Shimano Ultegra 6700 10 Speed Cassette, size?

[mirz]

i read lot about changing Shimano Ultegra 6700 10 Speed Cassette from 12-25 to 11-28 will make a lot difference on hills (where i'm still struggling).

but checking on my bike, all i can see its Shimano Ultegra 6700 10 Speed, it does not mention wether its 12-25 or 11-28.

only from Giant's website i can see that current cassette is 12-25. is there a way to findout this? thanks.

[TimW]

count the teeth on the big cog, if it equals 25, then it is a 25. Count the teeth on the small cog, and if it is a 12 it will have 12 teeth.Tim

[SouthWest]

count the teeth on the big cog, if it equals 25, then it is a 25. Count the teeth on the small cog, and if it is a 12 it will have 12 teeth.Tim

Hi There,

I hear a lot that, the more teeth, the better/easier it is for climbing hills. But how bout with less teeth? Would it translate to faster speed on flat road?

Thanks!

[TimW]

If the engine driving it is ok(Legs) then yes!!

[usernameforme]

you should be able to see the markings on each ring telling you how many teeth it has.

[NhiTrac]

I went from a 28 to a 25... Didn't think missing 3 cogs would make any difference but I sure do deal it! However I'm telling myself to stick it out as it'll make me stronger.

So yes it'll be a lot easier for you but if you can stick it out then do so...

[toolonglegs]

I run a 38/46 11-34 for training at the moment... still do 50kmph strava segments no problems, but can also climb 20-30% dirt climbs ( with different tyres ) on the same bike... kind of enjoying the big range on the road .

[Xplora]

My experience with this mirz has been that yes, the big gaps on the cassette for climbing makes the climbs much easier, BUT you have to be doing some incredible kms for it mean anything.

I actually found going from 12-27 to 12-23 was one of the best changes I ever made with my compact crank. You will naturally be forced to start building muscle, getting out of the saddle, by losing those big gears. Thing is, if you're like me, then slow twitch is your friend and getting a smoother cadence and some more power is going to help you a lot more than a big cassette. The perfect cassette IMO is the 11-21 DuraAce 10 spd. You want all the gears to be close, because that makes your spinning much easier. Dropping 2 gears from 21-27 is like changing cranks. It's a big change, and it won't make your spin easier to maintain - you'll actually just end up having to start from scratch and build your rhythm again.

Those super nasty hills you wanted the 28 for - don't push so hard on the flats next time, and stay in the 21 sprocket. You'll be surprised how little you REALLY need that gear. A lot of climbing is psychological... the climb I was testing these theories with was a 200m climb after a 500m of gradual increasing gradient. It was always the hill I bork on and find the lowest gears, about 16km into my ride home. On Friday afternoon, with 200km in the legs, it gets tough! Anyways, I actually have a climb that isn't that different about 2 minutes after that climb, after a long downhill run. It's almost as steep, but I have a fresher pair of legs after the descent and a lot more speed is carried towards the climb. I don't normally think about it, I think about the 50kmh I am going to try and maintain on the gentle descent on the other side. Unless you physically cannot climb those hills, and you are spending a LOT of time in the smallest gears on the cassette, your overall benefit will probably not exist. Smooth spins and easy transitions between gears will make your rides easier than a 28 sprocket.

In summary, HTFU.

[boss]

Those super nasty hills you wanted the 28 for - don't push so hard on the flats next time, and stay in the 21 sprocket. You'll be surprised how little you REALLY need that gear. A lot of climbing is psychological... the climb I was testing these theories with was a 200m climb after a 500m of gradual increasing gradient. It was always the hill I bork on and find the lowest gears, about 16km into my ride home. On Friday afternoon, with 200km in the legs, it gets tough! Anyways, I actually have a climb that isn't that different about 2 minutes after that climb, after a long downhill run. It's almost as steep, but I have a fresher pair of legs after the descent and a lot more speed is carried towards the climb. I don't normally think about it, I think about the 50kmh I am going to try and maintain on the gentle descent on the other side. Unless you physically cannot climb those hills, and you are spending a LOT of time in the smallest gears on the cassette, your overall benefit will probably not exist. Smooth spins and easy transitions between gears will make your rides easier than a 28 sprocket.

I don't disagree that you can get away with 23 tooth on gradients up to, maybe, 10%. I suspect the average rider will be standing up and grinding with 23t at 10%.

This isn't intended to be a brag, but as a rider who regularly challenges himself with 15-20% avg. grade climbs, a 28 tooth is indispensable. When I'm doing 20%, might get a hundred meters sitting down, but it really is a stand up and grind affair down on the 28. I literally cannot imagine doing that sort of stuff on 23.

[Xplora]

Brag away Jim - this is why I said "unless you physically can't do it". I found I could physically handle the climbs with a 23, especially with a compact, and the 27 actually made things worse.

If you're putting in massive efforts to climb with a 28 and bonk halfway up the hill anyway, then you need it. But I think you should only get the cassette you NEED. Mirz is new, they need to start climbing in the big ring and walking up the climbs when they reach exhaustion, rather than buying bigger cassettes.

[boss]

For starters we don't even know what cassette the OP has...

I guess we are saying the same thing, but we have two different experiences. For me, for the terrain that I enjoy riding, I wouldn't give up my 28 for much. For you, a much smaller/closer cassette will do.

I do think that encouraging a new rider to give up a few gears is a surefire way to bum them out when they can't make it up a climb. Or when their knees are so sore that they throw the towel in.

My thoughts on the question from the OP would be: sure, work out what cassette you have. However, spend a few months riding it (at least), then work out the weaknesses of your current setup, then make a decision on whether more or less teeth would be beneficial to the terrain that you enjoy riding.

I would also suggest that, the early stages of riding should be about building base, not grinding up hills in bigger than required gears to build power. Just my opinion on that and I'm sure there are other opinions out there.

[biker jk]

34-28 is 15% lower gearing than 34-23. You won't be spinning up +8% gradients in that gear. When climbing, high cadence (of 90 rpm or above) is better.

[TimW]

. the climb I was testing these theories with was a 200m climb after a 500m of gradual increasing gradient.

I'd like to know where the 200 metre climb is between seven Hills and parramatta i assume that is distance not vertical
or was it on the Trek Sat ride,Freemans reach? blue mountains?

[TDC]

When climbing, high cadence (of 90 rpm or above) is better.

Better for you or better for everybody?

[boss]

. the climb I was testing these theories with was a 200m climb after a 500m of gradual increasing gradient.

I'd like to know where the 200 metre climb is between seven Hills and parramatta i assume that is distance not vertical
or was it on the Trek Sat ride,Freemans reach? blue mountains?

Xplora hasn't mentioned gradients or elevation specifically in any of his posts so I assumed he meant it was a 700m long climb of unknown ascent or gradient, first 500m fairly easy and the last 200m ratcheting up.

Without knowing the grades or elevation it is hard to comment on whether its a sprinting climb (avg grade 2-5%), something a little harder (avg 5-8%) or a bit of a grind (8%+). Not that it matters to the OP.

[Xplora]

Xplora hasn't mentioned gradients or elevation specifically in any of his posts so I assumed he meant it was a 700m long climb of unknown ascent or gradient, first 500m fairly easy and the last 200m ratcheting up.

Without knowing the grades or elevation it is hard to comment on whether its a sprinting climb (avg grade 2-5%), something a little harder (avg 5-8%) or a bit of a grind (8%+).

It's exactly as jim says. The thing is, it really is all perspective. One man's Mount Doom is another's Hobbiton. It's a mongrel hill that is really hard for me to punish unlike much of my commute. I'm not sprinting it.

My guess is that the OP needs to focus on dominating these hills more.

[TimW]

which Hill/Road is it??

[biker jk]

When climbing, high cadence (of 90 rpm or above) is better.

Better for you or better for everybody?

It's a general rule with few exceptions. Just about all the literature on hill climbing suggests high cadence is better than mashing.

Here's but one example.

http://tunedintocycling.wordpress.com/2008/04/29/hill-climbing-101-pedaling-and-shifting/

[Xplora]

which Hill/Road is it??

I will humiliate myself by divulging the location of said road...

[TDC]

When climbing, high cadence (of 90 rpm or above) is better.

Better for you or better for everybody?

It's a general rule with few exceptions. Just about all the literature on hill climbing suggests high cadence is better than mashing.

Here's but one example.

http://tunedintocycling.wordpress.com/2008/04/29/hill-climbing-101-pedaling-and-shifting/

I have to respectfully disgree. I think that the most effective cadence differs from rider to rider, a lot of it depending on their physiology amongst other things.

Here is some 'literature' (with references!) that supports my point of view.

http://www.bikeradar.com/fitness/articl ... pro-12772/

[TimW]

which Hill/Road is it??

I will humiliate myself by divulging the location of said road...

Go on be a devil
The worst that can be said is HTFU

[Xplora]

which Hill/Road is it??

I will humiliate myself by divulging the location of said road...

Go on be a devil
The worst that can be said is HTFU

A big part of the problem is the Harden that occurs on the rest of the commute, followed by the Up. I do look forward to upgrading the crank to a standard and keeping the 12-23 onboard, that's surely enough

[TimW]

Spill the beans!!!!!!!the road son tell em the road!!!!

[Xplora]

Spill the beans!!!!!!!the road son tell em the road!!!!

I have started training today, doing some sprints and suchlike on the ride home to try and make the magic happen.

I went up that hill I was talking about in 50/19, maybe 50/18. Just grind grind grind. I think it really was psychological. I also made sure I was not busting my cafoofle leading up to it.

Anyways... Xplora 1, Hill 0.

[mirz]

I checked yesterday and cassette has smallest ring with 12 and largest with 25 teeth.

In front big has 53 teeth.

Totally agree with people here that power is all in legs, but for a biggener like me uphill is a struggle and won't like to avoid hills with experienced mates just because of this. I'm confident that with practicing over a next year or so I would improve.

It's more like a half way solution I was checking out.

Wiggle is apperntly selling this cassette for under $60.
Is this any easy DIY or should be done by LBS?