Cassette Expander on 9 speed?

buddy_club

Evening,

Is it possible to run a cassette expander on a nine speed cassette with a narrow wide up front? It's for my voodoo - I can't see any reason why not?

Cheers

Ben

jimothy78

viewtopic.php?f=10004&t=12996278

buddy_club

jimothy78 wrote:

http://www.bikeradar.com/forums/viewtopic.php?f=10004&t=12996278

Seen that but he wants to add to the 9 speed cassette with the expander to make it 10 speed - I just want to lose a smaller cog and keep it 9 speed - (if I understood his post correctly)

jimothy78

buddy_club wrote:

Seen that but he wants to add to the 9 speed cassette with the expander to make it 10 speed - I just want to lose a smaller cog and keep it 9 speed - (if I understood his post correctly)

No, he doesn't (well, he does as an aside, but no-one dignifies it with an answer because it isn't possible).

buddy_club

jimothy78 wrote:

buddy_club wrote:

Seen that but he wants to add to the 9 speed cassette with the expander to make it 10 speed - I just want to lose a smaller cog and keep it 9 speed - (if I understood his post correctly)

No, he doesn't (well, he does as an aside, but no-one dignifies it with an answer because it isn't possible).

There is a conclusion he should just go ten speed - not that he could add the expander to the nine speed...

The Rookie

Reasons why not
1/ 9 speed mechs are different to 10 and may not clear the bigger ring
2/ you will need have to find out for yourself how to make up a working rest of cassette and you may need a very slim spacer to get the correct 9 speed gap between gears versus the thinner 10 speed gap the expander is engineered to provide
3/ as the biggest 9 speed sprocket is 34 and not 36 you'll have a bigger gap between gears

You could fix some of that by buying a basic dismantle-able cassette in both 9 and 10 speed and matching up the gears you want to make the cassette you want but it wil be heavier.

buddy_club

The Rookie wrote:

you may need a very slim spacer to get the correct 9 speed gap between gears

Is that kind of thing readily available? How thick do you think?

The Rookie

buddy_club wrote:

The Rookie wrote:

you may need a very slim spacer to get the correct 9 speed gap between gears

Is that kind of thing readily available? How thick do you think?

There are some thin spacers available, not sure what the difference in thickness between 9 and 10 speed is, but about 1/2mm seems to ring a bell......

buddy_club

The Rookie wrote:

buddy_club wrote:

The Rookie wrote:

you may need a very slim spacer to get the correct 9 speed gap between gears

Is that kind of thing readily available? How thick do you think?

There are some thin spacers available, not sure what the difference in thickness between 9 and 10 speed is, but about 1/2mm seems to ring a bell......

Might as well just give it a go then - I may report back at some point as to if it worked or not....

The Rookie

As you'll have to jump down to a 34 not a 36 second sprocket, I'd suggest a 40 rather than 42 expander.

buddy_club

The Rookie wrote:

As you'll have to jump down to a 34 not a 36 second sprocket, I'd suggest a 40 rather than 42 expander.

Yep that's the plan

buddy_club

Here's the info from the shimano website:
Maximum Sprocket 36T
Minimum Sprocket 11T
Front Difference 22T
Total Capacity 45T

Is it the max sprocket (36t) that means I won't be able to fit an expander or is it total capacity (45t) which it seems I would get away with it?

jimothy78

Even the 10-speed rear mechs are only recommended for up to 36T largest sprocket - fitting a range expander is always a "non-supported" use. Because if this, you may need to replace the "B"-tension screw with a longer version to get enough clearance on the largest sprocket (you need 5-6m of space ideally).

buddy_club

Oh right - yes I see quite a few of the expanders come with a spare B screw...

nicklouse

buddy_club wrote:

Oh right - yes I see quite a few of the expanders come with a spare B screw...

not spare. replacement.

buddy_club

nicklouse wrote:

buddy_club wrote:

Oh right - yes I see quite a few of the expanders come with a spare B screw...

not spare. replacement.

That one

Cqc

Sorry to restart this everybody, but where would I get one of these spacers from? Cheers

The Rookie

Search cassette spacer on eBay, the thinnest I can find is 1mm, so you may find you need to file/sand it down to the thickness required.

Cqc

Thanks, so I'm aiming to make it 0.5 mm and stick it between the expander and the last cog in my cassette, right?

The Rookie

I'm not exactly sure of the difference between 9 and 10 speed gear separation is, you may have to search or measure

rockmonkeysc

Good luck filing a 1mm spacer down to 0.5mm. Very difficult to get parallel and it's going to take you a long time and will be forkin arkward. Forget about trying to sand it, you will get nowhere.

buddy_club

Spacer widths (From Shimano tech docs)

8 Spd: 3.00mm
9 Spd: 2.56mm
10 Spd: 2.35mm (1.0mm for lower spacer)


Would it be different widths with SRAM?

From here by the way:
http://bicycles.stackexchange.com/questions/17064/what-are-the-widths-of-shimano-8-9-and-10-speed-cassettes

The Rookie

I wouldn't expect it to be different for SRAM as the sprockets are the same width and the overall cassette the same width.

As its 0.2mm I think I'd be inclined not to bother with trying to make a spacer and see if it works without.

jimothy78

buddy_club wrote:

Spacer widths (From Shimano tech docs)

8 Spd: 3.00mm
9 Spd: 2.56mm
10 Spd: 2.35mm (1.0mm for lower spacer)

That doesn't apply to MTB - 10 speed ROAD cassettes need a spacer on a 9-speed freehub, but 10-speed MTB cassettes don't - they're the same total width.

As I stated in the other thread (linked to on page one), the difference in total cassette width caused by swapping a single sprocket (and associated spacer, if applicable) from 9 speed to 10 speed is about 1%, or 0.38mm. Personally, I'd be hugely surprised if this tiny difference meant that the lock-ring couldn't hold the cassette in place properly.

The Rookie

Its not about the lockring, it's about the shift from 1-2, but then a ten speed chain works on 9 speed anyway, so that would probably resolve that issue if a 10 speed chain were used.

Cqc

So the general consensus is just to avoid using a spacer, and put on the expander as if it's a 10 speed cassette?

njee20

Yep, that's what I'd do!

The Rookie

Given the info above, me to, also use a 10speed chain.

coulddobetter

I just switched a 10 speed cassette on road bike and inadvertently missed out one spacer. Result was poor shifting into cog adjacent to the missing spacer. Once spacer put in things were spot on , so I would say it does make a difference.

The Rookie

But I'd guess that spacer was mire than 1/2mm thick, did you read the thread?

Herdwick

http://faqload.com/faqs/bicycle-compone ... d-cassette

Found this, may be helpful on your attempt :!: