Kenda Kourier K-Shield Bicycle Tire, 700 x 40c

I bought this tire through Amazon last week for 19 USD shipped; today it's over 30. [As of 7/12/2014, it's back down to 20.]My opinion of the tire is strongly dependent on the price being charged. I think I would have gone with a Schwalbe tire if I had to buy at 30 USD. Good choices would have been these  2 x Schwalbe Marathon Tires (A PAIR) Road/Race/Cross Bikes (HS 420) - ALL SIZES - FREE SHIPPING - FREE VALVE CAP UPGRADE WORTH $4.99!  in 38B or 38C (I don't know the difference!) or this  Schwalbe Marathon GG RLX Wire Bead Tire .Out of the box, the Kenda Kourier in 700c x 40 looks and feels very different from the Kenda tires of the same size that came installed on my hybrid. The Kourier's have an extremely thick and stiff tread section that abruptly transitions to a thin sidewall. The tread section doesn't seem like it is integrated into the tire. It's like you cemented a hard, rigid cap onto the tread section of an otherwise thin and flexible tire. However, the appearance is conventional after the tire is mounted and inflated.The appearance of the K-Shield inspires confidence. There's no way that small glass shards are going to penetrate the tread cap. However, the sidewalls look fragile. A larger piece of broken glass might tip up and shred the sidewall.There is a weight penalty. I have a good digital bathroom scale. Many repetitions show a consistent 1.6 pound difference between my weight holding the tire versus without. The scale only reads in 0.2 pound increments, so the range of possible weights is roughly 1.5 to 1.65 pounds per tire. That's about 680-750 grams per tire.In my opinion, the weight penalty isn't excessive. All tires in 700c x 40 are fairly heavy. Even the Schwalbe Marathon Supreme with the folding bead option weighs in at 495 grams.I should mention that I ride a touring hybrid with a fairly upright seating position. Most of my 205 pounds is loaded onto the Kourier on the rear wheel, together with panniers holding a full tool kit, extra water, and food. The front tire is lightly loaded, so I'm able to get by with a much lighter tire there.I've got more than 2000 miles on the Kourier after two years of use. I haven't had a flat since putting the Kourier on. All of the sidewalks on the bridges over the Connecticut river are littered with broken glass. I don't even bother to try to avoid the stuff anymore.My impression is that downhill runs and hill climbing are both unaffected. I'm pretty sure that I'm averaging one gear slower on the flats for the same cadence. This speed penalty is not unexpected since I'm comparing a brand new tire with deep, full tread to an old tire that was worn smooth. On the plus side, I haven't wasted a moment of time repairing any flats.Speaking of the tread, the Kourier is a true hybrid tire with excellent hill climbing ability on hard packed dirt.Bottom line: I would definitely recommend this Kenda Kourier to someone who rides a hybrid both on and off pavement. I would also recommend this Kourier to a professional city bicycle courier who can't afford the time lost to repair a flat. For on road use only, maybe or maybe not. A rider with a higher budget might be better off with a pair of foldable Schwalbe Marathon Supremes, together with a third tire, spare tube, patch kit, and tire irons in an underseat bag.If it matters to you, the sidewall states that my Kourier was made in Taiwan, not mainland China.

I bought these tires because I got flats riding through a dirt path one day and ended up walking my friggin Diamondback Edgewood back 2 miles. So, the minute I got home I hopped on Google and searched for a bunch of puncture proof tires and the only one I found on Amazon that would fit my bike were Kendra K Shield.The tires did initially didn’t seem any different from my regular tires, same thickness, size etc… but then when I ran my fingers across the treads they seemed a lot harder. So, I plopped them on and I haven’t had any flats yet… I didn’t go through the same dirt path (cause, ya know, who wants to get flats on purpose?)… but I have put on about 40-50 miles since then and gone through other dirt paths and I didn’t get a flat. Also, the ride seems about the same, it doesn’t feel any heavier or more difficult, in-fact, I have this beast of a hill behind my house and with/without the new tires I can pretty go at my same pace and need to stop at the same spot.Also, it seems that K Shield is the entry level puncture protection for bike tires (please see below), I tried looking for K Shield Plus and Endurance on Amazon but couldn’t find them.I say if you’re in the market for puncture resistant tires, these wouldn’t be a bad bet. I’m sure there’s better brands/tires out there but these work for me.-------------------------------------------------------------K-SHIELDA layer of aramid and ceramic particles inside the tire under the tread area only. Designed to prevent punctures. This is Kenda's first line of defense against punctures. K Shield PlusK-SHIELD PLUSA plus size version of the standard K-Shield material. Five millimeters thick, the layer of aramid and ceramic particles under the tread surface serves to prevent punctures and provide extra comfort on the road. A premium version of Kenda's first line of flat protection at minimal cost. EnduranceENDURANCEThe new standard for Kenda in maximum flat protection, available in two different levels of protection and price. The premium level combines a 120tpi casing wrapped from folding bead to folding bead in Aramid Iron Cloak fibers and then topped with K-Shield under the tread rubber. The performance level wraps Iron Cap across a 60tpi wire bead casing and is then topped off with K-Shield under the tread rubber.CASING TECHNOLOGYTire casing is the fabric that the rubber compound adheres to. The fabric of the casing can be made in varying thickness and threads per inch (TPI). Generally, the higher the TPI number, the more supple the tire sidewall will feel and flex. This means a more comfortable ride compared to that of a lower TPI casing. The casings can be treated and reinforced with various materials in order to achieve different degrees of puncture resistance and ride qualities.IRON CLOAKKenda's best puncture resistant material, a blend of Aramid fibers, is laid up on the tire casing from bead to bead. Not only does this provide puncture protection underneath the tread of the tire, but it also reinforces the tire side walls minimizing slashes or tears; with a minimal addition to the overall tire weight. Iron Cloak BeltIRON CLOAK BELTA thin strip of Kenda's best puncture resistant material, Iron Cloak, built in directly underneath the tread rubber only, for added puncture protection and minimal weight. Iron Cloak Belt lets you rest assured that your tires are durable, but light and super supple for the ultimate in riding performance. Iron CapIRON CAPA layer of material that runs from bead to bead under the tread to prevent flats. IRON CAP combines some of the technology from the high-end IRON CLOAK material without all the added cost. Iron Cap BeltIRON CAP BELTUtilizing the same protective material that is in the full Iron Cap protection but limited to just under the tread surface, offering added puncture protection at a minimal cost and weight addition. Previously known as PRC2. Casing Added ProtectionCASING ADDED PROTECTION CAP or CAP PLYas it has been referred to is an added layer of material that is under the tread area and runs from bead to bead. Generally used in Kenda Premium Downhill Tires as a puncture resistant material designed to prevent pinch flats. K Shield