Drivechain conversion from 12 to 9 speed

[jimzenglish]

Hey there, I'm new to the forum and ride my Rocky Mountain Powerplay in New Zealand. We have steep and rough terrain but I never use the top two gears of my bike so am looking to convert the Shimano drivechain from 12 to 9 speed.
Benefits of this will be a more durable chain and much cheaper replacement parts with wear.
Just wondering if anyone else has done this their thoughts?

 

[Loe Rider]

I went for the Box Prime 9 setup but that also has a wide range so not quite the same reason as you. On paper it looked a great idea and I only binned it when my mech lost an argument with a tree (not impressed with the pivot wear but that's another story....). Chain durability seemed a little better than my 11 speed but not massively so. But my 11 speed is definitely wearing less than the 12 speed guys I ride with and I can buy a full drive train for about half of their cassette cost so that's why I am now sticking with 11 speed.

 

[ottoshape]

I went to the Shimano 10 spd from the SRAM 12 spd. The low-low SRAM was just eating too much debris and self-destructing way too often.

 

[bsquared]

I went for the Box Prime 9 setup but that also has a wide range so not quite the same reason as you. On paper it looked a great idea and I only binned it when my mech lost an argument with a tree (not impressed with the pivot wear but that's another story....). Chain durability seemed a little better than my 11 speed but not massively so. But my 11 speed is definitely wearing less than the 12 speed guys I ride with and I can buy a full drive train for about half of their cassette cost so that's why I am now sticking with 11 speed.

I also did this and love it! I really liked the single click up and down rather than the multiple click option.

 

[jimzenglish]

Thanks looking at previous forums either 9 or 10 spd would be the way to go. I'd be happy with either, which ever is most cost effective and compatible. I'd replace shifter, chain, rear cassette and derailleur. I would have to check if need to also change front sprocket and rear freehub. Then go with whichever was the simplest option.

 

[Gary]

If you want cost effectiveness don't make the mistake of simply choosing your drivetrain based solely on price
High quality 9 speed shifters are now quite rare and a higher quality shifter makes a lot more difference to shifting than you might think.
Single shift levers are really not required unless you're a beginner or can't trust yourself not to double shift by mistake under load. Multiple shifting isn't actually any more harmful than single shifting repeatedly and doesn't cause any more cassette/chain wear so long as you don't perform it under load
There's also not a great deal of choice for clutched 9 speed mechs. The clutch in a rear mech's pivot doesn't just increase chain retention. it also helps stop chainsuck. and chain suck with a motor that keeps turning when your chain is jammed between your chairing and lower chainstay more than sucks. The flip side of clutched mechs is that the jockey wheels tend to wear out a little quicker but most are cheap to replace (I'm not looking at you tho SRAM )
Shimano 9 and 10 speed cassettes are more durable than other brands and have the same shifting ramp technology no matter how low down shimano's groupset heirachy you choose to go. as pricing increases finish, construction and weight is what the extra price is paying for.

 

[bsquared]

Ohhh opinions….
30 year “beginner” here. Sorry. I didn’t go into the medical reasons why the single click works well. But I will. Nerve damage in the right pointer and I don’t feel the end of it. So can’t really shift well when you can’t feel. So, I shift with my thumb only. Because, you know, I can feel it.

 

[Gary]

Nah. Not opinions. Facts.
Plenty thumb only multi shift shifters are available. Shimano even do shifters with a one way multi shift thumb paddle (for shifting to the larger sprockets) with the other lever/paddle dual direction and operated by either pushing or pulling, using your finger or thumb.

Single shift levers are really not required unless you're a beginner or can't trust yourself not to double shift by mistake under load.

I think you'll probably agree your nerve damage put s you more in the highlighted category than the beginner category

 

[04fuxake]

Thanks looking at previous forums either 9 or 10 spd would be the way to go. I'd be happy with either, which ever is most cost effective and compatible. I'd replace shifter, chain, rear cassette and derailleur. I would have to check if need to also change front sprocket and rear freehub. Then go with whichever was the simplest option.

T7 and Evo are selling 9-speed SRAM X5 for pretty cheap.

 

[boBE]

I went from 12 speed (Eagle NX on Levo SL) to 11 speed mainly to get a close-ratio cog set (11-50 to 11-32). It required a new shifter, derailleur, and cassette. Since the 11-32 is a road cassette it also required trimming 1.85 mm off the mounting surface of the cassette but by staying with a MTB cassette you won't have that problem.

 

[jimzenglish]

If you want cost effectiveness don't make the mistake of simply choosing your drivetrain based solely on price
High quality 9 speed shifters are now quite rare and a higher quality shifter makes a lot more difference to shifting than you might think.
Single shift levers are really not required unless you're a beginner or can't trust yourself not to double shift by mistake under load. Multiple shifting isn't actually any more harmful than single shifting repeatedly and doesn't cause any more cassette/chain wear so long as you don't perform it under load
There's also not a great deal of choice for clutched 9 speed mechs. The clutch in a rear mech's pivot doesn't just increase chain retention. it also helps stop chainsuck. and chain suck with a motor that keeps turning when your chain is jammed between your chairing and lower chainstay more than sucks. The flip side of clutched mechs is that the jockey wheels tend to wear out a little quicker but most are cheap to replace (I'm not looking at you tho SRAM )
Shimano 9 and 10 speed cassettes are more durable than other brands and have the same shifting ramp technology no matter how low down shimano's groupset heirachy you choose to go. as pricing increases finish, construction and weight is what the extra price is paying for.

Thanks Gary good quality info, maybe a 10 speed setup might be the best option. And yeah a clutch 10 speed mech to go with it. Going from 12 spd Shimano to 10 spd do you think I'd need to change the rear freehub or is it compatible on Shimano setups.

 

[Gary]

10 speed needs a HG Freehub body.

If you have a 10t sprocket your 12 speed Freehub body will be XD or microspline.

 

[BrentD]

T7 and Evo are selling 9-speed SRAM X5 for pretty cheap.

X5 = no clutch unfortunately.

 

[Zagora]

Before buying my current bike I rode several different models before settling on a Merida E160.
One of the best bikes I rode was a Mondraker, think it was a Level RR, about a 2018/2019 model.
I'm sure it had either eight or nine gears which initially concerned me but actually It rode very well with no issues with changing gears or gaps between ratios. It had the older Bosch motor.

 

[04fuxake]

Thanks Gary good quality info, maybe a 10 speed setup might be the best option. And yeah a clutch 10 speed mech to go with it. Going from 12 spd Shimano to 10 spd do you think I'd need to change the rear freehub or is it compatible on Shimano setups.

Microshift Advent X gets good reports from the interwebs. And we can get it from Aus.

https://www.mtbdirect.com.au/search?keywords=microshift

 

[Dan63]

I also did this and love it! I really liked the single click up and down rather than the multiple click option.

Why would less features be a benefit?

You know you can still click the shift levers... only once... on any type of shifter?

 

[Gary]

Reading ability is quite a handy feature. Especially if employed before typing a question which has already been answered.

 

[Choc3]

I guess cadence is important?

.

 

[Savan]

Did you consider keeping your 12 speed so that you actually have a better chain line in the gears that you actually do use? If you go to 9 you’ll save a little weight but you’ll be cross chained more of the time.

 

[Savan]

That said I run the micro shift 11/46 on my analog bike and it suits me just fine. 250 mile bike packing trip last year right after installing and not a hitch.

 

[1oldfart]

My Ebike has 29x2.6 tires. It was sold with a 10S Deore 36 front, 11/46.
It is like a 9 S. I never use the 11 so it gives me a cassette of 13/46 wich is great.
I only need 8 shifts to cover my whole range.
I just ordered a chain to be ready only 22$US.
I will get a cassette when i find one but it is sure lighter than an 11 and a 12 S and
more affordable.
So from my experience a 9 or a 10S is what should be on most mountain Ebikes.

 

[Manc44]

Using XTR 9-Speed (M970) and 11-Speed (M9000) shifters, the 11s shifted better.

 

[Gary]

I guess cadence is important?

it is.
but the quite clearly light, physically fit looking guy in the video contradicts his own "theory" throughout his video footage.

You'll climb EVERYTHING faster on an Eeb so no. you don't need as low gearing. unless of course you purposely hunt out previously unclimbable climbs.
Personally I haven't climbed anything in 4 years of having Emtbs that couldn't be climbed on a normal bike but if you're the sort of rider who struggles to ride up the sort of inclines fitter riders on normal bikes can a wider range cassette is going to help you more. It doesn't have to be 12 speed though. 11 speed with an 11t smallest sprocket would offer you almost the same range just losing out a little at the top end from not having the STUPID 10t sprocket at a fraction of the cost of a 12 speed cassette.

 

[Manc44]

Before I had a motor: 48-36-22 chainset with 11-40t cassette (11-Speed).
Now with a 500W motor: 48-36-24 chainset with 13-23t cassette (9-Speed).

It's a luxury to have a run of sprockets going 13-14-15-16-17-18-19t

The lowest gear I have now is 24x23 and it's just about perfect with this motor.

 

[1oldfart]

Here in Quebec, Canada i am on snow 4 months. The reason i need a granny gear is to keep traction.
I can climb just about anywhere on medium or more assist without my tiny gear on some good days.
Some days i need to lower the assist and use my 46 teeth to avoid spinning my wheel. So my 10S
11/46 is nice with a 36 front for my 29 wheels. I could also when the time comes put a 32 front and
put an 11/42 rear.