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Discussion Starter · #1 ·
Hi there,

Currently Im running a +/- 6 degree 3T arx team 110mm stem which achieves a saddle to handlebar drop of 57mm. Can anyone tell me how much additional saddle to handlebar drop will be achieved by running a -17 degree 110mm or 120mm stem?

How much of a difference in reach (tip of the saddle to centre of the handlebar) would moving from a -6 degree to a -17 degree stem make? (current reach is 530mm - should be at 535mm)

(obviously, as I want to achieve a lower position, I have already slammed the stem on the headset cap).

Thanks in advance for your advice!
 

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Really want to see the math behind this...

Using a simple right triangle calculator online, I can determine that:

The -6, 110 stem has an effective reach of 109.4 and a drop of 11.5 mm

The -17, 110 stem has an effective reach of 105.19 and a drop of 32.2 mm
The -17, 120 stem has an effective reach of 114.76 and a drop of 35.1 mm
The -17, 100 stem has an effective reach of 95.63 and a drop of 29.2 mm

I *think* it's a simple matter adding/subtracting reach/drop against the -6,110 you have, but I'm not a fitter/frame builder. But I did sleep at a holiday inn express last night.
 

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Assuming your current stem is being used in the -6º position (+11º relative to horizontal), and assuming you have a 73º head tube angle:

Your current stem's effective horizontal length is 108 mm.

Going to a -17º stem (0º relative to horizontal), your stem's effective horizontal length will be it's labeled length. Increasing your reach by 5 mm will put you at a 113 mm stem length. Unless you're going to go custom, you're probably better off sticking with a 110 mm stem, which would increase your reach by only 2 mm.

Going to a horizontal stem, your saddle-to-bar drop will increase by ~21 mm.
 

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It's extraordinarily simple, even for the trig-challenged. Just plug the numbers into this handy calculator:

Bike Stem Calculator - Brightspoke

Another factor to consider: As you lower the bars, your torso pivots downward and forward extending your reach. So, if you're going lower, you may need to go longer a similar amount, and vice versa.

Here's a pic of my setup with a -17 deg stem.

View attachment 276196
 

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Discussion Starter · #6 ·
Ah, thanks for that.

so, going from -6 degrees to -17 degrees with a 110mm stem is going to make the saddle to bar drop about 2cm lower and about 2mm longer. that is, If Im right, which im probably not... Dropping 2cm is pretty massive! maybe too big?
 

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Dropping 2cm is pretty massive! maybe too big?
That does seem like a pretty excessive change in riding position, especially considering what looigi pointed out about a difference in reach with a lower bar height. You could also consider a stem angle somewhere in between the 6º and 17º. I believe, for example, Thomson makes a 10º stem.

You could also see if your LBS has some cheapo take-offs or used stems in the geometry you're interested in so you can put a few hours on it, first hand, before dropping the cash on something nice and light.
 

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Discussion Starter · #9 ·
Hey that's even better!

Thanks very much for all the help guys!

Im apparently abnormally flexible, so I could possibly handle going 2cm lower to ~7.7cm, its just whether I can get the core strength to back it up... You dont see that many guys at the crits and road races with a setup that low... aside from the NRS boys n girls.
 

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FWIW: I had been riding a 6 cm drop for years. On a trip using a rented bike with an adjustable stem I tried a 10 cm drop and rode it ~450 miles. I liked it and upon getting home immediate set up my own road bikes the same way.
 

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I made the same switch a few months back. I went from a -6/110 to a -17/110. So far I really like it. I found that I don't have to bend my elbows as much. I just had to tilt my saddle down ever so slightly.

Funny thing is that I made the switch from the suggestion of a local fitter after seeing me riding on the road.
 
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