Going Compact; Should I or shouldn't I?

morstar

The project is far from underway but at some point in the near future I'm going to start a bike build. It ain't going to be high budget but it ain't going to be cheap and cheerful either so I am considering all elements very carefully.

I am coming round to the thought of going compact despite never having ridden on a compact chainset. My one concern is as follows. I prefer setting up my gears so that I'm generally up and down the middle of the cassette with the extremes of the gear range only coming into play either going up or down hill. It looks to me as though riding a compact must necessitate regularly jumping up and down between the big ring and small ring of the chainset when on rolling territory much more frequently.

Is this the case and you just get used to it it can it be a bit annoying?

Particularly with the bigger difference between front rings I perceive regular shifts between the front rings as interupting rhythm.

Limburger

You will probably find you only use the 50 ring most of the time and make use of the 34 when its gets hilly. Depending on how you like to ride it could give you some nasty crossed chainlines. Or alternatively if you like to churn big gears most of the time it could suit you.

trtimothy

go semi compact...I have a bike with a proper 53/39, another with a 53/38/30 and finally one with a 52/36. The 52/36 is great and gives plenty of gears for climbing but stops u running out of high gears. The 52/36 is SRAM Red and is also really smooth.

morstar

Limburger wrote:

You will probably find you only use the 50 ring most of the time and make use of the 34 when its gets hilly. Depending on how you like to ride it could give you some nasty crossed chainlines. Or alternatively if you like to churn big gears most of the time it could suit you.

These are my concerns really. Try not to cross chain too often (can be guilty on occassions though) and really don't want to grind.

trtimothy, funny you say that about the 36 gear. I was just making a coffee and thought why limit yourself to predefined ratios and lo and behold you've suggested exactly that. Just out of interest, what cassette do you run on the rear? I've just stuck a 52-36 in Sheldons gear calculator and quite like the look of the ratios. I could do most of my rolling terrain on the smaller half of the cassette without cross chaining but sit in the big front ring on flatter stuff.

Anonymous

trtimothy wrote:

go semi compact...I have a bike with a proper 53/39, another with a 53/38/30 and finally one with a 52/36. The 52/36 is great and gives plenty of gears for climbing but stops u running out of high gears. The 52/36 is SRAM Red and is also really smooth.

I hagree, for this country I get on great with a 52/37. If it's really steep then I run a 27 rear cassette but I've yet to be beaten by a hill in the UK on a 37/25, and I'm pi55 weak!

morstar

Cheers for the responses. The fact is I can grind up pretty much anything in a 42-24 but what I discovered at the weekend is trying to grind for the longer rides that I now want to undertake isn't doable (unless I massively increase my fitness level). Much as I'd happily have that scenario, in the meantime I need to find a way to get past 35-40 miles of hilly terrain without dying completely.

DubaiNeil

I run "standard" compact 50-34 and very rarely use the smaller chain ring. Dependant on planned terrain I will either run a 12-23 or 12-27 cassette, as where I live is very flat, with deliberate trips to any proper hills.

I did make the mistake of attempting a (relatively) local hill which matches Alp D'Huez for distance, gradient & number of hairpins on the 12-23 cassette which proved to be a struggle! There was no real switching from large to small chainring though, as the hill goes straight up from the start with no gentle "introduction"

I have absolutely no compunction "cross chaining" (mostly large/large rather than small/small) if necessary. The chain wear doesn't seem to be dramatic, and little in the way of horrible noises when the front dérailleur is correctly set up. Although I do try and "spin" up the hills now, rather than grind, so keeping a lower effective pressure on the chain.

If you are budget concious (which appears to be the case) then perhaps not fixing a "perfect" solution in your mind will give you more flexibility when the time comes to click on the buy button? If Wiggle/CRC/Merlin/PBK et al have a fantastic clearance offer on a standard or a compact at the right time, then that (in my mind) would define the choice...

Neil

softlad

NapoleonD wrote:

but I've yet to be beaten by a hill in the UK on a 37/25, and I'm pi55 weak!

ridden them all..??

daviesee

If you go compact you can choose a rear cassette to get as manly, or wimpy ratio as you like. 50/11 is big enough for most and 34/27 should get you anywhere.
The only main consideration is the jump from 50 to 34 is quite large.
Most people manage this by "double shifting", changing at the back at the same time as at the front. It may sound complicated but it becomes second nature.

Just something to be aware of.

amaferanga

I changed to 39-53 after using a compact 34-50 for a few years and I am much happier. I found that on rolling/lumpy terrain I was too often running a crossed chain on the big chainring as I knew that if I changed to the 34 then I'd be back up to the 50 in no time. Having a 39 small ring is much more useful since it gives a decent gear that I can use on the flat and gentle hills, whereas the 34 was good only for hills.

Having said that, if I were starting from scratch I'd probably get a compact chainset and then get a second set of 39-52 rings for it.

SBezza

I race with a standard chainring, and both my road bike and my cross bike are compact. I have no issues with either setup, and it is not as if you are constantly changing from the inner ring to the outer ring, so I have never worried about the slightly bigger jump than a standard chainset gives you.

To be honest most of my riding is done in the 50 ring, and it is only the steep hills I use the 34 ring, or when doing a recovery ride. Then again I rarely use my 39 ring on my race bike, only for riding back to the HQ.

If you are happy riding with a standard chainset, and it is only the grinding away in the 42 ring that worries you, get a 53/39 chainset.

daviesee

Another thought came to me.

While watching the Giro on Eurosport they came out with the gem that the pros use compacts for training and the bigger rings only for racing.

Just something else to throw into the mix......................

softlad

daviesee wrote:

Another thought came to me.

While watching the Giro on Eurosport they came out with the gem that the pros use compacts for training and the bigger rings only for racing.

Just something else to throw into the mix......................

I wouldn't believe everything you hear on Eurosport...

Anonymous

softlad wrote:

NapoleonD wrote:

but I've yet to be beaten by a hill in the UK on a 37/25, and I'm pi55 weak!

ridden them all..??

I didn't say that no hill could beat me, I said I've yet to be beaten... :?

markos1963

I have a compact 50/34 but i find i can't use the inner ring on the flat, I always spin out whilst cruising. This because I have got a lot fitter this year, I have a 36 ring to put on but haven't bothered yet. I would say that if you were going compact I would start with a 50/36 as I found the jump too intrusive and that combo gives you a similar feel to the classic 53/39

salsarider79

A compact mated to a 11/25 cassette is I think the best for general riding. As had been said on here, 50/11 is a big enough gear (I had a Tarmac with 39/52 with 12/27 cassette, and the 50/11 is a bigger gear!) which is good enough for 32/33mph on the flat, and the 34/25 has got me up some stupid steep hills. If you want to spin not grunt, go for a compact. If you feel like you should go for the 39/53, then do.

TBH, you don't sound too fussed, so why not go with whatever you get a good deal on?

rake

i find 12-50 is big enough, i can go to over 40mph pedaling down hill and the tuck in, its energy wasted after that. the big jump down is handy when you hit an imediate steep hill and need to downshift several gears quickly. a 50 tooth keeps a straighter chainline most of the time at 19 20 mph @ ~85rpm.

dcab

compact ,do it i was there , i find mine ok!

vision267

I have a compact I live in a hilly area and I am 42 I need it.I find the 34 is crap on the flat really crap.I am always crossing my chain I'm asking for troble I know,a triple would be better for me.My ego would not allow me to get one,the hills where I live are pretty steep and the 34 is great for climbing but on the flat its sh*t.

nmcgann

rake wrote:

i find 12-50 is big enough, i can go to over 40mph pedaling down hill and the tuck in, its energy wasted after that. the big jump down is handy when you hit an imediate steep hill and need to downshift several gears quickly. a 50 tooth keeps a straighter chainline most of the time at 19 20 mph @ ~85rpm.

I'm with you on that - all my bikes apart from my TT bike have 50T big rings (and 38 or 40 inners) and I really like the combination of a 50T ring and a tight ratio cassette for the flat-lands riding around where I live.

I find a 34 or 36 inner ring is too small for my general riding, but I'd take a 36 and 12-27 cassetle for long rides in the alps/pyrenees.

huuregeil

This is possibly unfashionable, but there's a lot to be said for running a triple, say 50/40/30 with a 12-23 cassette. Close ratios in the cassette and no wild jumps between the rings. It's not as if it's a soft-man's option either, it's just permits more optimal cadence and a lighter cassette and the expense of one extra (and relatively light) chainring. e.g.

30-23 is 34"
34-27 is 33"

So, actually the people fitting compacts and then having to get wider range cassettes are doing themselves a disservice. Buck the trend, fit a triple!

Mossrider

I live in the (very hilly) South Pennines and ride a std 53/39 on the winter bike (13/26 rear) and a "semi"compact 50/36 on the summer bike with an 11/23 cassette, switching to a 12/25 if I have anything particularly tough to do (Etape du Dales, trip to the Alps). I prefer the 50/36 as combined with an 11/23 gives a very similar spread as a std, but offers the option to simply switch cassette. I'm an average club rider of 45 (although i am used to hills!), so not by any stretch super fit.

I'm not overly with Wiltshire but I guess it depends on the terrain - if you're reasonaly fit and the terrain is (as I recall) rolling, a standard should be fine, but might be a bit restrictive if you decide to go anywhere challenging. Quite a few of my club mates still manage fine on 53/39s around here: to a degree you get used to whatever is available. I'd recommend the 50/36 with a spare cassette....

morstar

Lots of useful advice everybody. Many thanks.

Dcab, this is something that has been very much at the back of my mind for a while but Sunday did very much push it up the priority list. Seeing you guys all on compacts definitely made an impression.

Fitness is a big part of it. I can ride 30-40 hilly miles with no issue but fatigue then kicks in and grinding becomes...well... a grind!. I fully intend to work on this but there are limitations.

I am leaning strongly towards going for a 36 smaller front ring.

Will respond to a few specific points when I have a bit more time but just wanted to indicate my appreciation for the constructive and very informative comments.

StanwaySteve62

I've only been on the road a few months with my double and I'm thinking of going to a 38 middle with a 12-27.
I love the 53 about halfway across the cassete (12-25) and have a feeling a 34 middle ring would be too small for most of my riding.
I'm 45 and not super fit (strong on the flat though as I'm a big lad) and find on hills that I end up on the 39/25 so maybe the 38/27 could be a good option for when things get steeper.

morstar

Just an update on this. I have to confess the self build never happened as economics have won out. Therefore, I pulled the trigger on a Boardman TC last weekend with compact gears.
Took it out for a modest but very hilly spin today. First of all, the bike is fantastic. Very pleased indeed.
Anyhow the gears. I found the compact very accomodating. It is very unusual for me to be changing the front gears so frequently but it is not overly intrusive doing so.
My fitness is very poor at the moment. I got hit VERY hard by flu in mid December and have only been back doing any physical activity for 3 weeks. I used the full range of gears on hills I have climbed regularly in 42:24. Funnily enough, the hills still feel tough but I was able to respond much quicker to flattening gradients with acceleration. I also took a much straighter line at key points where I would be wandering over the road in bigger gears. I suspect the difference on a longer ride may be very beneficial.
I suspect I may well go for a 36 inner when my fitness improves but time will tell, I may well not.
I think the 50 is great on the flatter stuff. I'm not powerful enough to power along in a 52 ring for long periods but the 50 will suit me well.