Compact V 39/53

[number21]

Forget the diet shakes, mate of mine in Spain reckons he knows a great butcher whose cuts make power to weight concerns a thing of the past.

you lost me, do you mean eat meat not drink shakes?

i think he means the Astana team Purveyor of Fine Meats

Bingo. Clenbuterol, helps reduces body fat while increasing muscle mass apparently.

Sorry can't help with the actual topic at hand but interesting reading though.

[pagey]

The change to compacts has really advanced my climbing, keeping my legs spinning at 90-94 RPM at 14 to 15 km/hr up the really steep kicks using the 34 front in combination with the 24 and 28 tooth rear cogs. The flat road cruising is also perfect now for me, holding the large front chainring 99% of the time with no crossing issues.

This is exactly my position. As a spinner I have not looked back going to a compact.

[anth73]

I thought I'd post a response given I've rode a compact for 2 years before moving to a standard crank when I got my new 6700 Ultegra groupset.

Both allow you to spin, in fact I was spinning at 100rpm on Saturday trying to keep warm as it pelted down with rain at Kinglake! The only difference is that running a compact gives you more closely spaced ratios, which is a benefit in climbing but a bit of a downer when powering on the flat or in a sprint.

For sustained climbing I think compacts are definelty the way to go and I'll look to getting the Ultegra equivalent for things linke the 3 Peaks or the Alpine Classic 250.

[MountGower]

Apple wrote:

So my question is: is there much difference in compact with an 11/25 at the back, to a 39/53 and 27 group set at the back

I run a 13-29 rear cassette and the gear inches for 39/29 are almost identical to a 34/25. The problem I have and I notice it with people using compact cranks aswell, is to cross chain more than is ideal. I went with a bigger rear over a smaller front because I thought larger sprockets and a longer chain would reduce wear.

Good luck sorting it out. The 11-28 option for Shimano and Sram users sounds like a decent option to me.

[sogood]

The only difference is that running a compact gives you more closely spaced ratios, which is a benefit in climbing but a bit of a downer when powering on the flat or in a sprint.

The "closer spaced ratio" should also assist when powering on the flat. Can't see any reason why it wouldn't. As for the sprint, until one can max out on 122.7 inches, it's a bit of a mute point. No?

[Mulger bill]

The only difference is that running a compact gives you more closely spaced ratios, which is a benefit in climbing but a bit of a downer when powering on the flat or in a sprint.

The "closer spaced ratio" should also assist when powering on the flat. Can't see any reason why it wouldn't. As for the sprint, until one can max out on 122.7 inches, it's a bit of a mute point. No?

*moot

Methinks you've hit it on the proverbial there sogood.

[bosvit]

The only difference is that running a compact gives you more closely spaced ratios, which is a benefit in climbing but a bit of a downer when powering on the flat or in a sprint.

The "closer spaced ratio" should also assist when powering on the flat. Can't see any reason why it wouldn't. As for the sprint, until one can max out on 122.7 inches, it's a bit of a mute point. No?

That was a good side effect of changing to compacts for me, better hill climbing sure but you can really notice the closer ratios going up through the gears. Only down side is descents as I run out of revs at a slightly lower speed.

[Apple]

The only difference is that running a compact gives you more closely spaced ratios, which is a benefit in climbing but a bit of a downer when powering on the flat or in a sprint.

The "closer spaced ratio" should also assist when powering on the flat. Can't see any reason why it wouldn't. As for the sprint, until one can max out on 122.7 inches, it's a bit of a mute point. No?

That was a good side effect of changing to compacts for me, better hill climbing sure but you can really notice the closer ratios going up through the gears. Only down side is descents as I run out of revs at a slightly lower speed.

I didn't think you need it for decent.
Well I ended up buying the compact and will ride it through Bobbin head tomorrow. I wonder if I will notice any difference.

[drubie]

Well I ended up buying the compact and will ride it through Bobbin head tomorrow. I wonder if I will notice any difference.

I used to love my 50/32 compact but I started running out of top end gears when I got fitter. Ended up with something close to the old "Alpine" gearing with a 52/42 rings on a compact chainset and I think it works better, other than a bit of flex on that 52.

[goodlookingcyclist]

Now mayby a silly question but it is topic related.

I have 53t big ring on one bike and a 50t on the other.
I feel more comfortable with the 53t. (I know there are other factors involved that influense comfort)

Could the diameter size play a roll in this ??
I know we are not talking a lot in difference, but for me it feels that I can push the 53t bike easier then i can the 50t bike.
(note; the 53t bike is heavier then the 50t bike, so it not weight related...)

[Nobody]

Now mayby a silly question but it is topic related.

I have 53t big ring on one bike and a 50t on the other.
I feel more comfortable with the 53t. (I know there are other factors involved that influense comfort)

Could the diameter size play a roll in this ??
I know we are not talking a lot in difference, but for me it feels that I can push the 53t bike easier then i can the 50t bike.
(note; the 53t bike is heavier then the 50t bike, so it not weight related...)

Yes. In theory the bigger chainwheel will turn the chain less under pressure (both front and back) at the same final drive ratio. So less chain friction loss is more power to the wheel. I've often had my compact crankset bike on the KK Road Machine (fluid) trainer to find a noticeable change in power when changing from the 34 to 50 by also changing the cassette gear to have the same approximate final drive ratio. So it appears to work in both theory and practice.

I believe the main reason people choose compacts are to make climbing longer hills easier, therefore improving the cyclist's effective long term efficiency. I don't think it does anything for mechanical efficiency.

[I've almost talked myself into changing to a standard crankset. ]

[Apple]

Nobody"]I believe the main reason people choose compacts are to make climbing longer hills easier, therefore improving the cyclist's effective long term efficiency. I don't think it does anything for mechanical efficiency.

Correct, that is the only reason I changed, I find I am grinding up hills and I do a lot of hills. I just hope I am not going to be disappointed when I try it out for the first time.
I also hope that my flat riding will not be compromised as I tend to ride with lots of power.
I am not getting younger and I see younger cyclists then me have compacts.

[I've almost talked myself into changing to a standard crankset.

I have dura ace standard if you are interested.

[Nobody]

I just hope I am not going to be disappointed when I try it out for the first time.

You are probably on your ride already, but the only thing you'll probably find troublesome in operation is the larger number of chainring shifts with a double shift on the rear to maintain the same overall ratio.

I also hope that my flat riding will not be compromised as I tend to ride with lots of power.

If you can outrun a 50/11 on the flat (~57Km/h) you're probably wasting your time here which may be better served training for women's pro racing.

I am not getting younger and I see younger cyclists then me have compacts.

Some MTBers use a 32 as their largest chainwheel and they could still leave both you and I in their dust, up and/or down hill.

I have dura ace standard if you are interested.

I'd only be mildly interested if they are 165mm crank length. I already have 165s on my road bike and I'm considering changing the 170s on the MTB to 165 too.

[Apple]

You are probably on your ride already, but the only thing you'll probably find troublesome in operation is the larger number of chainring shifts with a double shift on the rear to maintain the same overall ratio.

Yes I was It was amazing, I rode through Bobbin Head the hills felt like I was riding on the flats, well sort of anyway . I Cant beleive I didn't change it sooner.

If you can outrun a 50/11 on the flat (~57Km/h) you're probably wasting your time here which may be better served training for women's pro racing.

The answer to that, we both know, I am not a pro and I am not a Christine Tham

I'd only be mildly interested if they are 165mm crank length. I already have 165s on my road bike and I'm considering changing the 170s on the MTB to 165 too.

Not in luck mine are 170, so if you change your mind, whistle, "you do know how to whistle don't you. Put your lips together and blow."

[dodge]

You are probably on your ride already, but the only thing you'll probably find troublesome in operation is the larger number of chainring shifts with a double shift on the rear to maintain the same overall ratio.

Yes I was It was amazing, I rode through Bobbin Head the hills felt like I was riding on the flats, well sort of anyway . I Cant beleive I didn't change it sooner.

If you can outrun a 50/11 on the flat (~57Km/h) you're probably wasting your time here which may be better served training for women's pro racing.

The answer to that, we both know, I am not a pro and I am not a Christine Tham

I'd only be mildly interested if they are 165mm crank length. I already have 165s on my road bike and I'm considering changing the 170s on the MTB to 165 too.

Not in luck mine are 170, so if you change your mind, whistle, "you do know how to whistle don't you. Put your lips together and blow."

Good to see it worked out fine...I did a TTT a few weeks back on my bike.(compact) and had no issues of running out of gears..other than 96% average heartrate

[Apple]

Yes thank you
I was ecstatic today; I am not sure if it was the double shot times 2 espressos or the compact, but I felt strong and fast

[open roader]

Yes thank you
I was ecstatic today; I am not sure if it was the double shot times 2 espressos or the compact, but I felt strong and fast

Excellent, sounds like an enlightened move Apple............

[brit_in_oz]

Since SRAm have now launched apex you have the choice of a 50-34 with 32 rear cassette as standard, makes triples redundant. Personally i have just ordered force with 50/34 and 11-26 cassette - 4% better speed than a 12-25 and gear ratio of 2.7 vs 3.3 for climbing, makes ssense to me, with the option of a 12-28 for the alpine events

[ZepinAtor]

While on the compact subject I have a Sram Red BB30 (Cannondale Caad9) compact 50/34 I don't want & would like to swap it with a Similar 53/39 BB30 set. I'd accept Ultegra/ Durace or Red again if anybody's interested ? My current crank is good condition with low km's & only a couple of tiny marks on the drive side crank arm.

[sogood]

Hated the compact crank & fitted an FSA superlight carbon crank instead.

Why? Riding in hilly Sydney, I hardly ever have to swap out of the 50 except for long high grade climbs.

[Apple]

Hated the compact crank & fitted an FSA superlight carbon crank instead.

Why? Riding in hilly Sydney, I hardly ever have to swap out of the 50 except for long high grade climbs.

Sogood, I didn't know you were soft

[sogood]

Sogood, I didn't know you were soft

Soft? Staying in 50 all around Sydney is actually more hard core than regular double riders who find comfort in 39. And nothing soft about riding 50/11 when regular double riders never touch 53/11.

[ZepinAtor]

Hated the compact crank & fitted an FSA superlight carbon crank instead.

Why? Riding in hilly Sydney, I hardly ever have to swap out of the 50 except for long high grade climbs.

I'm a small ring spinner while training or social riding & find the 50 annoying as I'm constantly changing back to the small ring on undulating terrain. Racing crits isn't an issue though cause it's big ring all the way, but my race frame just became my training frame & the cranks aren't interchangeable hence the want to change cranks.

[Rider10]

Apple I was wondering how the compact is going now that you have had it a while?

[ldrcycles]

I looked at getting compact cranks a while ago after doing Razorback Road up to Mapleton on the Sunshine Coast (it's a very appropriate name!), in spite of remembering how much i hated the compacts on my first decent roadie. Couldn't find any cheap square taper cranks so i looked at the back end, changed the rear mech to a Deore mtb and an 11-32 mtb cassette, for under $100 it's great, makes the 53 MUCH more usable (i'm not too concerned about cross chaining as my frame has a very good chainline), without the sacrifice in top end you have with compact (if there's a downhill i want to go as fast as possible ).