Chain "Stretch" - Part 3 (diagrams)

After talking to a few friends trying to explain "chain stretch" I have decided a picture is worth a thousand words... so I built a few illustrations showing chain wear.

The pin, showing in black, wears away by rubbing the (orange) housing. This creates a looseness that increases its length.

When the chain is longer it rides up on the teeth of the gear reducing the contact, allowing it to "skip" under hard pedaling.  It will also wear the tooth away when it rides the incorrect location of the tooth, effectively eating it away.

So keep your chain clean and lubricated. And replace it when it gets "stretched."

Part 1: Measuring Chain Stretch
Part 2: Free Wheel Removal
Part 3 (this post): Chain Stretch Diagrams

2012 Kona Kahuna 29er Review

I have always loved Kona bicycles. Their brochure was one of the first that I picked up when my I started my love of bikes as an adult…it has been read so many times (by both myself and my son) that it is literally falling apart. So, when I had the opportunity to purchase a new bike, Kona was at the top of my list of bikes to research.

Other than being "my first," Kona is a smaller company compared to the brands often see on the local trails. I always try to help out the little guy if possible. But I was not going to discount the other brands just yet. There are other dream brands on my list too.

Here in Knoxville we are blessed with many bike shops with most major brands. So Saturday morning the son and I headed out. We checked out the Specialized Hardrock. Very nice looking paint scheme but the fork was not great. The Treks' paint was downright tacky. So much so that I didn't even pull one down as sit on it. Next was the Giant Revel 0. The paint scheme was nice (though it was that hard-to-clean flat black.) The small frame size fit me very well. But the brakes were mechanical and the fork only fair. Raleighs seemed much more expensive for the same components.

The last shop we could hit for the day was Tennessee Valley Bikes, home for Kona Bicycles in Knoxville. I did not get my hopes up as the Konas I liked were outside my price range. Their 2013 beginner line had similar components compared as the brands I had already found. But the paint scheme looked well, cheap. So I guess it was time to head back to order the Giant.

Then I saw a black-ish blue bike on the end of the rack. It was a 2012 Kahuna. Beautiful, subtle, good fork, hydraulic disk brakes, and it was in my size! After a small financial discussion with the shop worker I became the owner of a Kona!

And it rides as good as it looks!

The step up to 29 was one that I never thought I would do. How does it feel compared to my 26 wheeled Fuji? Apples to oranges. The 26" wheels are on a larger 17" frame, the 29s are connected to a 16" frame. The Fuji is somewhat lighter than the Kona. The fork of the Kahuna is light years ahead of the Suntour fork on the Nevada. Overall, the Fuji is quick "side to side", the Kona fast... forward. The only way I can describe its feel is - pulling. It was hard to tell if I was going a lot faster, or the added weight of the wheels built up inertia making it reluctant to make turns, or both.

The pros of the Kona: that awesome (to me) fork. The Rock Shox XC/32/TK has none of the slop found in the Suntour. The Sram X5 gear set: having 30 options it seemed I was always in the right gear, awesome! The shifters are going to take a little getting used to for me… the triggers on the Fuji used the forefingers for downshifting, the Kona uses the thumbs. Retraining my brain should take care of this one.

The "yet-to-be-determined" aspects: the handlebars are much wider than I am used to. It meant my hands are constantly bumping the gear levers. Going to do some testing by moving the brakes and shifters a half inch inward before getting out the hack saw. The Avid Elixr 1 brakes: I was really worried about this as they seem to lock up way to easily. But after remembering discussions on bike forums mentioning "one finger braking" I tried it. Really helped modulate better.

The graphics. I believe the art is shared with the King Kahuna that has a lighter colored carbon frame. But the base paint color is so dark that the logo and words were almost invisible. Some like it, others hate it. I lean toward the "like it" side but it could be a little less subtle.

The cons: #1: the price. Of course the Kona was much more expensive than the Fuji. But that was to be expected. #2: the pedals - unbelievably terrible! My feet slipped many times during the first ride. The $15 replacement pedals I threw on held my feet so much better. Just a guess but I think most people change the stock pedals out with clipless pedals as soon as they get the bike home, so Kona put on the cheapest things that can be considered petals.

So, if spending $100 more than I wanted and $15 for new pedals is the only negative things about the Kona, I can live if that!

6 month update -
After riding the Kahuna a few months now I can say this bike has really grown on me. It is much faster than the Fuji. Much like a race car that is difficult to drive in city traffic, when you get going fast, the Kona really comes alive. When riding the Fuji I was probably had it at 9/10s of its skill level. The Kona I feel like it is more like 7/10 meaning I can improve a lot on this bike.

And after the first tune up the brakes pads were moved out a little giving a lot more ability to modulate. Much better! However, the rear brake did get "spongy" requiring a bleed to get it back to normal. And sometimes they would over-pressurize when hot if left on the rack in the hot sun (the fluid would expand with the heat and rear wheel would not turn.) I had this happen a couple times but TVB assured me that it it is due to the fluid absorbing moisture and "overfilling" the system. A simple fluid flush/replace on a consistent basis will keep this from happening.