compatable with each other



> 3. I've found nicely priced new SRAM X5 shifters, and i already have a Deore rear mech. in good condition, are these compatible?


no you would need a sram rear D to work with the x5 shifter (which works very well in my experience)



> 4. Do i need to replace my front derailluer, which changes a 8 speed chain finely on 9 speed front chainrings


nope... you're good to go up front... although you will hear others say otherwise from time to time

so in short...
you must use matching shifters to what rear D you are using... beyond that it doesn't matter...

and you must use a chain sized for the rear cassette (6,7,8spd/9spd/10spd)

note 10spd is realy just a roadie thing still (thankfully) outside of sram X$X$ racing grouppo


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