Trek Superfly Elite 2013, Single Drivetrain Q

Croftuz

Hi guys,

Had this bike from new but due to injury it only has a few miles on it.

I see the Sram 1x11 or even 12 is popular these days and I’m trying to work out how different the gearing would feel compared to my 3x9 XT groupset.

Two questions, I mainly ride XC and road sections, would it be worth converting?

Is it even possible as I’m hearing even hubs & BB’s need changing along with the obvious parts!

Thanks for any quick tips!

JGTR

To run 12 speed and some (maybe all? Not sure) 11 speed setups you will need an XD hub. You should be able to run a wide range 10 speed casette on your current hub (google Sun Race 11-42), with a new chain and a narrow wide front chain ring.

The only issue you may have is the derailleur and whether it has the capacity for a 42T rear sprocket, you may get away with adjusting the B gap, fitting a longer B screw or a Goat Link.

Croftuz

Thanks for the reply!

Naturally being more traditional, I’m concerned that 10 speed will limit my ability. I mean technology seemed to be creating more and more gears for us until the last couple of years.

Before I travel down this road and google your great pointers, do we see large amounts of gears disappearing, or like 29ers etc will both coexist and it just be preference?

The one I rode was SRAM and 1x 11, super smooth and didn’t really find I missed the extra gears.

steve_sordy

Croftuz wrote:

........
Naturally being more traditional, I’m concerned that 10 speed will limit my ability. I mean technology seemed to be creating more and more gears for us until the last couple of years.

Before I travel down this road and google your great pointers, do we see large amounts of gears disappearing, or like 29ers etc will both coexist and it just be preference?

The one I rode was SRAM and 1x 11, super smooth and didn’t really find I missed the extra gears.

The number of gears is largely irrelevant, it is the gear range that is important. Going 1x reduces bar clutter and allows the dropper remote to be in a sensible place. It also reduces weight, but more importantly, it simplifies your shifting and reduces shifting mistakes. What's not to like?

The only downside is that you might have to compromise on which end of the gearing you might miss out on. Do you want to get up the steepest hills, or do just want to go faster on the flat and downhill? If your 1x range is less than what your 3x9 gives you, then choose your front ring size to suit what you want to do with the bike.

Croftuz

Thank!

So if I imagine I’m only using the middle cog on my front chain ring most of the time at the minute that suggests that if I select the right size for the single I’ll only miss for instance the ability to grab speed on down hill (esp road) but have a greater range for trail and climbing XC?

The choice of front chain ring size seems really important now! Are there generally lots of sizes to choose from?

steve_sordy

Croftuz wrote:

............

The choice of front chain ring size seems really important now! Are there generally lots of sizes to choose from?

It is and yes there are lots. But your current bike crankset may limit your choice. to front rings larger than 30t. That is no real hardship as most front rings for 1x mtb tend to be 30t-34t. I have heard of some heroes going for a 36t front ring, so I'm assuming they live somewhere flat or prefer to push up hills.

Croftuz

steve_sordy wrote:

Croftuz wrote:

............

The choice of front chain ring size seems really important now! Are there generally lots of sizes to choose from?

It is and yes there are lots. But your current bike crankset may limit your choice. to front rings larger than 30t. That is no real hardship as most front rings for 1x mtb tend to be 30t-34t. I have heard of some heroes going for a 36t front ring, so I'm assuming they live somewhere flat or prefer to push up hills.

Thank you!

I know I’m probably lingering on this too long, but let’s say I have XT crank arms and currently 27 speed 3 ring setup, where would the middle ring sit within that 30-34t? I guess I should count my own when I get home from work!

So to clarify, I need:

Longer B screw (possibly)
GOAT to give me cassette clearance on 10 Spd using my current XT rear mech.
Narrow / Wide front chainring.
New Chain

Can I use my current SLX shifter? I guess that’s what the B Screw allows?

Finally, I’m guessing a whole host of new tools to remove and some install?

steve_sordy

Croftuz wrote:

......
Thank you!

I know I’m probably lingering on this too long, but let’s say I have XT crank arms and currently 27 speed 3 ring setup, where would the middle ring sit within that 30-34t? I guess I should count my own when I get home from work!

So to clarify, I need:

Longer B screw (possibly)
GOAT to give me cassette clearance on 10 Spd using my current XT rear mech.
Narrow / Wide front chainring.
New Chain

Can I use my current SLX shifter? I guess that’s what the B Screw allows?

Finally, I’m guessing a whole host of new tools to remove and some install?

Yep, you should count up. But don't just replace the current middle ring with a N/W with the same number of teeth. You have the opportunity to take into account the range of the new cassette.

Of your list of four needs, the first two are both possibles. Do the last two first. Set the chain to the correct length for your bike and keep any bits that you cut off (they always come in handy). The shifter needs to be the same "speed" as the cassette and chain. A 9-speed shifter will not use all the gears on a 10-speed cassette.

The B screw is to move the upper jockey wheel towards or away from the cassette. It is nothing to do with the shifter (and vice versa). If you fit a cassette with a larger big gear, then the jockey wheel will need to be moved further away to allow the jockey wheel to clear the biggest gear and allow smooth shifting. If the current B screw is already fully screwed in, then you will need a longer one. Keep the jockey wheel pretty close but without hitting the big gear, say 3 mm away.

If none of that works, then maybe you need a goat link. But I've never had to fit one, so I'll stop there and hand over to someone who has.

Croftuz

Thanks ever so much for taking the time to help me, it’s a bit of a mine field, you must get posts like this all the time so it means a lot for you to write all that for me!

Is there a guide that can help me visualise my
Current range and pick where within that 10 spd might sit? I guess I need to know where the ‘Hardest’ or Highest gear possible is with largest chainring available and decide if downhill is important to my ride, then work back?

Or decide if climbing is important, I mean if I think of
My ‘easiest’ or lowest gear gear available now on 27, is that far lower than the smallest chainring will supply on a 10 Spd? But I’m getting an extra large cog on the cassette so..

JGTR

Get a calculator and work out the ratios, that’s exactly what I did when I went from 2x to 1x. Work out what you have now, what you use now and then work out the best compromise. I went with a 34T and 11-42 casette as I do a mix of longer distances and trails and didn’t want to lose too much from the low end. If I was just riding trails I would have gone for a 32 or 30.

Don’t worry about a goat link yet, quite often you can just adjust the B screw or fit a longer b screw.

steve_sordy

The easiest gear ratio is the smallest front ring driving the largest gear on the cassette, maybe 22t driving a 34t. ie 22/34 = 0.647. That is your best climbing gear.

The hardest gear is the biggest front ring driving the smallest gear on the cassette, maybe 38t driving an 11t. ie 38/11 = 3.455. That is your fastest gear.

Together they make your range. To put a number on it divide the big number by the small one, ie 3.455/0.647 = 5.34

For comparison, an Eagle 12-speed has a cassette where the smallest gear is 10t and the biggest is 50t. Because there is only one front gear, it does not affect the range. The range is 50/10 = 5.0

Also, an 11-42 single speed cassette has 42/11 = 3.818

It is only when you look at the range that you can see the compromise you will have to make when moving from 3x to 1x.

If my assumptions about your 3x gears are correct, then you have a range of 5.34 and if you go to 1x using an 11-42 then you will have a range of 3.818, which is significantly less. By choosing which size of front ring you can decide whether to go as fast as your current 3x or climb as well as your current 3x. So how to decide?

If you want to climb as well, your best climbing ratio is (as above) 0.647. If you install an 11-42 then what front ring do you need to drive the 42t to get 0.647 (or close enough)? The answer is 0.647 x 42 = 27.2. You won't get a 27t gear, you will be able to get a 28t. but you will probably have to change to a specific 1x crank. If you don't want to do that, you could bolt on a 28t where your granny ring is now, but you will have trouble getting your chain line correct. So use the middle ring position and you will probably have to settle for a 30t.

Do the calculation again 30/42 = 0.714, still not enough. But if you went to a 46t, then at 30/46 = 0.652 RESULT!

So, to get the same climbing ratio, you need a 30t front ring driving a cassette with a 46t gear on it (probably 11-46, maybe a 12-46).

Working out the other end, how fast you can go, just do the same sums but with the other end of the cassette.

Croftuz

JGTR wrote:

Get a calculator and work out the ratios, that’s exactly what I did when I went from 2x to 1x. Work out what you have now, what you use now and then work out the best compromise. I went with a 34T and 11-42 casette as I do a mix of longer distances and trails and didn’t want to lose too much from the low end. If I was just riding trails I would have gone for a 32 or 30.

Don’t worry about a goat link yet, quite often you can just adjust the B screw or fit a longer b screw.

So for rear cassette I can generally see 11-32 through 36, is yours 11speed to get 42T?

Croftuz

steve_sordy wrote:

The easiest gear ratio is the smallest front ring driving the largest gear on the cassette, maybe 22t driving a 34t. ie 22/34 = 0.647. That is your best climbing gear.

The hardest gear is the biggest front ring driving the smallest gear on the cassette, maybe 38t driving an 11t. ie 38/11 = 3.455. That is your fastest gear.

Together they make your range. To put a number on it divide the big number by the small one, ie 3.455/0.647 = 5.34

For comparison, an Eagle 12-speed has a cassette where the smallest gear is 10t and the biggest is 50t. Because there is only one front gear, it does not affect the range. The range is 50/10 = 5.0

Also, an 11-42 single speed cassette has 42/11 = 3.818

It is only when you look at the range that you can see the compromise you will have to make when moving from 3x to 1x.

If my assumptions about your 3x gears are correct, then you have a range of 5.34 and if you go to 1x using an 11-42 then you will have a range of 3.818, which is significantly less. By choosing which size of front ring you can decide whether to go as fast as your current 3x or climb as well as your current 3x. So how to decide?

If you want to climb as well, your best climbing ratio is (as above) 0.647. If you install an 11-42 then what front ring do you need to drive the 42t to get 0.647 (or close enough)? The answer is 0.647 x 42 = 27.2. You won't get a 27t gear, you will be able to get a 28t. but you will probably have to change to a specific 1x crank. If you don't want to do that, you could bolt on a 28t where your granny ring is now, but you will have trouble getting your chain line correct. So use the middle ring position and you will probably have to settle for a 30t.

Do the calculation again 30/42 = 0.714, still not enough. But if you went to a 46t, then at 30/46 = 0.652 RESULT!

So, to get the same climbing ratio, you need a 30t front ring driving a cassette with a 46t gear on it (probably 11-46, maybe a 12-46).

Working out the other end, how fast you can go, just do the same sums but with the other end of the cassette.

Thanks ever so much! Man there are some clever people out there!

Getting the calculator out on a Saturday night, living the dream!

Croftuz

So after counting I have:

Front Largest = 42t
Front Smallest=24t
Back Largest=36t
Back Smallest=11t

3.81/0.66 = 5.78

30t Front chainring and 46t Rear Largest =0.65 Climbing
30t Front chainring and 11t Rear Smallest =2.72 Speed against 3.81.

My question is could I now work out which of my current gears is the equivalent top end 2.72 and ride with my equivalent range to test if the style is right for me?

JBA

Is there any reason you feel the need to change from 3x9, Croftuz?
If the gearing works for you and is functioning as it should then why spend money on it needlessly?
There is a lot of pressure on us to have the latest innovation or trend but they don’t necessarily mean an improvement.
Not saying don’t do it, but will it actually be of any benefit to you?

Croftuz

JBA wrote:

Is there any reason you feel the need to change from 3x9, Croftuz?
If the gearing works for you and is functioning as it should then why spend money on it needlessly?
There is a lot of pressure on us to have the latest innovation or trend but they don’t necessarily mean an improvement.
Not saying don’t do it, but will it actually be of any benefit to you?

Really good point to be fair, I’ve had such a hard time adjusting the 3x9 from storage and found that I get loads of chain rub on the front mech. Finally got it as good as possible but noticed unless I’m tanking down hills on the road I rarely use the High gears (large ring) and I’m crunching through front mech gear changes (my skill definitely the culprit)

Your right though I probably should just ride this setup until it needs a new chain or cassette at least.

Found the gear ranging really interesting though!

steve_sordy

A 30 driving a 46 is 0.652
Your granny ring is a 24, so what gear on the cassette would you have to be in to give you a 0.652?
Answer is 24/0.652 = 36.8. Your nearest is your existing 36
So your current easiest gear is pretty close to what you'd get with a 30 driving a 46.

A 30 driving an 11 is 2.727
I'm guessing that your middle ring is 36t, so what gear on the cassette would you have to be in to give you a 2.272?
Answer is 36/2.727 = 12.8, which is close enough to the 13t that you will have.
Alternatively for your big 42t ring, 42/2.727 = 15.4. You should have a 15t to try.
The middle ring solution is closest, but not by much.

Croftuz

steve_sordy wrote:

A 30 driving a 46 is 0.652
Your granny ring is a 24, so what gear on the cassette would you have to be in to give you a 0.652?
Answer is 24/0.652 = 36.8. Your nearest is your existing 36
So your current easiest gear is pretty close to what you'd get with a 30 driving a 46.

A 30 driving an 11 is 2.727
I'm guessing that your middle ring is 36t, so what gear on the cassette would you have to be in to give you a 2.272?
Answer is 36/2.727 = 12.8, which is close enough to the 13t that you will have.
Alternatively for your big 42t ring, 42/2.727 = 15.4. You should have a 15t to try.
The middle ring solution is closest, but not by much.

I’ve just tested this and I think you’ve cracked it!

Having looked at Chainreaction I can see an XT 11-46t cassette, that requires me to update my 9 spd rear mech and shifter, reading it claims it fits the Hub due to not being 10-46 (sram) am I seeing that right?

steve_sordy

Croftuz wrote:

.............
Having looked at Chainreaction I can see an XT 11-46t cassette, that requires me to update my 9 spd rear mech and shifter, reading it claims it fits the Hub due to not being 10-46 (sram) am I seeing that right?

Yes.

For best results change the crankset too, but you can get away without doing that. Change it later.

Along with the narrow-wide chainring, make sure that your mech has a clutch, known as a "clutch mech". The clutch mech and the N-W ring will pretty much guarantee that you will never lose a chain again.

JBA

Croftuz - have you considered a 2x set up?
If you change your chain set for a 2-speed one you will be able to keep the 9-speed rear (although all the reviews say a 2013 Superfly Elite is 10-speed) and still have a wide range of gears. You may not need to change your front shifter as later left SLX and XT shifters have a selector on the underneath to change between 2- and 3-speed. I'm not sure when that came in though so you will have to have a look at your shifter.
An SLX M675 chain set with 24/38 rings will give you a nice spread of gears that will allow you to keep speed up on road and have low gears for the uphills.
Using the calculations in previous posts a 2x9 set up will give you a lowest gear of 0.67 and a highest gear of 3.45.

My full sus trail bike is 1x11 and my hard tail is 2x10. The hard tail needs a new chain and cassette so I contemplated converting it to 1x10 or 1x11. However, it is used for all sorts of riding from gentle canal path pootles with the family to bike park shenanigans and everything in between. I would estimate I spend 90% of the time riding in the big ring and am able to keep a good speed up on roads and smooth tracks. The granny ring though gives me a nice bale out option for climbs, especially off-road. Although there are gear overlaps this works better for me on the hard tail so I will be keeping it 2x10.