A mere couple of weeks after my delight in having the refurbished Selle SMP Hell saddle back from sneaker restorer RGSkills, I ran into another problem.
The saddle itself wasn’t to blame, however. Instead, it was the stock D-Fuse SL seatpost on Hyro, my 2014 Giant TCX.
More specifically, it was the seatpost’s saddle clamp.
A short recap: The D-Fuse technology first debuted on this specific bike, the 2014 TCX, before making its way into Giant’s more road-oriented offerings like the Defy and the TCR. This was the Taiwan company’s take on a D-shaped carbon fiber composite seatpost, which was more encouraged to bend backwards along the flat side and act as a kind of cantilever leaf spring, along with the carbon fiber construction.
As innovative as D-Fuse was, it was a seatpost technology and not a saddle clamp technology.
On the D-Fuse SL seatpost on the TCX, the saddle clamp is essentially a pair of shaped plates meant to capture the saddle rails up top. They sit on two plates that do the same for the bottom of the saddle, and move on a conical chamfer for angle adjustment. The chamfers then insert into each side of the seatpost’s hollow head. Holding the entire thing together and locking in the saddle position are a single long bolt, a captive nut that it threads into, and a coil spring that goes in the middle. As per Giant, the saddle clamp bolt is meant to be torqued to 15-18 Nm. This seems rather high, but in practice, I’ve tightened it to at least 16 Nm to reduce any chance of saddle slippage.
While riding on the trainer, the Hell just could not hold its position. I first noticed this as a gradual backward slide, and thought all it needed was more friction via a smearing of carbon assembly paste. When I cinched up the whole thing, it happened again. Only this time, I was now unable to take the Hell out of the saddle clamp. The captive nut that accepted all that torque had broken loose, and was now spinning along with the bolt as I tried to loosen it.
Fortunately, the folks at GiantBikeSpares.com, run by UK outfit Revel Outdoors, stock all the proprietary parts needed to keep Giant and Liv bikes running for that little bit longer. I had a spare D-Fuse SL seatpost on hand, having ordered it in 2021, so I pressed it into service, mounting my Selle SMP Drakon saddle so I could continue riding.
The same guys also carry all the small parts needed to rebuild the D-Fuse SL seatpost’s saddle clamp, too. I would not necessarily have to be left with a Selle SMP Hell-shaped paperweight attached to a seatpost it can’t be taken out from. It’s just as well, too, as I can’t really imagine any other way of tackling this problem other than drilling the saddle clamp bolt out.
I’m turning this over to you guys and crowdsourcing a possible answer. How would you tackle this problem, while still making sure both seatpost and saddle can be reused afterward?
the accidental randonneur 