1x11 - Front Chainr...
 

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[Closed] 1x11 - Front Chainring Sizing???

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Right - got the bike ready to roll... and found that my fitness has left the building so completely in the last 14 months of injury that I boked on a couple of teeny wee road climbs (about 150m long, 5m up twice and then a 400m loop around the road with that climb again).

Currently I have a 32T on the front and 10-42 out back on a 29"/27.5+ and live on the edge of the Lakes (Grizedale/Parkamoor/Blawith etc on the doorstep). What size chainring should I be going down to? Kinda thinking a 28T but wondering if I should consider going 26 and stepping up gradually as fitness levels return?

Thoughts please - the 1x thing is entirely new to me!


 
Posted : 22/11/2016 9:31 am
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What cranks you have will dictate the minimum size of ring


 
Posted : 22/11/2016 9:33 am
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easy maths, front/rear will give you a ratio to compare to 2/3x 32-42 is somewhere near to 26-34 etc. 30 is very low


 
Posted : 22/11/2016 9:36 am
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I'm currently 30 11-42. Works well enough for me though I'd consider 32 11-46 with the Sunrace cassette. That's Cairngorms so a few hills round here too. 26 (even 28) sounds very low but we're all different. Might be worth trying the 30 on the assumption you'd work back up to it regardless.


 
Posted : 22/11/2016 9:39 am
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SRAM GX cranks.

The 32 feels a good couple (or so) cogs in on the old bike! The tyres may account for some of the extra drag (Magic Mary/Hans Damph as opposed to Nobby Nic mk1), and the brakes may not quite be as well aligned as yet.

I could just stick with the 32 and see how I get on? I was chatting to someone that has gone to a 28 t'other day which is what got me thinking!


 
Posted : 22/11/2016 9:40 am
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Are they direct mount? I run a 28t SRAM steel direct mount ring on my X9 cranks on the fattie for much spinnyness, they're also dirt cheap and last forever.


 
Posted : 22/11/2016 9:44 am
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Well 28-42 is the same as 24/36 so the lowest most 2x10's went, the tyre combo is a little on the draggy end!! I'd stick with is for a bit, I think the GX does direct mount spiderless so you can run what you want


 
Posted : 22/11/2016 9:45 am
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The SRAM specs for the GX cranks only show 30T as the minimum size chainring which would suggest 104BCD. I've not seen any 28T chainrings for 104BCD only direct mount.

When I started with 1x I used a 30T (live in the Dales so a few hills here as well) but once I got used to it I've used 32T as well, Currently using an Absolute Black 32T oval chainring on the 29er HT and a direct mount 28T oval chainring on the fat bike which I find is fine for that.


 
Posted : 22/11/2016 9:50 am
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I'm in a similar boat and dropped to 28/42.. I decided it was less about whether the lowest gear was sufficient and more about whether the second lowest was - a bit more spiiny but less time wearing out the 42T (saved for when you [i]really[/i] need it)!


 
Posted : 22/11/2016 9:53 am
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I am just trying to work out if the GX cranks will take a direct mount chainring! The websites are about as clear as mud... and I can't quite be bothered to remove the crankset at the moment to have a look!!!


 
Posted : 22/11/2016 10:04 am
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If you swap between a 30/32 teeth for experiment purposes do you have to adjust chain length by the addition or removal of links? Or will a clutch mech step in to take up the variation?


 
Posted : 22/11/2016 10:09 am
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I've not bothered changing chain length, not noticed any problems or had any dropped chains.


 
Posted : 22/11/2016 10:10 am
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the SRAM idea was you could do 2t either way without changing the chain. You should also be able to see one of the T25's from the NDS


 
Posted : 22/11/2016 10:11 am
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32t oval on both bikes, 11-42 cassettes. 15 miles and anywhere between 3000-5000ft of climbing, considering dropping to a 32t round or 30t oval for the winter, as some of the climbs where we ride are getting a bit soft and would like a lower gear.


 
Posted : 22/11/2016 10:12 am
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Went to a 30t on my 29er. I was spending to much time in the 42 with 32t chainring. It's a compromise though, if like me you like to push on the pedals not coast its a bit spinny on road and fireroad descents.


 
Posted : 22/11/2016 10:22 am
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Hmmm - so if I go 30T I don't need to mess with the chain... I may give that a go then!

Still tempted by 28 mind 😉


 
Posted : 22/11/2016 10:26 am
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Just popped down to take a look - 2017 GX uses direct mount chainrings, not spiders... this should make life easier 🙂


 
Posted : 22/11/2016 10:53 am
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im on 28 front 10/42 rear and love it, Always liked to spin my legs with the granny ring on the old triple set up, top speed is a little bit down but I can live with that. As steve said steel front rings last a long time


 
Posted : 22/11/2016 10:43 pm
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Just found a direct mount SRAM steel 28 tooth chainring on t'interwebs so have gone with that! Figure I can always up it later on as fitness comes back if I want - but I tend to be a winch and plummet kinda rider anyway.

I have mass on my side!

Cheers folks!


 
Posted : 22/11/2016 10:54 pm
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My twice penneth
After having used a few bikes with lower gearing and then getting an enduro with 1x11 32chainring, 42 rear cog, my hip and legs were really aching after each ride, gone down to a 30t on the front and it's made such a difference, I boughtthe 28t but returned that , using the sram fit snaggletooth by blackspire, very happy with it,
Although I may try a 32t oval, as they are meant to cover the effective 30-32t range

I prefer to spin in the lower gears rather than grind out the climbs, so I can shift up earlier,
But as always it depends on the rider, terrain and climbing. I ride very hilly


 
Posted : 23/11/2016 7:11 am
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There will be situations using 1x where you need to walk, but, you might be walking with a 2x or 3x setup anyway. It's not for everyone but so long as your frame isn't one of those that will only accept a 1x drivetrain then it's not a big job to switch back.

The oval chainrings do make a difference so it's worth trying one of those out - you don't notice the none roundness after about, oh, 30 seconds.


 
Posted : 23/11/2016 7:28 am
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My plan is to start off with the 28 tooth, once I have a modicum of fitness back in a few months I am thinking I may throw a 30T oval on and see how I get on with that.

Kinda curious about that having cut my mountain biking teeth with (fake) Ovaltech - mine was Suntour's version as I couldn't afford the Big S 😉


 
Posted : 23/11/2016 2:46 pm
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I run 28t front rings with 11 speed 42t cassettes. I find it a great setup. I can spin up virtually anything now, much rather cycle up a climb then push. I don't find I spin out significantly unless it's a long flat/descending fire road. To be honest I am not bothered in that situation.


 
Posted : 23/11/2016 4:13 pm
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28 might be a PITA on any flatter / road sections in terms of you spinning out. Depends on your thoughts on that.

Don't underestimate what a change in tyres would do, too. Something faster rolling out back (and up front) would help. If your riding isn't too aggro, you could get away with something like a Schwalbe Rocket Ron perhaps.

Suppose it is cheaper to swap chain rings than tyres (or cassette) though. Also don't underestimate how much quicker you'll get your fitness back pushing a slightly harder gear. Short term pain and all that...


 
Posted : 23/11/2016 4:41 pm
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28T FTW. I race one with a 10-42


 
Posted : 23/11/2016 5:01 pm
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32 and 34 for races


 
Posted : 23/11/2016 5:06 pm
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Flatter sections... I live in the Lakes 😉

I am hoping that the fitness does come back quick, but a helping hand is always a good thing 😉

I did consider less aggressive tyres, but I am trying to keep off the road as much as possible! The winter clag is going to be here soon enough now.... I have a hardtail with something considerably less aggro on it, but I haven't quite got that fettled up and ready to go as yet! Probably a job for Christmas!


 
Posted : 23/11/2016 5:59 pm
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30t 11-46t here on the peak district bike. Perfect compromise for me.


 
Posted : 23/11/2016 7:22 pm
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I struggled at first with the 32T and 11-40T (XT cassette with Hope TRex) and it took a couple of months before I got used to it. Now 30T or 32T up front isn't a problem in the Peak, Dales or Lakes, still with 11-40 out back.


 
Posted : 23/11/2016 7:30 pm
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Amazingly... I forced myself out to see what would happen today - I have a hill outside the house, big road climb, that I thought I would use to test myself... see how many weeks of riding it would take to get up it. The main climb is only 50 vertical meters over 270m so it is a stiff climb, but nothing that dramatic!

Made it first attempt, 14 months (nearly 15) off the bike... and with the 32T upfront still!

This leaves me in a bit of a quandary. I may just pop the new 28T on the shelf for the time being and see how I get on for a bit longer!


 
Posted : 24/11/2016 3:08 pm
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28. No messing. When you are heading up hill and your eyes are popping out then you'll agree


 
Posted : 24/11/2016 3:47 pm