Compact vs. Standard

simonaspinall

What's the difference between a 'compact' and standard chainset+cranks? Who are they aimed at?

Ta

Slow Downcp

Compact has smaller chainrings, so lower gearing to make climing easier.

Chip \'oyler

simonaspinall wrote:

What's the difference between a 'compact' and standard chainset+cranks? Who are they aimed at?

Ta

Compacts are great. It means you can have lower gearing for big climbs, and If you fit an 11t cassette, your highest gear will actually be higher than 53x12. So you can have a good wide ratio of gears without the weight of a triple chainset.

However I'd only recommend them for people living in hilly areas. I can't see the point if you live in Lincolnshire

simonaspinall

Ahhhh I see - So what does the 'compact' term refer to? The size of the chainrings?

salsarider79

I've brought myself a Specialized Roubaix with a compact chainset. And I love it. I used to ride a Tarmac with a 39/52 chainset which was fine, but I find the compact more useful. Last week I sat at 34mph when the club run turned silly (chasing a Time Trialist on his race bike... :roll: ), but can also winch my way uphill when the legs have gone....

p.s. I use a 11/25 cassette which is perfect with a compact.

AllTheGear

simonaspinall wrote:

Ahhhh I see - So what does the 'compact' term refer to? The size of the chainrings?

I think it's because they give (almost) the same gear range as a triple but there are only two of them.

skyd0g

simonaspinall wrote:

Ahhhh I see - So what does the 'compact' term refer to? The size of the chainrings?

Yes.
There are pro's & cons with compact and standard set-ups. Generally speaking, a compact will give you a wider range of gears (at the expense of bigger gaps between gears). A standard set-up will give you closer ratios (ie. the change from one gear to the next) but a smaller range of gears overall.

simonaspinall

Cool

Thanks for the advice!

keef66

And with a triple you get a slightly wider range of gears and with only small jumps between them. Best of both worlds.

Downsides are reputedly:

Extra weight of 3rd chainring (negligible)
Harder to set up front mech (mine's stayed spot on with very little fiddling)
Don't look as nice as a double or compact (can't argue with that one)


The term Compact confused me at first, since it is used to describe compact gearing as above, and also to describe compact frame geometry (which I understand to mean the introduction of sloping top tubes and shorter wheelbases with the rear wheel closer to the BB?)

giantsasquatch

Standard double is 130mm wide which is from one bolt to the nearest bolt, the BCD diameter. The smallest chainring you can go down to for double is 38T(teeth). A compact crankset has a BCD of 110mm which lets you fit smaller chainrings.

If you have alot steep hills, then a compact is what you need. It gives you the advantage to train better, climb at a higher cadence, saving your muscles. A disadvantage is you less high gear and can't pedal down hill super fast. Having a 36 chainring instead of 34 means you will have higher gears to go down hill fast as well. A perfect combination.

The best cassette to cover all riding without wastage and keep the gear ratios close is 11-25 with a compact. If you really fit get 11-23. A even better compact chainring than 50/34 is 50/36. Other good chainrings to get are 52/36 48/36. Get the 50/34 and then get the extra chainrings later as it not easy to get the crankset you want with the other rings.

Older cyclists or those with knee injurys prefer compact cranksets.

It's a good solution and also for starting out. You can stay in the big ring for the flats all the time and use the small ring for the hills.

Here's some other crank sizes and help related.
http://www.sheldonbrown.com/gloss_bo-z.html

A double-chainring crankset with that permits the use of smaller chainrings than will fit with the common 130 mm B.C.D.. Most "compact double" cranks use the old standard 110 mm B.C.D. which permits the use of chainrings as small as 33 teeth (more commonly, 34 or 36 teeth.)

Compact crank sets usually come with a 50 tooth chainring, and will normally go with an 11 or 12 tooth top sprocket in back.

110 mm B.C.D. double cranks with full-sized (52-42, 52-40, etc.) were common in the late'70s and early '80s, but they had become nearly extinct for double chainrings. The rebirth of this format, with smaller rings, was pioneered by Tyler Hamilton who used one of these in the 2003 Tour de France

giantsasquatch

Good article on compacts.

http://bikehugger.com/2008/05/the-rise- ... crank.html

giantsasquatch

Now the juicy stuff.

Read this (easy to understand)

http://www.bicycle.net/2008/bicycle-gea ... act-cranks

10 spd cassette is best.

and then read this updated article and why 11-25 is best .

http://www.bicycle.net/2009/standard-or ... a-question

By blending an 11/23 and 12/25 cassette to make an 11/25, you can have your cake and eat it too. Because when you run the compact with the 50/34 chainrings and an 11/25 cassette you have gearing that is still easier than standard 53/39 and 12/27 gearing. With the top end the 50/11 combo is actually a BIGGER gear than the 53/12 combo. With that you now can spin easier than before up the hills and still being able to push the gear while rolling at 38+mph.

Now you armed to the T and ready to beat the 53/39 Pros!

Just call me compact man.

giantsasquatch

Used correctly, with a compact you will become a better cyclist.You will burn more fat pedalling at a higher cadence. Training at a higher cadence, you will build up better aerobic capacity.

So a compact is ideal for beginner's and pro's.

Convinced yet?

ride_whenever

giantsasquatch wrote:

Used correctly, with a compact you will become a better cyclist.You will burn more fat pedalling at a higher cadence. Training at a higher cadence, you will build up better aerobic capacity.

So a compact is ideal for beginner's and pro's.

Convinced yet?

Don't be silly, no cycling equipment is ideal for everyone.

AllTheGear

I have 50/34 with 11-25 and like it. However, surely this is down to individual preferences? There are some wide variables:

- riders can do anything from 100W (casual) to 250W (ride every day) or more
- favour 60rpm to 100rpm cadence
- ride in hilly or flat areas
- ride solo or race / drafting

The few percent between a 23 and a 25 tooth sprocket seem minor. I don't think you can say what is 'best' in general.

keef66

For a given power output, how does cadence influence fat burning or cardiovascular fitness??

giantsasquatch

ride_whenever wrote:

Don't be silly, no cycling equipment is ideal for everyone.

Well it down to individual taste, but to become a better cyclist it is far from silly.

One big factor that makes a great cyclist is bigger aerobic capacity. By pedalling at a higher cadence, you training the body to supply more oxygen to the muscles. Using a compact will give you easier gears to spin especially up hills.

It quite simple, learn to spin up the hills and save your muscles or use alot of your muscles and end up more knackered for the rest of the route.

markos1963

giantsasquatch wrote:

Used correctly, with a compact you will become a better cyclist.You will burn more fat pedalling at a higher cadence. Training at a higher cadence, you will build up better aerobic capacity.

So a compact is ideal for beginner's and pro's.

Convinced yet?

If that's the case why does the Pro Peloton still use standard cranks? You choose your kit according to your fitness and/or terrain. I run both types of chainset and I run a single speed as well.

keef66

For a given power output why would spinning the pedals faster require more oxygen? And if that is the case, surely that means it's less efficient.

Unlike us mere mortals, the pros are able to use high cadence with high gears. Now that will boost your cardio fitness!

giantsasquatch

markos1963 wrote:

If that's the case why does the Pro Peloton still use standard cranks? You choose your kit according to your fitness and/or terrain. I run both types of chainset and I run a single speed as well.

Because miles and miles of each stage is mainly on the flat. Some prefer to push a bigger ring especially for sprinting in races. They are the best of the best, gifted athletes with awesome aerobic capacity already.

giantsasquatch

ride_whenever wrote:

no cycling equipment is ideal for everyone.

That's because most cyclists cycle at a lower cadence below 90RPM. If you prepared to train to become pro like then a compact would suit better for pedalling at a higher cadence.

markos1963

giantsasquatch wrote:

ride_whenever wrote:

no cycling equipment is ideal for everyone.

That's because most cyclists cycle at a lower cadence below 90RPM. If you prepared to train to become pro like then a compact would suit better for pedalling at a higher cadence.

Not if you're running a 50/11

giantsasquatch

keef66 wrote:

For a given power output why would spinning the pedals faster require more oxygen? And if that is the case, surely that means it's less efficient.

Unlike us mere mortals, the pros are able to use high cadence with high gears. Now that will boost your cardio fitness!

Spin faster and faster to the point of silly and of course it get's to the point where it becomes not efficient,wasted energy. I not talking that much wastage.

If you train at a slightly higher cadence(with a healthy fit able body) than what your natural abilty cadence normally allows, then eventually the body adapts and builds a better engine to supply more oxygen to the muscles to cope with the higher cadence.

So it is not less efficient once the body has adapted to the higher cadence. The newly built engine can cope, resulting in a better cyclist! More efficient with less muscle usage.

giantsasquatch

keef66 wrote:

For a given power output, how does cadence influence fat burning or cardiovascular fitness??

Because when you pedal faster or faster anything you burn more fat overall. It's more cardiovascular, faster heart and lungs means more fat burning. When you use more muscle, you use more carbohydrate.

giantsasquatch

The greatest cyclists or trained pro's use there slow twitch fibres more efficiently. To use the slow twitch fibres better requires better aerobic capacity. To get better aerobic capacity you train pedalling faster. A compact will help you do that. It save your strength so you can perform better on the flat later on after a hill. Once you get elite then sure you can use a bigger chainring but until that time...use a compact.

Convinced yet?

DVV

From wot I wos told:

Slow pedalling with increased force = tendency towards using fast twitch muscle, less aerobic stress

Fast cadence with decreased force = tendency towrds using slow twitch muscle, more aerobic stress

(for a given fixed speed)

For a fit person it is supposed to be possible to obtain better endurance performance when using a fast cadence. Everyone is different though, and you will probably find a variety of cadence amongst even professional road riders. That said, you won't see a TdF rider churning out the 30 rpm associated with pensioners doing the shopping.

markos1963

No.
As far as I can see it makes no difference if its a compact or a standard, if you choose your cassette ratios carefully you can replicate nearly all the gears as a compact What the compact offers a beginner is an easy way to access lower gearing for tough terrain, once on the flat there is no real difference, nearly everybody ends up riding around 70inch gears on the flat.

ride_whenever

And if you already have (due to being some massive freak of nature) an astonishingly high aerobic capacity, and can spin a standard double quite happily?

giantsasquatch

ride_whenever wrote:

And if you already have (due to being some massive freak of nature) an astonishingly high aerobic capacity, and can spin a standard double quite happily?

The majority who want to improve, are not a freak of nature. To get to a high level you need to build a mega aerobic capacity base. A compact will help you do that.

giantsasquatch

If you train in higher gears with big chainrings and little sprockets, then how can that build better faster aerobic capacity than using a compact? It won't. You won't even have the choice to do that up hills. You end up more tired for future rides/training as you used more muscle, so your training won't be as effective. Sure you get better but not as good as using a compact. Compact even gives you the choice of all.

giantsasquatch

When you at elite/freak of nature status and so fit, then you at the stage where you can use a double effectively on the hills as well.