How to choose your cap, star nut and headset spacers for a road bike?

As these parts are essential for ensuring the correct operation of your cockpit, and in particular your steering, here is some information to clear up any doubts on the subject.

Standards

The fork steerer diameter: 1", 1"1/8 or 1"1/4
The type: star nut or expander

Types of caps, star nuts and spacers

The stem cap A is the component placed above your stem B to complete the assembly but also to adjust the headset play.

The star nut C is essentially a threaded insert that is pressed into the fork steerer so that the stem cap bolt can be screwed into it. There is another system called an expander D. This is not pressed into the steerer but expands when tightened, locking itself inside the steerer.

The headset spacers E are the washers placed under the stem to raise the cockpit if needed.

Whether it is the cap, the star nut or the spacers, they come in 3 different sizes directly determined by the fork steerer size F ; so in 1", 1"1/8 or 1"1/4.

Which cap, star nut and spacers should I choose?

Apart from the size, which is directly determined by the steerer size, you can fit whatever you like. It is not uncommon to fit an original cap and/or spacers to personalise your bike.

If you are unsure between a classic star nut or an expander, remember that the former is not recommended for a carbon fork steerer, for which a less aggressive expander is advised.

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ROAD - Plugs and Expanders

FSA 1"1/8 Alu Black Expander

Regular price 62,00 PLN

Regular price Sale price 62,00 PLN
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PRO 1"1/8 Long Expander

Regular price 114,00 PLN

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PRO 1"1/8 Alu Star Nut

Regular price 12,00 PLN

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DEDA 1"1/8 Stem Cap

Regular price 29,00 PLN

Regular price Sale price 29,00 PLN
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CANE CREEK ANCORA PREMIUM Expander

Regular price 142,00 PLN

Regular price Sale price 142,00 PLN
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RITCHEY WCS 1"1/8 Expander

Regular price 67,00 PLN

Regular price Sale price 67,00 PLN
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RITCHEY WCS Stem Cap

Regular price 52,00 PLN

Regular price Sale price 52,00 PLN
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FSA ACR Expander 1"1/8 TH 892

Regular price 119,00 PLN

Regular price Sale price 119,00 PLN
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