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Why changing 50T chainring to smaller 44T chainring is heavier?

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Why changing 50T chainring to smaller 44T chainring is heavier?

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Old 11-12-17, 12:12 PM
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hennypenny308
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Why changing 50T chainring to smaller 44T chainring is heavier?

Why does changing the standard 50T chainring to the smaller 44T chainring make the bike heavier? This is on the Brompton bike builder webpage.
I just assumed that the smaller 44T ring should weigh less than the larger 50T ring.
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Old 11-12-17, 12:15 PM
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dabac
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Steel vs aluminium perhaps?
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Old 11-12-17, 02:23 PM
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Old crankset being lighter (one piece) than the newer one where you can change out the chainring?
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Old 11-12-17, 02:48 PM
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Yes, both are good reasons, Ive seen a steel chainring fixed crank arm set in old SJS cycles parts for brompton listings

too bad the OP did not provide a link to their information source...

the 130 bcd current spider crank arm does take non brompton chainrings, a 39t (without the trouser guard) will weigh less than the B 50t with.


Chasing the gram shaving on your bike order? after its yours you can put that carbon fiber composite.. crankset on..

then all the after market Titanium hardware offered ..






..

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Old 11-12-17, 03:01 PM
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The foldable bikes with smaller wheels should have bigger chainrings so the gear ratios/inches make up for the smaller drive wheels. My foldable bike has 20" tires and I have (lucky) a chainring 60t. Sooo my highest gear is 85" gear inches. THAT allows me to keep up with the old fashioned "big wheeled" bikes on regular group trips. Also the pedal cranks must have the same length as other bikes for adultz, 170+ mm. These foldable bikes are verrry practical!
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Old 11-12-17, 03:15 PM
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fietsbob 
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there is the 3 speed hub , with an overdrive 3rd gear, of 4/3 so a 13t cog acts like its a 9.7tooth ..




.....
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Old 11-12-17, 08:52 PM
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I have both 50 and 44 tooth chain rings and they look the same to me apart from size. I think it's a glitch in the Brompton Builder software programming or specs - if there is an actual difference in weight, I'd be surprised if would make the tenth of a pound rounding.
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Old 11-13-17, 02:05 AM
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I'll speak to Brompton to get clarification. They are made from the same material, so it makes sense that a smaller ring should weigh less. I think the most likely explanation is a glitch in the Bike Builder software. I'm not the strongest cyclist and I wanted to get either a single speed or 2 speed with the smallest chainring 44T, so that I can have a nice relaxing ride on the flat and still be able to climb a small slope.
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Old 11-13-17, 12:21 PM
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Smaller ring/protector, shorter chain = should be lighter.
I have some weights listed towards the end of my video:
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Old 11-16-17, 02:26 PM
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Brompton's bike builder has not been updated since 2012. There are some errors, for instance, the reduced gearing should be -12% and -18% (not -19%). The explanation for the weigh discrepancy is another error.
Today, after trying out a 6 speed, I found the 2nd and 4th gears best suited me, so I opted for a 2 speed with -18% gearing.
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