SIRDAR S-900 MOUNTAIN BIKE Review 2021 | Complete Buying Guide

The Sirdar S-900 is an exemplification of an all-terrain mountain bike with lauding reviews on You are in for a smooth riding experience with its aluminum alloy frame and high carbon steel body to ultra-durable suspension. With upgraded features and relentless innovation, the MTB industry has been revolutionized.

In the market of such intense competition, it is evident for you to be rumbled a bit. But you do not need to worry anymore, while you are checking out one of the best bikes in the market, we will help you out with all there is to know with this SIRDAR S-900 mountain bike review.

So, let us not waste any more time and dive into what you are here for, knowing the sirdar mountain bike thoroughly in order to triumph the mountain roads.

Overview of Sirdar S-900 Mountain Bike Aluminum Alloy and High Carbon Steel with 2 Replaceable Seat:

SIRDAR S-900 27 Speed 27.5 inch Mountain Bike Aluminum Alloy and High Carbon Steel with 2 Replaceable Seat, Full Suspension Disc Brake Outdoor Bikes for Men Women

The Sirdar S-900 mountain bike is one of the most of the highest-rated bikes by customers. The reason for the overwhelming reception is the alluring set of features the bike has.

With a high-quality aluminum alloy frame and high carbon steel body, the Sirdar S-900 is an outstanding choice for a new user as well as a professional. The incredible build has allowed the sirdar mountain bike to be lightweight. Thus, the bike from sirdar is portable enough to carry over state’s mountain climbing.

It has 27 speeds with 9 to 3 rare and front derailleurs. So, you can smoothly change between gears and never have to slow down. It ensures the best performance with just its construction. 

It has a dual disc brake. So, the rider is ensured with the safest ride.

The 2 replaceable saddles provide comfort through customization, 1x mountain cross-country saddle, 1x wide soft saddle, suitable for mountain roads and highways.

The package itself comes with all the necessary accessories and is almost 95% assembled. The model is not only safe, durable, comfortable, and effective but also convenient with minimum prep work. The unit is quite easy to assemble. No wonder why it has the most positive reviews.

Technical features at a glance:

Type and Frame: Mountain bike, aluminum alloy body with high carbon steel parts
Number of Speeds: 27
Weight: Around 36 lbs. while shipped
Gender: Unisex 
Fork: High carbon steel front fork and a premium aluminum suspension fork, functions as excellent shock absorbers
Tires: Anti-skid and explosion-proof Kenda Tires
Front/ Rear Derailleur: 3 gears front derailleur and 9 gears derailleur
Brake: Dual disc brake
Pedals: 2 aluminum pedals
Saddle: 2 replaceable saddles; one 19.2x8.6in wide soft saddle and one 10.6x6.3in mountain cross country saddle. 
Shifter: Finger type shifter
Wheelset: 27.5x1.95in wide
Lights: 2; front and rear illuminating lights

Key Features of SIRDAR S-900 27 Speed 27.5-inch Mountain Bike:

High Carbon Steel and Mountain Bike Aluminum Alloy:

Since the frame of the mountain bike is the actual highlight, it has to be the most significant feature to mention. As mentioned before, the bike features a full aluminum alloy frame. The aluminum construction makes the bike lighter and stronger. The sturdy frame further prevents deformation. At this price point, a construction like this is truly remarkable.

Body- 27.5-inch mountain bike:

Apart from the frame, the other important body parts like handle bar, chains, suspension fork are constructed from high carbon steel. It has a thicker pipe tube which is made of stainless steel. These pipe tubes are durable and almost immune to damage, wear or tear. So whole and whole, it has a sturdy construction. High carbon steel is one of the most popular materials among manufacturers as it provides durability, sturdiness, and a long service life to the bike's components.

Excellent shock absorbing Forks:

The very bike is constructed with high-spec parts like high carbon steel front fork and a premium aluminum suspension fork. The combination makes the biker get smooth control of the bike. The front fork is adjustable. It can be conveniently looked at while riding on flat surfaces like highway roads, parks, and training grounds. You can always unlock it for shock absorption on a rough road. This makes this bike’s forks excellent shock absorbers.

Gearing and Speeding:

The bike has a 3-gears front derailleur and a 9-gears derailleur. It allows the bike to reach 27 speeds of ultra-smooth shifting and it has a finger-type shifter. This function makes shifting gear easier than ever. So, the benefits of having a flawless speeding bike will add value to any professional endeavor.

Brakes (dual disc brake):

Sirdar equipped the bike with dual suspension disk brakes, as mentioned before. The front and rear double disc brakes allow the bike to have a powerful braking system while working smartly as it does not make it easy to get dust into the brakes. Also, the effectiveness of the disc brake makes your rides safer. Dual disc brakes are far superior to regular brakes and a vital component for mountain bikes. 

Anti-skid Tires

The Sirdar S-900 mountain bike comes with two flawless mountain tires. It includes 27.5 inches wheels and anti-explosion & anti-skid tires. The tire pattern is wear-resistant and they have a solid anti-puncture ability. So, the manufacturer did not hold back in quality while making the wheels. This complements the dual disc brakes. With wheels and tires like this, Sirdar offers a great product.

Other Highlights: 

It has two front and rear lights. It does not just add value to the bike but also helps in a darker environment. The unit also comes with two different saddles: one 19.2x8.6 in wide soft saddle and one 10.6x6.3 in mountain cross country saddle that is easily interchangeable. And with two fine aluminum paddles, the bike package is complete. The reviews on are a testament to how incredible this bike is.

You should take a look at our comparison of the best road bike saddle bag if you want to learn some key features about saddle bags.

  • Hassle-free assemble
  • Two replaceable multipurpose saddle, comfortable seat
  • Two front and rear illuminating lights
  • High-end components like alloy frame and high carbon steel body
  • Advanced dual disc brakes
  • Suitable for both male and female
  • Durable components like handle bar, forks, disc brakes, wheels and chain
  • Chain remains steady during gear shifting
  • Price justifies the quality 
  • Rider height needs to be over 5 feet 6 inches 

SIRDAR S-900 Mountain Bike - Buying Guide

The resolution of buying a full aluminum alloy frame bike is most probably the finest decision while thinking of buying a mountain bike. Still, there are things to consider before actually choosing one for yourself. An aluminum mountain bike is generally far cheaper and lighter than one made entirely with elements like high carbon steel. So, let us not delay any further and jump into the complete buying guide for mountain bikes. Hopefully, this will come of use while you surf or eBay in search of the perfect purchase.


You should look for the weight and material of the bike. The lighter the bike, the more conveniently it can be managed. In mountain bikes, aluminum alloy is perhaps the best combination, which this model comes with. Components such as wheels, the seat, saddle, chain should also be made of material that are lightweight yet sturdy for a confident ride.

Torsional Stiffness:

The flex amount released as the biker stomps the pedals is called the torsional stiffness. The more comprehensive the torsional stiffness, the more elevated power is transferred. Carbon frames generally feel a lot stiffer than aluminum ones and, therefore they are a lot more active. However, for more harsh ground and aggressive biking, flexing in the aluminum frame can make for a more lenient ride. Make sure you can align the shifting of speeds with the stiffness.


Buying a mountain bike is a combination of many aspects, but ensuring comfort while on the seat needs two of the most important aspects- the fork function and the tire stiffness. The more effective the forks are, the greater the comfort during a ride. So, it is a must to check out the fork, the handle bar, and tire specifications before buying thoroughly. It is essential for the smooth-riding experience for mountain bikers.  Additionally, check the nature of the saddle.


Buying any equipment requires assembling parts. The hastier the assembling process, the more annoyed the customer as he/she sits confused with assembly tools. The customer may not even have the assembly tools. The mountain bike can be easily assembled like the bike in discussion; SIRDAR S-900 MB is already 95% assembled and the bike is to some extent customizable with its replaceable saddle. But there are other bikes that come in factory condition. Every part starting from the seat to the brakes needs to be assembled separately with the right assembly tools, which can take from hours to days. That is an inconvenience you ought to avoid. So, check for the assembly guide before you commit to buying a bike. It can save you a lot of time, trouble, and energy.

Shifting and Braking:

Mountain bikes with different speeds need twist shifters for convenience and safety. Additionally, double disc brakes made of sturdy materials are a must for mountain bikes as safe braking minimizes the possibility of accidents.


Budget is the most sensitive issue when buying anything. Products like this come off in different price ranges. The price can be under $400 and also above $2500 bikes. You need to understand the features and performance efficiency compared to the price. You undoubtedly know your budget beforehand, so looking for the best product with the best features is my comparison of buying sites and shops. Do not buy the first one you see, or don’t buy a bike with more price which actually is of less value. Take the help of popular sites like to compare each price.

Customer Service and Warranty:

The warranty is a part of proper customer service that’s essential for bikes, let alone any kind of products. The bikes are equipment that needs servicing for effective performance, and they are always used in harsh workloads. Mountain bikes are put through even more challenging phases. So having a convenient warranty/guarantee life is extremely helpful in the long run. Customer service is actually what creates customer value through safeguarding the mountain bikes and their components. A good customer service system creates a good brand name. Thus, you may need to look for brands that offer that facility with confidence.

Final Words

In final, we can come to this conclusion that the SIRDAR S-900 mountain bike (aluminum alloy) is one of the most complete products in the market at a good price. It has near to no bad reviews till now and has growing market demand.  With its dual disc brake and sturdy construction with appropriate materials, it has been in the riders’ hearts since its release. Doesn’t matter if you are a boy or girl because it is a unisex bike that will support your comfortable ride with its safe seat and comfy saddle. You can be a beginner or a professional mountain biker and it will still deliver the most satisfying optimal performance for both practices. And we are here to help you with the complete profile of the bike so that there is no research gap from your side when you choose it to scour mountain roads.

The SIRDAR S-900 Mountain Bike is unisex. However, if you are interested in women's road bikes for beginners, you should see what we wrote in our featured review of Best Women’s Road Bike for Beginners.

Frequently Asked Questions

  • What height is a 27.5-inch Sirdar S-900 bike for?

Answer: between 5’5” and 6’2”.

  • What weight is a 27.5-inch Sirdar S-900 bike for?

Answer: maximum weight of 330 lbs. 

  • Is the Sirdar S-900 a good mountain bike?

Answer: Yes. The average rating of the product is 3.9 out of 5 on and 4.1 out of 5 stars on other sites. It is in the top ten best mountain bikes in the MTB bicycle market.

  • Can the tires be quickly disconnected? 

Answer: Of course.

  • Can the Front derailleur be bolted or riveted?

Answer: Yes, it can be with a quick release.

  • Can the Sirdar S-900 bike be converted to a stationary bike?

Answer: With the correct equipment, this bike can very easily be converted into a stationary bike. 

  • Does it come with pedals?

Answer: Yes, two high-end aluminum pedals

  • Can you install a bottle holder in the mid-frame of the bike? 

Answer: Absolutely, it can be mounted without an issue.

If you liked this review of ours on the SIRDAR S-900 Mountain Bike, be sure to check out our review of the Huffy Hardtail Mountain Bike which is a great deal for the money.