


ACS Maindrive Integrated Step-down Headset
Marsoni
M251S
Get it in 3 business days with 1 day shipping.
Friday, May 29
ACS Maindrive Integrated Step-down HeadsetACS Maindrive integrated step down (AKA Reducer) headsets will suit mini to expert sized frames with an integrated 1 1 8" headtube and work with forks with a 1" steerer tube. Featuring an aluminum cap, bearing cover and crown race with super smooth rolling, precision 4545 bearings. Suitable for 1 1 8" integrated (41. 8mm) frames with 1" forks Crown Race: 26 S. H. I. S Lower: IS42 S. H. I. S Upper: IS42 S. H. I. S. Stem Clamp Diameter: 25. 4 Threadless
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Your ACS Maindrive Integrated Step-down Headset orders ship within 1-2 business days.
Delivery Options:
- Standard: 3-7 business days
- Fast: 2-3 business days
- Express: 1-2 business days
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Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
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★★★★★ 5
Good
Good
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Reviewed in the United States on April 27, 2026
★★★★★ 5
Works as it should
Works as it should
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Reviewed in the United States on March 24, 2026
★★★★★ 4
Four Stars
Just what I needed
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Reviewed in the United States on October 14, 2016
★★★★★ 5
Functioned as advertized.
Installed these in my Whalers 96 200 Offshore. No issues, used permatex gasket compound on aluminum engine parts after cleaning with fine brass wire wheel.
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Reviewed in the United States on November 20, 2024
★★★★★ 5
Fits 1988 Sea Ray V-135 2 stroke (Mercury)
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mercury that was branded as the "Sea Ray 135" and paint matched to the boat (i.e. Seville's and some others) this is the 147 degree thermostat for that motor. My Seville is an '88 and It's difficult to cross reference the serial numbers on those motors when searching for parts. Only buy Quicksilver parts for these motors. Happy to find them on Amazon because Boats.net as an example, is not clear on what you're getting.
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Reviewed in the United States on August 3, 2024
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