Tech Cassettes and chains compatibility

luka

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Jan 13, 2015
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#1
I have Ultegra drivetrain, with 11-25 cassette. I may be taking some time off to go to Europe in the summer and would like to take the bike with me. However, there will be much more climbing than in Tokyo, and I'm thinking about getting a spare 28 or 30 mountains cassette.

But I have doubts if the same chain can function with both 25s and 30s? Or do you have to get another (longer) chain too?
 

TCC

Tokyo Cycling Club
Jun 30, 2013
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#2
25 to 28 will probably be fine. 25-30 might cause you some issue.

Simply a case of putting on the cassette you want to use and checking if the chain is the right length. If it isn't, just buy a new chain. They are very cheap.

And really, most people who ride here in the mountains, are using 28T cassettes, so you might want to just switch over to that permanently and get a new chain in the process, and get rid of the 25T cassette.

In other news, are you the same Luka I met out on the Edogawa the other day when I caught up with a bunch of you going up to Sekiyado castle?
 
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luka

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Jan 13, 2015
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#3
Thanks for the tip! And yes, that was me on the Sekiyado ride. You've put amazing effort against that headwind that day!

BTW, how do you check if the chain is right length? If it can shift into that lowest gear, is that enough?
 
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TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
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#4
Measuring;

1. Get the bike in the largest cog on the rear, and the smallest ring on the front.
2. Look at the rear mech hanger. It should be as close to exactly vertical as possible, measured as a line going through the centre of both jockey wheel bolts. If the chain is too long, the rear hanger will be at an acute angle. If it is too short, the angle will be obtuse.

Haha, cheers. That was a monster catch up. I was going down the river and saw you lot coming up the opposite direction on the other side. I headed down to the next bridge, crossed it, and saw you as a tiny dot in the distance. Took about 10 minutes of absolute brutality to catch up with you. Haha.
 
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luka

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Jan 13, 2015
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#5
But you still had enough in you to go sprinting for the finish! Helmets off... Thanks for the mechanic tips too. I'm gonna give this some thinking over the following months and see what would work best for me. Just getting a 28 cassette sounds like a good all-rounder solution
 

Trek DJ

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Jan 27, 2009
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Kobe
#10
Definitely check chain length, as running a chain too short can rip off your RD or worse if that RD takes a chunk out of your seat stay. Especially if you like to sit in the big/big which for some reason many Jpns riders do...

30T is likely to max out your RD. You may be able to get away with it by playing around the the b-screw but pretty darn close on 105-DA RD's.

What are you running on the front? A compact 50-34 front with an 11-28 rear is a pretty wide setup.
 
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luka

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Jan 13, 2015
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#11
Thanks everyone. I'll most likely just get the 28 cassette, as I already have compact chain-rings (50-34). I got this bike 2nd hand, so I didn't have much say in such details, but I love it overall.

About the Dura Ace chain, I though it was golden in color, or at least every other link or so was? I'm pretty sure I've seen that somewhere. Maybe not all of them are like that...
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
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#12
Just follow the instructions I gave for checking the chain length.

Compact to 28-11 / 28-12 is what we all use.

Dura Ace chain; no, they are plain grey / silver, and always have been.
 

luka

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Jan 13, 2015
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#13
Do you think that will be enough on very long, demanding climbs? I plan to do some 30-40 km straight climbing, avg at 7-8, but peaking at 20 grade or so at some sections. Should 30 at the front and 28 at the back do even here?
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
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#14
If you have a compact Ultegra 6800 chainset on the front, that is a 34T chainring.

34T front, with 28T rear is standard climbing gear. Pretty much everyone uses that round these parts.

Some people use a bigger cassette, but usually 28T on the rear is fine for most climbing situations.

20% grade will have you standing up no matter what the gear you have. 7-8% over distance can be spun at a fairly alright cadence with 34-28 gearing.

Once you go over 28T on the cassette you probably have to start buggering about with getting a longer hanger rear mech, etc.

For the record, I have a compact front and 28T rear. As does @leicaman, @theBlob, @saibot etc. All of us can climb fine with these gears (and some of us can climb like ridiculous monsters).
 
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leicaman

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Sep 20, 2012
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Asakadai, Saitama
#15
@luka 30-40km of straight climbing? Sounds like fun. There can't be many climbs in Japan of this distance. I'm guessing you aren't talking about Japan. Where are these climbs?
I've done the kinpu-San climb which of I remember rightly, is about 33km of climbing from the Lawson at the bottom of the mountain. I have a compact crank and 28 on the back. Never felt like I needed to use the 28. In fact, I almost never use the 28.
 
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TCC

Tokyo Cycling Club
Jun 30, 2013
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#16
Yeah, same here. I only really use the 28 if I am knackered and need to spin for a bit, or if the incline is really gnarly. For stuff under about 6%, it is big ring action all the way!
 
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luka

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Jan 13, 2015
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#17
OK, seems like 28 is the way to go. Since I don't often have a chance (nor the willpower) to do these huge climbs anyway it's not like I'll need it a lot. So it makes sense to get an all-rounder cassette... Thanks for the help! And yes, @leicaman this would be in south Europe, late summer or early autumn is the plan for now.
 

theBlob

Bokeh master
Sep 28, 2011
2,865
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#18
Not me. I have a 38/52 and 12/ 30 for climbing. It is good but I would prefer a compact set up for the hills. I can't imagine needing more than 34/28 but that depends on preference rather than need. @GrantT climbs like a spinning beast with a 32 on the rear.
 

TCC

Tokyo Cycling Club
Jun 30, 2013
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#19
Ah sorry, thought you were on full compact.

38/30 = 1.26666666

34/28 = 1.21428571

So pretty much the same... You will definitely notice a lot more freedom going from 25 to 28. Even if you don't use the 28T for climbing, the fact that it is there as backup for when it gets steep, or your body gives up, is a cool thing to have.

Not sure if this is right, but I think @GrantT might be using a 32T due to knee / false arm issues (although I am sure he can speak for himself!)
 

zenbiker

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Mar 4, 2008
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Chofu
#20
Do you think that will be enough on very long, demanding climbs? I plan to do some 30-40 km straight climbing, avg at 7-8, but peaking at 20 grade or so at some sections. Should 30 at the front and 28 at the back do even here?
Where are you going to find 30-40km straight of climbing?

Ahhh... Europe!
I usually run a 52/36 F and 11/28 but have a wifi set up 50/34F 11/30 R
Strange thing is I'l use the 34/30 if I'm on it but wil manage fine with the 36/28 on the same climbs.
 
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