The D-Fuse system is Giant’s answer to road cycling comfort covering compliance in handlebars and seatposts.
Crank Boutique explores the technology and how it works.
Technology in Short
Giant have joined the Compliance Club with their series of proprietary parts called D-Fuse meant to introduce flex – and therefore comfort – into the bicycle system.
- Manufacturer: Giant
- Technology Type: Compliance
- Availability: Proprietary – Giant Bikes only
- Cost: N/A
What is D-Fuse Designed to Do?
As we’ve covered with Specialized Future Shock and Trek IsoSpeed, compliance and comfort is all the rage with some of the biggest bike manufacturers right now. Giant is also part of the comfort club with it’s D-Fuse (it’s meant to defuse the bumps) technology. Initially debuting as a proprietary seatpost on the brand’s elite level cyclocross bikes, the system has since expanded to other bikes across the range – including the ever-popular Defy and new Revolt – and has evolved into a suite of technologies for 2020 models with both seatposts and handlebars included.
D Fuse Seatpost
D shaped seatposts are now pretty common on aero and performance orientated bikes to provide extra comfort on what might otherwise be very firm bikes. Giant probably weren’t the first to experiment with D shaped seatposts, but their standardisation of it across a well selling bike like the Defy probably paved the way for its uptake by far more brands.
All D-Fuse seatposts are a carbon composite, with the flat back and rounded front helping to contribute extra flex in the seatpost providing extra comfort on rougher surfaces and long rides. Giant claims up to 12mm of flex, which is hard to quantify on test, but we can confirm that the 2019 Defy models we’ve ridden (Advanced 2) have been supremely comfortable bikes over long rides around some of the very average road surfaces around Sydney.
The 2020 models of Envy and Revolt will include Giant’s new Contact SL D-Fuse handlebar. This applies the D shape to the bar tops and introduces additional shaping into the drops, with Giant claiming additional 10% compliance for the bar in a downward motion and an additional 30% stiffness when pulling on the bars. The quoted claims are for the carbon version of the D-Fuse, although there an aluminium version which comes specced on some of the lower end models of the Defy and Revolt.
The higher models in the range will pair the new handlebar with the Contact SL Stealth stem for that cableless and integrated front end that everybody is hunting for at the moment.
Here’s a great demo of the seatpost in action:
Does D Fuse Work & Has it Been Well Reviewed?
We haven’t ridden a bike with the new handlebars as yet, and while we have ridden bikes equipped with the D-Fuse Seatpost, that seatpost comes on the Defy, which has been a comfortable bike for a long time. Press reviews of the newest D-Fuse bars and seatposts have been very positive:
2020 Giant Advanced Pro 0 Review
On the climbs the new D-Fuse bar feels as stiff as any carbon bar, so Giant’s claims of its compliance seemed just that — claims. But the D-Fuse bar came into its own on the descent of the Gavia. This legendary climb is for the most part pretty smooth, with some big exceptions. At the first steepening of the descent the road becomes a mixture of ripples, split surfaces and some devilishly deep ruts and potholes where line choice becomes all important and you need to throw in a bunny hop or two to clear hazards. When in the drops of the D-Fuse bar the flex when you hit a bump in the road is pronounced and it works in conjunction with the D-Fuse post, making for a smoothing path through the worst surfaces.
2020 Giant Defy Advanced Pro 0 Review
As promised, both the D-Fuse seatpost and D-Fuse handlebar visibly and tangibly move on a wide range of road imperfections, helping to cancel out smaller road buzz as well as dull the harshness of unexpected potholes. Combined with 70-75psi in the 28mm-wide tubeless tires, the Defy Advanced Pro 0 is the proverbial couch on wheels, even in the small size that I rode. Even better, the ride quality is finally very balanced from front to rear.
2020 Giant Revolt Advanced Pro Review
The compact position and effective damping of the bars provide yet more comfort, but you will still feel the sting of potholes if you hit them. It’s totally different at the rear. The large amount of exposed D-Fuse seatpost takes the sting out of anything and scores highly in terms of compliance.
2020 Giant Revolt Advanced 2 Review
The seatpost is Giant’s own D-Fuse, a narrow carbon post with a D-shaped profile. It does mean you can’t upgrade to an aftermarket offering, but it offers so much flex, I don’t see why you’d want to. Over the rough stuff it really takes out the worst of the bumps and vibration, so at speed you aren’t getting bounced around in the saddle, which makes you more efficient.
Are There Any Known Issues with Giant D Fuse?
While the finishing arms of the major manufactures – including Trek’s Bontrager and Specialized’s Roval – have come on leaps and bounds over the last 5 years in the quality of their kit, fairly not everybody loves proprietary kit on bikes. The unique shape of the D-Fuse seatpost means that the only thing you’re going to be able to replace it with is… another D-Fuse.
In past iterations, there were some grumbles around challenges with offset, although that has been addressed in models over the last 2 years.