/ Replacing chains

This topic has been archived, and won't accept reply postings.
Baron Weasel - on 15 Mar 2013
About to replace a chain for the first time and have a few questions.

When taking out the old Shimano chain, the Big Blue Book of Bike Repair seems to say there is a particular rivet to remove?

Current gearing is 50/39/30 x 12/25, but plan to change this when funds allow to 52 and 11/28 (student with tax rebate coming). This raises the question of if I set the chain the correct length, does this raise any issues with extending the chain at a later date. Again I have consulted the BBB of BR which suggests this may weaken the chain plates?

Cheers, BW
Baron Weasel - on 15 Mar 2013
Replacement chain is one of these: http://www.cyclesurgery.com/pws/UniqueProductKey.ice?ProductID=CKMC0008XN&gclid=CN_1qMDm_rUCFQq5...

Is there anything else to be aware of or general tips?

BW
a concerned citizen - on 15 Mar 2013
In reply to Baron Weasel: Buy some quick links http://www.probikekit.com/uk/kmc-missing-link-shimano-9-speed.html?utm_source=google&utm_medium=...

The amount of extra chain for a 52 vs a 50 is negligible. Add an extra inch of chain and you can always take it out later.
Oujmik - on 15 Mar 2013
In reply to Baron Weasel: Get a chain with a reuseable joining link (or just get the reuseable link separately). Search for "KMC missing link". You can remove any rivet you like from the old chain if you're going to throw it out.

I'm not sure that 52/39/30 x 11/28 is a feasible set of gears, although I could be wrong as I don't use a triple. The rear mech may struggle to cope with the difference in effective chain length between 52x28 and 30*11. If it does work, you will need a slightly longer chain in this setup.
AlisonSmiles - on 15 Mar 2013
In reply to Baron Weasel: Just whip the old one off any old how. It's scrap anyway!
Frank4short - on 15 Mar 2013
In reply to Oujmik:

> I'm not sure that 52/39/30 x 11/28 is a feasible set of gears, although I could be wrong as I don't use a triple. The rear mech may struggle to cope with the difference in effective chain length between 52x28 and 30*11. If it does work, you will need a slightly longer chain in this setup.

I'd guess the relevant issue is not so much the length of chain as the length of the cage on the OP's derailleur.
captain paranoia - on 15 Mar 2013
In reply to Baron Weasel:

> When taking out the old Shimano chain, the Big Blue Book of Bike Repair seems to say there is a particular rivet to remove?

Yes, and it's usually black. But, since you're replacing the chain anyway, just break any of the links... You can learn how to split and repair chains with the old chain, and learn not to make cock-ups. I'm a ssuming you've got a chain breaking/making tool.

I'd replace the current chain with the same number of links as the current one. If at some time in the future you replace the entire gear set, I'd replace the chain at the same time.

Chains need replacing fairly regularly (they're essential 'biking consumables'), so it may well be time to change when you fit the new gear set anyway. Plus, it will all run much smoother if everything starts from new...
Baron Weasel - on 15 Mar 2013
In reply to captain paranoia:

The old chain is in critical condition after at least 5000 miles, probably more, so needs replacing ASAP. New one has been dispatched today so will probably arrive Monday.

I can't afford to do the rest of the gears for another month so going to have to do with old ones until then. Only the front big ring shows any noticeable wear, so I'm sure they will do for now. (Owed well over a grand from tax man - can't wait. Have a broken car as well bike needing attention.)

Just had a play at splitting a mates old chain and reconnecting it with quicklinks which was pretty straight forward.

The new chain already has a quicklink in it, so I would prefer to re-rivet it if possible if I extend it again. The BBB of BR shows connecting rivets with a pilot part than breaks off, but suggests that re-using the same rivet hole wears the plates and may weaken the chain. I would prefer this to having 2 quicklinks in, but I guess it would not be the end of the world.

Regarding the new ratio's I have in mind, this is the bike http://2011.konaworld.com/bike.cfm?content=jake

Will it work?

BW



Frank4short - on 15 Mar 2013
In reply to Baron Weasel:

> The old chain is in critical condition after at least 5000 miles, probably more, so needs replacing ASAP. New one has been dispatched today so will probably arrive Monday.

> I can't afford to do the rest of the gears for another month so going to have to do with old ones until then.

You will destroy the new chain in days putting it on a drivetrain that has over 5,000 miles on it. Wear on the cassette in particular is rarely something that is obvious. At this point your best bet is to either sit on the new chain till you can afford to at least replace the cassette or accept the fact that if you replace the chain now it will likely have negligible effect and that the other worn parts on the drivetrain will likely do so much damage to it in the time you're waiting to purchase a new cassette and chainrings you will do so much damage to it that you may well have to replace it again.

> Just had a play at splitting a mates old chain and reconnecting it with quicklinks which was pretty straight forward.

Quicklinks are easy to use, cheap and reliable. Don't be afraid to put extra links on. re: the chain length the old rule of thumb is before installing the chain run it over the largest cassette and chain ring (outside of the derailleurs) and add 2 links. Sometimes I personally feel this leaves the chain too long especially on a drivetrain with a large differential. So I run the chain through the derailleurs on the middle cassette and ring and gauge the length as the point where the rear derailleur is point straight down. Failing that you could go tech nerd and use a chain length calculator like this one http://www.machinehead-software.co.uk/bike/chain_length/chain_length_calculator.html
Oujmik - on 15 Mar 2013
In reply to Baron Weasel: Regarding your new gear set-up, this is the relevant info from shimano for yor rear mech (assuming this is the correct part):

Model Number RD-4500-GS
Series TIAGRA
Cassette Compatibility 9-speed
Maximum Sprocket 27T
Minimum Sprocket 11T
Maximum Front Difference 22T
Total Capacity 37T

This suggests it might not be happy with a 28T rear sprocket. The front difference will be 52-30=22 so right at the maximum. The total capacity needed would be (52-30)+(28-11)=39, so over the maximum.

What this means is that your rear mech doesn't have the ability to take up enough slack to deal with such a huge gear range. If you have the rear meach fully 'stretched' at 52*28, the chain will be hanging loose in 30*11.
Baron Weasel - on 15 Mar 2013
In reply to Frank4short:

>
> You will destroy the new chain in days putting it on a drivetrain that has over 5,000 miles on it. Wear on the cassette in particular is rarely something that is obvious. At this point your best bet is to either sit on the new chain till you can afford to at least replace the cassette or accept the fact that if you replace the chain now it will likely have negligible effect and that the other worn parts on the drivetrain will likely do so much damage to it in the time you're waiting to purchase a new cassette and chainrings you will do so much damage to it that you may well have to replace it again.
>

Don't like the sound of that - don't really like the idea of a chain snapping on me either. Perhaps I should see if I can get another few (hundred) miles out of the old chain. Bike shop said it was at 1 on a scale of 0-10 and that 0.75 was certain death?

BW
Enty - on 15 Mar 2013
In reply to Frank4short:
> (In reply to Baron Weasel)
>
> [...]
>
> [...]
>
> You will destroy the new chain in days putting it on a drivetrain that has over 5,000 miles on it.

This ^^^ It might not even work either.

E
Frank4short - on 15 Mar 2013
In reply to Baron Weasel:

> Don't like the sound of that - don't really like the idea of a chain snapping on me either.

It's unlikely to snap though it will most probably jump like buggery (knee handlebar interface, anyone?) and continue to do that for the rest of it's days no matter what other running gear you use it with, old or new.
Baron Weasel - on 15 Mar 2013
In reply to Oujmik: So, should I look for 11/27 cassette then? I have a fairly set pattern of how I change gear and only use 2 biggest rings on the cassette with the granny and 3 smallest with big chainwheel. I never ever use big chainring to big sprocket or granny to small sprocket, so would that make it ok?

Thanks,

BW
Enty - on 15 Mar 2013
In reply to Baron Weasel:

Don't get too hung up on having an 11 sprocket. A 12 will be fine and give you one less jump in teeth elsewhere on the cassette.
Eddy Merckx won many races with a 13 sprocket on.

E
Baron Weasel - on 15 Mar 2013
In reply to Enty:
> (In reply to Baron Weasel)
>
> Don't get too hung up on having an 11 sprocket. A 12 will be fine and give you one less jump in teeth elsewhere on the cassette.
> Eddy Merckx won many races with a 13 sprocket on.
>
> E

Getting an 11 sprocket is actually the main reason for changing as round the Lakes there lots of ups and downs and I often run out of gears at the bottom of a hill where I'm trying to go as fast as possible to make it up the next.

BW
Baron Weasel - on 15 Mar 2013
In reply to Frank4short:


> You will destroy the new chain in days putting it on a drivetrain that has over 5,000 miles on it.

Been there, done that, wasted 18 euro on chain as a result! It's weird, don't quite see how it works but the new chain started breaking like the old one was doing.
Liam M - on 15 Mar 2013
In reply to Baron Weasel:
> (In reply to Enty)
> [...]
>
> Getting an 11 sprocket is actually the main reason for changing as round the Lakes there lots of ups and downs and I often run out of gears at the bottom of a hill where I'm trying to go as fast as possible to make it up the next.
>
> BW

Learn to spin faster; 52-12 at 120rpm gives you over 40mph - if you're getting to those speeds tucking yourself into a more aero position will be better than a slightly smaller cassette.


Enty - on 15 Mar 2013
In reply to Liam M:
> (In reply to Baron Weasel)
> [...]
>
> Learn to spin faster; 52-12 at 120rpm gives you over 40mph - if you're getting to those speeds tucking yourself into a more aero position will be better than a slightly smaller cassette.

Yep ^^^

E
Richard Carter - on 16 Mar 2013
In reply to Baron Weasel:

I have been using an 11-32 cassette on my cross bike (the rest of the drive train is 9 speed tiagra). While outside the recommended specs, it works. If you like you can have the 11-32 cassette, only did 100 mile or so on it and swapped it out for a far smaller one.

If you want it send me your address or something :)
FrankBooth - on 17 Mar 2013
In reply to Baron Weasel: I've got a basic Specialized Allez 16 which came with a Shimano HG-50 rear cassette. Would it be straightforward enough to put an equivalent 8 speed MTB cassette - I'm thinking of a HG-41 or 51 which I believe is available as 11-30T? Reading this thread (and others) I appreciate I'l need t replace the chain, but would I need to adjust the rear mech as well?
andy - on 17 Mar 2013
In reply to FrankBooth:
> (In reply to Baron Weasel) I've got a basic Specialized Allez 16 which came with a Shimano HG-50 rear cassette. Would it be straightforward enough to put an equivalent 8 speed MTB cassette - I'm thinking of a HG-41 or 51 which I believe is available as 11-30T? Reading this thread (and others) I appreciate I'l need t replace the chain, but would I need to adjust the rear mech as well?

Depends on your chainset - I think a standard road short cage rear mech can cope with a compact chainset and a 28T cassette, so you might struggle with a 30. It's only mean you couldn't use big-big though I guess?
Baron Weasel - on 18 Mar 2013
In reply to Frank4short:

>
> It's unlikely to snap though it will most probably jump like buggery (knee handlebar interface, anyone?) and continue to do that for the rest of it's days no matter what other running gear you use it with, old or new.

Despite this sage advice, I thought I'd try the new chain anyway and indeed it did jump like mad in certain gears. Old chain is back on with quicklink now.

BW
ads.ukclimbing.com
cousin nick - on 19 Mar 2013
In reply to Baron Weasel:

Just another comment regarding chain wear: I replaced my MTB chain and cassette (9-speed) just before Xmas. After a winter of graunching around in mud etc. its already worn between 0.75 and 1%. Just shows how quick they can go.

N

This topic has been archived, and won't accept reply postings.