Drivetrain upgrades (cassette / chainset)
#1
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Drivetrain upgrades (cassette / chainset)
I currently have 2022 Giant TCR with 52/36 and 11-30 cassette. I would like to get "easier" gearing for my riding style. I was thinking of two options but arent sure what will make more sense and be more economical.
Full Shimano Ultegra 11-30 and 36/52
#1. Switch small chain ring to 34 from 36 and leave all else as is. Will anything else need to be upgraded? No idea if I can just do this and will this be really noticeable.
#2. Replace cassette to 11-34, upgrade chainset to 50/34 and rear derailleur to medium cage (up to 34)
#3. Any other options??? Suggestions?
https://www.giant-bicycles.com/ie/tc...ed-1-disc-2021
Full Shimano Ultegra 11-30 and 36/52
#1. Switch small chain ring to 34 from 36 and leave all else as is. Will anything else need to be upgraded? No idea if I can just do this and will this be really noticeable.
#2. Replace cassette to 11-34, upgrade chainset to 50/34 and rear derailleur to medium cage (up to 34)
#3. Any other options??? Suggestions?
https://www.giant-bicycles.com/ie/tc...ed-1-disc-2021
Last edited by crazyravr; 06-02-23 at 06:53 AM.
#2
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if your crankset will accept 110 BCD rings, I suggest you order the 34 / 50 T combo
that will give you a somewhat lower gear and more useable gears on the big ring.
and if that's not enough, then do the rear cassette as it wears out.
if you're careful and don't use the big/big or small/small gear combinations you should not need to change the derailleur
/markp
that will give you a somewhat lower gear and more useable gears on the big ring.
and if that's not enough, then do the rear cassette as it wears out.
if you're careful and don't use the big/big or small/small gear combinations you should not need to change the derailleur
/markp
#3
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Changing the one ring to 34 might be the least expensive, but it might not shift as well going to the big ring. And, depending on what your crankset is, you may not find a single ring for it. Also, you'd need to be sure the smaller ring won't take it out of the max front difference for your rear DR. But possibly it won't take it out of spec. Or it'll work okay enough regardless.
If the cost doesn't matter to you, then do option #2. But you'd probably find that a 11-32 with the 50/34 will be enough lower gearing for you. And 11-32 stands a better chance of keeping you in the spec's for your rear DR.
But 11-34 might be in spec. However since you didn't tell us what was on your bike we just don't know for certain. SRAM? Shimano? Maybe a FSA crank? And know the series and version number of the DR's would be a bigh help too. It's on them. Usually on the back of the parallelogram. Maybe covered by gunk from the chain and road.
Option #3 is probably the most attractive if you have the wallet to make it chump change and not a big drain on your finances. And for that I'd say get a bike with the gearing already on it that you want.
If the cost doesn't matter to you, then do option #2. But you'd probably find that a 11-32 with the 50/34 will be enough lower gearing for you. And 11-32 stands a better chance of keeping you in the spec's for your rear DR.
But 11-34 might be in spec. However since you didn't tell us what was on your bike we just don't know for certain. SRAM? Shimano? Maybe a FSA crank? And know the series and version number of the DR's would be a bigh help too. It's on them. Usually on the back of the parallelogram. Maybe covered by gunk from the chain and road.
Option #3 is probably the most attractive if you have the wallet to make it chump change and not a big drain on your finances. And for that I'd say get a bike with the gearing already on it that you want.
#4
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1. Does your TCR have an 11-speed or a 12-speed cassette? (A different 11-30 cassette is available for either an 11-speed or a 12-speed drivetrain.)
2. What do you mean by easier gearing? One or more lower (i.e., lower than 36:30) gear ratio(s), or closer gear ratio(s), i.e., smaller gaps between shifts? Or both?
3. Are there any gear ratios in your current drivetrain that you would never use?
Once you answer these questions, your remaining questions can be easily answered.
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#1 is easiest but may or may not make a huge difference. #2 is another very viable option. #3 for me would be to get a 50/34 crankset and also swap the cassette to a 11-32t but only you can decide if that would make sense for you.
#1 doesn't require resizing the chain, but you're adding 2t to the derailleur's wrap. #2 you may need to add a link to the chain and it also adds 2t to the derailleur's wrap. #3 you should be able to keep the original chain but it also adds 2t to the wrap. I mention wrap because that's going to determine whether you'll need a new rear derailleur or not.
#1 doesn't require resizing the chain, but you're adding 2t to the derailleur's wrap. #2 you may need to add a link to the chain and it also adds 2t to the derailleur's wrap. #3 you should be able to keep the original chain but it also adds 2t to the wrap. I mention wrap because that's going to determine whether you'll need a new rear derailleur or not.
#6
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Thanx all. Should have posted the specs for what I have. First post edited now.
https://www.giant-bicycles.com/ie/tc...ed-1-disc-2021
Full Shimano Ultegra 11-30 and 36/52
https://www.giant-bicycles.com/ie/tc...ed-1-disc-2021
Full Shimano Ultegra 11-30 and 36/52
#7
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I went from
Cervelo R3 (11speed) 52/36 & 11-30 using FD-R8050-SS
To
50/34 & 11-36 by changing the crankset, rear derailleur to FD-R8050-GS and cassette to SRAM PG1170 11-36
this config does exceed the Shimano specs for “max cog” and “capacity”, for me this works great and I’ve 1000’s of happy miles on this setup.
Do be sure to get the chain length correct - I highly recommend the big/big+2 method.
Barry
Cervelo R3 (11speed) 52/36 & 11-30 using FD-R8050-SS
To
50/34 & 11-36 by changing the crankset, rear derailleur to FD-R8050-GS and cassette to SRAM PG1170 11-36
this config does exceed the Shimano specs for “max cog” and “capacity”, for me this works great and I’ve 1000’s of happy miles on this setup.
Do be sure to get the chain length correct - I highly recommend the big/big+2 method.
Barry
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I don’t know if an Ultegra 34t small ring will work with a 52t big ring - but I would not do this
Ultegra 34t small ring is prob best used with a 46 or 50t big ring
be aware - Shimano rings are expensive ... big ring alone can retail for $100 and over ... QBP currently has the 6800 46t ring ‘discounted’ to around $80 - and that is dealer cost ... small ring is much less expensive though
not sure which model Ultegra components you have - I believe 6800 RD (GS / long cage) is designed for 32t max rear cog - later R8000 series GS RD’s are designed for 34t max rear cog
Ultegra 34t small ring is prob best used with a 46 or 50t big ring
be aware - Shimano rings are expensive ... big ring alone can retail for $100 and over ... QBP currently has the 6800 46t ring ‘discounted’ to around $80 - and that is dealer cost ... small ring is much less expensive though
not sure which model Ultegra components you have - I believe 6800 RD (GS / long cage) is designed for 32t max rear cog - later R8000 series GS RD’s are designed for 34t max rear cog
Last edited by t2p; 06-02-23 at 07:53 AM.
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#9
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That's a sharp bike bty.
I wonder if a 46/30 crankset, or if possible a 46/30 double chainring would work for you. Keep the stock cassette and rear derailleur. Since some of the high speed gears are probably 1T steps they can all be used for normal cruising, unlike the 2T steps on many cassette's high speed gears which are too big steps IMO for normal cruising, but fine for down hill.
You would still get to about 37 kph with the 12T rear cog at a reasonable 75 rpm cadence and have a higher gear left. And with about a 27 gear inch low gear, you can get down to below 8 kph at a 60 rpm cadence.
I wonder if a 46/30 crankset, or if possible a 46/30 double chainring would work for you. Keep the stock cassette and rear derailleur. Since some of the high speed gears are probably 1T steps they can all be used for normal cruising, unlike the 2T steps on many cassette's high speed gears which are too big steps IMO for normal cruising, but fine for down hill.
You would still get to about 37 kph with the 12T rear cog at a reasonable 75 rpm cadence and have a higher gear left. And with about a 27 gear inch low gear, you can get down to below 8 kph at a 60 rpm cadence.
Last edited by xroadcharlie; 06-02-23 at 08:24 AM.
#10
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I did try, but there was not enough adjustment in my Ultegra Di2 (Road) front derailleur.
I’m told changing the FD will work, but I haven’t tried this combination.
Barry
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#11
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Step 1: Medium cage derailleur (RD-R8000-GS) plus a larger cassette (e.g., Shimano 11-34 or SRAM 11-36). Most likely requires a longer chain. Test ride. If Step 1 does not provide sufficiently low gearing, then ...
Step 2: Going from 52/36 to 50/34 chain rings is a small difference: ~ 4% reduction in all gear ratios with the big ring and ~ 6% reduction in all gear ratios in the small ring. Ask yourself if that 4%-6% is enough:
If yes, Step 2(a): 50/34 chain rings.
If no, Step 2(b): GRX crankset with 46/30 chain rings. Replace front derailleur with GRX model if unable to shift onto big (46T) ring.
Step 2: Going from 52/36 to 50/34 chain rings is a small difference: ~ 4% reduction in all gear ratios with the big ring and ~ 6% reduction in all gear ratios in the small ring. Ask yourself if that 4%-6% is enough:
If yes, Step 2(a): 50/34 chain rings.
If no, Step 2(b): GRX crankset with 46/30 chain rings. Replace front derailleur with GRX model if unable to shift onto big (46T) ring.
Last edited by SoSmellyAir; 06-02-23 at 10:27 AM.
#12
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Thread Starter
I went from
Cervelo R3 (11speed) 52/36 & 11-30 using FD-R8050-SS
To
50/34 & 11-36 by changing the crankset, rear derailleur to FD-R8050-GS and cassette to SRAM PG1170 11-36
this config does exceed the Shimano specs for “max cog” and “capacity”, for me this works great and I’ve 1000’s of happy miles on this setup.
Do be sure to get the chain length correct - I highly recommend the big/big+2 method.
Barry
Cervelo R3 (11speed) 52/36 & 11-30 using FD-R8050-SS
To
50/34 & 11-36 by changing the crankset, rear derailleur to FD-R8050-GS and cassette to SRAM PG1170 11-36
this config does exceed the Shimano specs for “max cog” and “capacity”, for me this works great and I’ve 1000’s of happy miles on this setup.
Do be sure to get the chain length correct - I highly recommend the big/big+2 method.
Barry
Didnt know I could get that 36T cassette into shimano system.
This will cost me $450 roughly to do and I am leaning this way for sure.