40t cassette range expanders

rockmonkeysc

Do 40t range expander rings leave you with an odd step in the ratios?

mac-cos

It can feel a bit odd if you pull the 17t and don't swap the 15t for a 16. Oneup now supply a 16t with its big cogs so the gap isn't as noticeable.

russyh

I run 40t trex, not noticed any gap, to be honest I think the slight jump in range is a load of rubbish. Put loads of miles on mine now, really happy. That's after trying most of the options on the market (general lee, one up etc.) 40t is plenty big enough even for my weak legs

Ferrals

Mac-cos wrote:

It can feel a bit odd if you pull the 17t and don't swap the 15t for a 16. Oneup now supply a 16t with its big cogs so the gap isn't as noticeable.

I'm thinking about getting one of the one up sets, putting the 16 in should even everything out. One step of 2, four steps of 3 and then four steps of 4 seems pretty resonable, or the last on is a step of 6 if you use a 42t obv.

Northwind

I put a 16T in mine, it felt a bit weird originally- I'm not generally overly fussed about gearing gaps etc but it seemed to be right in an annoying place in the block.

I'm using a 42T One Up and it's been ace tbh. Just added their Rad Cage to see what difference it makes, I think it's going to be mostly ease of setup and making things a wee bit less susceptible to bumps and stretch and general misadjustment.

rockmonkeysc

Thanks for the replys. I guess a short cage mech wont work with 11-40t. Do you use a medium cage?

felix.london

I'm waiting on an Absolute Black 28-40t adapter (should be here this week) - meant to be stronger and lighter (whole cassette weight) than the 40t single sprocket systems

Will report back when it's installed and had a couple of outings. Chainring arrived last week and def looks like good quality kit though.

Northwind

RockmonkeySC wrote:

Thanks for the replys. I guess a short cage mech wont work with 11-40t. Do you use a medium cage?

I think short cage might work... Especially in a bike without too much chaingrowth. But I use mediums, it's not so much about the cassette range as the chainslack imo- the longer arm can take up slack better.

(I've got a short cage on the dh bike and it's too short to deal with even a 34T on that bike because of the chaingrowth)

Chunkers1980

Take chain growth out of it you're going to be borderline/closer to ripping it off, most shorts have a capacity of 25/27t - with that you're on 29t difference.

Kai in the Borders

felix.london wrote:

I'm waiting on an Absolute Black 28-40t adapter (should be here this week) - meant to be stronger and lighter (whole cassette weight) than the 40t single sprocket systems

Will report back when it's installed and had a couple of outings. Chainring arrived last week and def looks like good quality kit though.

I've not seen that option before. Looks interesting.

frankspencer1979

I've got the one up 42t with the extra 16t cog. There is still a noticeable step, and it does seem to be in an awkward place, particularly when riding relatively flat sections, but before you know it your speed alters and it doesn't matter anyway. yhe overall set up is great. It runs so quiet, it shifts in and out odd the big cog no problem and the overall range is fine. I have noticed a bit of skipping when changing in and out of the 16t cog, but I'm sure I can tweak it out.

Ferrals

what rear mech are you using?

lawman

Just fitted a T-rex with a 16t shimano cog from Rose bikes and it works brilliantly. Smooth shifting, no noticeable gaps in the ratios and was dead easy to set up. Personally I think the 42t cogs are probably stretching it a little too far, but I'd be interested to try one up's RAD cage anyway, just to see if it does make any difference.

rockmonkeysc

I don't think I would want the 42t, I can do 95% of climbs with a 36t so I only want a bit extra. 42t seems to be quite a big step.

dusk

I have a OneUp 42t with 16t cog, the ratios feel spot on with no noticeable jump even up to the 42t. Without the 16t cog there was a noticeable jump

Ryan Jones

Have a Hope t-Rex 40t fitted, removed the 17t cog as per the instructions and whilst there is a noticeable step where the 17t was the 36-40t step is fine. It does drop the chain through the cassette on back pedalling however, and the shifting with a shimano Xt clutch mech and shifter is pants but hopefully the Rad cage on order should sort that out (both are issues which I've seen reported elsewhere with them components, Sram shifters and the one-up 40t expander apparently fare better).

dusk

I'm on Sram X0 with mine and it's as good as standard, I honestly can't notice a difference in shifting performance

frankspencer1979

SRAM X9 type 2 medium on mine. Chain never dropped. Shifting was spot on when it was first fitted, it's gotten a little sloppy through cable stretch, should be easy to sort out though. Never Any problem getting into the 42t cog. Overall, I'm well happy with the results.

mcnultycop

40t TRex with a Zee.

Shifting is good (not quite as smooth as an XT cassette, but good enough) and the gap where the "missing" sprocket is hasn't been an issue, I've just not noticed it.

Ferrals

frankspencer1979 wrote:

SRAM X9 type 2 medium on mine. Chain never dropped. Shifting was spot on when it was first fitted, it's gotten a little sloppy through cable stretch, should be easy to sort out though. Never Any problem getting into the 42t cog. Overall, I'm well happy with the results.

Sweet thanks, I've got an x7 type 2 medium, was wondering if there would be issues with the 42 but sounds like it will be fine

Out of interest, they say there is no duty to pay, but as it's from the states there should be.. Or is it posted from within uk?

dusk

posted within UK for OneUp

frankspencer1979

Thought I might as well post a pic of my set up. 32t NW chainring by superstar components. SRAM 11-36 cassette, X9 type 2 medium cage, one up components 42t sprocket. It's green.

Ferrals

Nice one, that looks good! I guess you like green!!

rockmonkeysc

frankspencer1979 wrote:

Thought I might as well post a pic of my set up. 32t NW chainring by superstar components. SRAM 11-36 cassette, X9 type 2 medium cage, one up components 42t sprocket. It's green.

What do you think of the superstar chainring? Does it keep the chain on well?

BloggingFit

I got one for a friend recently and he has had no issue despite running his chain a little long.

My AbsoluteBlack has also been fine although it should given the extra cost.

rockmonkeysc

Any idea how the wear compares for the two?
Saving 20% is good as long as it doesn't wear 50% faster.

BloggingFit

Too early to tell on his as yet. My 34t did 6 months including through winter with little wear apart from anodising on the teeth. It'll go back on for another winter season quite happily or on a planned HT build.

All I would say us that I would run a shimano chain on the AbsoluteBlack rather than KMC so this may sway things depending on what you currently run.

felix.london

RockmonkeySC wrote:

Any idea how the wear compares for the two?
Saving 20% is good as long as it doesn't wear 50% faster.

AB "guarantee minimum 12 months of excellent chain retention capabilities"

felix.london

Touchdown!

Ryan Jones

Just fitted the Rad cage to my XT rear mech, pleased to report that straight away it's made a noticeable difference for the better. Before there was reluctance to change both up and down on certain sprockets, since fitting it feels just like you'd expect from a new XT setup. Highly Recommended !

frankspencer1979

RockmonkeySC wrote:

What do you think of the superstar chainring? Does it keep the chain on well?

I've had no issues yet, and that's including some big, rocky days out in the Lakes