How to Adjust a Threadless Headset
Learn how to check the adjustment of a threadless (Aheadset) and align the handlebars.
In today’s tutorial, we’ll learn how to adjust a threadless headset, otherwise known as an ‘Aheadset. For this job, you’ll need either a 5mm or a 6mm allen key, depending on your stem.
To loosen the stem, simply turn the allen key on top counter-clockwise a few turns. Don’t remove it completely. Then loosen the two bolts on the side. Now your stem should turn freely.
To check if the headset is tight, lift the front of the bike off the ground. The handlebar should rotate freely and fall to one side or the other. If it doesn’t, you’ll have to loosen the top bolt a little bit and try it again.
To check for play, hold the front brake, place one hand on your headset, and rock the bike forward and backward. If the headset is loose you’ll feel it, and you’ll have to tighten the top bolt a little bit.
Once the adjustment is set, check the alignment. I find it easiest to line up the stem with the front wheel while you’re sitting on the bike. Once the handlebar is straight, tighten the two stem bolts and check the adjustment again just to be sure.
Related Links
- Park Tool: Threadless Headset Service
- Sheldon Brown: Servicing Bicycle Headsets
- Bicycle Torque Specifications
Recommended Tools
- Park Tool HXS-1.2 Hex Wrench Set
- Park Tool AWS-1 3-Way Hex Wrench
- Park Tool AWS-10 Folding Hex Wrench Set
- Park Tool WTK-2 Essential Tool Kit
- Park Tool SK-3 Starter Mechanic Tool Kit
- Park Tool PK-3 Professional Tool Kit
Categories
Discuss this topic in the Bicycle Repairs and Mechanics Forum
Derailleur moves the chain but won't stay in gear
Latest post 2 days agoHi, I have an older road bike. It's a 12 speed with the gear shift on the lower bar. The rear derailleur seems to work, that is it shift from the small sprocket to the largest, but it will not stay in anything beyond the the small one. I have replaced the cable and adjusted the high/low as in the video (thanks) but nothing is working, it will not stay in any other gears. ...
Read moreSchwinn Meridan Project
Latest post 4 days agoOk I need to know if this is even possible? I noticed on other sites there are 6speed and 7 speed Adult tricycles. I was pondering the idea of modifying a Schwinn Meridian 2008 model into maybe a 6speed. Before I go any further is that even possible without getting into major work? If so, then what about expanding that idea into a 12speed by swapping out its current crank with an older Schwinn 1...
Read moreBrake/hub issue
Latest post 5 days agoWhat causes the brakes to lock-up i have only rear foot brake on my cruiser im sure it has to do with the hub but was wondering if its an ez fix or major overhaul?...
Read moreDefective tire causing flats?
Latest post 1 week agoHello, As some of you know, I ride a fat bike everywhere, even for my bikepacking. Over the years, I've noticed that the same tire has been getting a lot of flats. Initially, I didn't think much of it, but this time, I found two tiny steel pin-like structures that were embedded strongly into the tire. I had to use pliers to pull them out, and they almost look like the thread of wires one sees wh...
Read moreModern rims crack at spoke holes
Latest post 3 weeks agoRecently, I was in one of the local bike shops. Someone had brought a bike back to have the back wheel re-trued. There were actually cracks in the rim, originating from the spoke holes. I have had the same problem with my bike. In past decades you could buy a bike, and the wheels were strong. With modern rims, the aluminum is getting thinner and thinner. Now the rims crack. With heavy riders, a...
Read moremeridian trike rear axle lubrication
Latest post 3 weeks agogood afternoon, i have spent the last week cleaning and changing parts on my old 2009 Schwinn Meridian Trike . The rear axle is in need of lubrication. Where is this done? do I just remove the axle retention nuts on each side and lube the bearings? What is a good brand of bearing grease available at Oreilleys? Thank you...
Read moreHow to refurbish a bicycle 101
Latest post 4 weeks agoI thought I would do a thread about how to do a quality refurbish on a bicycle that will be a good user trouble free for quite a while. The scope of this refurb will not contain content about dealing with battle scars it may have endured in its lifetime, primarily because the bicycle is merely an example of a solid platform to build from (vintage lugged frame circa 1990). Purchased for $15us ...
Read moreColnago restoration
Latest post 4 weeks agoHi everyone. A bit repetitive from my intro in GF, but this is the correct section for this post. I’m new to vintage bikes, but I’ve been eyeing a vintage Colnago to restore for a long time. Finally found one and the timing was right to pull the trigger. I’m still trying to identify the exact year, but from my research it’s 1991-1993 Colnago Super PiU. Mostly original, I think, apart from ...
Read morerear wheel for 26" cruiser
Latest post 1 month agoI need a new rear wheel for a 26" firmstrong one-speed bruiser cruiser. I didn't realize there were so many different kinds. Can anyone tell me the axle size. I know it is 36 hole and it is a coaster brake but I don't know the axle size or gauge of spokes. The side of the tires says (557-59) 26 x 2.125. Can anyone give me some advice?...
Read moreIssue recentering side pull brakes
Latest post 1 month agoI'm having trouble with my side pull brakes. One pad rests on the side, mostly stationary, while the other moves freely as I pull the brake lever. I'm fairly beginner at bike repairs, and having looked at youtube videos on recentering brakes, I loosened the mounting bolt, moved the calipers around so they were centred properly, and retightened the mounting bolt. However, after the mounting bolt h...
Read moreCooster brake won't pedal
Latest post 1 month agoMy 26-in coaster brake will not engage when I pedal it just spins and it won't break I've repacked them with grease multiple times tightened it too much didn't tighten it enough I can't figure it out...
Read moreClass Action Filed in Wake of ‘Inadequate’ Shimano Hollowtech Crankset Recall
Latest post 2 months agohttps://www.youtube.com/watch?v=Ny_i51lMTrg https://www.classaction.org/blog/class-action-filed-in-wake-of-inadequate-shimano-hollowtech-crankset-recall...
Read moreRim replacement for Old Cosmos SuperCorsa
Latest post 2 months agoHey guys so I have ~50 years old Cosmos SuperCorsa and the only problem with it is that the rims are bent to the center. I want to replace them but I can't find the exact same brand at a good price. The wheels are from Campagnolo. The bike is 700c with 36 holes. The inner width is 13,5mm and the rim height is 18mm. Are the last 2 measurements not required or it should be exactly as the ones I have...
Read moreSchwinn Meridian 7-speed Chain/
Latest post 2 months agoSo I have a couple of questions that I hope someone in this group might know about or have experience with. This is for my Schwinn Meridian 7-speed trike. 1. Are the derailleur chain and the drive chain the same type? Obviously they're different lengths; and I assume the derailleur chain is a typical 7-speed chain. But what about the main drive chain? Same thing? Or is it a standard single speed ...
Read moreShimano crank inspection process
Latest post 2 months agohttps://www.youtube.com/watch?v=HZLc3Ml4TXQ If anyone reading this takes their cranks for inspection, please share your experience....
Read more