Compact vs Standard on hill climbs

[John Edmondson]

Hi,

I have just bought by first bike with a standard double crankset with a 11-28 cassette.

I spend the vast majority of my time on the hills (Peak and Lake District). I target hilly road races and compete in hill climb competitions. As such I have never ventured away from my trusty compact setup.

On steep climbs (eg Hardknott Pass) I am grateful for the ratio's available from the compact setup but on long shallow climbs (eg Cat and Fiddle) I often feel frustrated at the loss of power when dropping into the small ring. After plenty of deliberating and some advice from fellow club members I have decided to change and the bike was ordered.

Although I appreciate that gearing is a personal thing, I have two questions:

1. Am i going to notice a massive difference and be unable to maintain an efficient cadence (between 80-100) on steep climbs (say 25%)?

2 If I want to change back to a compact setup, how easy is this? Can i simply swap the chain rings?

Many thanks!

John

 

[Dusty Bin]

Your ability to push a certain gear at a certain cadence is only limited by your fitness - nothing else. The BCD of the chainring will not play a part in this.

If you do opt for a 110bcd chainset, then 'standard' sized rings (ie 52, 53, 39, 42, etc) are available for them.

Not sure what you mean by 'loss of power' though - unless you are not shifting down correctly. If I ever need to shift into the inner ring on a climb, I will always drop a couple of gears on the back first, in order to maintain the same/similar cadence.

 

[ColinJ]

Am i going to notice a massive difference and be unable to maintain an efficient cadence (between 80-100) on steep climbs (say 25%)?

Yes!

80 rpm in 39/28 = 8.7 mph. 100 rpm = 10.9 mph.

If you weigh about 11 stone and your bike weighs 20 pounds, then you would have to be knocking out about 800 W to do 8.7 mph and about 1,000 W to do 10.9 mph on a 25% slope, which I suspect that you can't! (If you can, you should be winning lots of hill climb events ...)

I think that you should have gone for a triple so you could have had the standard 2 chainrings for most climbs plus a really small chainring for those 25% brutes.

 

[sreten]

Hi,

You can't lose power correct changing between chainrings and
on standard 52/42 rings I need to go up a gear on the rear after
dropping to the 42, to go down one gear. If I don't I drop 2 gears.
You might need 2 gears up on the rear with a compact.

I can't see the point of a bigger smaller chainring for shallow
hills if your also going to be taking on some serious hills.

rgds, sreten.

I can do shallow climbs on either front chainwheel.
52/42 with 14,16,18,20,22,24,28, : lots of gear overlap.
Not the gearing for the Peak District though .....

 

[HLaB]

Id personally stick with the compact chainset and experiment with larger chain rings and have the smaller ones up your sleeve for long hill climbs, go for a standard double and its harder to change. FWIW I run a 38/52 compact and doubt I'd get much extra out of one more tooth, instead I changed the cassette (12 to 11tooth) which was much more effective.

 

[John Edmondson]

Hi, thank you to everybody for their reply's. Generally i am happy with my selection of a 53/39 with a 11-28 cassette as I still have a compact setup on my other bike.

My only concern now is what my options are for hill climb competitions. I would like to use my new bike for these (as it is significantly lighter) but will I be able to swap my 39 chain-ring for a 34 when I am competing in a steep climb event?

Sorry for being so technically hopeless...! Incidentally, i would shake the hand of anybody irrespective of their chain-set who can sustain 10.9mph up a 25% hill!

 

[Dusty Bin]

Have you ridden a hill climb competition yet?

 

[John Edmondson]

Yes. Club and open events. I got hooked on them at the end of last season...

 

[Dusty Bin]

If you are on a standard 130bcd chainset, you won't get a 34 on it.

 

[John Edmondson]

Thank you. Any other options?

I guess I'm just going to have to wait and see how it feels. Just fretting a bit because I've only ever ridden compacts on very hilly terrain and I'm not sure what to expect!

 

[VamP]

You could get a compact chainset as well, and just change to that for the comps where sustained 25% was part of the parcours. I suspect there aren't that many in the UK though.

I find 39/25 completely adequate for the hill climbs I have done, in fact I have never used the 25 in competition. But then again our hills around here are very short, up to 5 minutes in duration.

 

[Dusty Bin]

Thank you. Any other options?

38 will probably be the lowest you can go on a 130 chainset. If you had a compact (110) crank, you could fit any chainrings you like, from 34 right up to 53 or higher.

 

[Rob3rt]

I think that you should have gone for a triple so you could have had the standard 2 chainrings for most climbs plus a really small chainring for those 25% brutes.

A triple, no way..... carrying 2 chainrings up a steep hill in a HC is taking the piss a little bit (I only ride with 2 chainrings because I wasn't sure how riding with 1 would effect my power meter calibration), 3? Not a chance!

Have you ridden a hill climb competition yet?

He is quite good at it.

Hi,

I have just bought by first bike with a standard double crankset with a 11-28 cassette.

I spend the vast majority of my time on the hills (Peak and Lake District). I target hilly road races and compete in hill climb competitions. As such I have never ventured away from my trusty compact setup.

On steep climbs (eg Hardknott Pass) I am grateful for the ratio's available from the compact setup but on long shallow climbs (eg Cat and Fiddle) I often feel frustrated at the loss of power when dropping into the small ring. After plenty of deliberating and some advice from fellow club members I have decided to change and the bike was ordered.

Although I appreciate that gearing is a personal thing, I have two questions:

1. Am i going to notice a massive difference and be unable to maintain an efficient cadence (between 80-100) on steep climbs (say 25%)?

2 If I want to change back to a compact setup, how easy is this? Can i simply swap the chain rings?

Many thanks!

John

1) You might have to grind it out, but there is nothing wrong with that, I averaged 75rpm up the Rake in 39:24 and you are probably as good if not better than me up the short brutal climbs. Didn't you beat Chris Dyke up one of the short steep climbs?

2) You can swap chainrings, but you probably won't be able to get a 34t, you might be able to go down 1 or 2 teeth?

 

[RecordAceFromNew]

I guess I'm just going to have to wait and see how it feels. Just fretting a bit because I've only ever ridden compacts on very hilly terrain and I'm not sure what to expect!

You don't have to wait. A 39/28 is close enough to the 34/25 or 34/24 you have currently.

As others said it is nearly certain that you won't be able to swap the stock 39 chainring by a 34. In terms of swap for the occasion it would be easier to change the 11-28 cassette to a 11-32 to duplicate the low of 34/28 IF that is what you have now, but to accommodate a 11-32 depending on your frame/hanger/rear mech if you are unlucky you might need to have a different mech, and the chain might need a pair of extra links. But the mech/chain set up needs to be done only once.

 

[ColinJ]

A triple, no way..... carrying 2 chainrings up a steep hill in a HC is taking the **** a little bit (I only ride with 2 chainrings because I wasn't sure how riding with 1 would effect my power meter calibration), 3? Not a chance!

Skim reading by me, I'm afraid!

I saw the first sentence and thought he had only just started cycling, and had bought his first bike, rather than his first bike without a compact setup!

No, I would not suggest a triple for competition. Even I didn't need my granny ring the year I got fit. I was climbing steep stuff on the 39.