6 speed wide range cassette?

[Private Repress]

Hi all, 

I’m contemplating adding some much needed gear range to my giant ‘do it all’ STP.

I’ve been riding it a fair bit recently and it’s a surprising capable trials bike, but I’d like to get it to a true all rounder (maybe hitting some trails or the odd easy going bike ride here and there, but with the ability to still be a trials bike). The gear range simply doesn’t allow for that! 

So up front I’m thinking of dropping the 22t chain ring and replacing with 32t narrow wide chain ring and bash guard.

Here’s where it gets interesting… At the back I’m currently running a Frankenstein cassette consisting of 6 gears, which sit on a Hope Pro2 trials hub which only allows for said 6 gears. I’d like to run a wide range cassette, largest cog at 42t, down to the smallest which is 11. 
 

The shifter is shot, so that needs replacing - so here are my questions 

1. Does anyone know of any wide range cassettes that can be split down to individual rings?

2. I appreciate the shifting ramps on the cassette are not designed to make large jumps between cogs, but let’s say I buy a 10spd cassette and remove a few mid range cogs, could it work (?) albeit not as smooth as intended.

3. To prevent the chain dropping I think a derailleur with a clutch will be the cleanest way, but is a long cage variant necessary to handle the larger cogs?

4. As mentioned, the shifter is dead and I think a clutch derailleur is needed, so if I’m replacing the shifter and derailleur, would there be any benefit of going 9, 10 or even 11 speed? I think 10 personally as I can’t seem to find a cassette with a 42t cog (let alone one that can be split!). 

Keen to get some views on this (ironic I’m asking for advice on gears on a forum where almost every bike is single speed!).
 

 

 

Edited May 12, 2022 by Private Repress
Typo

[AdamR28]

Yeah, you can chop a cassette apart. Usually involves grinding the heads off the 3 pins that hole them together.

Shifting won't be great if you have huge jumps, but it will work.

Definitely go clutch, each of the mechs should have a range value listed.

I'd buy whatever you can find at the moment!

@Maintenance Justice to the forum please.....

[monkeyseemonkeydo]

You might also need to use longer limit screws on the mech to keep things in range but no reason it won't work. Can you stick a mahusive dropper post in there too to give you the option to be able to sit and pedal?

In terms of speeds if you're only going to use 6 I'd find something that uses the chunkiest chain you can while still having a clutch...

[Maintenance Justice]

2 hours ago, AdamR28 said:

@Maintenance Justice to the forum please.....

Cue Flight of the Valkyries music....

 

10 hours ago, Private Repress said:

 

1. Does anyone know of any wide range cassettes that can be split down to individual rings?

2. I appreciate the shifting ramps on the cassette are not designed to make large jumps between cogs, but let’s say I buy a 10spd cassette and remove a few mid range cogs, could it work (?) albeit not as smooth as intended.

3. To prevent the chain dropping I think a derailleur with a clutch will be the cleanest way, but is a long cage variant necessary to handle the larger cogs?

4. As mentioned, the shifter is dead and I think a clutch derailleur is needed, so if I’m replacing the shifter and derailleur, would there be any benefit of going 9, 10 or even 11 speed? I think 10 personally as I can’t seem to find a cassette with a 42t cog (let alone one that can be split!). 

Keen to get some views on this (ironic I’m asking for advice on gears on a forum where almost every bike is single speed!).
 

 

 

So I have chopped down cassettes and it does work well with a few caveats.

1 - You're going to struggle here with the range you are proposing. The jumps between sprockets will be enormous removing every other sprocket, so shifting won't be ideal. It'll probably work, but be a bit lumpy. As a rule for bikes with derailleurs up front a 16t gap is generally the maximum between chain rings, however chain rings are ramped, pinned and shaped specifically to allow shifting across this range. Cassette sprockets are not, they're suited to shifting with about a 5 tooth difference at best going into the lowest gear (the biggest sprocket) and about 2-3 tooth difference between the mid to high range (smaller sprockets). Also, the lockring of the cassette is a limiting factor, it doesn't get a great purchase on sprockets any bigger than 13t. I've had the best results by ditching the bottom two sprockets and or top cluster, so there are even jumps in the mid-range and the high gear sprocket is small enough for the lockring to get purchase. On my example, it's a Deore 10 CS-HG50 speed 11-36 cassette with the top two low and bottom 11t high sprockets removed (7spd!!). You'll notice that the bottom two high gear sprockets on most of these type of cassettes have their own in built spacer - not using these means trying to space the cassette out with only the plastic spacers they are supplied with, and in my experience it never quite works to get the overlap of the free hub body required to tighten the cassette.

As Adam says you can split a cassette that is pinned, but my preference is a higher end cassette such as XT, SLX or any of the better SRAM cassettes as they contain more individual sprockets / clusters but it's getting hold them that's the issue!

2 - I used a Shimano Zee M640 10 Spd Clutch rear mech with the 'DH' hanger meaning it's rated up to 28T (they are available with a 'Freeride hanger rated up to 36t, but there are like hens teeth to find) which is ideal as that is the size of the lowest gear. These mechs work really well for this as they're designed for DH style cassette spacing, which is essentially what this conversion / bodge is in relation to chain line when using a single speed hub. An VERY important note here:

Because the cassette is sitting closer to the mech, there is less clearance between the chain and derailleur. I found trying to fit the cassette with the two big sprockets meant that as the derailleur swung across, it actually trapped the chain. I therefore opted for a smaller climbing gear and tighter ratio, which worked without issue. I suspect you'll come across the same problem using a wide range cassette. Derailleur hanger extensions are available from companies like Wolftooth which will give more clearance, but your mech will sit lower to the ground and be more susceptible to misalignment

3 - 10 Speed is the way to go in my opinion, the cassettes give enough range and are about right in terms of sprocket spacing to butcher. I've not tried this with 11 or 12 speed.

4 - Lastly, running a single chain ring on the front with an already limited range on the rear means a sacrifice in terms of gearing. 32t is a nice middle ground on a 26" MTB at least. On mine the 28t rear gives a 'good' enough climbing gear and the 13t high gear is enough for trail riding if you don't mind cruising a bit when speed takes over. This ratio of 13-28  / 32 gives some useable trials gears too. I do run a front mech because I want the range and I prefer the ratios that a 22t sprocket gives you for general MTB use but I also have lots of leg bruises from shifters whilst trialing the thing!

 

 

 

.

 

 

[Private Repress]

On 5/13/2022 at 8:30 AM, AdamR28 said:

Yeah, you can chop a cassette apart. Usually involves grinding the heads off the 3 pins that hole them together.

Shifting won't be great if you have huge jumps, but it will work.

Definitely go clutch, each of the mechs should have a range value listed.

I'd buy whatever you can find at the moment!

@Maintenance Justice to the forum please.....

Thanks Adam, figured I could split a cassette down as the mats what I’ve done with what’s currently on the bike. Clutch is definitely on the cards the cards then!

[Private Repress]

On 5/13/2022 at 10:53 AM, monkeyseemonkeydo said:

You might also need to use longer limit screws on the mech to keep things in range but no reason it won't work. Can you stick a mahusive dropper post in there too to give you the option to be able to sit and pedal?

In terms of speeds if you're only going to use 6 I'd find something that uses the chunkiest chain you can while still having a clutch...

I have been considering a dropper post, I run a 170mm dropper on my enduro bike, even at that length though (which is long) it wouldn’t be enough to get up to optimum riding height if at the lowest point in the clamp. It’s does have a lovely Thompson seat post mind

[Private Repress]

On 5/13/2022 at 11:19 AM, Maintenance Justice said:

Cue Flight of the Valkyries music....

 

So I have chopped down cassettes and it does work well with a few caveats.

1 - You're going to struggle here with the range you are proposing. The jumps between sprockets will be enormous removing every other sprocket, so shifting won't be ideal. It'll probably work, but be a bit lumpy. As a rule for bikes with derailleurs up front a 16t gap is generally the maximum between chain rings, however chain rings are ramped, pinned and shaped specifically to allow shifting across this range. Cassette sprockets are not, they're suited to shifting with about a 5 tooth difference at best going into the lowest gear (the biggest sprocket) and about 2-3 tooth difference between the mid to high range (smaller sprockets). Also, the lockring of the cassette is a limiting factor, it doesn't get a great purchase on sprockets any bigger than 13t. I've had the best results by ditching the bottom two sprockets and or top cluster, so there are even jumps in the mid-range and the high gear sprocket is small enough for the lockring to get purchase. On my example, it's a Deore 10 CS-HG50 speed 11-36 cassette with the top two low and bottom 11t high sprockets removed (7spd!!). You'll notice that the bottom two high gear sprockets on most of these type of cassettes have their own in built spacer - not using these means trying to space the cassette out with only the plastic spacers they are supplied with, and in my experience it never quite works to get the overlap of the free hub body required to tighten the cassette.

As Adam says you can split a cassette that is pinned, but my preference is a higher end cassette such as XT, SLX or any of the better SRAM cassettes as they contain more individual sprockets / clusters but it's getting hold them that's the issue!

2 - I used a Shimano Zee M640 10 Spd Clutch rear mech with the 'DH' hanger meaning it's rated up to 28T (they are available with a 'Freeride hanger rated up to 36t, but there are like hens teeth to find) which is ideal as that is the size of the lowest gear. These mechs work really well for this as they're designed for DH style cassette spacing, which is essentially what this conversion / bodge is in relation to chain line when using a single speed hub. An VERY important note here:

Because the cassette is sitting closer to the mech, there is less clearance between the chain and derailleur. I found trying to fit the cassette with the two big sprockets meant that as the derailleur swung across, it actually trapped the chain. I therefore opted for a smaller climbing gear and tighter ratio, which worked without issue. I suspect you'll come across the same problem using a wide range cassette. Derailleur hanger extensions are available from companies like Wolftooth which will give more clearance, but your mech will sit lower to the ground and be more susceptible to misalignment

3 - 10 Speed is the way to go in my opinion, the cassettes give enough range and are about right in terms of sprocket spacing to butcher. I've not tried this with 11 or 12 speed.

4 - Lastly, running a single chain ring on the front with an already limited range on the rear means a sacrifice in terms of gearing. 32t is a nice middle ground on a 26" MTB at least. On mine the 28t rear gives a 'good' enough climbing gear and the 13t high gear is enough for trail riding if you don't mind cruising a bit when speed takes over. This ratio of 13-28  / 32 gives some useable trials gears too. I do run a front mech because I want the range and I prefer the ratios that a 22t sprocket gives you for general MTB use but I also have lots of leg bruises from shifters whilst trialing the thing!

 

 

 

.

 

 

Wow thanks for the detailed feedback! This confirms some of my concerns and also gives me a bit more to think about. I was adamant I only wanted a single ring up front. Although… what I may consider doing is keeping the 22t for trials, having a 32t narrow wide ring as well but not running a front shifter. I could also them gift for a more conservative cassette range of say 36t to 11t. 
 

Zee derailleurs are kicking around on eBay but as you say seem to be just the DH configuration. I’ll see what I can source and report back on progress.

 

Thanks again! It’s super helpful 

[The dab]

1 hour ago, Private Repress said:

I have been considering a dropper post, I run a 170mm dropper on my enduro bike, even at that length though (which is long) it wouldn’t be enough to get up to optimum riding height if at the lowest point in the clamp. It’s does have a lovely Thompson seat post mind

One up do a dropper post around 210mm or 240mm can be reduced Upto 20mm with shims too

https://20twentystore.com/products/oneup-dropper-post-v2?variant=42333518889207

 

[forteh]

Sort of in the same vein...

What if I want a wide range 9 speed? Also how rigid are the maximum cassette sizes dictated by the mech?

I currently have an xt m786 10 speed running 32t on a 9 speed 11-34 cassette, driven by a 9 speed SRAM x5 shifter (1/4" thick spacer under the cable clamp on the mech to correct the actuation ratio).

When my current chain/cassette dies then I'm planning on putting a larger cassette and chainring on to improve both high and low gear ratios. The mech is rated for 36t maximum low sprocket, if it possible to easily increase this?

[Private Repress]

Better late than never!

 

After finding myself riding this bike more than any recently and arriving back at the problem of limited gears, I got talking to @Ross McArthur who happened to have some wheels, 12spd cassette along with an accompanying  mech and shifter. So the enduro bike got the 12spd gear upgrade (50t to 11t). the old Sram 10spd set up became a hand down to the Giant. I rebuilt the standard Hope Pro 2 hub onto the spank rim so I could run the 10 speed cassette (I contemplated chopping it up to run on the trials hub with 6 gears, but the aluminium spider body on which the cogs attach to where in blocks of three, and the alignment for the trials gear I use would have been a pain). So it now has a range of 42t to 11t. 

A quick eBay search and a lengthy series of gear ratio calculations later and I found a hope 34t sprocket with integrated bash ring - keeping things nice and simple at the front. 

 

The gears work flawlessly, and the trials gear lines up nice and straight. That said, I do think if I put it through its paces off road the chain will likely jump off the front sprocket, if it starts to happen I'll look into a clean minimalistic chain guide. But for a casual cruiser with solid trials capability I'm super happy! 

 

Sadly I had to tilt the seat forwards so that the Crown Jewels remained intact, its  doesn't look as good, but at least my pronouns are safe. 

I also changed the fork decals too (these ones take me back to an era when front sus on a 'trials bike' wasn't unusual)  

Which reminds me, if this sort of bike is up your street and you haven't seen Andrei Operas recent Giant STP build and his silky riding you should check it out! His insta handle is @andreitrial

 

Looking forward to some summer evening rides on this hitting up some good old trials spots en-route 

Edited March 13, 2023 by Private Repress
Adding picture

[Ross McArthur]

Looking good and happy to have helped!

No clutch in the rear mech I take it?

[Private Repress]

2 hours ago, Ross McArthur said:

Looking good and happy to have helped!

No clutch in the rear mech I take it?

Yes this one has a clutch, I’ll have to see how it handles off road!