Lugged vs monocoque frame

[BeR]

Hello,

What is the pros and cons of having either, particularly in strength, stifness and durability. I understand that EPS is better than classic construction, but what is about lugged/monocoque ?

Is it possible to have a list of monocoque aero road bike frames (like the R1058-D) ?

Thanks.

[Serge_K]

If it's not monocoque, it's 2 triangles bonded together, so in theory, it creates a failure point. Now, how often do you hear of frames braking there?
In theory, monocoque should be a tad lighter, and ride quality should be a tad better. I suspect that in practice, good luck discerning that.
I would assume it's a sign of quality, though, if someone is bothering to produce monocoque frames, i'd assume they know their bacon.

A lot of yishun bikes are monocoque. the long teng 266 is / was monocoque, afaik (not an aero bike). i think the carbonda 1056 is as well (not an aero bike)

[Sakizashi]

I think you are asking about single mold frame or a one piece mold rather than monocoque? Monocoque means that the load bearing structure is a "single shell" its the equivalent of a unibody in auto design. That doesn't mean its not made of joined parts. The notion of a "true monocoque frame" or "full monocoque" to mean a frame that comes out of single mold is only something I have heard with relation to bikes, but right now it's a production method does not yet tangible benefit to consumers. Maybe there is a future cost benefit as layups become automated or maybe it allows for the use of lower grade materials to make bikes that are closer in weight to top frames?

Theoretically the lack of joints should mean a lighter frame at the same strength with greater freedom of design when it comes to layup design. The reality is that the joints are often made stronger than the tubes to ensure there isnt a failure and the use of smaller molds or doing it in sections still allows for greater control of the local area. As far as I know, none of the high performance road bikes or MTBs raced at the World Tour or World Cup level use a single piece manufacturing method as the tradeoffs in terms of getting the right compaction, etc don't yet produce the lightest or stiffest frames.

[BeR]

I think you are asking about single mold frame or a one piece mold rather than monocoque? Monocoque means that the load bearing structure is a "single shell" its the equivalent of a unibody in auto design. That doesn't mean its not made of joined parts. The notion of a "true monocoque frame" or "full monocoque" to mean a frame that comes out of single mold is only something I have heard with relation to bikes, but right now it's a production method does not yet tangible benefit to consumers. Maybe there is a future cost benefit as layups become automated or maybe it allows for the use of lower grade materials to make bikes that are closer in weight to top frames?

Theoretically the lack of joints should mean a lighter frame at the same strength with greater freedom of design when it comes to layup design. The reality is that the joints are often made stronger than the tubes to ensure there isnt a failure and the use of smaller molds or doing it in sections still allows for greater control of the local area. As far as I know, none of the high performance road bikes or MTBs raced at the World Tour or World Cup level use a single piece manufacturing method as the tradeoffs in terms of getting the right compaction, etc don't yet produce the lightest or stiffest frames.

Thanks a lot for this clarification.