Spacers are how you move your bars up and down
Headset spacers are the rings stacked on your fork's steerer tube above the headset. Moving a spacer from above the stem to below it raises your handlebar by that spacer's height. Moving one from below to above lowers it. That makes spacers the cheapest way to fine-tune bar height without buying a new stem.
They also do a second job. The stem has to clamp the steerer, and the top cap has to have something to press down on so you can preload the headset bearings. Spacers fill the gap between the headset and the stem, and between the stem and the top of the steerer, so every part sits where it should.
How do spacers change your bar height?
Every millimeter of spacer you move under the stem raises the stem clamp by that same millimeter along the steerer. Move a 10mm spacer from the top of the stack to the bottom and the stem sits 10mm higher on the steerer, with the same stem and the same bar.
It is a little less than 10mm of straight-up height, because the steerer leans back at your head tube angle, so the stem also moves back slightly as it goes up. For a few millimeters of adjustment, the difference is small. We walk through the angles in our post on choosing a stem in the right order.
Wolf Tooth Precision spacers fit 1 1/8" steerers, which covers straight 1 1/8" forks and tapered 1 1/2" to 1 1/8" forks.
Single spacers come in 3, 5, 10, 15, 20, 25 and 30mm, and each one has its height laser marked on the end.
The four-spacer kit adds up to 33mm, and mixing the four lets you set the stem anywhere from 3mm to 33mm in 2mm or 3mm steps.
Which spacers do I need?
Start with the size of your steerer where the stem clamps. Check your fork's spec sheet. A tapered fork is 1 1/2" at the crown and narrows to 1 1/8" up where the stem sits, and a straight fork is 1 1/8" all the way. Wolf Tooth Precision spacers are made for that 1 1/8" top.
Then decide how much adjustment you want. If you are still working out your position, a kit of mixed heights is the most useful thing you can own, because you can try 5mm changes without anything new arriving in the mail. If you know you want exactly 10mm more under the stem, buy that one spacer.
The Wolf Tooth Precision Headset Spacer Kit shown here is four machined aluminum rings in 3, 5, 10 and 15mm heights. Combining them sets your stem anywhere from 3mm to 33mm above the headset, in 2mm or 3mm steps, so you can test small changes to your bar height without buying anything else.
We carry the Wolf Tooth Precision Headset Spacer Kit, the Wolf Tooth Anodized Headset Spacer Kit, and single 5mm Wolf Tooth Precision Headset Spacers. Wolf Tooth machines its Precision spacers from 6061-T6 aluminum in Minneapolis.
Before you cut a steerer, live with the spacers
Our take: do not cut your steerer tube until you have ridden your position for a few weeks. A cut steerer cannot be made longer. Spacers stacked above the stem look a little untidy, but they keep every option open while you find the height that works.
Your fork maker may limit how much spacer stack is allowed under the stem, especially on a carbon steerer. That limit lives in your fork's manual, so check it before you add height.
- Loosen the stem's steerer bolts, then remove the top cap bolt and the top cap.
- Slide the stem off the steerer, keeping a hand on the fork so it does not drop out of the frame.
- Move the spacers you want from above the stem to below it, or the other way around.
- Slide the stem back on, refit the top cap, and snug the top cap bolt just until the headset has no play and the bars still turn freely.
- Line up the stem with the front wheel, then tighten the stem bolts to the torque printed on the stem.
Common questions
What do headset spacers do?
Headset spacers set the height of your stem on the fork's steerer tube, which sets your handlebar height. They also fill the space so the top cap can preload the headset bearings.
Do headset spacers raise the handlebars?
Yes. Moving a spacer from above the stem to below it raises the stem by the spacer's height. Because the steerer leans back, the bars also move slightly toward you.
What size headset spacer do I need?
Match the spacer to the top of your steerer tube, where the stem clamps. Straight forks and tapered forks are usually 1 1/8" there, but check your fork's spec. Wolf Tooth Precision spacers fit 1 1/8" steerers.
What heights do Wolf Tooth headset spacers come in?
Wolf Tooth makes single spacers in 3, 5, 10, 15, 20, 25 and 30mm, plus a kit with one each of 3, 5, 10 and 15mm.
Can I just stack spacers instead of cutting my steerer?
Yes, within your fork maker's limits. If your fork manual lists a maximum spacer stack, stay under it.
Should I cut my steerer tube?
Only once your bar height is settled. A cut steerer cannot be made longer, so ride your position for a few weeks first.
Before you order spacers
Count the spacers on your bike now and note where they sit, above or below the stem. That tells you how much room you already have to move the bars before you buy anything. Wolf Tooth's Precision Headset Spacers page lists every height and color.
Questions about your fork? Ask us. If you want the lab to do the swap or cut a steerer, that is billed bench work.
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