What's a normal ratio for compact?
Can someone enlighten me as to what a decent set up for a compact is around reasonable bumps (Wicklow Hills), but with fair stretches of flat.
I have a 12-23 at the back is that about right?
I have a 12-23 at the back is that about right?
It's a little like wrestling a gorilla. You don't quit when you're tired. You quit when the gorilla is tired.
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what's the compact? 50-34?
all depends on your power /weight ratio and climbing skills really. I've got 50-36 and 11-25 at the rear which is a fantastic set-up. Got me through the Etape nicely. I'd suggest gonig for a 25 at the back and see how you get on.0 -
Hi, i would say a 12 to 27 cassette would be more useful.
If you have a short cage mech it will still work ok and it will give a reasonable hill climbing ratio. Certainly works for me on Hampshire / Dorset hills.He is not the messiah, he is a very naughty boy !!0 -
I have 50/36 and a 12-25, which seems good for me around Bristol.
A far cry from the 42/21 bottom gear I used to race on back in the day. I can't decide if was that much stronger then, or just ignorant!0 -
Mine is a 12-25 cassette with 50/34 chainrings...sweet as you like!0
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It's always hard to recommend gears. What's your lowest gear now? I know there are some very steep roads around Enniskerry and Powerscourt.
If you like fast riding on the flat too, keep the cassette on the back narrow, 12-23 and go for a 34 inner ring to bail you out. If you like riding up and down the hills or day, wider gaps on the cassette are ok, especially if you're not racing.0 -
the other thing i'd add is that if you've been ok with a 53/39, then a 50/36 is likely to be a better option than a 50/34. The latter has a really big jump between the chainrings0
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it's whatever you want it to be. Do your own thinking and testing.
I run 34/48 with a 12-25Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer0 -
Timoid. wrote:Can someone enlighten me as to what a decent set up for a compact is around reasonable bumps (Wicklow Hills), but with fair stretches of flat.
I have a 12-23 at the back is that about right?
I think the Wicklow Hills are a bit more than a bump. My road bike is fitted with a 34/50 chainring and 12-25 cassette. But if you are describing the Wicklow Hills as a bump, it might be too low for you?0 -
Thanks guys. I'm moving from a standard double set up 53/39 with 12-25 at the back as its a bit too much of a grind up some of the steeper hills (e.g. Enniskerry to Sally Gap). Would prefer to spin a bit more than I currently do.
Have been recommended a 50/34 12-23 set up and just wanted to see if it sounds about right. Seems from what you are saying that it is personal preference, so I'll go along with what the store recommended.
Okay the Wicklow hills are more than a bump, but they t'aint the Pyrenees.It's a little like wrestling a gorilla. You don't quit when you're tired. You quit when the gorilla is tired.0 -
I would stick with the 12/25. 34/23 is not much lower than 39/25. Check this out to calculate gear ratios and compare them.
http://sheldonbrown.com/gears/0 -
Gear Inches:
23__44.6__38.8
24__42.7__37.2
25__41.0__35.7
26__39.4__34.4
27__38.0__33.1
So, you are currently riding 39/25 (41.0 inches). A 34/23 would be 38.8 inches. This is 5.4% change and not even the equivalent of putting a 27 on the back of your double - which is another, cheaper option of course (approx £100+ for a compact & new cassette vesrsus £15 for a cassette for less...).
I would suggest going with the compact, but sticking with the 12-25 cassette.Rich0 -
The bike shop is probably trying to sell you a cassette as well, but as you can see from the calculations above, there wouldn't be much point in going to a compact then swapping the cassette to a smaller one. A change in number of teeth at the rear makes a bigger difference than the front, i.e. a 2-tooth difference at the rear is significant, whereas a 2-tooth difference at the front is a minor difference.
A 12-23 cassette would suit a triple, but it would be an unusual choice for a compact double. Looks to me like a case of bike shops trying to sell you stuff you don't need. Or just bad advice, which is often the case in even the better bike shops.0 -
i'm begginning to question my fitting of a compact chainset full stop now.
I stated before I had 50/36 and a 12-25 cassette, but actually i have a 12-23 on the back!
I probably would have been fine keeping my old 53/39 and just switching to a 12-25 or 12-26 cassette.
Too late now though, unless anyone wants to swap an R700 chainset for a full size one...0 -
hmmm
i am running 50-34 with a 12-26 on the back. I was thinking of changing the casette to 11-23 since i dont use the 26 much and i can spin out easily on a long downhill
i hindsight i wish i had got 50-36. The gap is big and makes shiting a little more dangerous (i.e chain dropping)0 -
Well there are no rules to follow here. You should do what you like, as long as it's legal.
But most people who switch to compacts want a lower gear for climbing, so it's on that assumption that I said it wouldn't make much sense to put a smaller cassette on the bike.
leonlikestrees: you're right, dividing 39 by 25 gives 1.56 exactly, which is actually slightly less than dividing 36 by 23 (about 1.565). So switching to the 12-25T cassette would have given you a lower gear than switching to a compact double, though you'd hardly notice the difference. But using a 12-26T cassette with the original standard double would have given you a noticeably lower gear than what you've got now.
A 12-23 cassette would be nice on the flat though, because there's not much difference between adjacent gears, so you can pick the exact cadence you want.0 -
I've just ordered a Rival groupset. UNfortunately, I got it on the cheap from Germany, so there was only a 50/34 option.
The daft thing is, I specifically chose it because of the compact. How silly is that.
I've never been a big fan of large gaps on the chainrings. I even used to think 53/39 was to much after 52/42 so ended up with 51/39.
Gaps at the back used to be important to me too, but with 10 sprockets it's much harder to get too big a gap. When I was on 7spd, I used to hate having to swap a 16 for a 23, but on 10 it's just not an issue.
, so now, if I wasn't limited to stock sizes, I'd go 52/38, and 12-26 at the back.0 -
That's for sure. When 10-speed cassettes came out many people thought they were a bit of a gimmick. But it really does help. You can have a wide range of gears and have close ratios, i.e. have your cake and eat it too! Certainly a big improvement over 7-speed.leonlikestrees wrote:Gaps at the back used to be important to me too, but with 10 sprockets it's much harder to get too big a gap.
You'll have to give us a report on the Rival groupset when you get it up and running.
I haven't even seen one in the wild yet, never mind ridden it. 0 -
Groupset should be here next week.
Hopefully have it all built up by the weekend, bu due to having a 7 week old baby am not allowed out riding at the weekends, so will have to wait until my commute on Monday to try it out - unless it rains! I'm not one for keeping nice bikes locked up if the weather turns, but I can't take a brand new groupo out in the rain! I want to eep the chin nice and shiny :-)0 -
grazer wrote:hmmm
. The gap is big and makes shiting a little more dangerous
You need to try sitting closer to the pan :roll:
More seriously you should have no problem at all shifting between 50 and 34. Is your front mech set up correctly, ie correct height? You may be having problems if it is a braze on rather than strap on fittingI want to climb hills so badly;
and I climb hills so badly0 -
i have a 50/34 with a 12-25 cassette which i use around hilly Holmfirth. It has most hills covered!0
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Look at what you use now and select accordingly. I believe the word 'compact' is a misinterpreted term .. it should not be used to define a particular set of chainrings.
I have posted many times that I consider many bikes are over geared unless you are a true competitive racing cyclist. If you have a 50 or 52 or 53 chainring, how many times do you actually use the 11 or 12 rear? Given that the highest ratio from the above equates to a 130" gear.
I have used a triple with 52/42/30 but found, as I suspect many others have found, that I rarely used the 52 ring. The 42 with a rear of 12 gave me a gear of 94.5 which I found perfectly adequate as a high gear ... I am not a racing cyclist and generally see no point in tearing downhill, preferring to enjoy the ride gravity assisted. And my usual cruising gear of about 70" allows me to bowl along at 18 - 22mph at a reasonable cadence.
As I said above, my style of riding may well not suit everyone and if you want higher gears then you should have them. My solution to the 'compact' was to have the front as 42/30 using Stronglight components. Mated with a 12 - 26 rear I have the complete range I want from my own 'compact'.
Cheers, Phil0
