I'm thinking of upgrading my 1 x 9 to 1 x 11. There are two options.
i) 170 or 175 cranks
ii) 30 or 32T front ring
Now, I'm a statuesque 5'9" and notorious struggler on the up hill. So the first question is am I right in thinking that a 170 crank will suit the more modest build?
The second question is 30T or 32T that is the question. What would the advice from the STW hive mind be?
170 and 30T
How big are your wheels?
Definitely 170. As for chainrings mtfu and get a 34/36! Honestly though 11 speed lets you have a massive sprocket, use that to embiggen your chainring for wider range at the bottom and the top.
175 or 170 - honestly don't think it makes much difference but everyone will tell you to go 170.
Unless we know what cassette are you putting on nobody can answer the 30/32 question IMHO. My slx is 42t, think some XT was 40?
Thanks scotroutes, really appreciate the forthrightness.
OWG - 26". Is there another size I've missed?
lustyd - 👿
stu - It's a 42
I'm 5'7" and prefer 165mm cranks; (a) climbing is easier (b) it sets my seat higer so I can fit a larger pack under it.
And if you are a "notorious struggler on the up hill" then why go bigger than 30T?
Another 170 and 30t.
With a SRAM 42 / 10 you get climbing and a reasonable top speed.
Superstar do a 30t 104bcd nw ring too.
On a 26" wheel the 32t ring will be fine.
All my bikes used to be 175, but I'm gradually acquiring 170s. Can't say I really notice the difference.
On a 26" a 38 will be fine with an 11 speed cassette. Tiny wheels make the gearing easier and 30/46 will send you over the back rather than propel you forwards So you need to be careful how low you go. Larger wheels are the reason 30t is popular these days, not because everyone suddenly prefers riding slowly!
You should know ow what chain ring if you have 1x9,do you want a lower gear? Same ring size.
Do you want the same? Bigger ring.
Front/back for your current ratio.
Comments like above make no sense unless you know the person, their fitness, pedalling preferences and terrain.
A 38t would be utterly pointless for me locally both for speed and climbing.
1x11 is exactly the same as 1x9 but you get to eat more cake and ride your bike less.
I don't understand why everyone here overthinks it so much.
I ride a 26" with 32 up front and 11-50 Sunrace at the back.
As a older (45) fatty, I find the lowest gear usefull when I'm knackered or the going is very steep and or loose.
Never felt it is too low and it saves my legs somewhat compared to the 11-40 and 32 on the other bike, 27.5+ wheeled thing.
If you're super fit then for sure you don't need a wide range cassette but I don't buy the 'man up' rubbish when there is no need to put yourself through the grinder.
As and when fitness improves you could always then go bigger on the front relatively cheaply.
Work out your ratios of current bike and intended new bike
If you current bike is 30t and a 36t largest cassette cog then you are running 30/36 = 0.83
If you want the same lowest gear on a 42t cassette then multiply it by the number above to get 35t equivalent although you'd need a 34t or 36t , there are numerous websites that then factor in wheel size for gear inch in simple terms the bigger the wheel the lower the calculation you'll need
It's all simple maths, but you need to consider local terrain climbing, how you ride uphill I like to keep cadence up and spin rather than grind it out
For that reason I'll run a 30 or 32t and a rear 11-42, on more xc bikes I run 34t with 11-46t Xt which provides the top gear for speed, whilst covering the granny
If you ride some road to get between off-road sections you need a top gear of at least 3.0 i.e. A 30t chainring with a 10t smallest cog
I was sent 170s when I ordered 175s for my last crank, ended up giving them a go as I'm too impatient to return, ended up liking them more than 175s.
Can't comment on the cranks, but when going 1x10 inworked out the gears I had for 2x10 and which ones were more important to me.
Think I had 28/42 at the front of something like that - with an 11-36 cassette.
Moved to a 32t at the front with an 11-42 atbthe back. Worked fine for me.
When ordering a new bike it was either 1x11'atba sensible price or Xo Eagle at a daft price so went for GX 1x11.
Took the opportunity to get a lower gear again for steeps hills (as the new bike is heavier and enduro) as I could do it by going for a 10-42 on the back. So specced a 30t chainring. So glad I did as it gives you a real bail out gear when you're struggling.
I've found 1x11 is just that bit slicker than 1x10 too - and it was Sram GX with both setups.
I am on a 27.5" wheeled bike if that makes a difference.
30t on a 26" bike will be very twiddly for anywhere that doesn't have lots of long steep ascents.
Got 30t chain rings on both bikes (FS & HT), the HT is 26 inch, the FS 27.5 inch.... Can't tell the difference to be honest.
I have a 10 speed Sunrace 11_42 cassette on the FS and an XT 11 speed 11_40 on the HT.
Both bikes are 170 cranks as I'm 5' 9"
Call me a big pussy but I get no joy from climbing and like it as easy as possible hence the tiny chain rings, my bikes are built for the downs.
Hmm... Deviant makes a compelling argument and is obviously as fond of climbing as I am.
Doesn't seem to be a lot of discussion on wider range cassette options, e.g shimano xt 11-46.. is the feeling they're not that helpful ? Not required? Too expensive/heavier?
I'm pondering a new build currently and will have to go 1x because of the frame and not sure if I should spec the wider cassette. (Won't be choosing sram)
Just checked and I'm running 34T front and 11-34T cassette. I suppose either 30 or 32 with a 11-42T will make life significantly easier! 😆
On a 26" with 175mm cranks - I found 32 fine for everything including extended, steep alpine climbs of c2000 feet.
On a 650b bike with 165mm cranks, I found 30 better.
I am currently very lardy at 98kg with 2 chronic health conditions, but still I found these ratios workable.
Once you get down to very low ratios then you just sit there spinning and making about as much forward movement as toddler learning to walk.
Do you really spin at 90rpm no matter what? I don't, I'll range from standing up and doing 30rpm all the way up to 120rpm for brief periods when seated.
Not sure on the wider range cassettes - I've a new frame on the way, I'm debating whether to go 1x10 or 1x11. All my current bikes are 10spd which makes for easier spares selection - speedlink? That'll be the ten speed sir! Like the idea of a wide 11 speed cassette though.
I'm about to go from 2 x 10 to 1 x 11.
Current thoughts are XT M8000 shifter, SLX M7000 long cage mech, sunrace 11-50 and a sram X1 chain. Just weighing up 32 or 34t narrow wide but will probably go 32 initially.
Where are getting the 11-50 cassette from? I don't even see one on Sunrace's web site.
I ride a 26" with 32 up front and 11-50 Sunrace at the back.
Does that cassette pick up much dirt? It must be a larger diameter than your wheels!
http://www.highonbikes.com/sunrace-mx80-11-speed-mountain-bike-cassette-11-50-silver.html
Is one place. Few others too. Google 'CSMX80'
The Xt 11-46 cassette is great and means you can up the front chainring to a 32 even a 34t,
Was thinking of going 11-42 on my lefty bike t decided my top gear isn't enough on a 32t so that extra cog on back means I can go up to 34t
If I lived in flat areas then a 36t on front would be better, but doing 2000 metres of climbing a week I like a granny
Surprised at the number of people suggesting tea cup saucer sized front rings....
Even the GF has a 32 ring and manages the climbs and we ride in the alps all the time with lots of climbs over 1000hm with 10% average.
I run 34 and have only had to push a couple of times.
You must be spinning like crazy up the Surrey Hills....
Call me a big pussy but I get no joy from climbing and like it as easy as possible [i][b]hence the tiny chain rings[/b][/i], [b]my bikes are built for the downs[/b].
Obviously not built for the downs... You big pussy. 😉
Even the GF has a 32 ring and manages the climbs and we ride in the alps all the time with lots of climbs over 1000hm with 10% average.
I run 34 and have only had to push a couple of times.
Even your girlfriend - who cycles in the alps all the time can manage alpine gradients with a 32t chainring. That's hardly surprising but I'm not sure that her sex matters much. Strong riders are strong riders, no?
If you are happy with the current range you have, use this: http://www.gear-calculator.com/
It can compare your 1x9 against a 1x 11 and you can take it from there on what to choose
I'm not sure that her sex matters much
it does matter....
Obviously not built for the downs... You big pussy.
Going fast DH has more to do with maintaining speed than adding it, most of the fsatest and strongest riders I see doing any kind of hills max out on a 32, maybe a 34. They will be faster through skill than pedalling
Obviously not built for the downs... You big pussy.
You've clearly never seen Sam Hill, Brendan Fairclough or Josh Bryceland ride DH....they're not fans of pedaling either, they choose fast lines and pump the trail....gonna tell Aaron Gwin he's a big pussy for winning that WC round without a chain and not pedaling?....or Neko Mulally when he took 4th in the World Champs without a chain and no pedaling?
Get with the times old man, there's more than one fast way down a hill other than pedaling furiously.
I'm not sure that her sex matters much
it does matter....
Sorry, I meant that there are loads of very fit, capable, strong women about. So her sex doesn't matter when it comes to chainring size.
Living in the alps does though, that's why I'm crap at climbing, it's flat around here
I was sent 170s when I ordered 175s for my last crank, ended up giving them a go as I'm too impatient to return, ended up liking them more than 175s.
I got a bike with 170's on .... I'd never bought about it .. in fact didn't even really notice the length as a number .. it just main my knee and hip pain go away ... which I thought was just the bike at the time...
It wasn't until I started building for Jnr I really looked into this...
Nothing on earth would get me to put 175mm back on...indeed I'm tempted to try 165mm I'm 50'10" (and a half) but short legs and whenever I ride a hire bike now with 175mm my knees and hips suffer...
I suppose with shorter cranks you'll get [i]slightly[/i] less pedal strike.
Any formulae or rule of thumb for what is the optimum crank length for a given leg/thigh length?
rOcKeTdOg - Member
Living in the alps does
That was my point when Alpin was suggesting any lower ratios than his other half uses were for wimps!
Any formulae or rule of thumb for what is the optimum crank length for a given leg/thigh length?
Best i found is hidden at the bottom of this page
https://highpath.co.uk/crank-shortening/
