As you readers of Twenty Nine Inches know, we have done several posts on Gates Carbon Belt Drive bikes and have tested their “traditional” set up in the past. (See some of theses posts here, here, and here.) We also have reported on the positives that the new “Center Track” technology was to bring to the system. Here we can finally say that Center Track bikes are currently available, (first from Spot Brand Bikes, others later in 2011), and after market belts and cogs to convert belt drive bikes out there already to Center Track will become available in July.


What Is “Center Track”?: The previous versions of Gates Carbon Belt Drive were very similar in appearance to automobile applications of belt and pulley set ups. There was the rounded tooth profile of the belt’s inner run that mated with matching profiles molded into the Gates pulleys. These “cogs” also had a flange on one side to help keep the belt from “walking off” the cogs due to flexure in the bicycle frame, or from slightly misaligned cogs.

Obviously, as you can see from the image above, there are no more flanges on the front or rear cogs, and rear cogs are now machined stainless steel in their entirety now. Front rings for Center Track are all aluminum. The cog features a center ridge which mates into a slot molded into the center of the belt. The belt itself is now 12mm wide to accommodate the “center track” and to avoid the carbon strands which are placed every two millimeters from belt edge to edge and which run laterally along the length of the belt in an unbroken circle. These carbon strands prevent the belt from stretching. Gates claims a “20% increase in tensile strength” over the older version of their belts, but this may simply be an outcome of having an extra carbon strand in the 12mm belt versus the 10mm ones before it.


Because the belt now runs in a track, it is more tolerant of mis-alignment and flex incurred by frames which can slightly mis align cogs while under hard pedaling forces. Another benefit of Center Track is that it can be used at slightly lower tensions than the older Gates Carbon Belt Drive Systems could be run at.


The new Center Track belt and cogs can be retro-fitted to current belt drive bikes as long as there is clearance for the wider belt. (Gates claims a “slimmer profile” for the cogs, but the belt is 2mm wider than what the older system had.) As of post time, we were told that Center Track cogs and belts would become available in July. No word on pricing, but be prepared to spend more than currently available Gates Carbon Belt Drive parts sell for.

Gates says the initial product launch for after market parts will be focused on the most popular sizes and will be expanded through the second half of 2011. For more information about Carbon Drive go to the Gates blog.

Twenty Nine Inches should be taking delivery of a Spot Brand Center Track equipped single speed soon for test/review. We’d also like to thank Spot Brand for providing information and images for this post.