Compact confusion ???

Mog Uk

Sorry, yet 'another' compact question, I've used search and am just getting more an more confused....

Bike is currently fitted with an 25-12 and a 52/39, on local climbs I'm on the 25/39 and still having to grind/stand up. Now I have a spare 50-34 compact that came with the bike. Seeing as I'm planning several sportives this year is fitting the compact the answer ? Will this stop me grinding and allow me to spin ?

Cheers for any help

Smokin Joe

It will give you lower gears, so yes you will notice quite a difference. A 12-27 cassette would also be a sensible upgrade, you won't miss the loss of an intermediate ratio and the 27 will be a lifesaver when you hit a steep one toward the back-end of a long ride.

Mog Uk

So swap to the Compact plus the addition of a 12-27 ?

Cheers for the reply........

JWSurrey

If you're riding Shimano, just check that a 27t cassette won't require a medium cage deureilleur - although if you don't cross-over it should be OK.

If you're running Campag. then from memory, 27t will work with a compact and the short cage.
I run 13-29, which winches me up most things - however that requires a medium cage.

If you check out the gear inches, a 29t cassette with 34t compact is equiv./better than a 30t triple with 25t cassette!

John.T

Standard short cage Shimano mechs will take 12/27 with 50/34 rings OK. Care is needed to set chain length but that is all. I have 3 bikes running this combo.
To check gear ratios use Sheldon Brown's gear calculator here. I find I understand the 'gear inches' better.
http://sheldonbrown.com/gears/
The whole site is worth bookmarking as it contains a lot of good information. It would probably answer most questions posted on here.

clanton

Just one thing - you may need a new chain as well unless it is very new.

oldwelshman

27 is ok for shimano, I use 39 x 52 with a 27 for some hard sportives.
Personally I would try the compact before also putting on a 27 and try it.
There is not that much differenc between 25 and 27 and not really worth that expense.
If he is still struggling that much a tripple would be better, or larger rear, but for larger rear would need longer cage rea mech and for tripple need new shifters so would try the compact and see how it goes.
Unfortunatelky some hills you just have to grind out

DavidTQ

Ive got a triple my low gear is 30:27 I still face some climbs that really test the legs, Dont know if its just that the hills I climb are particularly nasty or if Im just being a wimp, but I would be taking a longer easier route if I didnt have my triple I quite fancy a 11-28 cassette - giving me that bit higher top and that bit lower bottom gear. Will probably look into that in the summer when I get some lighter wheels and skinner tyres for summer use. Was going to get a new cassette and chain at the same time anyway.

oldwelshman

DavidTQ wrote:

Ive got a triple my low gear is 30:27 I still face some climbs that really test the legs, Dont know if its just that the hills I climb are particularly nasty or if Im just being a wimp, but I would be taking a longer easier route if I didnt have my triple I quite fancy a 11-28 cassette - giving me that bit higher top and that bit lower bottom gear. Will probably look into that in the summer when I get some lighter wheels and skinner tyres for summer use. Was going to get a new cassette and chain at the same time anyway.

A 11/28? Why would you want a 11 ? If your going down a hill fast enough that you think you need a 11, then you will go faster if you concentrate on making yourself smaller for wind resistance and stop peddaling
You try descending pedalling a 11 on a steep hill with some one tucked in and they will go faster than you
As you still struggle uphills I would go for a 13/31 or something and benefit more from the bigger rear for climbs than worrying about using a 11 for 0.001% of the time.

DavidTQ

oldwelshman wrote:

DavidTQ wrote:

Ive got a triple my low gear is 30:27 I still face some climbs that really test the legs, Dont know if its just that the hills I climb are particularly nasty or if Im just being a wimp, but I would be taking a longer easier route if I didnt have my triple I quite fancy a 11-28 cassette - giving me that bit higher top and that bit lower bottom gear. Will probably look into that in the summer when I get some lighter wheels and skinner tyres for summer use. Was going to get a new cassette and chain at the same time anyway.

A 11/28? Why would you want a 11 ? If your going down a hill fast enough that you think you need a 11, then you will go faster if you concentrate on making yourself smaller for wind resistance and stop peddaling
You try descending pedalling a 11 on a steep hill with some one tucked in and they will go faster than you
As you still struggle uphills I would go for a 13/31 or something and benefit more from the bigger rear for climbs than worrying about using a 11 for 0.001% of the time.

Well Ive currently got a 12-27 my front rings are 50/39/30 sometimes at 50:12 I find I pedalling a little faster than Im 100% comfortable with, Im a lazy git I dont like spinning my pedals that fast .

My average speed chair to chair is around 17mph (7 miles - 25 minutes) and thats including getting the bike out the door and locking up and getting the bike in at the other end etc, I dont have a wrist watch so Ive never timed just the journey time. I also dont go in for useing a stop watch and timing "dead time" at traffic lights and junctions etc.

But to be holding up an average speed of 17mph through busy roads with lots of lights round abouts and junctions etc I need to be spending a fair bit of time at well over 20 mph Currently top gear at 80rpm gives me 26mph which is a regular level cruising speed going up to an 11 gives me 28.5mph for the same cadence, just a bit more resistance on the pedals, which at those sort of speeds you are unlikely to notice. I know its not going to transform my 26mpg areas to 28mph areas but there are times when Im heading intot he 30's at the moment and I will be able to do so with a more "normal" cadence I like 80rpm it feels nice and natural to me, heading towards 90rpm seems to take the wind out of me very quickly...

Whilst I could improve my fitness, Im a utility cyclist I havent done a single leisure ride on a bike at all since I got back into cycling, Im a commuter, I enjoy my commute but I dont want to arrive for work knackered and out of breath but I do like to get there and back as fast as I can safely and comfortably.

If im getting a new cassette anyway why not go for one with a slightly higher top and slightly lower bottom with a bit more spacing between gears, the range I have is quite nice but I dont see why extending it a little each way is a bad thing. Im lazy by nature, I like to keep my cadence comfortable I dont like knackering myself pedalling too fast or too hard... if Im finding my current 12 borderline on too low then a 13 isnt really going to do me much good the 30 back could well be of use on the climbs, but I spend more time in top along the levels and down hill than I do in bottom on the really steep hills.

The top gear I use a lot on the level not just down hills! I actually dont like cannonballing down steep hills I do my best speeds along the level or on unoticeable gradiants...

I suspect if I had a 52 up front I wouldnt be wanting the 11 at all, but with just a 50 the 12 feels a little low at times, I spotted that this years edition of my bike comes with a 11-28 cassette as standard and thought that it would actually make a lot of sense to me, especially when the summer comes...

I CAN do my commute on my current setup, but I have many times thought of going to a 52 ring up front, but the 11-28 cassette would seem to me to give me both a slightly better hill gear and slightly better top gear without having to mess around with the front rings at all, or paying any additional money over what I was going to spend anyway when I get some new wheels.

I do spend a lot of my time up around 25-30mph but im a lazy git commuter not a clubman, time trialist, sprinter or track racer, I havent got and have no desire to attain the level of fitness required to pump out 120+ rpm all day long and I have no desire at all to grind hard than necesary up hills

dennisn

Mog Uk wrote:

So swap to the Compact plus the addition of a 12-27 ?

Cheers for the reply........

I use a 50-36 or 34 and a 11-21 rear most of the time because I live and ride mostly in really flat
terrain. When I make the yearly trip to torture myself for a week in the Rocky Mountains
I switch over to a 50-33 with a 12-27 rear. Plenty of gearing for long climbs and I don't
have to switch deraillers(Dura-Ace). T-A Specialties(I think) makes the 33 tooth compact(Shimano only) chain ring.

Dennis Noward