I'm building my first road bike, which means I'll have to find appropriate bar height through personal experience and cut the fork steerer in process at least once. I plan to start with the following combination, from down to top:

  1. 8mm conical spacer that came with headset.
  2. 20mm and 10mm spacers.
  3. 40mm high stem.
  4. 5mm spacer.

In summary, 38mm before stem, 5 after, resulting in total of 83mm of exposed steerer after cut. The fork has 1 1/8 inch (~28mm) tapered carbon fibre steerer, without metal liner inside. Headset is integrated, upper bearing is almost flush with head tube.

Will it be safe or I'll have to cut shorter? Fork manufacturer did not answer the question. I do not plan to ride out of saddle too much, at least during initial fitting, so bars won't experience significant load, and I'm pretty lightweight.

  • This is a question that only the fork manufacturer can answer definitively. I am surprised that you did not get an answer. Commented Jan 15, 2015 at 21:02

2 Answers 2


A total spacer height of 30mm below and 5mm above is quite typical, and certainly nothing to be worried about. The most important thing, since you have a carbon steer tube, is to make sure you use the proper compression plug and the specified amount of torque when assembling it. Also make sure the top of your top spacer is just slightly higher than the top of the steer tube, because the top cap needs to rest on the spacer (or stem), not the tube.

Don't forget you can achieve some bar height adjustment by flipping the stem, too.

  • Thanks, I am aware of all the points you mentioned, these are non-problem (actually, my expansion plug has 28mm flange, so cap can't sit on tube). The real question is if it's OK to have 38mm of spacers below the stem. Commented Jan 15, 2015 at 7:23
  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Gary.Ray
    Commented Sep 13, 2016 at 2:21

I've managed to receive an actual answer from the manufacturer. Turns out all my emails were routed straight to spam folder. The fork in question was Hongfu FM166, other resellers probably have it under similar name. Maximum recommended spacers stack size, as quoted by customer support, is 30mm.

  • Glad to see something official from the manufacturer. For an alloy steerer, on a bike used in anger (maybe a cross race or an aggressive rider on or off road) I wouldn't put more than 40mm of spacers between the stem and the top of the headset, carbon should be less. Thanks for posting their reply.
    – kellbell
    Commented Sep 12, 2016 at 9:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.