Advice needed- Replacing Chain Rings
Samvan77
Posts: 85
After 2 years and a couple of thousand miles I doing my first major service on my Giant Defy 2 2012 Road bike. I am replacing the chain, cassette and the chain rings.
This is where I am bit stuck though and hopefully someone can give me some advice here. My bike has an FSA Omega 34/50 crank set. So if I understand correctly I need to buy both a 34 and 50 teeth chain rings individually. I have noticed from www.ribblecycles.co.uk that there are different sizes of chain rings to select from e.g 110mm, 135 mm etc.. How do know I know which is the right size to select?
Many thanks in advance
This is where I am bit stuck though and hopefully someone can give me some advice here. My bike has an FSA Omega 34/50 crank set. So if I understand correctly I need to buy both a 34 and 50 teeth chain rings individually. I have noticed from www.ribblecycles.co.uk that there are different sizes of chain rings to select from e.g 110mm, 135 mm etc.. How do know I know which is the right size to select?
Many thanks in advance
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If you only have done a couple of thousand miles then you only need a new chain. Chain rings last way longer than chains and cassettes. Buy a tool to check for chain wear. You should be getting between 2000-2500 miles out of a chain, after you replace the chain three or four times should you consider replacing the cassette.0
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The numbers refer to the 'bolt circle diameter' or BCD
Compact chainrings - 34t/50t = 110mm BCD
Standard chainrings - 39t/53t = 130mm BCD0 -
After 2000 miles, none of that should actually need replacing. Not even the chain - unless it's been wilfully neglected...0
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Samvan77 wrote:After 2 years and a couple of thousand miles I doing my first major service on my Giant Defy 2 2012 Road bike. I am replacing the chain, cassette and the chain rings.
This is where I am bit stuck though and hopefully someone can give me some advice here. My bike has an FSA Omega 34/50 crank set. So if I understand correctly I need to buy both a 34 and 50 teeth chain rings individually. I have noticed from http://www.ribblecycles.co.uk that there are different sizes of chain rings to select from e.g 110mm, 135 mm etc.. How do know I know which is the right size to select?
Many thanks in advance
Really, my FSA chain rings are still fine after 12000 miles and about 18 months, the cassette is nearing the end of it's life after three or four chains.
Are you doing most of your riding on mud, sand and gravel in the rain?
Rule of thumb, four chains = one cassette, three cassettes = new rings.I used to just ride my bike to work but now I find myself going out looking for bigger and bigger hills.0 -
Initialised wrote:Samvan77 wrote:After 2 years and a couple of thousand miles I doing my first major service on my Giant Defy 2 2012 Road bike. I am replacing the chain, cassette and the chain rings.
This is where I am bit stuck though and hopefully someone can give me some advice here. My bike has an FSA Omega 34/50 crank set. So if I understand correctly I need to buy both a 34 and 50 teeth chain rings individually. I have noticed from http://www.ribblecycles.co.uk that there are different sizes of chain rings to select from e.g 110mm, 135 mm etc.. How do know I know which is the right size to select?
Many thanks in advance
Really, my FSA chain rings are still fine after 12000 miles and about 18 months, the cassette is nearing the end of it's life after three or four chains.
Are you doing most of your riding on mud, sand and gravel in the rain?
Rule of thumb, four chains = one cassette, three cassettes = new rings.
Wow, thank you for dispelling the myth pedaled to me my the local bike shops!0 -
Dowtcha wrote:If you only have done a couple of thousand miles then you only need a new chain. Chain rings last way longer than chains and cassettes. Buy a tool to check for chain wear. You should be getting between 2000-2500 miles out of a chain, after you replace the chain three or four times should you consider replacing the cassette.
Excellent thanks for the advice, I will have a look out for the tool.0 -
Imposter wrote:After 2000 miles, none of that should actually need replacing. Not even the chain - unless it's been wilfully neglected...
No, I have been keeping it well maintained - i.e degreased and lubed regularly at least once every month or two. The chain however does show a bit of rust and the tension seem to have dropped as well despite the derailleur setting and positioning right - at least I think so!
But thanks for your input it seems to substantiate and resonate with what everyone else is saying.0 -
As Dowtcha said, buy a chain checker. The park tools one is particularly good. Chains wear to varying degrees based on all kinds of factors. 3000 miles is a decent average but yours could be different.0
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Samvan77 wrote:No, I have been keeping it well maintained - i.e degreased and lubed regularly at least once every month or two
How much are you riding? Chain maint every other month doesn't sound particularly regular to me! (Well it is regular I suppose, just not frequent).
Depending on conditions you should be cleaning much more frequently - on a MTB up to every ride! It doesn't need a full degrease each time, but you are probably neglecting it (the rust is a good indicator!)
Dust/grit etc combines with the lube and wears the chain (from the inside). As the links are no longer tight due to the internals having been ground away by the dirt/lube 'grinding paste' that has been created each link is slightly longer when under tension - aka 'chain stretch'. It is the change in the distance between links that means that the teeth in your cassette will now be worn where they shouldn't.
In short - poor maintenance = premature chain stretch. chain stretch = cassette wear.
Mileage is hugely variable due to the previous. Zero maint in MTB conditions could lead to replacement in a few hundred miles. Pro level servicing after every ride in perfect conditions can mean many thousands of miles.
Your new chain measure should have 2 markers. the first will tell you to change the chain - the second will tell you you have left it too late and the cassette is rogered too! You may still find with a new chain that it now skips a lot. this may be due to the teeth in the cassette having been worn and needing replacement...0 -
Post a pic of the cassette and the current chain rings in the workshop section and someone will tell you if they need replacing. I get through 2 chains/cassettes every year on my MTB and chainrings every other. My roadbikes go 2-3 years on the chain and cassette.
Also you don't necessarily need to replace both rings even if you do have wear, as normally one get used more than the other. It can often be cheaper to replace the crankset than the rings. Certainly is on MTBs.
I would normally do chain and cassette together as you often get a deal on the chain that way.
basically you are looking to see if the teeth have gone shark fin like.0 -
Try a new chain first and see how it goes. If it's ok leave it as is, if it's not quite right give it a few miles - a couple of hundred should do it - and see if it settles. I've done that on the winter bike a couple of times as it doesn't warrant the cash, and both times a slightly jumpy chain in the most commonly used gears soon disappeared and became sewing-machine smooth quite quickly.
If it's still no good and jumping or obviously not sitting on the teeth properly, carry on and get a cassette, and rings if it warrants it. As above though, I get through half a dozen chains per cassette, partly by having two and swapping them at ~1000 mile intervals to decrease the cassette wear caused by an older worn chain. It seems to work. Clean & lube chains when you have 5 mins spare, when it looks a bit manky or when you've been caught in a proper downpour. Doing it every 2 months is like putting clean trousers on every two months.
Your LBS sounds a bit naughty tbh.
ps 2000 miles in 2 years is very light use, so it shouldn't need much doing to it. And chains don't take long to go from shiny new & tight to being a bit loose. It's just how they are.0 -
My chain cleaning method does not involve 'degreasing'.
I simply thoroughly wipe the exterior of the chain (and derailleur pulleys & chain rings) with paper towels to remove the majority of the accumulated grit & grim). I don't attempt to get the chain 'spotless' clean.
Then apply a good dosing of fresh lube to the entire chain, and wipe off the excess lube with clean paper towels.
I don't degrease because there isn't a good way to remove the degrease fluid that gets into the interior of the chain links - and the interior of the links is what really needs the lube in the first place.
Yes, I know there are chain cleaning gizmos that are supposed to do wonderful things....
Jay Kosta
Endwell NY USA0 -
JayKosta wrote:I simply thoroughly wipe the exterior of the chain (and derailleur pulleys & chain rings) with paper towels to remove the majority of the accumulated grit & grim).
Whatever you are doing, you are not removing the majority of the accumulated grit and grime. Most of that's on the inside. Removing the dirt on the outside with paper towels will make the chain look nicer but won't clean it in any functional sense. I cook my chains in degreaser to get that stuff out - after re-oiling, you really can tell the difference. To what degree this matters probably depends on how dirty your chain gets. If it is always sunny, then a paper towel is probably all you need. If you live in Wales then a paper towel isn't really going to help.shmooster wrote:As Dowtcha said, buy a chain checker. The park tools one is particularly good.
No, it's just averagely bad. It measures roller and pin wear but doesn't distinguish between the two. Roller wear doesn't matter, doesn't cause 'stretch', pin wear does. A Park tool could theoretically suggest you need a new chain when only the rollers are worn. Therefore it tends to be very conservative and results in more frequent chain replacements than necessary. The best use of a Park tool is to tell you when to start using a ruler to check specifically for pin wear.Faster than a tent.......0 -
I've tried using a steel ruler held against the chain, but even with the bike in a workstand at a comfortable height I find it tricky to hold one end exactly in the centre of a pin while looking at the measurement at the centre of another pin 12 inches away.
Am I alone in finding this difficult?
I routinely use the Park Tools chain checker because it's quick and easy with the bike on the floor. I just hate that nagging feeling I'm replacing chains unneccessarily early.0 -
keef66 wrote:I've tried using a steel ruler held against the chain, but even with the bike in a workstand at a comfortable height I find it tricky to hold one end exactly in the centre of a pin while looking at the measurement at the centre of another pin 12 inches away.
Am I alone in finding this difficult?
Use a small G clamp or a strip of masking tape to hold the ruler in place, it will make holding the beer bottle easier too
my isetta is a 300cc bike0
