MTB weight obsession - unnecessary?

[LuckyLuke]

use to ride a 10kg carbon hardtail, me weighing 88kg I still was left behind on the climbs and it never felt planted on descents etc.. sold it and build a steel hardtail more for trails,  bike weighing 12.5kg and super comfy, did my first race on it the other day which was 80km with 1700m climbing, thought I was going to be murdered by all the 9kg gravel bikes and the R80k carbon duellies however I never felt out gunned on the climbs, came in 10th out of 110 people and was pleasantly surprised. Dont think the carbon hardtail would have been so much better...however I could barely walk the next day, felt like I had done about 600 squats the previous day

[Super Sywurm]

9 minutes ago, LuckyLuke said:

use to ride a 10kg carbon hardtail, me weighing 88kg I still was left behind on the climbs and it never felt planted on descents etc.. sold it and build a steel hardtail more for trails,  bike weighing 12.5kg and super comfy, did my first race on it the other day which was 80km with 1700m climbing, thought I was going to be murdered by all the 9kg gravel bikes and the R80k carbon duellies however I never felt out gunned on the climbs, came in 10th out of 110 people and was pleasantly surprised. Dont think the carbon hardtail would have been so much better...however I could barely walk the next day, felt like I had done about 600 squats the previous day

And in most cases, your body take less of a hammering on a steel bike than a carbon bike.

[ChrisF]

20 minutes ago, Ruben Hechter said:

What do you guys think about rotational weight? 

 

Especially on trails where the turns are slower and you have to put the power down constantly to get back up to speed.

 

Rotational weight is THEE killer !!

 

Exactly why the likes of Nino risk paper thin tyres on the Epic.  

 

Sure, you can save significant rotational weight with nice ($$$) carbon rims ... but the tyre has the final say on rotational mass, and with the worst radius to boot ...

 

 

Put the calculators down ... go TRY the effect of lighter wheels on tight trails ....

 

 

 

All that said ... despite the 20kg I have lost, a few more needs to go before any of these benefit me .... (if I was still on a normal bike)

 

 

Then again, common sense and bragging rights are seldom friends ....

[Dexter-morgan]

I must be honest, I almost got caught in this weight thing, My current bike weight is 15.5kg(trek Top fuel 7 - with pedals and some spares in the frame) so off I went to cycle lab, saw Scott Spark for around R70k without pedals and bottle cages was like 13.8kg, add pedals around 350grams, pushes the bike into the 14kg, I could not justify spending R40-45k after trading my current bike in for just over a kilo of weight. I will just enjoy this bike for its capabilities and suffer on the climbs.

[NotSoBigBen]

There are very few people that can honestly 'feel' the difference frame material (carbon,steel,Alu etc.) makes... Unless they are justifying their spend on whatever 'cool' thing they've built

Weight .... Unless the weight difference in bikes is significant anyone that's not at their optimal racing weight probably benefits by reducing weight elsewhere i.e not on the equipment 

Maar nou ja hier sit ons

[DieselnDust]

6 hours ago, JayLow said:

I recently went through the process of upgrading my mountain bike and I gained quite a few new perspectives around the "bike weight" obsession.

I strongly desired a lightweight (<12kg) dual suspension XC bike, not an easy (read "cheap") feat when you run an XL frame, but in the end decided on a slightly heavier but better specced Titan Cypher 120mm Carbon frame with dropper and heavy duty Lyne wheels.

When I saw the calcs of the impact of a few kilograms extra weight on a climb, I felt vindicated in going heavier - I will almost certainly make up the climbing time losses with more confident descending - especially in the way I ride:

Source

There are so many factors at play when determining how fast you will climb, but on the level I play, bike weight really does not have to be the be-all and end-all.

So, all this just to say, if you are moderately fit, and ride for fun, I don't think it's worth it to spend tens of thousands of Ronds to shave of a few tens of seconds of your climbing time...

Keen to hear the the thoughts of the other hubbers...
 

That’s 40sec over 2km

1.82 m/s vs 1.76m/s

thats a difference of 14cm for every second of riding.

of by the end of the first min it’s 60x 0.14 or 8, 4m further up the road with the lighter bike.

at the end of the climb, that 40sec is a huge benefit in race distance.

for snots and giggles that weight difference is fine but if you’re  racing you may as well stay at home 

Edited May 21 by DieselnDust

[Koos Likkewaan 2]

absolutely agree! Our Saffa culture is big on status symbols (just look at all the luxury SUVs on the road) and a lightweight R150k Trek Supercaliber ridden by a round ballie radiates that baller message...

 

What have I done to get this treatment ? 😁

[JayLow]

20 minutes ago, DieselnDust said:

That’s 40sec over 2km

1.82 m/s vs 1.76m/s

thats a difference of 14cm for every second of riding.

of by the end of the first min it’s 60x 0.14 or 8, 4m further up the road with the lighter bike.

at the end of the climb, that 40sec is a huge benefit in race distance.

for snots and giggles that weight difference is fine but if you’re  racing you may as well stay at home 

Lots of calculation errors in there but yes, for racing lighter would be better, all other factors being equal. However the effect is very very small: in the example it's 4cm/s or 2.4m/min for a 3.3kg difference in weight.

My point is that the gains in performance with going lighter are not commensurate with the cost to reduce weight (for the vast majority) of riders.

Edited May 21 by JayLow
edge cases included

[JayLow]

1 minute ago, Koos Likkewaan 2 said:

absolutely agree! Our Saffa culture is big on status symbols (just look at all the luxury SUVs on the road) and a lightweight R150k Trek Supercaliber ridden by a round ballie radiates that baller message...

 

What have I done to get this treatment ? 😁

Please forgive: I am just jealous because I find a Supercaliber to be very desirable.

[Headshot]

You might be faster on your heavy dual trail bike because you can klap the really rocky climbs and descents more efficiently though. 

[Spafsack]

I think its hard for all of us to admit that we just need to go on a diet, loose 5kg, versus loose 5kg on upgrading to a 10kg or 12kg MTB. Probably because its easier to trade your bike in than starve yourself 😁

 

 

[The Ouzo]

5 minutes ago, Spafsack said:

Probably because its easier to trade your bike in than starve yourself

its cheaper too, have you SEEN the price of diet food ?

 

thats my story and I'm sticking to it.  

[DieselnDust]

21 minutes ago, Koos Likkewaan 2 said:

absolutely agree! Our Saffa culture is big on status symbols (just look at all the luxury SUVs on the road) and a lightweight R150k Trek Supercaliber ridden by a round ballie radiates that baller message...

 

What have I done to get this treatment ? 😁

Too many beers???

[DieselnDust]

24 minutes ago, Headshot said:

You might be faster on your heavy dual trail bike because you can klap the really rocky climbs and descents more efficiently though. 

It will be less pitch sensitive 

[PhilipV]

1 hour ago, Spafsack said:

I think its hard for all of us to admit that we just need to go on a diet, loose 5kg, versus loose 5kg on upgrading to a 10kg or 12kg MTB. Probably because its easier to trade your bike in than starve yourself 😁

 

 

Oi!!! Speak for yourself.  
 

 

I can probably lose a few kgs on my bike, not much on myself, but I’ll rather take a rugged and fun bike than a fragile thoroughbred. 
I will however unashamedly swap to lighter, faster rolling tyres for gravel adventures and back to the thick and grippy tyres for trails action. 
On tyres you’ll feel a noticeable difference way faster than a 500g frame difference.

1 hour ago, Koos Likkewaan 2 said:

absolutely agree! Our Saffa culture is big on status symbols (just look at all the luxury SUVs on the road) and a lightweight R150k Trek Supercaliber ridden by a round ballie radiates that baller message...

 

What have I done to get this treatment ? 😁

Bought a fast bike? How dare ye!!

[MORNE]

3 hours ago, Ruben Hechter said:

What do you guys think about rotational weight? 

 

2 hours ago, ChrisF said:

 

Especially on trails where the turns are slower and you have to put the power down constantly to get back up to speed.

 

Rotational weight is THEE killer !!

snip.

Not completely true, although lower rotational mass will get rolling faster, higher mass will keep that speed easier.  If you can find that place where you arent loosing too much momentum in, over or around things, heavier wheels might actually help purely because its harder to slow down a heavier spinning thing and its centrifugal force.  
 

These days a properly strong carbon wheelset for gravity riding is chosen more for feel than weight anyway. They basically weigh the same. Same with big hitting carbon bike frames. Ive had steel bikes lighter than my plastic bike lol.  They feel different though.