Chain breaker

[j beede]

My ancient chain tool doesn't align very nicely with my 10-speed Shimano chain. Do modern chains require an updated tool? The pin-to-pin spacing hasn't change so I wouldn't think the tools have changed either. My Shimano chain has "peened" pins which I am also unaccustomed to--maybe that is my problem.
...j

[Bill]

Yes they have different ones now, as a reference here is a couple of park tools..... http://www.parktool.com/products/category.asp?cat=5

[jr14]

I wouldn't put a lot of stock in the peening. We used to peen aircraft parts when I worked at a plasma coating shop. If those little pins were properly peened, they'd be useless as pins. They'd be warped and deformed. Chances are, they throw a bazillion pins into big tumbler with a pound or two steel shot and call it peened.

As for the chain tool, I never used a REALLY old one, but if you buy a new one, it shouldn't set you back more than $25 bucks, and then you won't have to worry about it.

(By the way, typing one handed with your non dominant hand is REALLY hard! Bill responded while I was typing))

[Bill]

You can double check but I think this is the exact one you need .... http://www.parktool.com/products/detail.asp?cat=5&item=CT-4.2 .

Some reading information for ya too involving peening... http://www.parktool.com/repair/readhowto.asp?id=25

Lol jr not an easy thing to do especially while eating or hand writing something.

[jr14]

Actually I was holding my kid. He had just woken up from his nap.

That's the chain breaker you need alright. You'll probably never need another one unless you convert to belt drive.

I find that peening article on Park's site a little misleading. That little mushroom head on the pin isn't a result from peening, it's just manufactured that way. Peening is a process you use to harden surface metal. Check out this article on wikipedia: http://en.wikipedia.org/wiki/Peening

You would think two industry giants like Park and Shimano would know better.

[Bill]

Maybe it is a you say "Tah' mah' toe" they say "Toe' may' toe'" thing lol??

[j beede]

"Peening" seems to have multiple definitions. I have always known "shot peening" to mean surface hardening of metals by bombarding with hard "shot". I see from the article referenced by Bill that Park Tool uses "peening" to mean flaring or deforming the ends of chain pins. In any case I didn't know that Dura Ace (and other) chain pins cannot be extracted and re-inserted like old-fashioned, thick plate, roller chains. Also, I was stunned by the force required to push a pin out of my CN-7801 chain. That's why I thought I needed a different tool. Impressive strength in those pins. They broke free with a startling "bang"--nothing like an old DID chain.