Pacenti's P-Dent bar and stem is a unique and high effective way to sharpen up the steering response of a bike, thanks to a design that allows for a much shorter stem. It's really well made, comfortable to use and the only downside is the price.
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The traditional limit for how short a stem can be is limited by the fact that at some point, the steerer and handlebar contact - meaning an effective minimum of around 30-35mm for conventional designs. Mondraker's original Forward Geometry bikes came with a 10mm stem, but as the bar sat on top of the steerer, it drastically affected stack height.
Pacenti has got around all this by using a specifically designed carbon handlebar with a notch at the centre that pairs with their own stem to give you the choice of either a 25mm or 20mm length. According to Pacenti, this doesn't affect the strength, stiffness or general integrity of the bar as the area between the two clamps isn't highly stressed. The carbon handlebar comes in an 800mm width with the choice of either 15mm or 25mm rises, both having a 5° rise and 8° sweep.
The benefit of using such short stems is that it noticeably reduces the amount of effort it takes to steer, speeding up the steering of a bike - especially long and slack modern machines - without hurting the descending capabilities of the bike in the way a steeper head angle would.
I tested the 20mm stem with the 15mm rise bars and found that even when compared to a 35mm stem, the setup made a significant and entirely positive chance to the handling. The broad clamp and short length of the stem give an immediate feel to the steering, while the bars have enough give to be comfortable without being overly soft or unnervingly bendy when you haul on them. The sweep and rise are about perfect too, in my opinion.
The biggest revelation is just how easy it is to re-adjust a line mid-corner, even with a slack head angled machine. It absolutely minimises the self-steering tendency that can happen when you're seriously weighting the bars in a high-G force corners, such as a berm or heavilt banked, high load corner. For such a relatively small change in stem length, it makes a surprisingly big difference.
At 210g for the bar and 125g for the stem, the weight on the money for a high-end combination and there's no doubt as to the quality of the manufacturing either. At £250 for the bar and stem, there's no getting away from the fact that it's an expensive upgrade, but I'd argue that it's one that's worth making if you're riding a bike with modern geometry - I suspect that it might not be so positive a change if your bike is already on the steep side.
