datlas 

I know you are not "supposed" to reuse these pins but assuming I can push it back in, is there really a good reason not to?

I had to disassemble the chain yesterday and pushed the pin through just enough to get the chain out. It's really tempting just to push it back like the good old days.

Comments?

leob1

Push it all the way out, throw it away, use a quick link.

dsaul

Bring a chain tool with you for when the chain comes apart and hope it isn't when you are standing and climbing a hill. Although, that's when its most likely to happen.

Seriously, just get a quick link.

Brofessor

Try it! The worst that can happen: Rolling down the hill 30mph, chain breaks, flies into your front wheel, locks it up.... Yeah, don't try it, be safe.

Andrew R Stewart 

When you push out a chain pin that has had it's ends peened over (as pretty much all chains for indexed systems have to one degree or another) the peening punches open the side plate's hole. If this pin is next reinserted into the side plate's hole it will fit more loosely then it should. In time the prying forces that the chain suffers with during shifting will cause that pin to not be able to stay in the side plate's hole, your chain breaks usually when you're applying significant power too.

Shimano's replacement pins are slightly over sized to make up for this bigger side plate hole (and that's why the chain's instructions say to not remove a replacement pin, as there's only one oversize made, not two steps of oversize). Additionally the replacement pins have a ramped portion to the pilot part (the part that gets snapped off after install). This ramping acts to ease the oversized pin's entry into the side plate without further opening up the hole. I like to put a drop of lube on the replacement pin, I find it slides in more smoothly.

Given the wide availability, low cost and high reliability of connecting links I agree that they are the more sensible way to assemble a chain these days. Andy

datlas 

Message received.

I will use a quick link. I think I have a few lying around somewhere.

Thanks.

Bigbus

I'd shove it in there, mark it for later identification, and ride to the local bike shop to get a quick link or oversized pin, plus some spares for next time. Unless there is a steep hill between you and the bike shop, then I'd consider walking the bike because I would never trust putting a whole lot of force on the chain until it was fixed properly. You asked and this is my opinion only.

AnkleWork

You really don't need permission to just do what you want, but here it is: permission granted.

Bill Kapaun

Smart move.
I pretzled a RD when reusing a 9 speed pin.

Slightspeed

In a hurry to make the Pasadena vintage ride, I threw an old 10 speed chain on my six speed Super Course and re-used the pin. I had new pins somewhere, but couldn't find them. 4 or 5 miles out, the drivetrain locked up solid. The pin had worked loose and jammed in the derailleur jockey wheel. It was still in the chain, just barely. I started walking back to the car, but saw a big rock alongside the road. I used the rock and the flat side of a wrench to push the pin back in. I rode gingerly back to the car. I learned to not re-use chain pins, but I haven't learned to carry a chain tool. The new KMC chain arrived in the mail the next day.
I put a new chain on my Peugeot the other day, using the quick link. I put a chain tool in the saddle bag, just in case, but haven't needed it ... yet.

fietsbob

Once chains went past 6 speeds the chain pins no longer were wider than the chain , but flush ..

if you throw the big bucks on the counter, you can get a chain tool that re rivets the pin head ..

as when you pushed the pin out, you stretched the hole, and so unless you enlarge the rivet head..
lt can come loose easily..

Basically, You cannot do a better job than the chain making machine in the factory..




....

RockiesDad

Been there, done that, got the t-shirt...

Well, had to walk back to the car as my prize. Get a quick link...