For those who are joining the conversation, PDent is literally a dent in the center section of the handlebar that allows the fork's steerer tube and Pacenti's carbon handlebar to occupy the same space. Without the dent, the shortest that a conventional stem that can be made is about 32 millimeters before the bar and steerer tube touch. "Conventional" is the keyword here, because shorter stems are presently available that place the handlebar above the steerer tube, but at the expense of a ridiculously tall handlebar height. So, designer Kirk Pacenti's patented PDent solution is to dent the handlebar in a place where stresses are actually quite low, in order to create stem lengths in the neighborhood of 25 to 15 millimeters that share the same low profile as the 50-millimeter shorties that all-mountain and enduro riders presently know and love. PDent Bar and Stem
• Stem: CNC-machined aluminum, black anodize, four-bolt clamp, 15 or 25mm extensions
• Steerer diameter: 1, 1/8"
• Clamp diameter: 31.8mm
• Handlebar: Carbon, 31.8mm clamp area, 8-degree sweep/5-degree up, 15mm rise, 800mm width
• Weights: Handlebar - 220g, stem (25mm) - 140g
• MSRP: TBD (Apx. $180 USD for bar and stem)
• Delivery: January, 2016
• Contact: Pacenti Cycle Design
Pacenti sells the PDent stem and handlebar as a combination - or we should say, "will sell," because no MSRP has been published as of this moment, and delivery is scheduled for January 2016. We received production versions to test, so when they do hit the stores, this is one combination that you will actually be able to purchase. Pacenti intends to engage OEM customers before he makes a less expensive aluminum handlebar and a more manufacturing friendly forged-aluminum stem. Presently, handlebars are carbon fiber only and sold in 800-millimeter widths with a 31.8 millimeter clamping diameter. PDent stems are beautifully machined from aluminum, with a four-bolt clamp to fit 1 1/8-inch steerers. Our test stem was a 25-millimeter model and, as mentioned, a 15-millimeter stem will also be available. Weights on our scale were 220 grams for the bar and 140 grams for the stem, which is lightweight for an all-mountain combo. Pacenti's PDent stem is machined from just about every direction to reduce its weight. The window in the center marks where the handlebar and steerer would normally overlap.Riding PDent
Kirk Pacenti says that the ultimate stem length for a trailbike designed to maximize technical riding is between 10 and 30 millimeters - with the caveat that the top tube length be adjusted to compensate for proper reach. His take is that because it is difficult to make stems shorter than what we presently have, that the industry at large has yet to experiment with geometry that incorporates stems in that range (Mondraker
being the exception here).
To test his theories, I bolted the PDent combination to a Commencal Meta V4, which is slightly large for me and thus, has a top tube length long enough to make up for most of the 25mm (one inch) difference created by substituting the 50-millimeter stem I had been using. I also cut the handlebar from 800 millimeters to a more useable 770 - a bit wider than the 760-millimeter bar that I prefer, but experience shows that a shorter stem usually requires a wider bar to compensate for the faster steering response generated by the stem's reduced moment arm.
Alrighty then. As one may expect, the first sensations I experienced were that I was much more in contact with what the front tire was doing, and that the steering was way quicker than I was comfortable with. After an hour of playing around with small jumps and boulder drops, however, the Commencal's forgiving handling returned and I was able to enjoy the changes that PDent brought to my once-familiar trailbike.
Climbing was somewhat plagued by a wiggly front end that never quieted - a situation that continued after I had arrived at the point where I was no longer conscious of the other changes that PDent had made to the Commencal's handling. As I have become handy at figuring out how to be comfortable on a wide variety of bikes, I'll call the wiggly climbing out as a negative handling trait that some could overlook in light of the benefits that the system provides to other aspects of the bike's handling.
It would be easy to assume, because direct mount fork crowns allow DH bikes to be regularly ridden with stem-lengths in the 25-millimeter range, that a trailbike would perform similarly, but such is not the case. The trailbike's steeper head angle, combined with its shorter fork length, places the front tire nearly two inches closer to the rider, so there is a significant forward weight shift that the trailbike rider must compensate for in all aspects of its performance envelope. That is especially so on the downs, where the rider can put much more pressure on the front tire and is looking well ahead of the bike.
But, there is a plus side to that lean-forward stance. The front tire tends to stick like glue to the trail surface, and it doesn't push much, even if you forget to properly bank the bike into the bends. Better still, once you get over the face-forward attack position that PDent encourages on the steeps, you'll discover that the bike can be steered with a remarkable sense of security while descending chutes that most riders skid their way down, using hope as a line choice.
I found that I could brake with the front tire much harder and later too. The greatest paradox of the PDent's shorty stem and lean-forward stance, however, is that it becomes easier to loft the front end on the downs while you are hovering closer to the handlebar and putting more weight on the front wheel. Of course, that is usually the case - anytime I actually do
get forward enough on my bike and attack a steep descent.
The magic of PDent is that it curtails the option to get too far back over the saddle and screw it up. I'd swear that the bike was handling the downs better, but the truth was that PDent was forcing me to adopt a better riding position. Once I was shamed by that fact that I was using the "eject" and not the "attack" position, I began to ride equally as well with my 50-millimeter stem bikes. Of course, most trail bikes are designed around 50 millimeter stems, which underscores Kirk Pacenti's statement that PDent was developed to allow bike makers to progress to the next level of chassis design - one based upon super-short stems, of course. Until that time, PDent will be a godsend to those who have been wishing for sub-30 millimeter stems and a nudge for designers to consider different paths towards making the ultimate trail bike.Pinkbike's Take:
|PDent is going to be popular with riders at the more extreme end of the all-mountain category who live for the downs and yet, possess the fitness to smile at passersby as they muscle their thousand gram tires, Fox 36 fork, and 160-millimeter-travel chassis uphill for two hours to access the tastiest morsels on the mountain. PDent could also gain popularity among mainstream trail riders, but not until bike makers incorporate their frame metrics to blend seamlessly with the different steering attributes of sub 30-millimeter stems. Simply buying up to the next frame size in order to match a longer top tube with a shorter stem is not enough. After riding PDent, I believe that splitting the difference, by choosing a bike with a one-degree slacker head tube angle, paired with a ten to fifteen millimeter longer top tube, would deliver a better PDent handling package in all theaters of the trail riding experience. PDent gives riders and bike makers a new option. - RC|