29 September 2009

Chain Smoker

Just thought I would share this with you.

In my ride report on MtB riding in Yokohama I mentioned that I snapped my chain while out riding, well on Friday last week the same happened again and I decided to bin the chain and get a new one for my Mt Bike and replaced it with a 9-speed Hyperglide chain which last an age!

Yesterday morning I was commuting in to work and alas, just outside Shibuya on the 246 pushing off from the lights I snapped the Dura Ace 7900 Hollow chain on the Pinarello. Fortunately my cat like reflexs helped me stay on the bike and also allowed me to continue having children.

Turns out that the Shimano Dura Ace 7900 hollow chain have issues with them and Shimano are no longer making them. Apparently they have 2 problems, the first is that the "Quick Link" is prone to stretching and if you are using one of these chains and doing a lot of sprint training or aggressive hill climbing then your best off getting rid of the "Quick Link" and replacing it with standard Hollow chain links.

The Second issue is with the Hollow pins, these fail rather quickly especially if you have removed or replaced a link and used the original link pins. If you have I would suggest you take a look at where you made the joins and replace them with replacement pins that once inserted require you to snap off the remainder of the insertion pin.

Please note that Shimano have not recalled the chain but have stopped making them, so if you need a new chain make sure that you are getting the new version that doesn't have the "Quick Link" and has the new reinforced pins.

I have to say that I'm rather glad it went yesterday on my commute rather than on Saturday durring the "King of Endurance" Race in Shin- Yokohama!

Safe Riding Guys.......


mob said...

Interesting. Who would have thought that Shimano develops quality issues on a relatively simple item like a chain. But then again, who would have thought that Toyota never would have these issues? Adn they have as well now.

I am Ultegra, except the rear derailleur which is 105. Ludwig might be affected, otherwise I am not sure.

Manfred von Holstein said...

I have the old Dura Ace (7800), and this vindicates my policy of not buying the latest when it comes to safety-related components/products. I belief in buying what has proven save over a couple of years.

mob said...

Thinking about it, I remembered a video I posted some time ago on the blog:

... of course the Positivo Espresso instruction books tells us all precisely what to do in the case of a chain failure:


Did we used the Dura Ace chain too?

AlanW of TCC said...

You should never use the original pins to rejoin any Shimano hyperglide chain. The ends of the pins are enlarged (peened) when the chain is made. when you push them out with a chain tool, the hole in the outer link is enlarged; it actually deforms plastically. The joining pins as shown in your picture are bigger and fill the newly enlarged hole properly. You can feel them pop into place when you use them. The joining pins themselves should never be removed; if you subsequently need to cut the chain, pick one of the other pins.
A properly joined Shimano chain is very unlikely to break.
I believe the quick-link is no longer made as it was wearing too quickly and causeing rough running of the chain.