Compact v Triple

[Maz]

My current bike (Sirrus) has a triple chainset. To be honest I can't remember when I last used the smallest chainring.

Is a compact chainset the same as the triple but with the smallest chainring removed, or are the 2 rings on the compact different (more teeth, larger diam?) compared to a triple, to still offer a wide-ish range of gears?

Does that make sense? I hope so...

 

[John the Monkey]

Maz, there's a good article on it here.

To answer your question, compacts tend to be doubles with slightly less teeth, e.g. instead of a 53 big ring, it'll be 50.

To muddy the waters further, my Giant has a compact triple

 

[Maz]

Cheers, JTM, I'll take a look at that article.
'compact triple', eh? I won't worry about that just yet!

 

[k-dog]

Is a compact chainset the same as the triple but with the smallest chainring removed, or are the 2 rings on the compact different (more teeth, larger diam?) compared to a triple, to still offer a wide-ish range of gears?

No, that would be a regular chainset - something like 53/39 - your triple is probably something near 53/39/26.

A compact will be around 50/34 - so you've got a slightly narrower range - but still should be able to do most of what you want it to - but a 34 is more useful for everyday riding than a 'granny ring' - unless you're in the Alps or something.

 

[Will1985]

Even then you could probably get away with a compact plus a suitable cassette - 13-28/9 or 14-28/9 or even a 30t big sprocket!

 

[k-dog]

^ yeah, I nearly put that (but I thought it was getting complicated enough).

34/28 should be enough for most people.

 

[dodgy]

34/50 with a 12/27 is pretty ideal for the majority of riders I reckon.

Dave.

 

[Chris James]

Yes, but it isn't just about gear ranges. Ideally your gears should be stepped with small percentages between them and with the best chain line for the most usable gears.

I had an old style Stronglight touring chainset with 48/36 and 14-24 block which was quite good. Compacts are really only modern versions of these. However, the drop between chain rings is pretty big at typically 16 teeth and some users complain that they have to chian rings at the point at which they do most of their cycling which they find annoying. Whereas it may be that the middle ring of a triple would be more useful as it is typically about half way between the size of the two compact chain rings.

Putting a megarange type block on the back gives you lower gears but usually at the expense of massive jumps in gear ratios as you get to the lower gears. Also road type rear derailleurs won't cope with anything above 27on Shimano (and similar for Campag).

Personally I think that for non competive riding a triple makes the most sense. Ideally the rings should be sized so that you use the granny for uphills, the middle ring towards the middle of the cassette should be a decent gear for the flat / slightly undulating. And the outside ring for flat out and downhill.

I have a 52/42/30 triple on my audax bike and I think the top two rings are slightly over geared. I see that new Shimano triples are coming with 50 & 39 rings which makes more sense to me.

 

[Pottsy]

I agree with Chris ^^.

I bought a bike with a compact chainset recently and I find the 50-34 gap quite irritating, right in the area I spend a lot of time cycling. Much more so than a 52/42 that I used many years ago.

I'm seriously considering changing to 48/36 - just buying two new chainrings. Anyone done this? I assume all I'll need to adjust os the front mech?

 

[asterix]

When I changed the rings on my double I had to move the front changer down just a little and then it was fine.

Cycling in hilly country, I have a triple and tend to go for long rides. Usually I use only the middle and outer but there have been times when the inner has been a god-send.

 

[Fab Foodie]

Chris James and Pottsy have it Spot-on.
Personally I'd find a 36 or 34 inner ring as much use as a cardboard toothbrush for most of my riding whereas a 42 nmiddle ring on a triple is just fine on my road-bike. Also agree about the big drop between the front chainrings, 12T difference is nice, 14 just about bearable.

In my regular training group we have 2 triples, one 53/39 trad double and a Compact. The guy with the Compact hates-it, is always trying to find the right gear and is most-often running a bad chainline.
Triples or fixed for me, you can keep Compact doubles... neither fish nor fowl.

 

[alecstilleyedye]

i have to agree with fab foodie. i did the whole compact or triple thing a couple of years ago and went triple (52/42/30). never regretted it. i have a gear for almost every situation, from peak district pass to the club 10 mile tt.

because i am a "spinner" when climbing (peddling a low gear quickly), the triple is a much better bet as i can go as low as 30 x 25, but if the need arises, i could probably go as low as 30 x 30.

if style is important, and you don't anticipate going up any serious hills, go compact. if you need low gears (and be honest with yourself about that) for hills and high gears for flat, get a triple.

 

[Smokin Joe]

I have 50/36 and 48/34, both with 13-26 cassettes and they are ideal for me. 50/34 was a pain in the arse, the gap was just too big.

 

[lifeson]

Twas one of the best moves I made changing from a standard double to a compact double.
I might be quite as quick top end but i can keep a better average over a longer distance

 

[HLaB]

I had similar doubts when I bought my road bike, the Sirrus has a triple , road bike could come with a compact or a triple . In the end if I wanted a triple I'd have to wait 6 week +, the compact was standard. I couldn't wait and a year on I think I made the right decision.

PS I went to use the granny of the Sirrus last week for the the first time in ages on a 21.1% hill (Dunning to Middle Third/ Pathstruie) but it refused to change down so I was stuck with the middle ring (42 T), I would have preferred the 34T on the compact.