Hi-Ten steel stands for high-tensile steel. This type of steel showcases greater tensile strength than lower grade alloys thanks to additional ingredients, namely chromium, molybdenum, silicon, manganese, nickel, and vanadium, which add to its elasticity and ability to sustain pressure.
The properties of Hi-Ten steel and the relatively cheap production process have turned the material into a popular choice for entry-level bicycles and components.
Nonetheless, the availability of more expensive but also stronger and more compliant steels such as 4130 Chromoly makes many people wonder whether a Hi-Ten steel bike is a good investment.
Hi-Ten steel frames are notably weaker than those made of materials with greater tensile strength. In consequence, Hi-Ten frames are not recommended for aggressive riding (e.g., big drops, extreme BMX stunts…etc.)
If that’s the intended purpose of the bicycle, it’s better to buy a stronger frame as it will have a longer lifespan and save you money in the long run.
But if you’re riding isn’t as extreme (e.g., commuting), a Hi-Ten frame could be sufficient.
What Are The Main Downsides of Hi-Ten Steel?
Hi-Ten steel has a few major disadvantages worth mentioning:
1. Weaker Than Other Steels
Hi-Ten steel is a vague term. Steel marketed as Hi-Ten does not always have impressive tensile strength. The name only says that the particular material has higher tensile strength than other alloys.
The most common Hi-Ten steel found on BMX, commuters and fixed-gear bicycles is known as 1020 and has the following properties:
Hi-Ten 1020 Steel
|Tensile strength||420 MPa*||60900 PSI**|
|Yield strength||350 MPa||50800 PSI|
|Modus of elasticity||186 GPa||27000 KSI|
*MPa stands for megapascal pressure unit and quantifies internal pressure, stress, and tensile strength
**PSI stands for pounds per square inch and measures the pressure that the material can withstand per square inch.
What is yield strength?
To understand what’s yield strength, one has to become familiar with the so-called yield point.
The yield point defines the moment when the elastic behavior of an element begins to transition into plastic.
Before the yield point, the element will bend under pressure, but then it will return to its previous position once the external force is removed.
Past the yield point, plastic deformation occurs and prevents the recovery of the element.
Or in simpler words, before the yield point, the element is flexible. Past it, it bends and becomes permanently deformed.
The yield strength indicates when the yield point comes. In the case of Hi-Ten 1020 steel, that would be 50800 PSI.
What is the modus of elasticity?
The modus of elasticity is a quantity measuring an object’s resistance to elastic deformation. Stiffer materials have a higher modus of elasticity.
The main steel rival of Hi-Ten steel when it comes to basic bicycle frames is known as 4130 steel or Chromoly (Cr-Mo).
Chromoly has the following characteristics:
4130 Steel Cr-Mo
|Tensile strength||670 MPa||97200 PSI|
|Yield strength||435 MPa||63100 PSI|
|Modus of elasticity||205 GPa||29700 KSI|
- 1020 Hi-Ten steel has a 37.4% lower tensile strength than 4130 steel/Chromoly.
- 1020 Hi-Ten steel has a 19.5% lower yield strength than 4130 steel/Chromoly.
- 1020 Hi-Ten steel has a 9% lower modus of elasticity than 4130 steel/Chromoly.
2. Hi-Ten Steel Frames = Heavy and Strong or Light and Weak
The lower tensile strength of Hi-Ten steel gives it a low strength to weight ratio.
As a result, the manufacturers have to use more material to increase the strength of a frame or a component made from Hi-Ten steel.
Therefore, it is practically impossible for a Hi-Ten frame to be as strong as one made from 4130 Chromoly without weighing noticeably more.
However, that doesn’t mean that all Chromoly frames and forks on the market weigh less than the Hi-Ten steel options.
Sometimes, Hi-Ten frames and those made from 4130 steel have the same or similar weight. Unfortunately, the lighter weight of the Hi-Ten frames comes at the cost of strength and integrity.
Ultimately, Chromoly frames offer more strength and resilience for the same weight.
Some high-quality Hi-Ten steel frames produced in the past were stronger than the modern ones because manufacturers weren’t forced to compete with the lighter Chromoly versions.
But when the transition from Hi-Ten steel to Chromoly began, the Hi-Ten frames got lighter, thinner, and subsequently weaker to match the weight of bikes made from Cr-Mo.
Logically, the new Hi-Ten steel frames quickly developed a reputation for being soft and weak.
The old-school Hi-Ten steel BMX bikes were strong but often reaching weights around 35-38lbs/16-17kg.
Meanwhile, most Chromoly bikes are/were around 23-27lbs/10.5-12.2kg. (a 30% difference) while offering the same strength and thinner more graceful tubing. (Aesthetics matter!).
Naturally, Chromoly won the war and became the preferred steel for BMX bikes, MTBs, fixies…etc.
3. Hi-Ten Steel Bikes Often Have Poor Overall Quality
Since Hi-Ten steel is a fairly cheap material, it’s often found on department store bikes known for their inferior quality and low-end components.
Unsurprisingly, those bikes come with a multitude of problems and are very often a great display of poor quality control.
Don’t be surprised if you examine one of those models only to find subpar welds and rims seemingly made of pot metal.
Having said that, there are also reputable companies that produce higher quality Hi-Ten bicycles. However, those are usually models that you find in specialized bike shops rather than a supermarket.
4. Hi-Ten Steel Is Not As Compliant As 4130 Chromoly
4130 steel is technically slightly stiffer than Hi-Ten due to its higher modus of elasticity (205 GPa vs. 186 GPa in favor of 4130), but it ends up being more compliant thanks to its strength.
The strength of 4130 allows manufacturers to use less material and to rely on the so-called butting process during which the critical parts of a frame (the ends of the tube) are thickened whereas the non-critical segments between the welds are left thin to save weight.
The result is a compliant and yet strong frame minimizing the effect of road vibrations and providing the “springy feeling” that steel is known for.
Conversely, Hi-Ten frames are not butted because the strength of the material does not permit it. In consequence, Hi-Ten frames lack compliance and have a “tank-like” feeling to them.
The Hierarchy of Steel Alloys Used For Bike Frames and Forks
The table below classifies different steel alloys used for bicycle production by their ultimate tensile strength.
|Material||Ultimate Tensile strength*|
|Hi-Ten Steel||60900 PSI|
|Cold-drawn Chromoly (E.g., Reynolds 520)||116030 PSI|
|Air-Hardened Steel (E.g., Reynolds 631)||123282 PSI|
|Heat-Treated Chromoly (E.g., Reynolds 725)||156640 PSI|
|Heat-Treated Air-Hardened Steel (E.g., Reynolds 853)||174045 PSI|
|Maraging steel (E.g., Reynolds 953)||268319 PSI|
*The numbers represent the ultimate or peak tensile strength of the alloys. In practice, the actual tensile strength could be lower depending on the manufacturer and the product. Nonetheless, the hierarchy in terms of strength stays the same even when the values are lower.
In What Cases Is Hi-Ten Steel Acceptable?
(Hi-Ten steel has its downsides, but in some situations, it may be an acceptable compromise.)
1. Something Is Better Than Nothing
Hi-Ten steel bikes are more affordable. This lowers the barrier to entry and allows more people to experience some form of cycling (BMX, commuting…etc.)
If companies were only selling high-end bikes, then the prices would be too high for many potential riders.
I’ll draw a small parallel to explain what I mean by that.
Back in high school, I decided that I want to be a skateboarder. Unfortunately, at the time, our family wasn’t doing well financially, and my mother couldn’t afford to buy me a brand new skateboard.
Eventually, I saved money for a second-hand skateboard which came with a deck made by a local guy, Independent trucks on their death bed, and Element wheels with lots of cuts.
I broke the board after six months because it was built from inappropriate wood. But in the end, this poor skateboard got me into the sport and allowed me to train.
People who find themselves in a similar position, but with a bike, could benefit from some Hi-Ten steel offers.
2. If you buy a bicycle from a reputable company.
Cheap Hi-ten steel bikes produced by unknown brands often showcase poor craftmanship (e.g., weak welding) and come with malfunctioning components.
It’s better to avoid those bicycles because they will drive you crazy while offering little resilience, no comfort, and a greater risk of injury.
If you’re buying a Hi-Ten bike, make sure it’s from a reputable shop and brand.
3. If you’re not sure whether the person who will ride the bicycle is serious about the sport.
If you’re buying a bike for somebody who finds a new hobby every two months, investing in an expensive bicycle may not be the wisest decision because the product will not be put to good use.
I know a woman that bought a USD 2500 MTB for her 12-year-old son just because she can.
While the bike is gorgeous, there is no doubt that the kid would never push the machine to its full potential. A USD 500-700 bicycle would have been more appropriate for him.
4. If you’re not planning to use the bike for hard riding.
If you’re looking for a cheap, non-pretentious commuter that will ride like a tank while deterring potential bike thieves, a decent Hi-Ten bike could be a good solution.
In What Cases Is Hi-Ten Steel Unacceptable?
In some situations, Hi-Ten steel is just a bad choice. Those would be:
1. If you plan to do extreme riding
If you’re looking for a BMX that will certainly face a lot of abuse, do yourself a favor and stay away from Hi-Ten steel.
Not even the highest quality Hi-Ten steel can survive the abuse that a BMX goes through unless the frame weighs as much as a pile of bricks. In that case, the weight will just hinder your performance and slow down the learning curve.
Therefore, if you are a dedicated rider or plan to become one, a full 4130 Chromoly bicycle is the way to go.
The initial purchase will be more expensive, but it will save you money down the line.
If you go for a Hi-Ten frame, break it after 10 months, and only then buy a better one, you will end up spending more on bikes than if you get a Chromoly machine right from the start.
If you have the money and plan to go the distance, invest in a stronger material.
2. If you want to keep the resale value of the bike as high as possible.
A 4130 Chromoly bike keeps its value better than one made from Hi-Ten steel.
3. If you want to decrease the chances of hurting yourself.
An often overlooked part of cheap bicycles is that they aren’t safe when used for extreme riding.
If a frame or a fork breaks, the rider can get seriously injured.
A stronger bicycle is a safer bicycle.
4. If you want to get the benefits of steel
The main advantages of steel as a frame material is that it’s strong, slick-looking (thinner tubes) and compliant.
Unfortunately, Hi-Ten steel frames don’t back those points as well as other steel alloys do.
Frames Combining Both Chromoly and Hi-Ten Steel
Some BMX frames combine Hi-Ten and 4130 steel. For example, it’s not uncommon to see Hi-Ten frames with a front triangle or a down tube made out of Chromoly.
The purpose of this engineering is to lighten the frame and strengthen it at some critical junctures.
While those frames are technically stronger than the Hi-Ten ones, the welds could potentially become a weak spot because they connect two different alloys and make the room for error during welding exponentially smaller.
When similar frames break, it’s usually right at the welds where the Hi-Ten steel meets the Chromoly tubes.
A front triangle Chromoly frame would have its head tube, down tube, seat tube, and top tube made out of Chromoly, but the welds connecting it to the Hi-Ten rear triangle (seat stays + chainstays) would be a major point of compromise.
In general, stunts that would break a regular Hi-Ten frame have a very high chance of disintegrating a mixed one too.
Ultimately, a full Chromoly frame is a significantly better investment and sometimes even cheaper.
Frequently Asked Questions
What’s the downside of buying a Hi-Ten steel fixie?
The main downside of a fixed-gear bicycle manufactured out of Hi-Ten steel is that it’s heavier and less agile than one made from 4130 steel.
Chromoly offers more strength for the same weight and can be butted to become even lighter without compromising the integrity of the bike.
Also, Hi-Ten is steel is not as compliant as higher grade steels.
What is the difference between “butted” and “straight gauge” tubing?
Butted tubing is strengthened at the most critical points near the welds and thinned down the main shaft.
Single butting = only one side of the tube is butted;
Double butting = both ends of the tube are butted;
Triple butting = double reinforcement at both ends with even thinner walls in-between;
Straight gauge or plain tubbing = the tube has the same thickness over its entire length;
The main purpose of butted tubing is to reduce the weight of the frame and make it more “lively”.
Is Hi-Ten suitable for touring cyclists?
It depends on the overall quality of the bicycle. If it’s a cheap bicycle sold in a supermarket, chances are that the components on it are dangerously unreliable, and the quality of craftsmanship is also low. It’s better to stay away from similar products.
If the bicycle is in good condition and produced by a fairly reputable company, then it could work just fine.
What is the cheapest way to get a Chromoly frame?
It depends on the type of bicycle you’re after. If you’re into BMX, the cheapest way to get a full Chromoly one would be to buy from the second-hand market.
If you’re a beginner, it’s advisable to get an expert opinion on the bike you’re considering. If you have friends more experienced than you, send them a link to the particular offer.
If you are just starting and don’t know anyone who can help you, join a local BMX forum and post a link to the second-hand bicycles you’re looking at.
If you want a simple Chromoly commuter, the cheapest way to get your hands on one is to buy a retro mountain or road bike made out of Cr-Mo.
Not long ago, I purchased a full Cr-Mo vintage MTB (plain gauge tubing) for USD 40.
Everything on the bike needed replacement, but the fork and the frame were in decent condition. I sanded them to remove the rust and repainted them.
What is the difference between Reynolds 520 and 4130 Cr-Mo?
In the world of cycling, Reynolds 520 refers to a custom butted tubing that relies on 4130 Cr-Mo steel as a base material.
Or in simpler terms – 4130 is the steel used for the product; Reynolds 520 is the brand name of the product.
Note: A frame marketed solely as 4130 Cr-Mo may have plain/straight gauge tubing whereas Reynolds 520 tubes are butted when used for cycling.