Compact (Sloping) vs. Regular Frame - What's the Difference?

Martingale

What difference do these two frame types make to the bike riding?

Thanks

The The

On a good frame, not a heck of a lot.

Martingale wrote:

What difference do these two frame types make to the bike riding?

Thanks

gundersen

On a good frame, not a heck of a lot.

yes there is

One slopes and the other doesn't

campagsarge

Am I right in saying that a sloping/compact frame uses less material so should be lighter - plus the triangles are smaller making for a stiffer frame?

gundersen

in theory yes - but today with carbon fiber no

cooper.michael1

If you look at professional results and magazine tests you have to say there is no performance difference.

Petacchi does seem to lack any stiffness with his traditional Colnago frame does he?!

campagsarge

Petacchi does seem to lack any stiffness with his traditional Colnago frame does he?!

Not at all and a lot of the pro's have some input in frame design as well, which is fair enough given that they are the only ones on the planet that are able to put kit through its paces.

I would imagine there is a fair amount of marketing going on hence different frame shapes and sizes, although I am digressing from the OP question - :oops:

synchronicity

A compact geometry frame might be stiffer, but the seatpost is longer so flexes more.

Apart from that, in my opinion, compact frames suck. And I'll reiterate that that's my opinion. They confuse people when it comes to their sizing, and the S, M, L designation doesn't exactly help matters. I've noticed that people who ride with compact frames generally do not know how to measure a frame correctly. So when they come to me, they say:

i am 5 foot 8 inches, 160 lbs. i currently ride a 50cm specialized tarmac.

The only thing they are good at is reducing stand-over clearance for real shorties... but then XS bikes should have a smaller headtube anyway.

campagsarge

I'd agree with you there Syncronicity - I have two frames with a sloping TT and both frames are different sizes. One a 55cm the other a 57cm and I don't really know which is the best one - i probably need a 56! Both bikes are set up identically in terms or rider fit by using different length stems - which is probably not ideal.

Steve I

Riding, probably little or no difference. I think sloping just looks better, can't explain why. I also like the fact that with sloping there's enough seatpost sticking out to be able to clamp in a workstand, much preferable to clamping the frame.

meagain

Sloping gives a better weight/stiffness trade off AT ANY GIVEN PRICE POINT in my opinion. Also I prefer plenty of stand over cllearance. And longer seat post. Just cannot see the point in lugging around more frame mass than need to.

At my age this is no doubt close to heresy, but just because a design is old doesn't make it good!

mr-ed

Hasn't only one person (Pantani?) won the tour on a compact? The rest have all be on regular frames, maybe wrong tho!

redddraggon

mr-ed wrote:

Hasn't only one person (Pantani?) won the tour on a compact? The rest have all be on regular frames, maybe wrong tho!

The new Madones have sloping top tubes and Contador used one in the tour in 2007.

aracer

What's been used to win the Tour is hardly a very good reason to choose kit, as they'll simply use whatever they're paid to, rather than what's best - after all, the last 9 have been won on Shimano :twisted:

redddraggon

Surely it was Campag in 2006?

sloboy

I don't reckon there's mucg difference - and with an extended or integrated seatpost probably even less.

Interestingly, if you look at the Look 585 geometry (might only be in the optimum) for some sizes, it's sloping (so kind of semi compact) but as slope varies, at one size, it's level.

I think compact was originated on the theory that it gave a more flexible fit so that a manufacturer could get away with fewer sizes.

If that's the case, then it was probably a key feature in making moulded carbon commercially viable.

andrewgturnbull

Hi there.

Yup - compact geometry was always about manufacturing efficiency and marketing.

Mike Burrows introduced the compact geometry while he was working for Giant, which allowed them to bring what I think was the first monocoque carbon frame to the mass market.

The expensive bit about monocoques is making the moulds. Compact frames allowed for more flexibility in sizing, so that Giant only had to make 3 moulds - a small, a medium and a large. Otherwise they'd have had to make moulds in 2cm increments from 48 up to 60cm.

Anything else that you hear about stiffer triangles, lower weight etc was made up by the marketing department after the fact.

Cheers, Andy