Standard-issue on the top-end Trek Domane road bikes, the Bontrager Race X Lite IsoZone bars are built to tame rough roads. But, this is no cruiser bar, no-sir-ee, this is a pure race bar with a soft side in just the right places.
Bontrager Race X Lite IsoZone Features:
- IsoZone pads displace vibration by 20% neutralizing vibration and reducing hand numbness
- Lighter and more compact than adding layers of tape or aftermarket pads
- Includes two upper and two drop pads
- Odor free closed-cell pads won’t absorb water
- Includes one front and one rear cable groove for optimized bar wrapping
- Lightweight OCLV carbon construction
- VR-CF profile maintains compact VR-C shape with ergonomic flare at ends
- Includes guide lines for alignment of stem and brake levers
- Replacement pads available, Clip-On Compatible
- Weight: 225 grams (42cm – as tested)
- Reach: 85mm
- Drop: 125mm
- MSRP: $299
Bontrager Race X Lite Isozone Carbon Bars Review
When it comes to road bike components, Bontrager is one of the most respected names in the business. Synonymous with Trek, Bontrager can certainly stand alone as one of the most respected component manufacturers on the market for both road and mountain bikes. Their new Race X Lite IsoZone bars are built stiff for high-output racing, but also feature strategically-placed IsoZone pads to improve comfort for the long haul.
Installation of these bars is a breeze. The clear markings for brake lever placement as well as center lines for stems are more extensive than you’ll find with other brands. Built-in cable guides keep a flush look when wrapped. When placing the IsoZone pads, I was a bit leery that once I placed them down they would never come back up. While you certainly don’t want to mess it up too much, minor adjustments are easy and didn’t damage the pads or the adhesive. I installed these bars on my Scott Foil 40 test bike.
Depending on the layup of the carbon fiber, it can be stiffer and stronger than alloys or it can be softer and more compliant. In this case, the OCLV Carbon is laid out to give this bar UCI-level stiffness. Just to clarify, stiff doesn’t immediately mean they won’t absorb road vibrations, it just means that these are going to give you the ultimate in steering precision and err on the side of road feel.
As I mentioned, the IsoZone gel pads are strategically located on the bars for maximum comfort. Their research has shown a 20% increase in vibration dampening and I could certainly feel that difference. The tops are only slightly ovalized, but with the pads, I didn’t long for flat tops. As I pushed myself on long climbs, I was able to find just the right home for my hands where the IsoZone could do its magic. It’s truly amazing stuff and worked in perfect harmony with the Bontrager RL Fusion Gloves to give me the most responsive handling and comfortable ride possible.
The drops measure 125mm with a reach of 85mm. Bontrager calls this their compact VR-C shape and feature slightly flared ends. The drops don’t have a fully-ergo bend in them, but the IsoZone material sort of acts as though they do and works in concert with the modified curve in the drops (a.k.a. Variable Radius). When descending in the drops or accelerating, these bars don’t flex one iota. They simply respond in spades while the IsoZone significantly reduces fatigue and discomfort. Large bumps are softened and then the IsoZone pads take over the rest.
At $299, these are on par with the more expensive carbon bars on the market, but are certainly worth the price. As a strong recreational rider, I could go for just a tad more compliance in addition to the IsoZone. However, this entire package is hard to beat.
Learn more about IsoZone testing and performance: Bontrager IsoZone Presentation (PDF)
Good Race X Lite Isozone
- IsoZone pads dramatically increase comfort
- Bars remain stiff and responsive under hard efforts
- Small chatter is naturally reduced, but liveliness remains for excellent road feel
- Cable channels provide easy setup and a more fluid wrapping surface
- Still ultralight — even with IsoZone pads
Bad Race X Lite Isozone
- Aside from the IsoZone pads, these bars are extremely stiff — some may want more compliance
- I’d prefer a little more ergonomic drop
Bottom Line: Bontrager Race X Lite IsoZone Bars
Road chatter has met its match with the race-worthy Race X Lite IsoZone bars. Trek’s OCLV carbon fiber is laid up to give you the most responsive bars on the market with excellent vibration dampening qualities.
Buy Now: Visit Bontrager.com