I could explain in my own way, but you cannot call a compact a double as we already have used that term, so a compact is a compromise between a double and a triple, but have a read here, it will answer all you need to know and more:- http://www.chainreaction.com/triples.htm And talking about doubles and triple's, the weekends here, "ger em in". I wonder if I could confuse the landlord and ask for a "compact", well its between a double and a triple but in a smaller glass maybe
A compact is simply 'a waste of time' go for a normal double, or a triple. Basically with a compact you get gears for going up very steep hills or going down very steep hills and NOTHING for on the flat, unless you're either extremely slow or very fast! Why? Never worked that out! Marketing by the big brands to sell us more stuff that they make us believe we need. The idea was to increase the range of gears without using a triple chainset but what happens is you lose the middle range gears, and those are the ones most people use most of the time. Most people find they suffer badly from poor chainline with compacts as they use the small ring with small sprockets or large ring with large sprockets - which isn't good.
The difference mainly comes down to how you use your gears, if you don't mind double shifting then compacts can offer a wider gearing range than a double but where you'd find that your bottom ring on a triple was used once in a blue moon. The other option is to use a closer cassette over the same gearing range as a double but with closer gears. Forget about the chain line argument, it doesn't actually work. Most of the time if you look at people riding doubles they'll be on the smallest 3 sprockets of the cassette for the flats if they prefer the bottom chainring or spend a lot of time in the the bottom half of the cassette when climbing shallow inclines if they prefer the top chainring, result is the chain line is just as bad as a rider on a compact but they don't have the ratio range at the bottom end.
For years I have stuck with a standard 53/39 double. I always found the 53 hard going esp towards the 14 12 sprockets. Hills also seemed hard work. Then about three years ago I switched to a compact on my audax bike 50/34 and eight speed up to 25 at the rear. To be honest I have found it a revelation and really enjoy the gearing now, seems to suit my style of riding just right. I also have a compact on my road bike as well now. Hills I struggled with before I seem to get up with relative ease now. I have a tripple on my touring bike, but thats for other reasons ie luggage.
I wouldn't just forget about it. If people riding doubles are using the gears you suggest, what would they be using if they had a compact? Those gears don't even exist on a compact! If you are only using the granny ring 'once in a blue moon' then clearly that rider would be better off with a double. I'm not so against the 50T ring as for a lot of normal riders the 53T is too large, but the 34T ........ If you need low gears, get a triple - simple!
I don't think so... A double with 12-25 v's 2 compact setups... one with a wider range than the double if you're more concerned with dealing with hiller terrain & another with a closer ratio set. All 3 ratio sets would be very usable in the real world & leave few meaningful holes in the gear range. shows a complete lack of imagination as to how one can use the chainrings given a choice cassettes. I've been switching between compacts & doubles for a while now & I've found that the compact format gives the rider more choices if they know how to chose ratio sets. The one thing find is that a triple is the worst of the lot as it never lets me have ratio sets which feel natural to me. If they work for you sure use them but don't try & tell me they're superior because they're blatantly not, they are different however & different means more scope for choice.
OK fair point, but to get an increased range of gears you have to give up a few gears in the middle of the range. If a large proportion of your riding is done on flat roads, having 7 gears for 'flat' conditions is better than 4; especially because I use these gears about 90% of the time.
Quote: Originally Posted by tundragumski Compacts are rubbish in my opinion - how they became so common I will never know. I would swap the 34 for a 38 or 39 and have a 38/50 or 39/50 - much more useful. They might be rubbish in Norfolk where you don't have hills, you should try them in Yorkshire. You can't convince tundragumski, this is from a previous thread.
Only if you don't understand the use of gears and why different types of rider and different terrains need their gear ratios taylored to their own needs. A compact will give you the same range as a standard, but with a lower top and bottom ratio. That suits me at my age and wher I live, neither a standard double or a triple would suit my riding style and fitness level. Ferraris and Ford Fiestas do not come with the same gear ratios, it's horses for courses.
nonsense, what ratio do you like to go around the flat on and then get the cassette to match... the only draw back I can see of a compact is top end and the odd double change which is hardly difficult esp if you look ahead
I bought a double and as good as it is, I could never get up the steepest hills without busting a b****k, but on the flat roads and gently rolling countryside its brilliant, so for my next bike I wanted a compact to tackle the steep hills but the LBS talked me into a triple, and it was the best thing I did. I get up steep hills far faster than I ever did and managed to knock off between a half to a third off all my hill climbing times. Why bust a gut trying to turn a big gear with a low cadence crawling, when you can turn a very low gear with a fast cadence and fly up hills, that is till you start gasping for air, but you simply pedal slower and just crank yourself up, but still faster than a double.
Because it doesn't suit everybody. I have a 20% gradient on one of my routes and I climb it in 36/23. I have a 25 sprocket but if I drop to that all that happens is that I slow down, the climb doesn't get any easier but takes longer. Re HJ's reference to busted knees, those of us who were riding when chainrings were 52/42 and few riders bothered with anything bigger than a 21 sprocket on the back because we only had 5-speed blocks are proof that the knee thing is just a latter day myth. Walking up stairs puts more strain on the knee joints than cycling, let alone running or playing football.
Say I'm producing 275w up a 10% hill... I fail to see a meaningful difference between 65 & 58ppm (the difference between a triples 30t & a compacts 34t chainrings with a 25t sprocket on 700x28c tyres). tundragumski, you may have more discrete gears but they're interspersed in the overlap of 2 chainrings, so to step up the gears smoothly you'd need to be double shifting on every change. With a compact setup if you play the same range card you've got a smoother progression through the gears with a single large double shift to make, your overlap with the top chainring is mainly on the large tooth step gears. This lets you deal with shorter inclines without the need to drop to the bottom chainring but you can still drop if you have a longer incline where you do want better gearing granularity. Personally I find that better progression with a small overlap works better for my riding style, however other people prefer to have a wider range on each chainring. What is more using a low-overlap setup you actually end up with more non-overlapping gears so you effectively have more gears in between the same ratio points.
