Compact Crank vs Semi-Compact

singleton

Imposter wrote:

Depends on your fitness, but I would take a 34 as a 'nice to have' - you don't have to use it.

Visions of major roadside work being done when my legs are shot half way up

I may put one in may bag and see how it goes after day 1...

dennisn

Imposter wrote:

Singleton wrote:

Term1te wrote:

I'm going back this year, and am still not sure if I'll stick with 36 or go down to 34 again. I have an 11 -28 cassette, anything larger than that looks odd to me.

I'm heading to the alps for a short trip in August with my new 52/36 setup which is currently matched to an 11 speed 11-28 cassette. I was wondering whether I should change the front ring from a 36 to a 34 - so going with a 52/34 for the trip....

Best of both?

Depends on your fitness, but I would take a 34 as a 'nice to have' - you don't have to use it.

Let's see. This is road beginners column and you're advising a newbie going to the Alps that he should mount a 34 on the front. That's VERY good advise. However telling him that "..you don't have to use it.." is idiotic. No one climbs the Alps in a 52. He'll be in that 34 most of the time and most likely wishing, at times, he had something a bit bigger on the back than a 28.

singleton

dennisn wrote:

Let's see. This is road beginners column and you're advising a newbie going to the Alps that he should mount a 34 on the front. That's VERY good advise. However telling him that "..you don't have to use it.." is idiotic. No one climbs the Alps in a 52. He'll be in that 34 most of the time and most likely wishing, at times, he had something a bit bigger on the back than a 28.

I took the advice to mean that I should take a 34 chainring with me in my luggage and I could always put it on in place of the 36 if I needed it.

bigmat

I took it to mean the 34 would give him a few lower gears that he could hold in reserve and didn't necessarily have to use if he didn't need them. Don't think there was ever any suggestion that he might not need the inner ring!

dennisn

Singleton wrote:

dennisn wrote:

Let's see. This is road beginners column and you're advising a newbie going to the Alps that he should mount a 34 on the front. That's VERY good advise. However telling him that "..you don't have to use it.." is idiotic. No one climbs the Alps in a 52. He'll be in that 34 most of the time and most likely wishing, at times, he had something a bit bigger on the back than a 28.

I took the advice to mean that I should take a 34 chainring with me in my luggage and I could always put it on in place of the 36 if I needed it.

What possible good will it do in your luggage when you're climbing up something that a 34 would make a whole lot easier.
I suppose you could change out your crankrings alongside the road. Riiiiiiight.

imposter2.0

Maybe I could have been clearer. The 34 will give you added security and some ratios you might not need Just ignore Dennis, the guy is an argumentative troll who thrives on debating trivia..

dennisn

Imposter wrote:

Maybe I could have been clearer. The 34 will give you added security and some ratios you might not need Just ignore Dennis, the guy is an argumentative troll.

I'm an idiot because you should have been clearer? Heh heh

imposter2.0

dennisn wrote:

Imposter wrote:

Maybe I could have been clearer. The 34 will give you added security and some ratios you might not need Just ignore Dennis, the guy is an argumentative troll.

I'm an idiot because you should have been clearer? Heh heh

Nobody said you were an idiot, but we can certainly add that to the list now you've mentioned it. Anyway, I'll put you back on 'ignore' now...

paulmon

Singleton wrote:

Term1te wrote:

I'm going back this year, and am still not sure if I'll stick with 36 or go down to 34 again. I have an 11 -28 cassette, anything larger than that looks odd to me.

I'm heading to the alps for a short trip in August with my new 52/36 setup which is currently matched to an 11 speed 11-28 cassette. I was wondering whether I should change the front ring from a 36 to a 34 - so going with a 52/34 for the trip....

Best of both?

The only time I have span out my compact and wished for more gears was descending in the Alps. However I was more than happy to suffer some freewheeling on the descents at 40-45mph and have the 34-32 going up some of the climbs. 90-120mins @ over 7% can take its toll.

I have a semi on my winter bike but my summer bike has a compact.

paulmon

dennisn wrote:

Why wouldn't you simply buy a 52 and a 36 tooth set of chainrings for your compact crank? Why bother with a new crank?

The cost of a new Ultegra crank is around £120 the chainrings will cost you almost £100. It's a no brainier.

ForumNewbie

newcycle wrote:

I have a currently 50/34 compact crankset, and everyone says I should buy a 52/36 semi-compact crank because I'm loosing speed on the flats compared to my friends.

Sometimes it is true, I feel I can't keep up with the crowd on the peloton because of my 50/34.
If i change to a 52/36, what difference will it make ?? on the flats ??

thank you,

In answer to the original post, I doubt that a change to a semi-compact will make a difference on the flat. Getting fitter and increasing cadence will make the difference. On the flat in 50/11 you are not going to be spinning out.

wotnoshoeseh

PaulMon wrote:

dennisn wrote:

Why wouldn't you simply buy a 52 and a 36 tooth set of chainrings for your compact crank? Why bother with a new crank?

The cost of a new Ultegra crank is around £120 the chainrings will cost you almost £100. It's a no brainier.

I'd say keep the 50 tooth outer and just change the inner to a 36.
Club rides that I do on a compact often sees me looking for another gear while spinning on the inner ring, so I'm considering doing this on both my bikes.

Anonymous

The mainstream introduction of semi compacts is one of the best things to happen to the industry of late IMO.

I cannot see it will help the OP on his current bike, and would be a waste of money unless the current chainset is worn out.

That said. If the OP is looking to get a new lighter 11 speed bike, I would definitely say try semi compact.

ravey1981

Anything over a 28t cassette on a road bike should be illegal....big cassettes look rubbish and are for mtbs.

An ideal cassette has close ratios so the jumps between gears are small. I ride an 12-25 with compact rings which gives as low a gear as i need and its pretty hilly here (Yorkshire Dales). The thing I don't like about compact and the same is true of semi compact is the large jump when dropping onto the small cog, which then requires 2 or sometimes 3 cogs up at the back to get the next gear.... What I am going to try for my upcoming build is paring a 11-28 cassette with 36-50 rings at the front which should make shifts between chainrings less of a faff. Very slightly lower geared than my current setup and a bigger top end gear while still having a cassette that isn't ridiculously massive.... (I blame sram and wifli for this nonsense)

meanredspider

Semi- compact is a nonsense in my book. Putting big gears on the front means running bigger gears at the rear and a longer chain. What's missing in regular 11-sp is a 12-23 cassette - lovely close ratios which mean that you can get everything that the semi-compact can give without the drawbacks of more weight.

As for the step between chain rings, Di2 is the perfect antidote - either an auto change at the rear on a front shift or, as I do, just similutaniously shift both with a couple of finger twitches. But that will just offend those who think electronic shifting is an offence in the eyes of the Lord....

Anonymous

I tried a 10 speed 12-23 for close ratios, but wish I had got 11-23 as I think it would have looked aesthetically better (which is the opposite of what I originally thought), the close ratios are not as needed at that end, and the higher gear 50/11 would be handy sometimes.

There is an Ultegra 6800 11-23.

Gearing is very personal but I think 52/36 11-28 11 speed is great for a lot of people.
Just the fact that it is there as an option has got to be good for cycling.

I am not normally 'elitist' about gearing, but have to agree that aero bikes with a compact do look silly.
I also like the way that stock bikes split between compact and semi compact.
i.e. a SuperSix will have semi compact, but a Synapse full compact.

dennisn

I think an 11 tooth cog is totally useless to the average rider. Everyone likes to tell everyone else that they use it "all the time" but that's just vanity talking

Anonymous

Do not see how its totally useless, especially with the compact chainset that most average riders will have

Do people really say they use it all the time?
Its very usable IMO. Could live without it though I guess (which is why I was happy to get a 12-23).

Not sure how you can be that macho about an 11 tooth sprocket when coupled to a 50 tooth chainring anyway.

pblakeney

dennisn wrote:

I think an 11 tooth cog is totally useless to the average rider. Everyone likes to tell everyone else that they use it "all the time" but that's just vanity talking

I guess that makes me an above average cyclist then! 8)
I don't use it "all the time" but I do use it a lot.

dennisn

PBlakeney wrote:

dennisn wrote:

I think an 11 tooth cog is totally useless to the average rider. Everyone likes to tell everyone else that they use it "all the time" but that's just vanity talking

I guess that makes me an above average cyclist then! 8)
I don't use it "all the time" but I do use it a lot.

Let's say you're running a 50-11 at 80 rpms. This equates to over 30 MPH. You're saying you run 30+ MPH "...a lot."? Does that sound like you? So, at least a quarter up to a half of your time spent riding is over 30 MPH? Does that sound like you? :roll:
Even on a good TT bike I would think that 30 MPH over an hour would leave you gasping and done for the day.

pblakeney

Less than 29 mph, actually. On a descent, slight downhill or with a tailwind? Yes, quite a lot.
It might leave you gasping and done for the day, but we are not all the same. Thank goodness!

dennisn

PBlakeney wrote:

Less than 29 mph, actually. On a descent, slight downhill or with a tailwind? Yes, quite a lot.
It might leave you gasping and done for the day, but we are not all the same. Thank goodness!

Are you saying that you could do 30 or 29 MPH on a TT course for one hour? This basically equates to a 50 minute, 40/km(25 mile) time trial. This would be less than 5 minutes from the British 25 mile TT record of Matt Bottrill of 45 min. 43 sec.

pblakeney

dennisn wrote:

PBlakeney wrote:

Less than 29 mph, actually. On a descent, slight downhill or with a tailwind? Yes, quite a lot.
It might leave you gasping and done for the day, but we are not all the same. Thank goodness!

Are you saying that you could do 30 or 29 MPH on a TT course for one hour? This basically equates to a 50 minute, 40/km(25 mile) time trial. This would be less than 5 minutes from the British 25 mile TT record of Matt Bottrill of 45 min. 43 sec.

I never claimed to do 30mph for an hour, but nice try. I claimed to use that gear a lot.
It may be 10 minutes in each hour of a 6 hour ride on a slope or with a tailwind, but it is worth having. I change gear during a ride. Surprise, surprise.

meanredspider

I like having an 11 on my compact set up - lots of long hills in the Highlands and I'm not a racing snake so I love powering down the hills as fast as I can go. Do I use it "all the time"? No - but I'd use it a lot on my commute - I'd use a 28 a lot less.

Anyhow, if we don't think an 11 at the rear is useful then a 52 up front is unlikely to be much use - unless you're riding in bigger groups all the time when you're only doing a share of the work. For most solo riders, a 50 at the front is plenty with an 11 or 12 at the rear. If a 34 seems too short, just fit a 23 at the back.

I have to say it makes me smirk when people say certain gears are aesthetic and others not - it's what gets road bikers the reputation of being knobs

Anonymous

meanredspider wrote:

I have to say it makes me smirk when people say certain gears are aesthetic and others not - it's what gets road bikers the reputation of being knobs

I said that a certain cassette was aesthetically pleasing, which it is.

It was a small point/part of a bigger reason for trying something.
I wanted to try the closest ratio cassette, (12-23) but on reflection felt an 11-23 would have been better.
Aesthetics was just one of the reasons for this reconsideration.

Aesthetics is a major factor in life and its very odd to weirdly rule it out of cycling.
Its nothing to do with road cyclist in particular, and nothing to do with being a knob

The look of gears (i.e. compact on an aero/TT bike) will have a direct impression of how it will ride (to a cyclist), so its not just a superfluous thing like other things can be.

Its much more s'nobby to say something like "I don't care what it looks like, as long as it works"
When people say this they usually have an 'I am better than you' attitude about them.

Personally I want both!
You can call me greedy if you like, but not s'nobby.

pblakeney

Carbonator wrote:

The look of gears (i.e. compact on am aero/TT bike) will have a direct impression of how it will ride (to a cyclist), so its not just a superfluous thing like other things can be.

Eh? Incomprehensible.
Once on the bike, a gear ratio is a gear ratio. Aesthetics play zero part, unless the rider is very impressionable.

Anonymous

Aesthetics never play zero part.

Your quote is also out of context.

pblakeney

Carbonator wrote:

Aesthetics never play zero part.

Your quote is also out of context.

Aesthetics play a huge part in buying, and choosing what to ride, but not actually riding. For me at least.
I copied your entire paragraph so can't see the loss of context.

meanredspider

I don't think your average person in the street, when seeing a skinny guy cycle down the bypass in a pointy hat, all-in-one skin-tight romper suit and socks on the outside of his shoes, is going to look at the rear cassette and say "that bike would look better with an 11 rather than a 12 on the back"?

You're all, of course, welcome to your opinions on the importance of bike aesthetics over performance but I can't raise a semi over the harmony created by one cassette over another...

imposter2.0

Me neither. In any case, proper aesthetics would dictate the use of a straight-through 12-21 with no silly jumps in between...