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Saturday, October 27, 2012

THOMSON Goes Carbon With Bars


A whopping 730mm wide for a flat bar, Thomson offers exacting precision and versatility in their line of bars.  Included is this flat bar, a riser bar, a road bar with flattened tops, and a CX bar.

First up the flat bar:

Coming in at just 185 grams for the flat bar keeps everything light.  6 degrees of sweep is good middle ground that should be comfy for all riders.  The bar can be run flip/flop for a difference of 5mm.  As mounted the top is flat across from the stem.  The bulge tapers up only.  Flip it and you have a 5mm drop.

click for larger view
A nice touch is that the bar is exactly 31.8mm diameter under the clear coat.  The clear coat compresses when clamped, so mated to a Thomson stem that is exactly 31.8mm you get a perfect fit and a reduction of stress to the bar as well as a tighter fit.

The bar comes with a tiny tube of carbon application lube, that is a gritty gel to increase friction between the stem and the bar. This reduces the clamping force necessary to hold the bar.  A torque wrench should be used to 4Nm when tightening the stem bolts to avoid over-clamping and crushing the carbon.

Thomson found that the sticky goo other bars have at the clamp area only cause the bar to slip easier, especially in the drop test.

1 lb of nano fiber can stretch to the moon.

"All our cloth is from Toray, it is 3 different strengths and uses cycling specific nano particles," reports Thomson.  

Destructo-Matic: Along with many popular brands of carbon bars, the Thomson bars were tested until failure.  With heavy weights attached to the ends of the bar, the system was dropped from one foot, two for some test, to simulate more downward force than the human arms could produce.  It is interesting that carbon breaks under pressure or compression, not tension, so the breaks were all under the bar (at the compression point), while the tops were intact (tension).  

All the destructive test on the Thomson bars showed that even when the bars broke they stayed intact enough to give the rider time to stop, and maybe even ride back home, but like the engineer said, the force it takes to break the bar like this would shatter the human body, so the bars would be the least concern.

The Ride:  Going from a 680 width carbon bar to a full 730 width is wonderful.  The handling is superb, cornering more confident and the extra length seems to further isolate the hands from vibration.  Even powerful sprints were easy with the bar - no flex when pulling up hard.  Yet, riders would still grab the bar at the very ends at times, so how wide do they want it, how wide is too wide?  Time will tell, but the weak concern of a wide bar not fitting through trees has not been an issue on the test rides; the increase in handling is much greater and a joy to ride.

730mm may be wide for some riders, but the Thomson carbon bars are meant to be cut, and the ends have hash markings every 5mm as cutting guides.  

Small bar-ends can be accommodated, within reason, as the ends are beefed up a little to handle the clamping force. Care should always be taken when clamping on carbon though, as not all clamps are as precise as the Thomson stems and could pinch or crack the bar.

click for larger view
A nice part of the ascetics is the marbled black finish on the bar.  With only the small Thomson graphic on the drive side the bar gives off a stealthy black glow that just speaks of its coolness.

Update:  After many more miles of riding the bars are still the favorite of all time.  The extra width means there is ample room between the stem and the accessories to get aero with your hands with room to spare.  This is handy for fast stretches of pavement or gravel, and is even offers a good alternative hand position for long climbs.

This bar will not be cut down, but for those needing a more narrow front end you will still get a great bar and at even lighter weight.

10-28-2014 update:  2 years later: Same bars, still working perfect.  I have over 10,000 off-road miles on these and no complaint from rider or bar.