24 tooth chainring?

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24 tooth chainring?
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flag Cureton
Posted: Feb 18, 2019 at 20:23 Quote
Hi, I was wondering if putting a 24 tooth chainring or 28 tooth chainring would help on longer climbs. And would you have to get another chain if the chainring size is changed?
flag R-M-R
Posted: Feb 18, 2019 at 20:46 Quote
(sorry, double post)
flag R-M-R
Posted: Feb 18, 2019 at 20:49 Quote
Cureton wrote:
Hi, I was wondering if putting a 24 tooth chainring or 28 tooth chainring would help on longer climbs. And would you have to get another chain if the chainring size is changed?

I ride a 28T with a 9-46 cassette, as do many of my ride buds, and we all wish we had downsized sooner. One of my friends uses a 24T and he's super happy with it. The climbs in our area are fairly steep and the fitness of the riders in question ranges from a bit below average to above average.

When selecting gearing, most riders start with the question "What is the largest first gear I can possibly manage?", then end up with at least a couple gears at the high end that never get used. I've seen riders who never get beyond the sixth sprocket. I don't know about you, but I don't need to be pedaling when descending at 30 mph! Even when I have to ride sections of pavement, I only spin out on descents when it's equally fast to tuck and coast as to pedal.

Instead, I recommend asking "What is the smallest top gear I can live with?" That was the approach of the rider using the 24T. His top gear is just tall enough on typical rides and his lowest gear is needed only on the most ridiculous climbs, but it does let him pedal in comfort while other riders walk up.

You can shorten your existing chain. You'll need only a new quick-link or connection pin. 24T is too small for most chain guides and most bash guards are far more prominent than necessary. You can get guides and bashes that fit if you search hard enough.

A very small ring will increase your bike's anti-squat. For most bikes, this is a good thing, as anti-squat levels have been increasing and bikes pedal a lot more efficiently for it. I'm riding a bike that's tied for fourth-highest anti-squat on the market and I love it. Bit of pedal kickback, but I rarely notice it.

Very small rings can give you an opportunity to do something special: most bikes will have enough clearance that you can move your chainring inboard (i.e. reduce your chainline). The "recommended" chainline for almost every drivetrain is actually outboard from the midline of the cassette - not that it even matters to perfectly align with the midline. If your chain gets tangled around your cassette when you backpedal in first gear, or if you just want a smoother and more efficient drivetrain in your climbing gears, reduce your chainline! I'm using a non-Boost ring on a Boost drivetrain and it is so much better. Wolf Tooth has a great article on this.
flag Cureton
Posted: Feb 18, 2019 at 21:54 Quote
R-M-R wrote:
Cureton wrote:
Hi, I was wondering if putting a 24 tooth chainring or 28 tooth chainring would help on longer climbs. And would you have to get another chain if the chainring size is changed?

I ride a 28T with a 9-46 cassette, as do many of my ride buds, and we all wish we had downsized sooner. One of my friends uses a 24 T and he's super happy with it. The climbs in our area are fairly steep the fitness of the riders in question ranges from a bit below average to above average.

When selecting gearing, most riders start with the question "What is the largest first gear I can possibly manage?", then end up with at least a couple gears at the high end that never get used. I've seen riders who never get beyond the sixth sprocket. I don't know about you, but I don't need to be pedaling when descending at 30 mph! Even when I have to ride sections of pavement, I only spin out on descents when it's equally fast to tuck and coast as to pedal.

Instead, I recommend asking "What is the smallest top gear I can live with?" That was the approach of the rider using the 24T. His top gear is just tall enough on typical rides and his lowest gear is needed only on the most ridiculous climbs, but it does let him pedal in comfort while other riders walk up.

You can shorten your existing chain. You'll need only a new quick-link or connection pin. 24T is too small for most chain guides and most bash guards are far more prominent than necessary. You can get guides and bashes that fit if you search hard enough.

A very small ring will increase your bike's anti-squat. For most bikes, this is a good thing, as anti-squat levels have been increasing and bikes pedal a lot more efficiently for it. I'm riding a bike that's tied for fourth-highest anti-squat on the market and I love it. Bit of pedal kickback, but I rarely notice it.

Very small rings can give you an opportunity to do something special: most bikes will have enough clearance that you can move your chainring inboard (i.e. reduce your chainline). The "recommended" chainline for almost every drivetrain is actually outboard from the midline of the cassette - not that it even matters to perfectly align with the midline. If your chain gets tangled around your cassette when you backpedal in first gear, or if you just want a smoother and more efficient drivetrain in your climbing gears, reduce your chainline! I'm using a non-Boost ring on a Boost drivetrain and it is so much better. Wolf Tooth has a great article on this.

Ok thanks for the info. All I needed to know about it!
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