Mountain bikes can be hard to maintain. Especially when you get confused about the travel fork. Because that can take a heavy toll on your riding experience if not done right.
The two most confusing travel forks are 100mm and 120mm.
So, should you go for a 100mm or 120mm travel fork?
100mm travel forks are shorter and lighter compared to 120mm travel forks. That’s why you can get a better commuting experience on your day-to-day rides. On the other end, a 120mm travel fork is better suited for mountain trails. But they are definitely heavier and hard to maneuver.
While you got to know some differences here, there are plenty more! But to know all of that, you need to be a bit patient.
So, let’s get on with the light comparison.
A Light Comparison
Everything starts with little things, even your Mtb bikes too. From its fork travel to track compatibility, your bike is dependent on many things. As I’ll focus on the two travel forks, I want you to understand their characteristics thoroughly.
Otherwise, you’ll find yourself being more confused than ever. Because 120mm travel Mtb is obviously not the same as a 100mm bike.
Having said that, here are a few of those contrasting differences listed in this comparison table-
| Characteristics | 100mm Travel Fork | 120mm Travel Fork |
| Travel Distance | 100mm | 120mm |
| Weight | On average 1300g or 45.85 oz | On average 1500g or 52.91 oz |
| Rider Weight Limit | Around 145lbs | Around 160lbs |
| Attachment Point | 45 degrees | 55 degrees |
| Tube Angle | Firm | Slackened as 20mm difference results in 1-degree tube angle change |
| Maintenance | Inexpensive and easy to repair | A bit costly and tough to maintain |
| Cost | On average $300 | On average $350 |
| Where to Buy | Check latest price | Check latest price |
These are just a sneak peek to the discussion of the difference between 100mm and 120mm forks. If you want to know the full details, follow me to the next segment right away!
The Heavy-hitting Discussion
This is the highlighting segment that you’ve been waiting for. Try to pay close attention to the discussion about these two travel forks. Because often they can feel very similar, but they are actually not.
Another thing! To get an immersive hang of it, this video can be a start to understand the forks-
So, take a seat and follow along.
Size & Weight
As obvious as it may seem, you have to look further into the size & weight factors. Because it’s important to understand how much you want your bike to weigh. If the fork is too big then you might not feel the same way while riding.
100mm fork 29 sizes can be pretty minimal with its 100m radius. Even the weight can be lower by as much as ½ pound than a 120mm fork. So, for making a feather-light build, you may be more inclined towards 100mm.
On the other end, 120mm is bulky but because of that, you get better geometry. While the weight can feel a bit difficult, you’ll have more actuation in the mountains.
So, in this 100mm vs 120mm fork hardtail battle, the winner depends on the user.
Winner: Depends on the biker’s choice and usage.
Head Tube Angles
Head tube angles can become a problem for your MTB if you’re not careful. In this category, 120mm proves better than 100m fork because of the flatter angle. Because of that, you get better ergonomics and control.
However, your average 120mm travel fork tube angle is steeper. While it may not create any complications for you, it’s definitely not a fun one. The response is harsh sometimes and that diminishes the riding experience.
So, you really have to think hard about these two hardtail forks!
Winner: Flatter and more enjoyable response from the 120mm forks.
Attachment Point
Attachment to your wheels is a major factor for mtb travel forks. The 100mm has a flatter 45-degree angle to the front wheels. But that does not mean it’s better. In reality, it can feel loose when driving on mountain terrains.
Interestingly, having a steeper 55-degree angle offers better rigidity in 120mm forks. Even the trail response and feedback are superior to its lightweight counterpart.
Winner: Better attachment point is found in the 120mm travel suspension fork.
Rider Weight Limit
Now, this is an interesting topic to compare. As a rider, you definitely want to check this one out.
If you weigh more than 150lbs, it’s better to go for a 120mm fork. Because it can take up to 160lbs of stress with ease. But your average 100mm forks fall behind with 145lbs of the weight limit.
So, a 120mm fork on an xc bike will perform better in this case. Now, the thing about forks are they can get easily damaged even if the rider limit is maintained. So, getting some service accessories for your bike can be extremely beneficial for you.
Again, it’s not easy to get the best products for fork maintenance, is it? But I’ve found some quality products when I searched through multiple Mtb forums! Let me share what I’ve found to be useful-
- RockShox Fork Service Kit is the best thing that can happen to your fork! You can trust me with this one completely!
- Getting a good Suspension Oil like WPL Forkboost Lube also makes the bike experience smoother.
- Mimoke Bicycle Fork Repair Tool is another great inclusion for your forks
I truly believe these maintenance kits will take your bike riding experience to the next level.
Winner: 120mm forks offer better rider weight limits.
Cost
When it comes to pricing, a very atypical situation arises. I think you can already guess what it is.
The 100mm travel forks are shorter than 120mm ones. That’s why you can find 100mm travel forks at an affordable price range. Even with the same model, the 100m version can cost you $30-50 less at the entry-level.
If you’re planning to purchase 120mm forks, you’ve to consider the price. With the premium models, the price jumps as much as $100 compared to 100mm. So, set your budget first and then decide which way to go.
Winner: 100m travel forks are more affordable than 120mm forks.
Which One Should You Go for?
I’ve tried to highlight the most interesting and important bits about these forks. Still, a good summarization may help you to finally decide on one!
If you’re going for marathons and bulky size, there’s nothing better than a 120mm fork. It’s quite robust and offers an inclined head tube angle. So, you get firm and sturdy responses from your MTB.
Here’s a rider’s thrilling experience of going into the fall mountain biking with 120mm fork-
While both can be used for cross-country, 120mm is better for efficient mountain climbers. Because these can’t get any better when you’re trail mountain biking.
However, it’s tough to find good deals on 120mm forks nowadays. From my extensive research, I’ve found some promising offerings! Here they are-
| Image | 120mm Forks | Reasons to Buy | Where to Get |
|---|---|---|---|
  | RockShox Reba RL Suspension Fork | Click to Edit | Check on Amazon |
  | BUCKLOS 26/27.5/29 Travel 120mm MTB Air Suspension Fork | Click to Edit | Check on Amazon |
On the other end, 100mm is better compatible with cross-country traveling. Its lighter build allows you to enjoy a smooth riding experience with awesome paddling. But it’ll fall short if you’re constantly going on different mountain trails.
While fiding a 100mm fork, you might get confused a lot. To avoid such baffling situations, you can start looking for them from here-
| Image | 100mm Forks | Reasons to Buy | Where to Get |
|---|---|---|---|
  | RockShox Judy Silver TK Suspension Fork | 1. Best for cross-country and commute 2. Durable build 3. Compatible with OneLoc | Available on Amazon |
  | BUCKLOS 26 x 4.0 inch Fat Tire MTB Suspension Fork | 1. Customizable 2. Cost-effective | Available on Amazon |
Even going further beyond 120mm like using 140mm fork with hardtail can perform better in mountains. However, that’s another discussion on its own.
So, in the end, you have to decide depending on your biking needs. I think you’ve gained enough knowledge to make that call!
FAQs
Can I Put a 120mm Fork on a 100mm Bike?
Yes, you’ll be perfectly fine with using a 120mm fork on a 100mm bike. But there’s a catch. If you are still in the warranty period, switching the fork can nullify your warranty. Because most of the brands don’t allow that. However, you can get away with 120mm if you’ve passed the warranty phase.
What Does 120mm Travel Mean?
The fork travel means the compression of your bike’s fork. Basically, how short it can get when you push the bike’s fork. So, for a fork with less than 120mm travel, the best use case is long riding. For a bike with a medium travel count within 160, it’s best for the mountain tracks.
Is More Fork Travel Better?
Fork travel depends on your usage of your mountain bike. More fork travel means that you’ll face a harder time when going uphill. If the travel is far greater than your usual, then it’ll only feel cumbersome and rigid. So, maintaining the fork travel according to your needs is the best way to ride.
Endnote
I hope you got the differences between 100mm or 120mm travel fork. It’ll be easier for you to pick one for your bike.
One last reminder for you. Just make sure to ride with full confidence and thrill!
Best of Luck!
