Just broke a fairly young chain...

[Paul M. Hobson]

....and I'm not that strong @ 61 kg (135 lbs). It was a SRAM PC-48
chain. I was powering through an intersection to get away from an very
aggressive and verbally threatening taxi driver. My right knee hit the
DT shifter and took me up a few gears. I seem to remember going through
the shifts and pedaling a couple of times before it broke.

The loss of power transfer made me pretty squirrelly and head towards
oncoming traffic. Thanks to my lucky stars for good brakes/reaction
time (of myself and the red Civic). All this happened at the same
@$#@#ng intersection where I got hit and run in November of 2006.

Was it the shifts that broke the chain, a random failure, or I'm just a
beast?

Photos here: http://www.flickr.com/photos/p_myron_h/2279963463/

Alls I know is that I need a new route to school.

\\paul
--
Paul M. Hobson
..:change the f to ph to reply:.

 

[jim beam]

Paul M. Hobson wrote:
> ...and I'm not that strong @ 61 kg (135 lbs). It was a SRAM PC-48
> chain.
<snip fluff>

the chain in the pic is a pc971, not a pc48. if you're running 7-speed
gears, there's a chance you have a chain width problem that's
exacerbating the other problem... which is re-use of a peened chain
pin, not joining with the link provided.

 

[Dre]

"jim beam" <[email protected]> wrote in message
news:[email protected]...
> Paul M. Hobson wrote:
>> ...and I'm not that strong @ 61 kg (135 lbs). It was a SRAM PC-48 chain.
> <snip fluff>
>
> the chain in the pic is a pc971, not a pc48. if you're running 7-speed
> gears, there's a chance you have a chain width problem that's exacerbating
> the other problem... which is re-use of a peened chain pin, not joining
> with the link provided.
>

Aren't the SRAM PC9xx chains 9 speed chains?? I thought the number after
the PC stood for the amount of gears on the cluster?

I wouldn't have thought that a 9 speed chain would even fit over a 7 speed
rear sprockets! (width wise) They certainly dont fit over BMX or some SS
rear sprockets as I found out trying to use a 9 speed chain on a freecoaster
hub (with a BMX type sprocket fitted), it simply wouldn't fit. An 8 speed
chain was no problems though.

Cheers Dre

 

[Tom Sherman]

Paul M. Hobson wrote:
> ...and I'm not that strong @ 61 kg (135 lbs). It was a SRAM PC-48
> chain. I was powering through an intersection to get away from an very
> aggressive and verbally threatening taxi driver. My right knee hit the
> DT shifter and took me up a few gears. I seem to remember going through
> the shifts and pedaling a couple of times before it broke.
>
> The loss of power transfer made me pretty squirrelly and head towards
> oncoming traffic. Thanks to my lucky stars for good brakes/reaction
> time (of myself and the red Civic). All this happened at the same
> @$#@#ng intersection where I got hit and run in November of 2006.
>
> Was it the shifts that broke the chain, a random failure, or I'm just a
> beast?
>
> Photos here: http://www.flickr.com/photos/p_myron_h/2279963463/
>
> Alls I know is that I need a new route to school.
>
I think the preying mantis is to blame.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

 

[Paul M. Hobson]

Dre wrote:
> "jim beam" <[email protected]> wrote in message
> news:[email protected]...
>> Paul M. Hobson wrote:
>>> ...and I'm not that strong @ 61 kg (135 lbs). It was a SRAM PC-48 chain.
>> <snip fluff>
>>
>> the chain in the pic is a pc971, not a pc48. if you're running 7-speed
>> gears, there's a chance you have a chain width problem that's exacerbating
>> the other problem... which is re-use of a peened chain pin, not joining
>> with the link provided.
>>
>
> Aren't the SRAM PC9xx chains 9 speed chains?? I thought the number after
> the PC stood for the amount of gears on the cluster?
>
> I wouldn't have thought that a 9 speed chain would even fit over a 7 speed
> rear sprockets! (width wise) They certainly dont fit over BMX or some SS
> rear sprockets as I found out trying to use a 9 speed chain on a freecoaster
> hub (with a BMX type sprocket fitted), it simply wouldn't fit. An 8 speed
> chain was no problems though.
>
> Cheers Dre
>
>

Yeah. Sorry 'bout that. I used to run PC-48s on my single speed and
when the bike was 8spd. When I went to nine. I told the bike shop guy
to give me a 9spd chain similar to the PC-48 and ended up with PC-971.
My bad.

\\paul

--
Paul M. Hobson
..:change the f to ph to reply:.

 

[Dre]

"Paul M. Hobson" <[email protected]> wrote in message
news:[email protected]...
> Dre wrote:
>> "jim beam" <[email protected]> wrote in message
>> news:[email protected]...
>>> Paul M. Hobson wrote:
>>>> ...and I'm not that strong @ 61 kg (135 lbs). It was a SRAM PC-48
>>>> chain.
>>> <snip fluff>
>>>
>>> the chain in the pic is a pc971, not a pc48. if you're running 7-speed
>>> gears, there's a chance you have a chain width problem that's
>>> exacerbating the other problem... which is re-use of a peened chain
>>> pin, not joining with the link provided.
>>>
>>
>> Aren't the SRAM PC9xx chains 9 speed chains?? I thought the number after
>> the PC stood for the amount of gears on the cluster?
>>
>> I wouldn't have thought that a 9 speed chain would even fit over a 7
>> speed rear sprockets! (width wise) They certainly dont fit over BMX or
>> some SS rear sprockets as I found out trying to use a 9 speed chain on a
>> freecoaster hub (with a BMX type sprocket fitted), it simply wouldn't
>> fit. An 8 speed chain was no problems though.
>>
>> Cheers Dre
>
> Yeah. Sorry 'bout that. I used to run PC-48s on my single speed and when
> the bike was 8spd. When I went to nine. I told the bike shop guy to give
> me a 9spd chain similar to the PC-48 and ended up with PC-971. My bad.
>
> \\paul
>
> --
> Paul M. Hobson
> .:change the f to ph to reply:.

Well if you are running a PC-971 on a 9 speed cluster its not the chain
width thats the problem. You didn't by any chance split the chain at that
link before and re-use it??

I personally dont like breaking chains on normal links then putting them
back together at that point, I get the feeling they are never as strong.
When I first saw a powerlink I was sold, I've now converted all my chains
over to power links and have never looked back

Cheers Dre

 

[Paul M. Hobson]

Dre wrote:
> Well if you are running a PC-971 on a 9 speed cluster its not the chain
> width thats the problem. You didn't by any chance split the chain at that
> link before and re-use it??
>
> I personally dont like breaking chains on normal links then putting them
> back together at that point, I get the feeling they are never as strong.
> When I first saw a powerlink I was sold, I've now converted all my chains
> over to power links and have never looked back

Never used a chain tool on the chain except to take 1 or 2 links off of
it before connecting the ends with the gold power/master/whatever link,
which is still perfectly in tact.

--
Paul M. Hobson
..:change the f to ph to reply:.

 

[Dre]

"Paul M. Hobson" <[email protected]> wrote in message
news:[email protected]...
> Dre wrote:
>> Well if you are running a PC-971 on a 9 speed cluster its not the chain
>> width thats the problem. You didn't by any chance split the chain at
>> that link before and re-use it??
>>
>> I personally dont like breaking chains on normal links then putting them
>> back together at that point, I get the feeling they are never as strong.
>> When I first saw a powerlink I was sold, I've now converted all my chains
>> over to power links and have never looked back
>
> Never used a chain tool on the chain except to take 1 or 2 links off of it
> before connecting the ends with the gold power/master/whatever link, which
> is still perfectly in tact.
>
> --
> Paul M. Hobson
> .:change the f to ph to reply:.

Well that is very bizarre then, certainly not what I would have expected...

Maybe it was just a dodgy link?

Cheers Dre

 

[[email protected]]

On Feb 21, 4:31 pm, "Paul M. Hobson" <[email protected]> wrote:
> Dre wrote:
> > Well if you are running a PC-971 on a 9 speed cluster its not the chain
> > width thats the problem. You didn't by any chance split the chain at that
> > link before and re-use it??
>
> > I personally dont like breaking chains on normal links then putting them
> > back together at that point, I get the feeling they are never as strong.
> > When I first saw a powerlink I was sold, I've now converted all my chains
> > over to power links and have never looked back
>
> Never used a chain tool on the chain except to take 1 or 2 links off of
> it before connecting the ends with the gold power/master/whatever link,
> which is still perfectly in tact.

7-speed, 9-speed, powerlink vs. chain tool and so on, you guys
are overthinking this. Accidentally shifting while under heavy
load (esp. in a stressful situation like this) is a good way to break
a chain. The chain is briefly bent during the process of shifting
and if you get unlucky, or it tries to jump multiple gears at once,
you're bending it while putting force on it. Most of the time it
won't break, but sometimes it will.

Ben

 

[Paul M. Hobson]

[email protected] wrote:
> 7-speed, 9-speed, powerlink vs. chain tool and so on, you guys
> are overthinking this. Accidentally shifting while under heavy
> load (esp. in a stressful situation like this) is a good way to break
> a chain. The chain is briefly bent during the process of shifting
> and if you get unlucky, or it tries to jump multiple gears at once,
> you're bending it while putting force on it. Most of the time it
> won't break, but sometimes it will.

Thanks, Ben. That's what I was looking for.

\\paul

 

[Dre]

<[email protected]> wrote in message
news:[email protected]...
> On Feb 21, 4:31 pm, "Paul M. Hobson" <[email protected]> wrote:
>> Dre wrote:
>> > Well if you are running a PC-971 on a 9 speed cluster its not the chain
>> > width thats the problem. You didn't by any chance split the chain at
>> > that
>> > link before and re-use it??
>>
>> > I personally dont like breaking chains on normal links then putting
>> > them
>> > back together at that point, I get the feeling they are never as
>> > strong.
>> > When I first saw a powerlink I was sold, I've now converted all my
>> > chains
>> > over to power links and have never looked back
>>
>> Never used a chain tool on the chain except to take 1 or 2 links off of
>> it before connecting the ends with the gold power/master/whatever link,
>> which is still perfectly in tact.
>
> 7-speed, 9-speed, powerlink vs. chain tool and so on, you guys
> are overthinking this. Accidentally shifting while under heavy
> load (esp. in a stressful situation like this) is a good way to break
> a chain. The chain is briefly bent during the process of shifting
> and if you get unlucky, or it tries to jump multiple gears at once,
> you're bending it while putting force on it. Most of the time it
> won't break, but sometimes it will.
>
> Ben
>

I guess I've been really lucky then I've never ever broken a new chain
like that before, only a very very old worn as hell chain that I needed to
split, I must not have put the pin back in properly because later on it
broke at that pin in exactly the same way as the OP.

Stretched chains? I have a hell of a lot of those

Cheers Dre