Niner SIR 9 29er Mountain Bike Review

Niner SIR 9 is composed with strong steel structure and devoted solely for experiencing bigger wheels on singletrack. We all know that Niner is the only company fully dedicated to build frames for 29inch wheels, now they also started making quality components for 29er bike. Good quality steel is possibly the Ideal frame material for a 29er hardtail bike and Niner has used high end steel for SIR 9 with proven Bio-Centric bottom bracket design and custom style dropouts. This makes it a most versatile and a light weight bike that runs on either geared or single speed.

29er bikes always enjoy the status of giving a quality ride and turning any resistance into smooth ride. They can accelerate faster over any obstacles than 26in bike. But bigger wheels and longer fork with short head tube could create flex and make it difficult to find good tracking on trails. The flexi steel frame of any 29er bike is a natural tendency that reacts to any deep track in the ground. It may also raise a sharp creek sound while on climbs or when plucking on roots. But SIR 9 steel frame would overcome the issues that 29er bikes normally face. Niner has built a quality frame for SIR 9 which is capable of adapting to turning easily from one to another of various tasks. You need to follow Niner instructions for bike setup and ask their expert views on custom built.

Super Smooth Performance

Niner SIR 9 is the most versatile and popular bike in the market with key important features. It gives the whole benefit of smooth ride over any stuff that other bikes normally chattered through. With the long frame tubes, this mountain bike would make any rock filled ruts, long singletrack and front-hard trail into softer, it avoid any fatigue to your hands and body. With the option of setting up the bike with full gear would even add more speed and smoothness on the trail. It lets you to enjoy full speed on freewheel without pedalling.

The handling is very impressive and still you can gain full stability at any speed. This light weight bike is easy to control and manoeuvre around just about anything. When built with suitable components the bike would respond well in any section of the trail with true riding experience. This super smooth steel frame got all-rounder geometry suitable for all day adventure no matter what you fit in. If you are a trail rider and do little race then you need to look at a very stiff bike but not SIR 9.

This all-to-do bike frame is comfortable with small-bump damping fork system which is probably available in most forks. If you prefer to do little downhill with consistent big bumps, get the suspension fork, otherwise this mountain bike rocks in full rigid fork with single speed or geared.

Reliable Steel Frame

Niner wanted to make this mountain bike light, fast, flexible and comfortable enough for longer ride. They built the frame with Custom Reynolds 853 steel tubing, one of the finest steel frame structures built from size-specific tubes and posses light weight riding quality. Each size bike use different diameter tubes this means each tube are specifically tuned across different size range which gives perfect spring/strength balance. This muscular steel frame is suspension corrected with gusseted head tube and down tube. This allows you to use either Niner Carbon rigid fork or any fork between 80mm – 100mm of travel without any changes to the geometry of the frame.

The rear triangle of this steel frame feature full set of skinny ‘S’ bend seatstay and chainstay. The Chainstay has been slightly curved to maximise the tyre clearance, any larger tyres can easily fit. It also offers vertical compliances on rear wheel and makes for a comfortable feel over a long ride. The head tube is built to fit any standard headset size but Niner recommends Chris King headset for specific and tight riding feel. The seat tube is externally ringed for 27.2 seatpost length and the stainless steel head badge on head tube adds good look to the frame. The frame is available in Moondust grey and Kermit Green colours which look like a luxurious metallic paintwork.

Eccentric Bottom Bracket

Flexible Dropout System

Flexibility with Single Speed or Geared

Specific highlight of this mountain bike is the improved Bio-centric Bottom Bracket (EBB) design with clean downtube cable routing that allows the riders to easily switch between either single speed or geared. The replaceable dropout can also be used which gives the preference for any number of gear choices. It can also be easily removed when you ride the bike for singlespeed. Bio-centric BB weighs just 100 gms and it is the lightest bottom bracket available in the market that helps the riders to get perfect chain tension and vertical dropouts.

This functional chain tightening system gives perfect alignment to the crankset and there is no need to deal with disc brake to remove the wheel. This eccentric BB combined with relatively non-interfering down tube routing is a perfect system to take up chain slack. But it needs regular maintenance, when the BB gets into grit/dirt you need to clean it thoroughly with rubbing alcohol and fix it again.

Bike Setup

This 29er mountain bike comes with flexible dropout system; this dropout can be replaced with single speed insert or replaceable derailleur hanger that normally comes with the bike. Both these dropouts are designed and custom manufactured by Niner specially to be used in SIR 9 bike. This 29er steel frame is available with built kit option and you can choose between Shimano or SRAM drivetrain components. You can also customize your SIR 9 bike with Niner Carbon fork or suspension fork from Rock Shox or Fox; Wheelset option is also available. Frame only option includes the Niner Bio-Centric Bottom Bracket and both singlespeed and rear-derailleur compatible dropouts.

Our analysis

It is a long lasting, all-purpose hardtail bike which allows everyone to own high end steel frame without having to pay the premium of a custom build. Great steel makes for a very comfy ride and Niner has proved that in SIR 9.

Shop Online Niner SIR 9 Mountain Bike