Does a worn chain really make that much of a difference?

johnnyb47

Veteran
Location
Wales
Hi,
Since Christmas my average ride speeds have taken a tumble. The flighty 17/18 mph rides had slowly dropped to the low 16mph avg.
I've been just putting it down to getting older and the less cycling done during the cold dark winter months.
Recently though i noticed my chain was worn and duly replaced it just last week. Since being replaced ive done around 180 miles and my average speeds have jumped right up to the mid / high 17mph again.
Surely a worn chain couldn't scrub that much speed off a ride? as let's be honest I'm not exactly a fast rider.
If it is the case, all i can say is wow what i difference a new chain makes in making a bike more efficient,
All the very best,
Johnny
 

Eric Olthwaite

Insert witty self-deprecating description here
my average speeds have jumped right up to the mid / high 17mph again. Surely a worn chain couldn't scrub that much speed off a ride? as let's be honest I'm not exactly a fast rider.
I don't think many riders regularly average 17.5mph+ on their rides, so in my book you are a fast rider.
 
OP
johnnyb47

johnnyb47

Veteran
Location
Wales
@Eric Olthwaite .Saying that though, it all depends on where you're cycling and what type of bike you've got. A road bike going along mile after mile on quiet county roads is going to be a lot quicker than using a utility bike in a built up city 👍👍
 
Last edited:
OP
johnnyb47

johnnyb47

Veteran
Location
Wales
@fossyant ,That's crossed my mind too. It's only been this week that the weather has warmed up. I've also started using my summer cycling clothing again. It certainly makes you wonder whether it's just a combination of everything
 

Sunny Portrush

Veteran
Location
Musselburgh
When I used to work in Aberdeen in the late 80`s, early 90`s, I cycled to work every day for seven years (10 mile round trip), no matter the weather (I was too tight to get the bus). Never once in those seven years did I do any maintenance, I even remember cleaning the gunk out of the cassette occasionally before liberally applying 3 in 1 to every part of the bike - it never gave me a day`s trouble.

These days, the bike gets cleaned down after every ride but as we all know, things were always better in the olden days
 

SkipdiverJohn

Veteran
Location
London
I cycled to work every day for seven years (10 mile round trip), no matter the weather (I was too tight to get the bus). Never once in those seven years did I do any maintenance, I even remember cleaning the gunk out of the cassette occasionally before liberally applying 3 in 1 to every part of the bike - it never gave me a day`s trouble.
You mean you didn't religiously measure your chain using a checking tool and immediately replace it at 0.75% wear? :laugh:. You're lucky you weren't struck down by a bolt of lightning.
 

Lovacott

Über Member
Surely a worn chain couldn't scrub that much speed off a ride? as let's be honest I'm not exactly a fast rider.
Only if the worn chain was causing you issues like slipping under load etc.

But, if the chain was that bad, putting on a new chain would not have fixed it. Your chainwheels and cassette would have also been knackered.

Most likely, it's the difference between riding through cold air and warm air.
 

Lovacott

Über Member
You mean you didn't religiously measure your chain using a checking tool and immediately replace it at 0.75% wear? :laugh:. You're lucky you weren't struck down by a bolt of lightning.
You may mock, but the chain wear thing is actually true.

A year ago when I started commuting, within six weeks, my chain was slipping on the hills and no amount of farting around with indexing or alignment would stop it.

So I put on a new chain which improved things slightly. Then I put on a new freewheel which made things a bit better but none of it was perfect until I'd fitted a new crankset.

It's pretty simple really. As the chain wears, the pins and plates are not so snug against each other and the chain elongates very slightly.

This reduces the number of pins in direct contact with the freewheel and drive cogs which in turn increases the level of wear on the teeth. The teeth lose their shape and the chain begins to slip.

The best way to get around this is to treat the chain as a consumable and replace it before it gets to the point where it causes damage to the drivetrain. The easiest way to tell if a chain is worn is to use a cheap chain checker (I check mine weekly).

In my case, a KMC Z7 costs less than £8 so I have a couple in the shed on standby. I replaced one only last week. It's literally a five minute job.

A slipping chain is not only annoying, it can in fact be as deadly as being struck by lightning. Nothing worse than standing up on the pedals to get a burst of acceleration only to find yourself lurching wildly downwards as the chain loses all grip.
 
You may mock, but the chain wear thing is actually true.

A year ago when I started commuting, within six weeks, my chain was slipping on the hills and no amount of farting around with indexing or alignment would stop it.

So I put on a new chain which improved things slightly. Then I put on a new freewheel which made things a bit better but none of it was perfect until I'd fitted a new crankset.

It's pretty simple really. As the chain wears, the pins and plates are not so snug against each other and the chain elongates very slightly.

This reduces the number of pins in direct contact with the freewheel and drive cogs which in turn increases the level of wear on the teeth. The teeth lose their shape and the chain begins to slip.

The best way to get around this is to treat the chain as a consumable and replace it before it gets to the point where it causes damage to the drivetrain. The easiest way to tell if a chain is worn is to use a cheap chain checker (I check mine weekly).

In my case, a KMC Z7 costs less than £8 so I have a couple in the shed on standby. I replaced one only last week. It's literally a five minute job.

A slipping chain is not only annoying, it can in fact be as deadly as being struck by lightning. Nothing worse than standing up on the pedals to get a burst of acceleration only to find yourself lurching wildly downwards as the chain loses all grip.
I have read your other related posts as well. There is something wrong with your setup or the way you ride. Chains don't wear out like the way you describe. If you can't get 2000 miles give or take 500 miles without slippage, something is wrong. And I am considering the terrain and the environment.
 
Location
London
When I used to work in Aberdeen in the late 80`s, early 90`s, I cycled to work every day for seven years (10 mile round trip), no matter the weather (I was too tight to get the bus). Never once in those seven years did I do any maintenance, I even remember cleaning the gunk out of the cassette occasionally before liberally applying 3 in 1 to every part of the bike - it never gave me a day`s trouble.

These days, the bike gets cleaned down after every ride but as we all know, things were always better in the olden days
you were either very tolerant of issues or that bike was a marvel. Will it take a bow? A pic?
You must have at least changed a brake block?
On the chain thing, on average bikes (not your sainted one) I would replace the chain pretty regularly to avoid trashing the chainrings.
 

Lovacott

Über Member
I have read your other related posts as well. There is something wrong with your setup or the way you ride.
It was maybe 30% setup and 70% bad riding.

Before I replaced the front and rear mechs four months ago, I had issues with selecting lower gears when I needed them so I would change down on the front well in advance to compensate. I'd change to the highest gear on the back to maintain speed and then use the back gears only during the ascent. As a result, I was spending a lot of time with my chain crossed (big to big, small to small).

Getting the mechanics sorted has allowed me to use the gears more appropriately. My chain runs pretty much straight all of the time now.

I'm keeping track in excel of things like my mileage and when I change parts on the bike. I'm expecting the new chain to last double what the old one did. Time will tell.

As for the environment I ride in, from now on in, about four miles of my ride will be splattered with cow dung as the herds are moved around the fields for summer grazing. I cycle right past a milking parlour and the road is a permanent sea of shite even when the cows are in the sheds opposite eating silage in the winter. They have to cross the road to get milked and they seem to like $hitting on the road. I don't think that cow poo is very kind on drivetrains.
 

Lovacott

Über Member
you were either very tolerant of issues or that bike was a marvel. Will it take a bow? A pic?
You must have at least changed a brake block?
On the chain thing, on average bikes (not your sainted one) I would replace the chain pretty regularly to avoid trashing the chainrings.
I can buy three new chains for the price of one single crankset or four new chains for the price of a freewheel.

I can change a chain in five minutes but it takes me an hour to change either a freewheel or crankset.

I wouldn't be overly bothered if I had to change my chain every two months. £1.00 per week commuting costs seems pretty good to me.
 

Lovacott

Über Member
I used to absolutely fly in the summer, anything in the high 20s, low 30s C, I seemed to be superhuman...and loved it.
I wonder how much of it is down to being a bit more "carefree" on a warm and sunny day?

When it's wet, dull and cold, don't we all take it a bit steadier "just in case"? (this applies to all forms of transport).
 
Top Bottom