The stem is a tiny part of a bike. But it has a significant influence on the overall riding experience. The size or angle of it determines your sitting position on the bike. The angle will frequently fluctuate if it does not tighten well.
As a result, your sitting position will change again and again. Thus, it will cause unstable and inefficient riding. Besides, the steering control will be poor if the stem is not tightened well.
Anyways, there can be numerous reasons why the bike stem will not tighten. But very few are familiar. I will explain them. Then we will figure out the solutions together. Here you go.
Why bike stem will not tighten
The bike stem will not tighten if its size is wrong. Besides, it happens when there is a loose stem expander. However, it can occur due to faulty wedges. In rare cases, the stem will not tighten when it gets too oily.
If the problem is still unclear to you, let me clear it out. Here are the reasons why the bike stem won’t tighten.
- Wrong-sized stem: If you have a threadless stem, its size is the only reason it will not tighten. The stems come in various lengths, angles, and diameters. However, you should choose the diameter according to the diameter of the handlebar and headset. If the stem’s diameter is higher than theirs, it will never tighten.
- Loose stem expander: It’s a typical problem in the quilled stems. If you have loosened the stem expander too much, the wedge will fall down at the bottom of the headset. As a result, the bolt fails to reach the wedge, and you fail to retighten the stem.
- Faulty parts: Sometimes, you can fail to tighten the stem due to its defective parts. However, it can be the expander bolt or the wedge. When there are broken threads on the bolt, it won’t tighten. Besides, it occurs if the wedge is somehow damaged.
- Over lubrication: You can face it quite often. You must lubricate the steering for smooth control. If the oil somehow penetrates the stem, it will get slippery. As a result, it will keep loosening no matter how hard you tighten it.
A quick fix to loose bike stem
In most cases, the problem gets resolved with minimum effort. If it’s about an oily stem or loose expander bolt, follow the below tips. The problem will get fixed quickly.
- Clean the stem: If excessive lubrication is the problem, clean the stem. You can simply do it with soap and water. Or you can apply Degreaser on it. If the stem is still not tightening, remove it from the bike. Then, clean it again and retighten it.
- Tighten it right: This is the simplest and most exciting solution to a loose stem. If you suspect a loose expander, try it. Rotate the bike upside down when the wedge falls down at the bottom. Thus, the wedge will reach the bolt, and you will be able to tighten the stem.
How to tighten a loose bike stem
If the item is damaged or has faulty parts, there is no other way than replace it. Here, I will explain the replacement process. Before that, you should get the stem right. So, I have divided the process into 2 steps. Check it out.
Step-1: Get the right stem
You have already learned the stem keep loosening when the size is wrong. Well, a correct-sized stem can provide an efficient and comfortable ride. If the size is wrong, it can cause inefficiency and pain. Alongside size, the material is also crucial for getting the expected durability from a stem. Here are the factors you should consider while getting a bike stem.
- Material: Aluminum alloy is the most standard option for a bike stem. It’s comparatively light in weight and decent in strength. However, you can also find titanium and carbon in the bike stem. Carbon is super light, and titanium is less corrosive. But they will cost double or triple of aluminum alloy. So, I suggest getting a high-grade aluminum stem instead of carbon or titanium. It will be high-performing and pocket-friendly as well.
- Size: I have already talked about stem diameter. It should be according to the handlebar and headset diameter. Now, let’s discuss the length and angle. The length and angle of a stem influence your sitting position while riding. Higher length and lower rise allow you to sit in an aggressive position. It is suitable for a speedy ride. Lower length and higher rise offer a comfortable upright position. It is necessary for excellent control and comfortable riding. Now, you have to decide which one you want.
| Freaky Tip: A stem with 90-120 mm length and a 15-degree negative rise is standard for road racing. Whereas a stem of 30-50 mm length and 15mm positive rise is considered comfortable for off-road riding and hill tracks. |
Step-2: Replace the stem
There are 2 types of bike stems; threadless and quilled. The threadless stem is easy to install. Whereas installing a quilled stem is a bit complicated. But there are similarities too. So, I am describing them together.
1. Remove the handlebar: This step is almost identical for threadless and quilled stems. Firstly, remove the faceplate. Get a compatible hex wrench and loosen the pinch bolts on the faceplate. It will be open. Now, carefully bring the handlebar out. After this step, the handlebar will fall down. To avoid damage, tie the handlebar with zip ties or velcro straps and secure it with a frame.
2. Remove the stem: If you are doing the job on a repair stand, secure the fork with velcro straps. Because the fork will fall down after this process. For the threadless stem, remove the pinch bolts on the steerer tube. Then remove the top cap and top spacer. The stem will be removed.
Rotate the expander bolt anticlockwise 2-3 times for the quilled stem. Now, you can remove the stem. If the item is still not coming out, hit the bolt gently with a punch. Thus, the wedge will be free, and you can remove the stem.
3. Install the stem: If the new stem is threadless, put the stem and top spacer in the steering tube. If you want to adjust the handlebar height, you may need to swap the spacers’ positions. Now, seal the stem with the top cap. You can apply a little grease on the top cap and pinch the bolts.
However, tighten the pinch bolts, but don’t over-tighten them. Then adjust the stem to 180 degrees with the top tube and tighten it correctly. Lastly, use a torque wrench to give the bolts the correct amount of torque according to manufacturer specifications.
If you get a new quilled stem, slightly grease the quill and top tube. Then insert the stem according to your preferred height. Hold the stem straight with the top tube and maintain your preferred height. Then rotate the expander bolt clockwise with 2 revolutions. Finally, apply torque to the expander bolt to achieve the suggested range.
4. Install the handlebar: This process is universal for both quilled and threadless stems. Firstly, put the handlebar on the stem and place the faceplate correctly. Screw the pinch bolts but don’t tighten them too much. Now adjust the handlebar to the correct position.
Make sure the stem stays in the middle of the handlebar. Adjust the angle according to your preference. Now, tighten the pinch bolts. Don’t tighten the bolts one by one. Instead, each bolts little and keeps doing it until they get tight enough. Lastly, apply torque to the pinch bolts, and you are done.
Frequently asked questions about bike stem
Do you need a torque wrench for the bike stem?
Yes. You will need a torque wrench for the bike stem. Look, the stem is a sensitive part of a bike. If you over-tighten it, the handlebar or the headset will damage. So, you should do it with a torque wrench. By this, you can control the tightness of the stem bolts. Then you can apply torque according to the manufacturer’s specifications. However, this is not applicable if you are already an expert in bike repair jobs.
What torque should a bike stem be?
The torque on a bike stem should not be above 6 Nm. However, 4 to 6 Nm is the average torque range on a bike stem. If you fail to maintain the range, the stem will be too loose or tight.
Should you grease a quill stem?
Not really. If you lube the stem, it will get slippery and loose. But, you can apply a little grease when it is stuck. But this is only for the removal process. While installing, you should use an assembly compound instead of grease. It will keep the parts free from rust and damage.
Conclusion
Throughout the post, you learned that stem can heavily influence the riding experience. So, it should get fixed immediately when you find any fault or damage. However, repairing the stem is not just about tightening or installation. It’s more than that. Getting a suitable stem is the most crucial step of them.
The easiest way to choose a bike stem is to get one identical to the old one. In most bikes, the specifications are written on the stem. Otherwise, you will find it on the user manual or manufacturer specification. After getting the right stem, install it according to the process I described earlier. I hope all the problems will get solved.
Cheers!
