Originally Posted by
Carbonfiberboy
That could mean you need more strength, which might be helped by weights, though that's probably not the most efficient use of your time if it's limited. If it's not, then gym work is good.
This man is already cycling so time obviously is not his main concern. Weight training will give you more gains in strength, muscular growth and fat-loss with less a time commitment then cycling or any other aerobic exercise could ever hope to do. So I'm pretty lost on your claim here.
mtb man, I take it you are a swimmer by competition and your training involves weights, yes? Are you doing squats (and for that matter full depth, or at least past parallel squats) as part of your lifting routine? Are you deadlifting? If not, start both ASAP.
Also, just try and keep up with the paceline no matter how killed you are at the end of the ride. If you get dropped by the group, so be it. Just try and hold on longer the next ride.