I've been running a 26T or 28T on my 1x11 hardtail as it
- suits my spinning style (skinny tired legs!)
-means I'm running often in middle of cassette so chain wear reduced
- allows me to run a closer range cassette so lighter, cheaper, closer steps between gears with still a v low gear on offer (suits my routes)
- I do occasionally spin out but on my regular rides, v v seldom and at my age, speed is not the main goal!
But I assume there's a technical downside e.g. more friction on the ring, otherwise I'd have thought it'd suit others too (I've fitted plenty to riding buddies).
What are the technical downsides, just out of interest? Or am I more an exception?!
Chain wear is distributed over fewer teeth, so it will wear faster.
Your bike will be lighter so you might get too much air on jumps and overshoot the landing.
I think the closer range cassette that you run is not something that works for most people. I run an 11-51 cassette and make sure my chainring gives me a low enough gear. A smaller chainring would mean I could have a smaller cassette but the 11 tooth cog can't go any smaller so I lose out at the top end. It's all a compromise to a certain extent and depends what you value most
Small chain rings do weird things to full suss geometry, but that not an issue in your case. so, spinning out, maybe a bit of faster wear.
Potentially more damage to chain stay, small rings mean the chain is closer to the chain stay. Also watch out for the chainring offset, I'm sure it'd be fine but could affect gear changing and drivetrain wear but probably pretty negligible.
If the gear range suits your typical rides and you aren't bothered about running out of top grunt, happy days.
These days, it doesn't take much of an incline gradient for me to be reaching for easiest gear on my road bike (34/34), or the 26(?) "granny" ring of the triple on my Voodoo Marasa (with 9-speed 12-36 cassette).
I'd recommend an oval chainring over going for a very small chainring IME.
I'm a huge fan of em. I run a 28T on my Jeht.
Less excuse to get off and push?
Fewer chainguides that work with them?
I’d recommend an oval chainring over going for a very small chainring IME.
My preference has been for a round ring over oval, both for effect on suspension (N/A forOP obvs) and for my pedalling style. Also think I drop the chain more with oval rings, as the chainguide can't cover the gap to the low part of the ring. Accept this is personal preference though.
Maybe I'm doing it wrong but I've never needed a chain-guide since the invention of narrow wide chainrings and clutch mechs. If I drop a chain then I take it as a sign that the chainring is at the end of it's usable life and replace it. But I ride mostly hardtails but then again my old full sus didn't drop the chain either.
If you're not spinning out there's no real downside on a hardtail. On a full-sus you get more anti-squat (which can be a good thing) but more pedal kickback (which can be a bad thing). I run 30:18 on my singlespeed to get more ground clearance when teetering over logs.
Potentially more damage to chain stay, small rings mean the chain is closer to the chain stay
This. My Occam runs a 28t, but I've had to tighten the limit screw so the 10t rear isn't used. Otherwise the chain saws on the chainstay.
So back to 11 speed, but with ludicrously expensive bits....
I run a 28t chainring with an 11-51 (11spd) cassette on my hardtail and with 11-52 (12spd) cassette on my Orbea Occam.
Many of my friends now do the same.
Stirling and the Ochils has steep climbs and so why wouldn't you.
On a full-sus you get more anti-squat (which can be a good thing) but more pedal kickback (which can be a bad thing)
Is this due to the chain height relative to pivot point?
“Is this due to the chain height relative to pivot point?”
Exactly! It’s the force vector of the chain tension and the torque it causes around the pivot point (actual or vertical). On my Levo I’d rather go up two teeth for the gearing but down two teeth for the anti-squat…
Chain wear is distributed over fewer teeth, so it will wear faster.
Less cassette wear on the big alu cog(s) though, unless you're running an all-steel cassette.
Can't see a few more teeth making up for the material difference, e.g. 51T alu would wear faster than a 39T steel.
A new 30T oval ring has just arrived to go on my Bird Aether 9c FS to replace the round 32T. I decided after my last proper ride that I needed it on long climbs. It's a mountain bike and never sees tarmac so I really don't think I'll miss the top end.
Suspension designers have it so much easier now than in the days of triples. Now, a 2 teeth change is considered enough to be considered to make a difference - suspension used to have to handle a 22T change every ride.
