KHS SixFifty 606 review

Interbike 2009 Main Mountain Biking Reviews Screen first heard about the KHS SixFifty 606 just before Interbike 2009. Excited with the 650b concept, I couldn’t wait to see it in person in Las Vegas. To date, there are only a few manufacturers entertaining this wheel size as part of their line-up. The 650b (27.5”) is the third option in mountain bike tire size. It falls in between the established 26” and the revolutionary 29er (29”). The 27.5” tire is fairly new in the current MTB arena however the tire size itself has been around for many years. The 650b is designed to roll faster than a 26” bike, yet is lighter than a 29er and will fit smaller riders.

650B” Full Alloy, Hydroformed Tubing, Gussetted Headtube
Fork X-Fusion Velvet, 650B
Headset Cane Creek A-Headset 1-1/8″
Rims Weinmann XM280 Disc Specific, Doublewall, Black, 650B
Hubs Alloy 6-Bolt Disc, QR, Cassette
Tires Kenda Nevegal Folding Kevlar, 650B x 2.1
Spokes 15G FT/14G RR Black Stainless, 32°
Front Derailleur Shimano Deore
Rear Derailleur Shimano SLX
Shifters Shimano Deore Pods w/Optical Gear Display
Chain KMC Z9000 w/Master Link
Crankset Truvativ Fire 44/32/22
Bottom Bracket Truvativ GXP outboard cartridge bearing
Cassette SRAM PG950 11-34, 9 Speed
Pedals Wellgo Alloy Platform
Seatpost Alloy micro-adjust
Saddle WTB Siverado
Handlebar FSA XC300 31.8, Alloy
Stem FSA OS190 31.8, 3D Forged
Grips PowerTools Dual Density
Brake Levers Hayes Stroker Ryde
Brakes Hayes Stroker Ryde, 6″ rotors
Color Gloss Red w/White Panels
MSRP: $1199


5’10” 195lbs, 40 year old male, mountain biking enthusiast.

SoCal’s finest: Aliso Woods, Whiting Ranch, Fullerton Loop, Santiago Oaks, Turnbull Canyon and Santa Ana Mtns. (Coal Canyon & Skyline).

The KHS SixFifty 606 was ready to ride from the day it was picked up from the KHS office. Already pre-assembled, there were only minor adjustments and changes that I had to make. First were the pedals. The SixFifty 606 came with the generic plastic flat pedals. To give it a thorough testing, I installed one of my Crank Bros Candy pedals. I then made an adjustment with the handlebar position pushing forward by a few degrees. With its initial set-up from the factory, I felt cramped the way it was laid back. Last were the throw on the brake levers of the Hayes Stroker Ryde. These seemed to be installed right “out-the-box” where they were too far for my index finger to reach. From here I was ready to go! Later on I installed Ergon GC2 grips with integrated bar-ends.

The KHS SixFifty 606is truly a good looking bike. The top tube is a unique hydro-formed shape that resembles a hexagon shape. It’s a solid hardtail frame. I love the color scheme of red, black and white. Looks very sharp and FAST!!!

The components paired up with the KHS SixFifty 606 would be considered mid-level. Far from the top of the line, however the performance was exceptional. First is the Hayes Stroker Ryde. Like its predecessors, it provided excellent stopping power. At high speeds I was able to control the corners on a fireroad descent with light dabs on the lever. The Shimano Deore shifters and the SLX rear derailleur performed really well. The shifting was precise and crisp. (during a race I had minor issues with shifting; it was later resolved with adjustments).

The X-Fusion Velvet is a very good fork. For a 100mm of travel it performed really well through the trails I frequent. Although geared for XC, I did take it on a few runs down technical/rocky sections such a Rock-it in Aliso and portions of the Troy Lee trail in Corona. Short of additional travel, it handled the well.

Rounding it off with Kenda Nevegals. All of my bikes are equipped with the Nevegals, so off the bat I’m already partial to it. Needless to say, it performed well to my standards.
Climbing: Ascents on the 650b, whether it was on a long grinding fireroad or technical switchbacks, the semi-big wheel motored up without any issues. You are centered in the best position to make a quick fore-to-aft shifts in upper body weight that make a difference in handling. I always felt balanced on the SixFifty 606. When I was crawling up tight switchbacks the 650b felt like a 26” bike. On sandy sections where I had struggled on my 26” bike, the semi-big tires motored through it. Finally, climbing on and off the saddle felt great… off course it’s a hardtail.

Descending: Through the various trails that I rode the SixFifty 606, there were never any descents where I was uncomfortable on. The bike felt great and rolled exceptionally well over rocks. Off course I didn’t ride it on a six inch (or more) required gnar-gnar trail… after all, it is a XC bike. But for the likes of Chutes (Santiago Oaks), Rock-it (Aliso Woods) and portions of the Troy Lee Trail, the SixFifty handled really well. The 90mm stem placed me in a better position than the traditional 110-120mm XC stems.

Cornering: The SixFifty 606 was very nimble. It felt light and responded quickly to my steering.

I had the opportunity to race the SixFifty 606 at the Mt. SAC Fat Tire Festival. The course laid out dry, sandy un-groomed trails as well as hard-packed dirt. The bike plowed throughout the course. Then somewhere in the middle of the race I started experiencing “ghost” shifting which hindered acceleration on certain areas. Never the less, I finished the race however did not place.


At the same race but in the Pro category, a better testimonial came from a Charles Jenkins, Professional Racer who won on the KHS SixFifty 606. See video below:

I found no weakness with the SixFifty 606’s performance. Other than the mis-shifting that I had encountered during a race the bike has performed exceptionally well on the trails. The gears shifted on queue, the fork was plush and reacted well to the trail.

One thing that it can benefit from is a diet. At 29lbs, for a hardtail there are plenty of areas where lighter components can be used. Short of wheel selection for the 650b size, the rest are standard in the market. However with an MSRP of $1199.00, it’s spec’d appropriately with the components listed above.

SUMMARY: The Good just got Better…
Since taking possession of the KHS SixFifty 606, I have logged approx 300 miles on it. Riding the 650b I did notice a faster rolling bike. In the beginning I wasn’t quite convinced, however I rode it frequent enough were I eventually felt the difference. It has many characteristics of the 26” yet the benefits of the big wheeled 29er. I would often switch between my 26” bikes and the 650b throughout the week and on the same trail. The SixFifty is so enjoyable to ride, that I would have smiles for miles on the trail. I wouldn’t mind having a 650b in my stable however I’ll have to rid some of my 26” bikes first 😉

For more information on the KHS SixFifty 606 visit

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7 thoughts on “KHS SixFifty 606 review

  1. Great review Joe! I can’t wait to give the 650b a try, being a 29er rider and racer (but not a zealot), I would like to compare the “feeling” between the two.

  2. thanks been trying to get some geo on the bike as it’s not on the site, what’s the ett or effective top tube on the med?

  3. I like the 650b concept, but man a 29lb hardtail? If manufacturers want to get the 650 thing rolling, they will need to produce a bike with more benefits than wheel size alone. You can buy at 24lb sette 29er hardtail with great components for $1200. I’m personally a 29er HT guy, but I would love to add a 650b FS bike to arsenal if they can streamline them abit.

  4. I have a notubes 650b rim, a new front hub and a 650b Racing Ralph on the way. Will keep the 26″ on the back and run the fork at 80mm. I can’t wait.

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