How much do you care about bike weight?
 

I probably won't buy any times soon but I have been looking for some time and have 2 on my shortlist now, cost almost the same. Components are equivalent. Already test rode one, the other I will too at some point.

However, one is 1.2kg lighter. The other one isn't heavy for a disc brake endurance bike (8.4kg) but 7.2kg is just very, very light. Now I know I am neither a pro nor does weight actually matter that much, but I do ride a lot up. For sure the light one (sadly I only test rode it on the flat, I will go back to go uphill too) feels light. It was a nice ride. But yes, what do people here think? Should I be less swayed by the weight (depending on test ride, at same weight I would go for the other one).

Not much, within reason. I'm not chasing every gram savings possible. Losing it off my body is cheaper.

It sounds as though one bike is an endurance bike with disc brakes. Does that mean the other bike you are considering is more of a race bike with rim brakes? If so, then you are not comparing apples to apples. Your decision between the two bikes should be based on which one you feel will serve your needs better. Endurance bikes are supposed to be designed in such a way as to make riding the bike all day more comfortable. That means there will be some amount of isolation of vibration from the road to the rider. A race bike is designed for speed and is likely more rigid so the rider will feel the road much more. In addition, the disc brakes on the endurance bike will weigh more than rim brakes and could be most of the weight difference between the two bikes. As I see it, weight isn't what should dictate here but how you intend to ride should dictate your choice.

While light weight really doesn't matter to me ( I carry a lot of extra weight around my waist) there is something about a light bike that seems to be ingrained in the culture. I recently purchased a bike that was weighed in a road test at 7.55 Kg for size M. I got a small, so less I would guess. didn't need light, but it has a certain cache to it, and I think the weight difference of my 2 choices (maybe more than 500 g, 1 lb) played a part in my purchasing decision.

I am more concerned with fit. If the bike is is the $3,000.00 or more range, it will be light enough for me.

It would depend on what the bike was for/how it fit within my riding habits. I'm no weight weenie, but lighter is funner, all other things equal, if it's to be an all-around bike. If it were something like a dedicated long-distance bike, I'd go with the heavier if it meant more comfort and better performance for long days.

Get the cheaper one. The way I think about bike weight is riding a heavier bike makes me stronger and lighter - truly. I have 3 classics that are 25lbish and a moderno that 17-18ish and they are all much loved and ridden.

No, not really.

Both are endurance bikes both are disk brake both have the same groupset.

Price difference is negligible to be honest. Like less than 5% for sure. And not really. Just pedal harder on a lighter bike...

Ok. Then is there a price differential between them? If price is comparable, I'm buying the lighter bike, all other things equal. You said same groupset. Any differences in the quality of other compnents such as the wheelsets? If not, I'd go with the lighter one with similar pricepoints. If the lighter one is significantly more expensive, then I'm no longer counting grams and would go with the less expensive one, all other things equal.

If they fit the same, i like the look equally, and they cost the same- then sure grab the lighter option.

I ride steel road bikes and am 6'5, so while weight is important to me, it is obviously a different area of the weight spectrum that I operate in. I will never have an incredibly light bike just based on size and what I would be willing to spend.
But yeah, I still consider weight when looking at framesets and all components because why would I want to get a heavier than necessary bike within the parameters that I am considering?

8.4kg or 7.2kg?...if they fit the same and all components are the same/equal, then get the one that looks best. Either way your bike will be very light and you will hold it back instead of the other way around.

I'm good with anything 18 lbs. or lighter.

If you want to get stronger by riding a heavier bike, you need to ride a tandem with your wife.

Light bikes are a fun hobby to chase.

I'd always choose the lighter of two otherwise identical bikes if I had a choice that cost me nothing.

However, in real life it really doesn't matter that much to me compared to other factors. I have a 15.5 lb bike and a 19.5 lb aero bike. I always race the aero bike.

Color and aesthetics will still play a bigger part at that weight difference for me. Assuming fit, components, price and other things have been justified in my mind.

But it wouldn't be wrong in my opinion to let that be your tie breaker. While others might goad us that we have much more body weight to loose, this is one thing you can do toward the total ride weight that is immediate and relatively permanent.

Fit
Material/Components
Aesthetics
Weight (last)

In that order. None of my bikes are under 19lbs (riding weight).

not all that much really. As long as my road bike is under 25lbs I am good. Mine are closer to 20lbs.

I am more concerned about my weight than my bike.

It’s a tiebreaker, and worth a bit extra money or effort to reduce, but it’s a low priority.

Did both manufacturers provide their weight on the same size frame? Look to see if independent tests of the bikes provide weights different from what that manufacturer has provided. You may find that the bikes weigh the same.

Physics and common sense disagree with you.

Indeed, and I cannot lose much more bodyweight unless I really start to eat conscientiously, which I don't want to. I am already quite low body fat% by most standards.

With that much of a difference?

If you do the same workout (effort x time) you get the same benefit with a lighter, more aero bike; you just go further in the process. It works if, and only if, the slower bike forces/ allows you to spend more time pedaling on a time-limited workout.

No, not really.

Nobody I know rides until they've burned a specific amount of energy=calories and then stops. Excepting special cases, for a given route=ride=course a person will do more work on a heavier/less efficient bike that a lighter/more efficient bike, and more work requires more energy/calories - it's physics and common sense.