I'm thinking about changing my current bike to BMC RM 01 five '23, there is one in my city in a good price and it just looks amazing (I love that black stealth look and angular shape) it's the same as this one https://uploads.tapatalk-cdn.com/202...ff870b253b.jpg

Mainly to have disc brakes (not so important) and bigger tires (maybe a bit more useful?) and to have a bike that can stay with me for years.
Currently I ride S-Works Tarmac SL6 rim brakes (weight is around 7kg I recon, dura-ace and ultegra components + 1280g roval CLX32 wheelset) - I like its sporty geometry and handling and of course lightness
I like climbs and I do a few gran fondos during a year (with >2-4km climbs), maybe i'll try some crit racing next year (my FTP can get to ~4W/kg), still, for fun, in +45y cat.

With a new bike it'll be almost impossible to match or even be close with my current bike weight :/ (I don't plan to spend 10k on a bike)
I guess RM 01 frameset will be ~400-450g heavier (I found some weights on internet for frames and forks) than my SL6 and disc brakes will add another 300-400g :/ (so 700-800g heavier in total, similar configuration - Ultegra)
I measured RM and I saw that if I lower stem (with only 5mm cap/spacer) I'll have similar setup as mine Tarmac SL6.
But how is the handling? anyone can compare? HTa is 1.5* slacker, but stem is 10mm longer (overall length in size 56 is the same).
Also I heard that ICS is a bit problematic? (not round steerer tube related?) and of course only BMC heavy stem (unless it's full carbon stem-handlebar integrated, which is very expensive (even comparing to Specialized or FSA etc.), but I can run ICS stem with any handlebar anyway.

Or should stay with Tarmac (and look for SL7 ) or Teammachine.

Unless the bike is a few pounds lighter, I'm not certain it'd be any different than your Tarmac. If it is heavier, then you might not like the perception of how it accelerates compared to the Tarmac.

You seem to be saying the BMC is heavier than your Tarmac. I thought the RoadMachine was suppose to be a pound or two lighter. Even with it's disc brakes which aren't the weight hit they once may have been.

i have the slr one and there are a few things i dislike.

- d shape seat post is over expensive and fragile.
- the rear seatstays require a longer seatpost or you might risk to crack one (for my friend i repaired a 2018 slr 3 with this problem).
- headset require his own brand stem or willl it looks ugly as heck.
- the paint and clear coat is basically is so think, it will flake whitout any reason.

bike is pretty solid and rigid but for the price probably there are more good around.
im late, im going to add more on the list later

new bikes in that price range 5-7k, quite often weight ~8kg

S-works frame is around 750g + 360g fork (that's the weight i found on internet, could be unpainted?)
and RM 01 - 1100g + 450g (pictures of real painted frame, maybe with some minor hardware, maybe I should substract 100g)
maybe you're thinking about highest Teammachine? it's a race bike, so probably weight could be similar to S-Works Tarmac

Frameset weights aren't going to matter as much for telling you what the actual bike weight is. And that actual bike weight is going to be what you feel when you accelerate or climb.

If you're referring to a 2023 Roadmachine, I have one and love it...

Suggestions for an endurance/all-road bike with new Ultegra 12 speed groupset

Loved My Two Streets.

I assume you meant it's a '23 (that ain't a 21 year old bike)?

My bad, I wouldn't change 2018-9 s-works tarmac SL6 to 21y old bike

plus


- his own bottlecage is very expensive and useless.
- if you use his own bottlecage you will ruin the paint because it moves laterally, paint will be worn out were it touch. Same thing on different aero bottlecage, i used a giant one and the same results (but it was so cool damn it!!!)
- the stem ics is an handlebar's killer, i broken one made from carbon because there is nothing online express compatibility, basically the garmin mount (that kind of mount inserted in the stem's face) became a sort of "spacer" pressing into a specific point. plus probably i'll need to swap handlebar again since after a crash the stem pressed more in a specific point (note: i have an expensive torque and years of experience on bikes).
- as i told already the stem will match the spacers , so you must use this damned thinghy or the aestetics would be a nightmare.
- oh i forgot the funny part, if you planned to use normal bottlecage beware that some of them allow the vertical bottle to touch the frame.... you should use a very short bottlecage or as i did modify one, but honestly i kinda crazy because i don't think everyone is able to modify carbon or alu (depending on the bottlecage).
- as other carbon monococque frame some of them will have some issue regarding the bottom bracket not totally allign (this one is a common problem not very noticeable, almost every brand has it).
- fork tube from the inside do not appears smooth, first time i inspected the bike i contacted the support. they said it was fine.
- paint is not fully replicable, i found a match with the red itself but the clear coat flakes (the rainbow flakes they call red prism effect) is impossible to find. the most thin flakes bag i found was marked as the thinnest on the market, still when paint any piece the difference is huge. Basically if you are going to repaint a part or even the entire frame would be very noticeable to people who understand a bit regarding the paint. Funny story , in this way i spotted that my friend superbike (second hand) was repained and he did even know that.
- no information regarding the type of carbon used for frame or fork, not even how the frame is made.
- bmc sound cool but is funny that the name means bike manufactory , glad they chose this instead of steak house or smt.
- if you inspect the paint is not applied in a super precise way, i noticed near the headset there is a little accumulation, noticeable again to who have experience with paint. (basically there is an agglomerations of flakes noticeable with a strong lamp, only when bike is disassembled).

choosing a bike right now is pretty hard, the quality is so low compared to the price. if you want an advice go local and find the most good deal for a new bike.
for example when i bought my bmc the seller decide to exchange my old roadbike for a big discount. Before that i never had a thought about buyng a bmc, i have nothing against the brand but honestly giant seems better in sales management and warranty itself. for example bmc has 2 years of warranty.

Within say 1 kg, can you really tell the difference in acceleration or climbing? If the rider weighs say 75 kg and the bike is 8 kg, then 1 kg is just over 1% of the total mass being accelerated. Bodyweight naturally varies by 1-2 kg over the course of a day, so it’s kind of in the noise.

Or to put it another way, if you are at 4W/kg FTP then 1 kg extra mass is costing you approx 4W when climbing or accelerating at FTP. It’s not nothing, but it’s mostly a perception rather than a significant loss. On the flat when up to speed, 1 kg is really nothing at all and the more aero bike will be faster.

I said that it might be perceived as faster or slower during acceleration in my initial comment about it. Emphasis on the might.

I'm not certain why you quoted what you quoted for the point I think you are trying to make. Perhaps I'm just totally misunderstanding the entire thought you are suggesting.

I'm just making the point that total mass (bike + rider + clothing + bottles +helmet + tools etc) is the only thing that matters for objective acceleration, so the bike weight is not super critical within the scope of what the OP is talking about i.e. less than 1 kg difference. Perception of acceleration is what magazine reviews tend to focus on, not the reality. When comparing bikes at this level, the differences are going to be more related to fit, geometry, overall compliance and ergonomics. In most cases, aero (heavily influenced by fit) is going to have the biggest influence on objective timed performance, if that really matters to the OP.

and color

Do it!

Not even 4W when climbing since the gravity effect will depend on gradient.

Of course. It’s just a simple way of putting power/weight ratio into some perspective. We often talk about our ability in terms of W/kg, especially when climbing. So if I’m climbing a hill at tempo (which for me is around 3 W/kg body mass) then 3W is the approx value of each kg of additional mass. It would actually be slightly less because I should really be calculating W/kg based on total rider+bike weight. So if my bike is 10% of my body weight, then my overall power/weight ratio at tempo would drop to around 2.7 W/kg.

So if I add 1 kg to my bike I need to increase my power by 2.7 W to maintain the same overall W/kg at tempo. The actual importance of my overall power/weight ratio varies depending on the slope gradient as you rightly said. On the flat W/kg is of very little importance, but becomes a key parameter on a steep climb.

For a pro climbing at 5W/kg, an extra kg is worth 5W to maintain their power/weight ratio. So that could be the difference between riding at 350 and 355W. On a long climb that might be significant.

Hm.... after reading about some problems with BMC RM.... I think I'll look at Tarmac SL7,
however, I learnt that new SL7 are made from lower grade carbon and weight a bit more - ~1000g for the frame. Ok, a bit heavier, however it's possible that frame is a bit less stiff/more compliant than previous SL7 (something that people were complaining a bit, and in result, SL8 is less stiff)

Personally... none of this sounds better than the S-Works.