110BCD 32t small chain ring?
08-18-16, 11:14 AM
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Lots. With mere mortals unlikely to tolerate low cadences better than professional riders we need gears half the size at 50% less power.
This ignores the fact that pros are considered over-weight at 7% body fat, while 74% of American adult men are over-weight and 36% obese.
A 5'9" guy like Alberto Contador who should race at 137 pounds is overweight at 169, and obese at 203.
Riding a 15 pound bike at the UCI minimum weight with 4 pounds of water/shoes/gear makes combined weights of 156 pounds when racing-fit, 188 over-weight, and 222 pounds obese; calling for 21% and 42% increases in gearing.
Climbing a moderate 8% mountain like l'Alpe d'Huez where pros use 39x23, at half the power 5'9 guys who look like POW survivors should be riding gears like 30x36, the barely over-weight 26x36, and obese 22x36.
Those of us with 10% grades should use 20% smaller granny rings when going all-out.
Obviously things like all day endurance rides in the mountains and loaded touring call for even lower gears.
This ignores the fact that pros are considered over-weight at 7% body fat, while 74% of American adult men are over-weight and 36% obese.
A 5'9" guy like Alberto Contador who should race at 137 pounds is overweight at 169, and obese at 203.
Riding a 15 pound bike at the UCI minimum weight with 4 pounds of water/shoes/gear makes combined weights of 156 pounds when racing-fit, 188 over-weight, and 222 pounds obese; calling for 21% and 42% increases in gearing.
Climbing a moderate 8% mountain like l'Alpe d'Huez where pros use 39x23, at half the power 5'9 guys who look like POW survivors should be riding gears like 30x36, the barely over-weight 26x36, and obese 22x36.
Those of us with 10% grades should use 20% smaller granny rings when going all-out.
Obviously things like all day endurance rides in the mountains and loaded touring call for even lower gears.
08-18-16, 11:51 AM
#27
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There's always this option: https://www.compasscycle.com/shop/co...-double-crank/
Get as small as you need.
Get as small as you need.
Again, as small as you need. Also is compatible with 11-speed drive-trains, and (if it matters), made in US.
08-24-16, 09:43 AM
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So turns out Praxis is using a typical 110mm BCD with standard chainring positions. I searched on bike rumor and found an article from earlier in the year.
"Shown here with their new Micro Compact rings, gravel riders will appreciate getting down to a 32 tooth ring thanks to the stepped mounting tab machined down to allow enough space for the chain on that tiny gear.
Yep, that’s a 110BCD road ring setup that gives you a tiny 32 granny gear, while pretty much everyone else doesn’t go below a 34 because of the chainring bolts and tabs of the spider otherwise hitting the outer plates and rollers of the chain with a gear that small."
"Shown here with their new Micro Compact rings, gravel riders will appreciate getting down to a 32 tooth ring thanks to the stepped mounting tab machined down to allow enough space for the chain on that tiny gear.
Yep, that’s a 110BCD road ring setup that gives you a tiny 32 granny gear, while pretty much everyone else doesn’t go below a 34 because of the chainring bolts and tabs of the spider otherwise hitting the outer plates and rollers of the chain with a gear that small."
08-24-16, 11:30 PM
#30
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So turns out Praxis is using a typical 110mm BCD with standard chainring positions. I searched on bike rumor and found an article from earlier in the year.
"Shown here with their new Micro Compact rings, gravel riders will appreciate getting down to a 32 tooth ring thanks to the stepped mounting tab machined down to allow enough space for the chain on that tiny gear.
Yep, that’s a 110BCD road ring setup that gives you a tiny 32 granny gear, while pretty much everyone else doesn’t go below a 34 because of the chainring bolts and tabs of the spider otherwise hitting the outer plates and rollers of the chain with a gear that small."
"Shown here with their new Micro Compact rings, gravel riders will appreciate getting down to a 32 tooth ring thanks to the stepped mounting tab machined down to allow enough space for the chain on that tiny gear.
Yep, that’s a 110BCD road ring setup that gives you a tiny 32 granny gear, while pretty much everyone else doesn’t go below a 34 because of the chainring bolts and tabs of the spider otherwise hitting the outer plates and rollers of the chain with a gear that small."
08-25-16, 01:04 AM
#31
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That looks a little like the mod required to run a 41T ring on a Campy 144 crankset.
12-07-18, 02:39 AM
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Omg
To the rocket scientists on here that don't quite get it: 4 bolt 110BCD is smaller than 5 bolt 110BCD, THAT'S how it can fit smaller tooth numbers. If you still don't understand, picture a square with sides of 110mm versus a pentagon with sides of 110mm. Which is smaller? LMFAO!!!
12-07-18, 06:10 AM
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Found these rings for the Ultegra 6800.
https://absoluteblack.cc/oval-road-c...for-110-4bcd/#
30/46 & 32/48.
Reading the page, they are doing several optimizations. First of all, the Ultegra 4 bolts aren't oriented on a square, but rather on a rectangle. That allows an oval ring to be used that fits onto the bolt holes better.
Second, they're adding an extra spacer, spacing the small rings off of the spider, and I assume the large ring overhangs slightly to compensate.
Third, they use special bolts. 7mm for the 32, and a mix of 5mm and 7mm for the 30.
https://absoluteblack.cc/oval-road-c...for-110-4bcd/#
30/46 & 32/48.
Reading the page, they are doing several optimizations. First of all, the Ultegra 4 bolts aren't oriented on a square, but rather on a rectangle. That allows an oval ring to be used that fits onto the bolt holes better.
Second, they're adding an extra spacer, spacing the small rings off of the spider, and I assume the large ring overhangs slightly to compensate.
Third, they use special bolts. 7mm for the 32, and a mix of 5mm and 7mm for the 30.
12-07-18, 08:06 AM
#35
don't try this at home.
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To the rocket scientists on here that don't quite get it: 4 bolt 110BCD is smaller than 5 bolt 110BCD, THAT'S how it can fit smaller tooth numbers. If you still don't understand, picture a square with sides of 110mm versus a pentagon with sides of 110mm. Which is smaller? LMFAO!!!
The 110mm isn't the sides of the square, it's the diameter of the circle through the center of the bolts. (That's why it's named "Bolt Circle Diameter"...) The circle is the same either way -- 3,4,5 bolts.
Last edited by rm -rf; 12-07-18 at 08:43 AM.
12-07-18, 08:27 AM
#36
don't try this at home.
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Found these rings for the Ultegra 6800.
https://absoluteblack.cc/oval-road-c...for-110-4bcd/#
30/46 & 32/48.
Reading the page, they are doing several optimizations. First of all, the Ultegra 4 bolts aren't oriented on a square, but rather on a rectangle. That allows an oval ring to be used that fits onto the bolt holes better.
Second, they're adding an extra spacer, spacing the small rings off of the spider, and I assume the large ring overhangs slightly to compensate.
Third, they use special bolts. 7mm for the 32, and a mix of 5mm and 7mm for the 30.
https://absoluteblack.cc/oval-road-c...for-110-4bcd/#
30/46 & 32/48.
Reading the page, they are doing several optimizations. First of all, the Ultegra 4 bolts aren't oriented on a square, but rather on a rectangle. That allows an oval ring to be used that fits onto the bolt holes better.
Second, they're adding an extra spacer, spacing the small rings off of the spider, and I assume the large ring overhangs slightly to compensate.
Third, they use special bolts. 7mm for the 32, and a mix of 5mm and 7mm for the 30.
It appears they move the chain line in a little, use special bolts, and just barely clear the chain plates on the small chainring mount points.
From the description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
IMPORTANT
Due to very special 2.5mm offset construction of BOTH chainrings towards the frame and custom bolts:
*30T can only work with 46T and special bolt set 46/30. (bolts included with small ring)
*32T can only work with 48T and special bolt set 48/32. (bolts included with small ring)*No other combination or mix of rings will work. Due to special mounting construction, aesthetic bolt covers are not offered for this design
*We Only recommend Dura-ace 11spd chain or Sram Eagle 12spd chain for proper clearance of mounting tabs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Two normal bolts, two smaller bolts! This works with the ovalized ring.
It's bolted from the outside. Stock Ultegra is bolted from the inside, without through holes to the outside of the big ring.
Ugly, but a cool hack.
Big ring from outside:
Big ring from inside:
....
Small ring:
A tiny bolt in this position, and minimal clearance!
Last edited by rm -rf; 12-07-18 at 08:45 AM.
12-07-18, 09:46 AM
#37
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To the rocket scientists on here that don't quite get it: 4 bolt 110BCD is smaller than 5 bolt 110BCD, THAT'S how it can fit smaller tooth numbers. If you still don't understand, picture a square with sides of 110mm versus a pentagon with sides of 110mm. Which is smaller? LMFAO!!!
ride more.
12-07-18, 12:26 PM
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I'm always happy to learn something new.
12-07-18, 01:45 PM
#39
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Anyhow ..gear down and watch, as you fall behind.. & Guys like Museeuw,
pass you climbing on the big chainring..
12-07-18, 03:01 PM
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Big or little ring, I don't think I have to worry about keeping up with most pro cyclists, or retired pro cyclists.
Some of my fastest hill climbs are those short climbs of < 1/4 mile, where I'm cruising along on the level at around 20 MPH (snappy for me), then transition from seated to standing on the hill, hardly dropping a gear. But, that only works for the short hills.
I've started doing fewer standing hills, and more seated hills. But, the speed is still similar. Although, there is always the temptation to gear down too much, and creep up the hills.
Still, my "climb cassette" is a 9/23 (great for going down too). I did have to go to a 34T small front sprocket though, primarily for one intense hill climb in Portland.
12-07-18, 03:43 PM
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12-07-18, 03:46 PM
#43
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09-28-20, 11:54 PM
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My Praxis Alba 48/32 110BCD is a 5 bolt arrangement. Crank spider arms interfere with KMC 11 speed chain when on small chain ring. Very annoying! My conclusion is that 32 tooth chain ring is too small for 5 bolt 110 BCD chain ring.
09-29-20, 07:13 AM
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EDIT: Shoot.... just realized I am responding to a 4-year old post
Last edited by Kapusta; 09-29-20 at 07:25 AM.
09-29-20, 06:32 PM
#46
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Lots. With mere mortals unlikely to tolerate low cadences better than professional riders we need gears half the size at 50% less power.
This ignores the fact that pros are too big to compete at 7% body fat, while 74% of American adult men are over-weight and 36% obese.
A 5'9" guy like Alberto Contador who races at 137 pounds is considered overweight at 169, and obese at 203.
Riding a 15 pound bike at the UCI minimum weight with 4 pounds of water/shoes/gear makes combined weights of 156 pounds when racing-fit, 188 over-weight, and 222 pounds obese; calling for 21% and 42% increases in gearing to maintain the same cadence.
Climbing a moderate 8% mountain like l'Alpe d'Huez where pros use 39x23, at half the power 5'9" guys who look like POW survivors should be riding gears like 30x36, the barely over-weight 26x36, and obese 22x36.
Those of us with 10% grades should use 20% smaller granny rings when going all-out.
Obviously things like all day endurance rides in the mountains and loaded touring call for even lower gears.
This ignores the fact that pros are too big to compete at 7% body fat, while 74% of American adult men are over-weight and 36% obese.
A 5'9" guy like Alberto Contador who races at 137 pounds is considered overweight at 169, and obese at 203.
Riding a 15 pound bike at the UCI minimum weight with 4 pounds of water/shoes/gear makes combined weights of 156 pounds when racing-fit, 188 over-weight, and 222 pounds obese; calling for 21% and 42% increases in gearing to maintain the same cadence.
Climbing a moderate 8% mountain like l'Alpe d'Huez where pros use 39x23, at half the power 5'9" guys who look like POW survivors should be riding gears like 30x36, the barely over-weight 26x36, and obese 22x36.
Those of us with 10% grades should use 20% smaller granny rings when going all-out.
Obviously things like all day endurance rides in the mountains and loaded touring call for even lower gears.
10-03-20, 08:30 PM
#47
Who is Austin Dunbar?
I ride a 46/30 on one of my bikes. With an 11/28 cassette, I have all the gearing I would ever need for climbing and still keep nice close ratios. On the high end, a 46/11 is the same gearing as 50/12 which means I only lose one gear compared to today’s typical road gearing. The one thing I don’t do any more is a lot of shifting up front. With a 50 tooth ring, I was doing a lot of shifting to keep cadence where I like it. With the 46, I rarely need the small ring except when climbing. I am thinking of converting my other bike.
10-05-20, 08:18 AM
#48
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Both were silent and produced no known run.
One was for sure a kmc 11sp chain too.
