Going smaller than a 30T chainring

Forums Mountain Bike Forum Going smaller than a 30T chainring

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    • #207205

      After Endover’s post last week about upgrading his bike it has fueled my passion expeditiously to upgrade my own. So thanks Endover!

      With that being said, I ride a Specialized FSR Comp 6Fattie. It came stocked with the Stout XC 30T crankset. I’m contemplating going to like a 28T chainring as I’d enjoy a little more assistance climbing. At 53yrs old some of the climbs I come upon begin to look quite daunting.

      My question is this guys: Is going to a 28T chainring enough to help me with this and, besides lighter weight (which I don’t care about) what other benefits or advantages could I expect by making this change?

      KW

    • #207208

      All depends on the kind of trail you’re riding. But personally, 28t is too small for me, unless its a fatbike. I swapped my fs with an oval though, a WF 30t, and AB 28t on my fattie . As a mid-age slow rider, Id say give it a try. You are upgrading anyway 🙂

    • #207210

      Here on the Eastern slope of the Continental Divide Where climbs are steep and long, 26t is not uncommon.

    • #207212

      Hahaha.   You got my name almost right.  And you’re welcome.

    • #207217

      Thanks for starting this! I have 2×10 and want to go 1x… to keep the best climbing/descending ratio which size chainring is recommended?? Sorry for halfway jacking your thread… Sorry i’m in the same boat as you so I can’t help! 😀

    • #207228

      I think it depends on what your cassette is, if you are rolling a 34 tooth or smaller you will probably benefit from a smaller chain ring.  I am contemplating converting from 2×10 to 1x and will probably go with a 28 tooth ring up front.  Like you I am mid 50’s and value the ability to spin my way up hills over having top end ratios for down hill.  Good luck!

    • #207244

      Let me know how this works out for you, if you decide to make the change.  I’m right behind you age-wise (about to turn 50) and haven’t run out of lower gears yet on any of the rides I’ve done, but also haven’t faced any huge uphills.  The worst part on one of my normal rides is a mile-long uphill gravel road near the trials at Briar Chapel in Chapel Hill, NC.  It’s down hill on the way in to the trails for me, so uphill on my ride home after blasting around the trails for a couple hours.

      Looks like I have the same bike as you as well, so interested in finding out the details.

    • #207319

      How many teeth are on your biggest cog on the cassette?

      Bumping down two teeth in the front will have a noticeable effect on your climbing. The rule of thumb is 1:2 for chainring vs. cassette. So dropping two teeth in the front is basically the equivalent of adding four teeth to your biggest cog.

      Are your wheels setup tubeless? If not, that would be step one before swapping rings. You may find you don’t need the smaller ring once you convert to tubeless.

    • #207373

      I bought a 1×11 last year (biggest ring in rear was 42) and was concerned about the lower gearing, since it won’t go as low as a 2×10.  Immediately I bought a 30T and it was pretty good.  Still needed just a bit lower.  Found a “dished” or offset 28T from a Canadian company, North Shore Billet, that fit the 64BCD mounting of my SRAM crank.  Only slightly moved the chainline in about 1 mm.  Worked great.  Got the low gear I needed, and still had decent top gear.  (I am 62 years old, BTW.)

    • #207487

      What is your cassette?   And have you tried oval chain ring, ,for me an oval gives me the feel climbing of two teeth less with out giving up actual speed. There are no long climbs around here. I actually run 1×9 with 32t oval and a 11-36t cassette and very seldom use 1st gear.

    • #207500

      My tires have been tubeless Aaron. I know that I am going to be giving up top-end speed in my highest gear but, in reality I never really go there unless Im up for a good hard sprint back to the car. Which is rarely ever cause it’s all I can do to just breathe coming back in.

      My LBS is going to get one and put it on. I’ll try it out and see if it’s beneficial or not. If not, I’ll change back. I’d rather gain climbing ability and sacrifice speed.

    • #207534

      I put a 26t (I do a lot of ascending and I’m not an endurance athlete) blackspire on my 2016 Fuse with the same stout crankset.  In short, it was an ordeal and I no longer have those cranks on the bike.

      The problem I had was that the stout crank on the fuse has an oddball 76mm BCD and no removable spider.  This led to me getting the blackspire–it was affordable and one of the few rings in 26t and 76mm BCD.  The problem arose because the blackspire is designed to use the same bolts as the SRAM XX1 cranks that use that BCD.  These are proprietary 8.5mm diameter bolts and are different than the standard 8mm bolt/nut combo that came on the Fuse.  So I ordered those bolts, only to find that they are too long to fit through the fat spider on the stout crank.  There was no way to fit this chainring to the stock crank.  I ended up buying a used Gx crank and an XX1 spider to fit it.

    • #207535

      It’s funny you mention that Carver. I was hoping that I could possibly pick up a good Race Face 28T chain ring for like….$50, right? Wrong. The bike repairman at my LBS called me yesterday and told me that SRAM was my only choice and it would be close to $100. I just hope it’s worth it all in the end. I tend to have an old love affair for climbing and the more technical it is the better. My riding buddy is always standing up to ascend and while I know we’re all different in how we ride I can come right behind him remaining seated and he is incredulous how I was able to do so. LOL. Why work harder if you really don’t have to?!

    • #420393

      I’m running a 28T up front on a SRAM 1×11, and I love the climbing, but it seems to wear chains out faster than the old 32 did. Does this make any sense?

    • #420639

      It’s worthwhile to spend a little time learning about gear ratios and gear inches. The lower the “gear inches” calculated the easier climbing will be – the term refers to the number of inches the bike will go for each revolution of the pedals. The exact figure depends on both the chainring size, tire size and the rear cogs. Some bikes come with a 30T chainring and a 12 speed rear cassette with the largest cog being around 50 teeth. This calculates to about a 16 inch gearing for a 27 inn tire. This is about as slow as most people can go without spinning out or falling over. Anything less than 20 is considered pretty good for most climbing. To put it in perspective the old pros doing the Giro D’Italia climbing the Alps back in the day used a “small” 42t chainring and a “large” 24t rear cog – close to 47 inches. I think they use more reasonable gearing now. A 26t chainring and 42 tooth rear cog gives about the same gear inches as the 30-50. It will spin out out the descents  in a big gear, if you’re concerned at all about that – most aren’t.

      There’s also nothing wrong with doing an occasional “hike a bike”. It takes some pressure off your derrière and can save a fair bit of money.

      Here is a link to a gear calculator: https://www.bikecalc.com/gear_inches

    • #420686

      I buy a “new to me” bike every couple of years and have done several 1x conversions.  I use a bike gear calculator (gears.mtbcrosscountry.com) when deciding on a new cassette and chainring combination.

      In your case going to a 28T or a 30T oval ring probably makes the most sense, but the gear calculator will let you see how a different cassette, a larger cog or even a different wheel size will effect your gearing.

      A gear calculator is especially useful when converting from 2x/3x to 1x.

       

    • #420693

      Wow, just noticed this thread is a blast from the past.

    • #508553

      I had changed over to a 1x from a 2×10 on an old Norco. don’t recall the gear ratio of the old cassette. I had thrown a 10 piece 42 tooth on the back coupled with a 26 up front. Stressed over the decision though. Kept me in a nice granny mode on the climbs. won’t win any races peddling on the flats or downs however.

      I’m also running a 28 tooth with a 46 (1×11) on my Knolly. Mush more effective.

    • #508593

      Sometimes reviving an old thread is helpful. This is a good blast from the past thread,  because the North Shore Billet tip on a 64 bcd 28t chainring is what I was looking for on my son’s Frankenbike.  We cobbled up a fat bike for him and the crank we had is a 2x but it does not have a front derailleur. That solution with put a big chainring on the natural chainline

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