Turnon Components Bunker Dropper Post – Long-Term Review
Pretty much everyone who considers themselves a mountain biker has experienced a dropper post at one point in their biking lives. It’s one of the seminal pieces of bike technology and would be hard to imagine life without them. The Turnon Components Bunker is one of the latest dropper posts to join the post-revolution.
Turnon Components have recently joined the dropper post market and we had the opportunity to review their new dropper post, the ‘Bunker’. Initially, this was going to be a quick turnaround in terms of review, but life got in the way with illnesses, urgent overseas travel, and poor weather hindering our on-bike testing. But the upside of this is it has allowed us to have more time with the Bunker and has turned into a long-term review.
Turnon Components Bunker Dropper Post – More ride without maintenance.
Turnon Components Bunker – Features
Turnon Components has released its first dropper post, the ‘Bunker’, highlighting its robust design and a double air chamber with high-performance wiper seals. This design ensures both water and dust resistance and boasts a durable maintenance schedule of 400 hours or three years.
After an extended period of development and bolstered by nearly ten years of expertise (the team has worked for both KS and Bike Yoke) in crafting dropper posts, the Bunker introduces an innovative double-air chamber configuration alongside superior wiper seals. This combination establishes a robust system impervious to both water and dust.
At first glance, the Bunker appears like a lot of other dropper posts on the market but don’t be fooled by its generic looks, a lot is going on inside. The Bunker brings some unique tech to the table. One of the main features of the Bunker is its completely sealed feature, stopping grease from escaping or dirt from entering the system.
Photo credit: ©Sam Clarke
The Bunker is a fully serviceable post.
Most dropper posts on the market have a gap at the bottom that allows air to escape when the post is pushed down and lets air in when it pops back up. This action, over time, can cause grease to escape and debris to get back up into the post which compounds over time to cause poor drop/return action or just stop working altogether.
The Bunker dropper seatpost is designed with a unique dual-chamber system. It utilizes two air chambers divided by an oil bath. When the seat post is activated, it opens a port that drives a piston through the oil, enabling the slider to move into the seat post body. Similar to Wolf Tooth’s Resolve, it features a self-bleeding system that automatically purges trapped air with every compression without forcing any grease out of the system due to its fully sealed system.
The Turnon Bunker dropper post comes with a CNC machined remote wire actuated lever that features IGUS bushings in a lightweight package. The clamp is one of the most adjustable designs we’ve seen, allowing you to adjust X-axis 9mm, Y-axis 4.5mm, and Y-axis angles. Rather than opting for a longer lever, the Bunker remote uses a small crank that requires less force making for a very smooth and light thumb action.
Bunker 1-by remote is NOT compatible with all droppers. Currently, the only droppers compatible with this lever are the Turnon Bunker and the BikeYoke Divine SL.
The lightweight CNC machined Turnon Bunker remote with IGUS bushings and smooth actuation.
Technical Specifications:
Dropper Post:
- Double air chamber hydraulic design (Patents pending)
- One air chamber in the cartridge PSI:300~350
- Second air chamber in the lower tube (Pressure from volume compression doesn’t need to be checked)
- Waterproof (IP68) and Dust-proof wiper seals
- High compressed air doesn’t cause seat sag
- Self-bleeding
- Self-lubricating
- Quick actuation
- Re-buildable
- @TecnoLan @IGUS @Shell in use
- Travel: 125mm / 160mm / 190mm
- Routing: Internal only
- Weight:
- ø30.9/31.6-125 422g/442g (Post only)
- ø30.9/31.6-160 475g/495g (Post only)
- ø30.9/31.6-190 525g/550g (Post only)
Bunker 1-by remote
- Adjustment X-axis 9mm, Y-axis 4.5mm, Y-axis angle
- Best remote reaction for Bunker
- CNC carving remote
- Igus bushing used
- Lightweight
- Not recommended for cable pull over 6mm dropper seat post
On The Trails
We’ve been using the Bunker dropper post for almost 4 months and trust us, it has seen a decent amount of usage and awful weather conditions in that time. From deep, powdery dust to sloppy mud and rain, and hasn’t missed a beat.
The overall build quality of the Bunker is exceptional, definitely on par with other top-tier brands. Installation of the dropper itself was straightforward forward but the lever was a little finicky mainly due to the amount of adjustability in the lever clamp.
Insertion lengths may not work for everyone due to the Bunker length being a little longer than other brands due to its dual air chamber. There is also only a 30.9 and 31.6 diameter on offer with no 200+mm drop versions for us longer-legged folk. This could cause some exclusions for Turnon. We hope they come out with a 200+mm version and 34.9mm diameter version soon.
The actuation speed is fast and super-responsive and the small textured thumb lever on the remote is very comfortable to use. The amount of force needed is minimal and offers a buttery feel. And over time, the lever has not required any more adjustment, it is still as tight and responsive as the day we installed it. If you’re like us and enjoy that thunk sound as the post returns to the top, then the Bunker will put a smile on your face.
Turnon recommends air pressure range for all users should be between 200 and 420psi. Their formula is rider weight in kgs x 3.6 – psi. So for myself, sitting at around 90kgs that would be 90kgs x 3.6 = 324psi. What you will notice is the strong force needed to push the dropper down by hand. This is down to the way the Bunker is sealed. The sealed system is so efficient it causes this high breakaway force, however, once on the bike, your body pushes the post down just like any other post.
Photo credit: ©Sam Clarke
So far the seals have proved their weight in gold with no issues regarding drop and return rates, meaning nothing has gotten into the system or stanchion since this time. The claimed weather protection is doing exactly what it says on paper. The bike has also been involved in a couple of heavy crashes and we have experienced zero play in the post, which is an indicator of excellent build quality.
The Bunker boasts a maintenance schedule of 400 hours or three years, double that of most other dropper posts.
Conclusions
There are not many new brands that make such a good first impression but the Turnon Components Bunker dropper post has done just that. A fully sealed unit featuring unique patent-pending internals and super tough wiper seals that protect against the foulest weather conditions, combined with a lightweight CNC machined buttery smooth remote lever, makes it a serious contender for the top of the dropper charts.
With exceptional build quality and no signs of deterioration in performance over 4 months of heavy use and abuse, the Bunker is a dropper that can stand shoulder to shoulder alongside any of the top-tier brands.
The Bunker dropper post may be one of those products that just go under the radar only to be picked up by a lucky few. Well, we’d like to help push this brand and product out to a wider audience because we have been so impressed with it. Currently (at the time of this review) there is no Australian distributor, so all you Aussie distros out there, why not get in touch with Turnon?
Price/Where to Buy
Turnon Components Bunker Dropper Post:
- 125mm – $368.80 AUD
- 160mm – $393.70 AUD
- 190mm – $422.90 AUD
Bunker 1x By Remote:
- 1x By Remote – $80.50 AUD
Free shipping for orders over $300 AUD.
Contact Turnon Components for more info.
