1x10 how many teeth

g1b

Hi, my current setup is 3x10 slx crank 42.32.24t was looking at changing to a race face narrow wide but i am unsure as to what number of teeth is best 30-32-40t etc

i mostly ride roads and cycle network paths so would like to keep a decent top speed but also have enough low end

thanks

Chunkers1980

Well, you can't do that

g1b

why not ?, thought i could remove the existing 3 rings and replace with a 104mm bolt single narrow wide and use my existing m786 rear clutch mech

Chunkers1980

I didn't mean technically

g1b

ok so you are saying its better to stick with the 3x10 ?

Chunkers1980

Yes, unless you know specifically what you want and how you'll get it.

rockmonkeysc

For tarmac and cycle routes 1x10 makes no sense at all. You probably have the ideal set up already.
Why do you want 1x10?

g1b

will be replacing the cassette soon and already have a clutch mech so was thinking it might be worth going with a 1x10 as i don't use the lower gears much and could save a bit of weight

was unsure if it was was suitable and what number of teeth was best for top speed ie more teeth = lower or higher ratio/speed

supersonic

More teeth at the front = a higher gear. But you need to work out what you need by what you are using at the minute. Do you use all of the rear gears with all the chainrings?

g1b

keeping the chain line straight/quite i probably use most of the gears on the 32-11 cassette and just the middle and big cog up front don't think i would miss the small front cog

supersonic

You could cover the same range of gears if you get an 11-42 cassette, and use a 32t N/W. But this will mean either 11 speed, or fitting an expander to a new 10 speed 11-36 SRAM cassette:

http://www.chainreactioncycles.com/e-thirteen-extended-range-ex-cog/rp-prod119451?gs=1&gclid=Cj0KEQjwrdetBRCJg92s44SB77IBEiQAEIWmVY3P2Z-12DTVkwOMTgH8lFL3pXKkOnw2ORbwXNpAoLAaAhDS8P8HAQ&gclsrc=aw.ds

g1b

thanks supersonic

current shifters and mech are deore xt with kmc chain will a sram cassette work with them

supersonic

Yes, a SRAM cassette will work fine, however you will need to adjust the derailer B tension screw so it cab work with a large rear cog - in fact you may need a new longer screw.

cooldad

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19666526#p19666526]g1b[/url] wrote:

keeping the chain line straight/quite i probably use most of the gears on the 32-11 cassette and just the middle and big cog up front don't think i would miss the small front cog

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19666537#p19666537]supersonic[/url] wrote:

You could cover the same range of gears if you get an 11-42 cassette, and use a 32t N/W. But this will mean either 11 speed, or fitting an expander to a new 10 speed 11-36 SRAM cassette:

Well no, he'd be missing the high gearing if he rides mostly roads and cycle paths.

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19666318#p19666318]g1b[/url] wrote:

i mostly ride roads and cycle network paths so would like to keep a decent top speed but also have enough low end

thanks

g1b

put my current setup into a gear calculator
http://gears.mtbcrosscountry.com/#26/2.20I2I327

wheel - 26/2.20
front cog slx 24-32-42
cassette slx 11-32

shows my setup as

Max ratio 3.85
Min ratio 0.76
24 32 42
11 9%
2.20 2.93 3.85
12 17%
2.02 2.69 3.53
14 14%
1.73 2.30 3.02
16 13%
1.51 2.02 2.65
18 11%
1.34 1.79 2.35
20 10%
1.21 1.61 2.12
22 14%
1.10 1.47 1.92
25 12%
0.97 1.29 1.69
28 14%
0.86 1.15 1.51
32
0.76 1.01 1.32
Speed (km/h)
Cadence: 60 80 100 120
Highest gear 29.0 38.6 48.3 58.0
Lowest gear 5.7 7.6 9.5 11.4


using the calculator in the above link am i right in thinking a 40 or 42t n/w with a new cassette and t rex expander would be closer to what i have now ?

cooldad

Do they make one that big with the right BCD?

g1b

sorry dont know BCD means

cooldad

http://www.wolftoothcomponents.com/pages/how-to-measure-bolt-circle-diameter-bcd

g1b

thanks cooldad ,yes you are right 38t looks the biggest i can go

The Rookie

You can go bigger if you fit a 5 arm crank

cooldad

Sounds like a more and more pointless exercise for the type of riding involved.

g1b

yes starting to think that myself but i already have a clutch mech and due a new cassette soon,superstar 38t n/w is cheap enough to try without going all out with a expander

at least i now understand it better

supersonic

Yep, typo, I meant a 42t ring, but as you say, doesn't look like can find them in NW. Or just use a chain guide. I agree is looking a lot of faffing for no real gain.