Long Chain, Les Wear?
 

As I mentioned, I just got a Rans CF bike and am enjoying it quite a
bit. A friend of mine got his last spring. So far he has about 2,500
miles on it (4.000 kms).

He mentioned that the Rans doesn't wear chains or sprockets like
conventional bikes. He said he has no appreciable chain wear over that
period where he'd have at least detectable wear and maybe a new chain
needed if it were a conventional bike. He said the reason was the longer
chain meant less stress per link thus less wear thus the entire drive
train lasts longer.

I can't see it. Take a chain of 10 links. Suspend it from an overhead
and hang a 30 kg mass from it. The stress per link is 30 kgs plus a bit
for the mass of the chain links downstream. Now take the same setup, but
make the chain 40 links. IMO, the stress per link is the same.

I can't deny his chain is almost new after 2,500 miles but I am having a
tough time believing it's due to the longer throw between chain ring and
cassette on the Rans compared to conventional bikes.

Am I missing something?

Long Chain, Les Wear?
 

On 2008-11-18, slide wrote:
As I mentioned, I just got a Rans CF bike and am enjoying it quite a
bit. A friend of mine got his last spring. So far he has about 2,500
miles on it (4.000 kms).

He mentioned that the Rans doesn't wear chains or sprockets like
conventional bikes. He said he has no appreciable chain wear over that
period where he'd have at least detectable wear and maybe a new chain
needed if it were a conventional bike. He said the reason was the longer
chain meant less stress per link thus less wear thus the entire drive
train lasts longer.

I can't see it. Take a chain of 10 links. Suspend it from an overhead
and hang a 30 kg mass from it. The stress per link is 30 kgs plus a bit
for the mass of the chain links downstream. Now take the same setup, but
make the chain 40 links. IMO, the stress per link is the same.

Correct.

I can't deny his chain is almost new after 2,500 miles but I am having a
tough time believing it's due to the longer throw between chain ring and
cassette on the Rans compared to conventional bikes.

Am I missing something?

One factor is chainline: big/big and small/small combinations wear the
chain faster because it's at a bad angle. The angle is more extreme the
closer together the chainrings and sprockets are.

Another is more wear may occur while the chain is bending its way around
the sprockets, chainring and jockey wheels. If you've got a longer chain
then each link spends a higher proportion of its life just cruising in
straight lines.

But the chain is so long on a Rans CF that maybe you have to buy two
chains and join them together when it's time to replace it? I don't
know. If so then it needs to last twice as long to be as cheap.

Long Chain, Les Wear?
 

The chain makes fewer trips around the loop per unit of bicycle travel. Of
course, this is different in each gear, but for any particular gear, the
longer chain goes around less. However, in terms of chain cost, they are
identical.

Long Chain, Les Wear?
 

On Tue, 18 Nov 2008 09:15:27 -0700, slide may
have said:

As I mentioned, I just got a Rans CF bike and am enjoying it quite a
bit. A friend of mine got his last spring. So far he has about 2,500
miles on it (4.000 kms).

He mentioned that the Rans doesn't wear chains or sprockets like
conventional bikes. He said he has no appreciable chain wear over that
period where he'd have at least detectable wear and maybe a new chain
needed if it were a conventional bike. He said the reason was the longer
chain meant less stress per link thus less wear thus the entire drive
train lasts longer.

I can't see it. Take a chain of 10 links. Suspend it from an overhead
and hang a 30 kg mass from it. The stress per link is 30 kgs plus a bit
for the mass of the chain links downstream. Now take the same setup, but
make the chain 40 links. IMO, the stress per link is the same.

I can't deny his chain is almost new after 2,500 miles but I am having a
tough time believing it's due to the longer throw between chain ring and
cassette on the Rans compared to conventional bikes.

Am I missing something?

Yes. Chain wear is not from linear strain, but from flexure and
rub/roll on sprocket teeth. Each link on a long chain makes fewer
trips around each end of the drivetrain than a shorter chain would, so
wear is less per link. Sprockets wear more quickly when run with a
worn chain, so the wear rate reduction carries over to them as well.

This does not mean that adding links to your correctly-sized
conventional-frame bike's chain will make it last appreciably longer;
the cited effect is due to the dramatic length difference in the
radically crank-forward layout of the 'bent.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Long Chain, Les Wear?
 

Werehatrack wrote:


Yes. Chain wear is not from linear strain, but from flexure and
rub/roll on sprocket teeth. Each link on a long chain makes fewer
trips around each end of the drivetrain than a shorter chain would, so
wear is less per link. Sprockets wear more quickly when run with a
worn chain, so the wear rate reduction carries over to them as well.

This does not mean that adding links to your correctly-sized
conventional-frame bike's chain will make it last appreciably longer;
the cited effect is due to the dramatic length difference in the
radically crank-forward layout of the 'bent.


Ah, yes, thx to all. Fewer runs around the sprockets is something I
failed to consider.

Long Chain, Les Wear?
 

On Tue, 18 Nov 2008 11:51:09 -0700, slide wrote:

Werehatrack wrote:


Yes. Chain wear is not from linear strain, but from flexure and
rub/roll on sprocket teeth. Each link on a long chain makes fewer
trips around each end of the drivetrain than a shorter chain would, so
wear is less per link. Sprockets wear more quickly when run with a
worn chain, so the wear rate reduction carries over to them as well.

This does not mean that adding links to your correctly-sized
conventional-frame bike's chain will make it last appreciably longer;
the cited effect is due to the dramatic length difference in the
radically crank-forward layout of the 'bent.


Ah, yes, thx to all. Fewer runs around the sprockets is something I
failed to consider.

Doesn't (probably) matter.

Assuming the major part of the wear comes from link joint action, and that
this is lineraly related to that action - more links wear less but cost
more. Unless you can buy two chains for much less than twice the price of
one the two factors cancel each other out.

Long Chain, Less Wear?
 

"slide" wrote:
As I mentioned, I just got a R[ANS] CF bike and am enjoying it quite a
bit. A friend of mine got his last spring. So far he has about 2,500
miles on it (4.000 kms).

He mentioned that the R[ANS] doesn't wear chains or sprockets like
conventional bikes. He said he has no appreciable chain wear over that
period where he'd have at least detectable wear and maybe a new chain
needed if it were a conventional bike. He said the reason was the longer
chain meant less stress per link thus less wear thus the entire drive
train lasts longer.

I can't see it. Take a chain of 10 links. Suspend it from an overhead
and hang a 30 kg mass from it. The stress per link is 30 kgs plus a bit
for the mass of the chain links downstream. Now take the same setup, but
make the chain 40 links. IMO, the stress per link is the same.

I can't deny his chain is almost new after 2,500 miles but I am having a
tough time believing it's due to the longer throw between chain ring and
cassette on the R[ANS] compared to conventional bikes.

Am I missing something?

Chain wear mostly occurs as the chain is being bent around the rear
sprocket(s). I get about one-half the rate of chain wear on my RANS
Rocket as I do on an upright with the same model Shimano HG chain (which
is fortunate since a replacement chain for the Rocket costs twice as much).

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

Long Chain, Less Wear?
 

Tom Sherman wrote:


Chain wear mostly occurs as the chain is being bent around the rear
sprocket(s). I get about one-half the rate of chain wear on my RANS
Rocket as I do on an upright with the same model Shimano HG chain (which
is fortunate since a replacement chain for the Rocket costs twice as much).


We weren't concerned about cost. The only question was why his chain
showed little or maybe no appreciable wear in over 2k miles.

Long Chain, Les Wear?
 

On Nov 18, 9:15*am, slide wrote:
As I mentioned, I just got a Rans CF bike and am enjoying it quite a
bit. A friend of mine got his last spring. So far he has about 2,500
miles on it (4.000 kms).

He mentioned that the Rans doesn't wear chains or sprockets like
conventional bikes. He said he has no appreciable chain wear over that
period where he'd have at least detectable wear and maybe a new chain
needed if it were a conventional bike. He said the reason was the longer
chain meant less stress per link thus less wear thus the entire drive
train lasts longer.

I can't see it. Take a chain of 10 links. Suspend it from an overhead
and hang a 30 kg mass from it. The stress per link is 30 kgs plus a bit
for the mass of the chain links downstream. Now take the same setup, but
make the chain 40 links. IMO, the stress per link is the same.

I can't deny his chain is almost new after 2,500 miles but I am having a
tough time believing it's due to the longer throw between chain ring and
cassette on the Rans compared to conventional bikes.

Am I missing something?

Who is Les Wear anyway?