All the numbers and figures don’t mean much if the Idylle doesn’t ride well, and given that the RockShox Boxxer and the Fox 40 are both pretty solid options these days, the Idylle has its work cut out for it if it’s going to justify its price.
Running on 37mm stanchions, the Idylle falls between the Boxxer and the 40 in terms of size, and that about sums up where it lands in terms of stiffness, too: it’s stiffer than a Boxxer, but not as stiff as a 40. That applies to both fore-aft stiffness as well as torsional stiffness.
Notably, even though the Idylle isn’t the absolute stiffest fork out there, I never noticed the fork bind up under load. Particularly on the Boxxer, I’ve found that the fork’s action can become less smooth when hammering through deep holes, since the fork flexes and the bushings bind. The 40 is better about that issue, but that extra stiffness comes at a cost—it’s less forgiving, and can beat up my hands and forearms a bit more.
The Idylle strikes a good middle ground between these two: it’s definitely more comfortable after a day of riding than the 40, but it also didn’t have any of the stiction problems that are sometimes an issue on the Boxxer. Supposedly this is due to BOS’s insane attention to tolerances and perfectly honed internals and bushings; the dialed internals are apparently far less inclined to bind under load.
I can’t personally say whether their tolerances are actually that much different than other brands, but I can definitely say that the Idylle is incredibly smooth in all situations, and that there’s no bushing knock or play whatsoever.
After a brief break in period, it was time to assess how the fork did when the going got rough. Two things became apparent pretty quickly:
First, the Idylle has really, really good small bump sensitivity. Even when I was running pretty high pressure (210psi), the first ~60mm of the stroke is extremely supple and smooth. I can honestly say that this is very close to the level of suppleness that you get out of a coil sprung fork.
While current model Boxxers and 40’s are pretty good in this regard, the Idylle is better. I’m admittedly somewhat baffled that a fork that’s running such high pressures is still so smooth at the beginning of it’s stroke, but I suppose that’s another testament to the Idylle’s high quality seals and tight tolerances.
The second thing I noticed is that it’s quite progressive. The Idylle uses a hydraulic bump stop, which combined with the natural progression of the air spring, makes for a fork that’s fairly hard to bottom out.
I find that some forks are a bit too progressive (i.e., the ramp up comes too early, and I don’t use all of the travel except on absolutely massive hits), but more often for downhill forks, I find them to be a bit too linear. On my prior Boxxer World Cup, I had a hard time getting the air pressure at that magic number where it was supple over small bumps, but still retained mid-stroke support and bottom out control. While I haven’t spent as much time on one, I’ve found the Fox 40 Air to be better in this regard.
The Idylle, like the 40 Air, is very good on this front. Once I got the air pressure in the Idylle to where I liked it for mid-stroke support, I felt that the progression was about right. I’d get deep into the travel on fairly large hits, but only on huge hits would I notice the front end bottoming.
On a few large drops that had bombed out, brake-bumped landings, I did get a “clunk” on bottom out. But on a “normal” hard hit, the fork would ramp up significantly in the last ~30mm of travel, thus avoiding any harshness. And perhaps most impressively, as I noted above, I could add or remove a bit of pressure to fuss with the mid and late stroke firmness, but the suppleness at the beginning of the stroke remained really good.
I did investigate reducing the volume of the air chamber to make the fork even more progressive, not because I really wanted that, but mostly because I was curious about what was going on in the air spring. The air spring uses an internal tube within the stanchion that you can’t get into without tearing the fork apart. Given the lack of serviceability of the Idylle (more on that below), I didn’t go any further, but suffice it to say, it’s not as easy as simply adding something like a bottomless token.
NEXT:The Damper and the FCV System, Maintenance and Support , Etc.