Alter Cycles has worked to highlight the performance of their design putting out only a few sample drop-bar versions that host a variety of components. The drivetrain on the Reflex 300 we tested was comprised of Shimano Tiagra, an excellent choice for dependability, durability and value, and a choice of 50/34t chainrings serves a majority of riders. Matched to the rear 10-32t Tiagra cassette, a combination that offers a healthy range of gearing for the flats as well as steep climbs. The shifters are comfortable in the hand, and shifts are precise with consistent and expected movement.

To keep your speed in check, the Reflex brings 160mm Shimano disc brakes, utilizing their refined hydraulic brake system. The choice allows for a wide selection of tire widths, and in the spirit of adventure, the Dual Action 700x33c tires from Arisun fit the part. They are a grippy set of cyclocross tires that beg to be taken on dirt, gravel or to your local ‘cross race. Matched to Vuelta alloy rims, the assembly is a dependable and bombproof pair. The Shimano hydraulic braking makes stopping consistent and quick, with a healthy amount of modulation that continues even after long descents without fade, or weather when rim brakes would otherwise have a tendency to lose their responsiveness.

Frame Design Separates the Competition

What differentiates the Reflex from other bikes brings us to its frame design. Mark Groendal, inventor of the Reflex, essentially redesigned the classic diamond frame that was designed over a hundred years ago. By modifying the front triangle into an “modified triangle” that flexes changes everything about the ride and the performance. All of the Alter Cycle bikes have an interchangeable flexible downtube made of curved and compressed .035 wall HS90 steel tubing, a much stronger, more resilient steel than traditional chromoly. This tube allows and limits the frame flex.

Even the way the frame flexes is different than traditional frames. Instead of thinking about the normal twisting or torsional type of flex, these frames have what Alter calls “linear flex” which, while ridden, is an almost continual stretching and retracting of the frame and wheelbase in small amounts. This motion smooths the ride and helps keeps the tires on the ground significantly better.

The interchangeable tubes, which they call Rider Fit Tubes, or RFT’s, are designed for different weight riders. There is a #1 for riders up to 200 lbs., #2 up to 250 lbs and #3 up to 290 lbs. The surprising thing is that everyone who tested the bike, preferred the most flexible tube for their weight range. Not only is the ride smoother, the bikes actually perform better as they flex.

Rider Fit Tube

The RFT works like a spring but the term ‘spring’ is somewhat misleading. The frame itself is quite firm and there is no ‘bouncing. It is a dynamic flex that rebounds energy while pedaling which provides a more efficient transfer of power into the cranks, resulting in faster speeds when compared to traditional rigid bikes.

Reports from the various riders that rode the bike have commented on using one gear higher on the same climbs than they would normally be using. The results on the flats are more difficult to articulate in terms of performance. It feels faster, though this could also be due to the smoothness of the ride. The smoother ride still retains responsive steering and maintains a nice road feel. We noticed the tires really stick to the ground and found this to be a very versatile bike.

Quantifying Frame Flex

Speaking with Rick Vaughn at Alter Cycles, I mentioned our inability to quantify the speed benefit for our readers. Yes, it seems faster and easier, but how would we actually measure in a way that accurately captured a fair comparison? My “daily-driver” is 4 pounds lighter (and 4 times as expensive) so a comparison would always seem to come up short. To answer, he told me a story of a recent alumni function he attended where he chanced on sitting next to an old college friend who, like most people, was not buying what Rick was peddling, a bike with a frame that flexes that is supposed to be more efficient to pedal than rigid frame bikes. Raising the conversational stakes, he told Rick he had access to the lab at the college physiology department where he worked and offered the challenge for Rick to prove his claims at their facility.

Taking him up on the chance to quantify the performance of their design is something that the company has always wanted to do. So, seven riders were brought in to test their VO2 (oxygen consumed) while riding on a stationary computrainer for resistance on both the Reflex and an identically equipped rigid frame bike. The measurement gives an idea of how much oxygen your body is requiring while simultaneously measuring how much power you’re producing, essentially your efficiency and how hard you are working while riding. This measurement of both the input and output allow for a more complete comparison and the results surprised even Rick.

Four out of seven riders consumed less oxygen on a test with light resistance, but at higher resistance, all seven riders consumed less oxygen to produce the same amount of output while riding the Alter Reflex by an average of 4.6% benefit to the rider. Because this was an ‘after-hours’ challenge between old college friends, there are no published results in a journal to reference, but to this, Rick said Mark would be happy to lend a bike to have anyone who would recreate the test and accurately report the results. The results of the sited test can be downloaded from Alter’s website.

The Alter folks believe people will eventually realize that the right type of flex, linear flex, is valuable to every aspect of performance and comfort, and that having a frame with a mechanical advantage that provides a rebound in its pedal stroke, is much more efficient than trying to get faster by shedding a little weight and is a lot less costly.

The Case for Drop Bars

As a small company entering a new market, Alter has found that requests for the drop bar bikes to have a wide variety of component builds and price points. They are not a big enough company to provide enough arrows to hit the center of that target. So, to simplify they have decided to provide frames only and let people build up custom versions the way they want for now. Frames are priced at $699, not cheap, but not bad for a revolutionary, high-tech frame. All are matte black with color choices lie in the selection of the down tube.If you want to try one of these bikes and keep the cost down, you can opt to buy one of the fitness versions which share the same frame as the model we tested. These bikes complete are priced at: Reflex 100 $749, Reflex 300 $999 and Reflex 500 for $1399.

Keep an eye on the Alter website for dealers near you that begin to carry them. You can find additional information on Alter Cycle website at