There are a growing number of excellent dropper seatposts that we’re happy to recommend to MTBR readers: Wolf Tooth’s Resolve, BikeYoke’s Revive 2.0, PNW's Loam, and OneUp Components’ V3 Dropper are all reliable options. After more than a year of testing, we’re ready to recommend a lesser-known Taiwanese brand that’s affordable, incredibly smooth, and has proven to be very reliable. Meet Turnon Components’ Bunker dropper seatpost.
Turnon Bunker Dropper Seatpost Highlights
Turnon Bunker Review
✅ Pros: Flawless performance during our year+ test period, adjustable travel, rebuildable
❌ Cons: Limited range of diameters and drops, longer insertion depth than some competitors
💲 Buy if: You want a reliable, set-and-forget dropper post with a reasonable price tag
Turnon is a lesser-known brand compared to the top-droppers on the market today, however, Turnon development team members had previously worked for both KS and Bike Yoke. The Bunker is one of a handful of droppers with a cartridge designed to purge air when dropped. Bike Yoke’s Revive and Wolf Tooth’s Resolve also feature cartridges that allow the rider to purge air from the oil chamber. What makes this dropper unique is its dual-chamber design, which features two air chambers separated by an oil bath. When the rider actuates the seatpost, a port opens, pushing a piston through the oil bath and allowing the slider to drop into the seatpost body. As with Wolf Tooth’s Resolve, this system is self-bleeding and purges air each time the seatpost is compressed.
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The upper air chamber is set to approximately 3.6 times the rider’s weight in kilograms and supports the rider at full extension. According to the company’s formula, my air pressure should be 70kg x 3.6 = 252psi. As a fan of swift seatposts with an audible “thunk” at top out, I increased the air pressure on my test post to 320psi. Turnon notes that the recommended air pressure range for all users should be between 200 and 420psi. The lower chamber is set at the ambient air pressure, and both chambers work together to return the post to full extension when the lever is depressed again.
The Bunker’s air-oil-air sandwich design proved rock solid during testing, with no sagging and zero need for maintenance during more than a year of testing. Turnon relies on IGUS bushings to limit play, and a high-quality wiper seal prevents the ingress of dirt and debris. The service interval for this dropper is also impressive. Turnon claims the Bunker should be serviced every three years or 400 hours—double that of many dropper seatposts.
Turnon’s dropper lever features a short throw design, pulling the cable just six millimeters. It has a very light action and is quick to engage with a light touch. The lever is also highly adjustable, allowing the rider to angle it around the main axis and move it 4.5mm closer or further away from the handlebar. Riders aren’t locked it using the brand’s remote, though some aftermarket levers may require more lever force. I also tested this post with Wolf Tooth’s ReMote Pro lever and didn’t notice much of a difference in lever feel.
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Speaking of more force, before sending this seatpost for review, a Turnon representative emailed me a list of the Bunker post's highlights and several cons of its design relative to the competition. I’m not accustomed to this level of candor from cycling companies, but I respected their honesty. One of the cons listed is its higher breakaway force—a byproduct of a well-sealed system. It’s noticeable when using one’s hand to push the saddle down in a parking lot test, but a non-issue when riding.
Is the Turnon Bunker dropper post a good buy?
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With a price range of $252 - $289, depending on the amount of travel, it’s a great buy compared to several of the top-droppers I mentioned in the introduction. Its performance has been flawless—the Bunker seatpost is smoother and more affordable than many of its competitors. I would rate its action as smoother than both OneUp and PNW, and on par with the performance of Wolf Tooth and BikeYoke. Despite this, there are a couple of nits left to pick.
First, the drop and diameters are rather limited. The 190mm version I tested is the longest option currently available. Many long-legged riders would appreciate having 210mm or 240mm versions to choose from. Second, due to its dual air chamber cartridge, the Bunker's insertion length is longer than several of our favorite droppers.
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Is this a deal breaker? That will depend on you and your bike. If you’re on the cusp of being able to run a longer-stroke dropper on your frame, a seatpost with a lower stack height and shorter insertion length might be a better option for riders looking to maximize their drop. The Bunker is an excellent choice if you have plenty of room in your seat tube.
In the United States, Turnon is distributed through BTI, so virtually any bike shop in the country should be able to order one. They're also available directly through Universal Cycles.
Turnon Bunker Dropper Seatpost Verdict
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Throughout our test period, the Bunker provided faultless performance. If the drop, diameter, and insertion length work for you and your bike, the Bunker is a budget-friendly seatpost that delivers smooth, set-and-forget performance that rivals the best (and most expensive) droppers available today.
Turnon Bunker Dropper Seatpost Highlights
- Self-bleeding cartridge
- Diameters: 30.9 and 31.6mm
- Stock travel options: 125, 160, 190mm
- Travel adjustable in 5mm increments
- Measured weight: 550g (31.6mm 190mm post w/o lever)
- User serviceable
- Three-year warranty
- Price: $252 - $289.00, $55 Lever ($39.00 when purchased with a dropper seatpost)
- For more info, visit: https://en.turnoncomponents.com/
Turnon Bunker Review
✅ Pros: Flawless performance during our year+ test period, adjustable travel, rebuildable
❌ Cons: Limited range of diameters and drops, longer insertion depth than some competitors
💲 Buy if: You want a reliable, set-and-forget dropper post with a reasonable price tag
Turnon is a lesser-known brand compared to the top-droppers on the market today, however, Turnon development team members had previously worked for both KS and Bike Yoke. The Bunker is one of a handful of droppers with a cartridge designed to purge air when dropped. Bike Yoke’s Revive and Wolf Tooth’s Resolve also feature cartridges that allow the rider to purge air from the oil chamber. What makes this dropper unique is its dual-chamber design, which features two air chambers separated by an oil bath. When the rider actuates the seatpost, a port opens, pushing a piston through the oil bath and allowing the slider to drop into the seatpost body. As with Wolf Tooth’s Resolve, this system is self-bleeding and purges air each time the seatpost is compressed.
The Bunker’s air-oil-air sandwich design proved rock solid during testing, with no sagging and zero need for maintenance during more than a year of testing. Turnon relies on IGUS bushings to limit play, and a high-quality wiper seal prevents the ingress of dirt and debris. The service interval for this dropper is also impressive. Turnon claims the Bunker should be serviced every three years or 400 hours—double that of many dropper seatposts.
Is the Turnon Bunker dropper post a good buy?
First, the drop and diameters are rather limited. The 190mm version I tested is the longest option currently available. Many long-legged riders would appreciate having 210mm or 240mm versions to choose from. Second, due to its dual air chamber cartridge, the Bunker's insertion length is longer than several of our favorite droppers.
Is this a deal breaker? That will depend on you and your bike. If you’re on the cusp of being able to run a longer-stroke dropper on your frame, a seatpost with a lower stack height and shorter insertion length might be a better option for riders looking to maximize their drop. The Bunker is an excellent choice if you have plenty of room in your seat tube.
| Seatpost Make & Model | MSRP | Weight w/o Cable and Lever | Max Insertion Length + Cable Actuator | Stack Height (Dropper Seatpost Collar Height) |
| Turnon Bunker 190mm | $289.00 | 550g | 312.4mm | 36.3mm |
| Wolf Tooth Resolve, 200mm | $379.95 | 563g | 291.2mm | 32mm |
| BikeYoke Revive 2.0, 213mm | $380.00 | 645g | 327mm | 42mm |
| OneUp V3, 210mm | $269.99 | 538g | 305mm | 30mm |
| PNW Loam, 200mm | $209.00 | 598g | 290mm | 50mm |
In the United States, Turnon is distributed through BTI, so virtually any bike shop in the country should be able to order one. They're also available directly through Universal Cycles.
Turnon Bunker Dropper Seatpost Verdict
