Can a Off-Road bike be too light?

[tintin40]

Also depends on he riders weight to.
Not so certain on wheel weight as i've the same wheels on two different mtb's one was 17 lb 4oz and now on a 14lb 10oz the lighter bike was a lot quicker. Later i put heavier rubber on them. Took the the weight up to 15lb 10 oz still rode a lot quicker than the 17 .4 all the same hubs,spokes,rims.

 

[drystonepaul]

[ moved ]

 

[LesterOfPuppets]

All I got is full rigid rigs and my 26 pound KHS is a lot more stable on rough fast sections but the 24 pound Mongoose is more fun overall.

27 pound Alu Trek is kinda in between in the fast ruffness. Less fun than the steelies overall.

 

[Andy R]

In general, lighter is said to be better, and there's some truth in that. it'll accelerate quicker, handle lighter and be better uphill. However for off-road riding or cobblestones, I reckon 30lbs is just about perfect. In those circumstances I'll take a 30lbs bike over a 20lbs one any time.

In my experience lighter is always better anywhere, uphill or downhill, regardless of the surface. Same goes for the rider too.
I only have one bike that falls into the "light" category (sub 20lbs/9.0kgs) but after riding that, getting on any of my other bikes initially feels like I'm dragging a boat anchor around. Of course, as I'm far from light at 68kgs, it would be a lot easier for me to lose a few kgs than to shave it off the bikes.

 

[tintin40]

Of course, as I'm far from light at 68kgs, it would be a lot easier for me to lose a few kgs than to shave it off the bikes.

You are very good Andy. I've found it a lot easier to loose weight off the bike by just going on line and spending £££

I also found that in my case once i got the 'hang' of riding my mtb with a few pounds less so things got more fun.
Also i've noticed that ultra light parts don't like being tightened up to much and it time to get a torque wrench.

 

[02gf74]

no doubt about it uphill favours lightness but I am not so sure going downhill.

I have weightweenied a couple of bikes, lightest of which is sub 8.4 kg for front suspension hardtail. Being light, the bike is easily deflected off course when descending rough terrain, whereas a heavier bike and full suspension bike tend to follow the line.

I do not know what the optimum weight is though.

 

[bm0p700f]

Of course, as I'm far from light at 68kgs

I am 87kg and when kitted up a bit more, hwat does make me?

I think you can go too light i.e 14lbs :shock: I would probably break it.

 

[Raging_Bulls]

I've seen wheel weight being mentioned a few times.

Mine has actually gained 76g there due to the heavier brake rotors (Formula RX 180mm = 110g, Hope Saw 180mm = 148g).
Nearly all my weight savings happened above the frame (seatpost, saddle, stem, handlebar, spacers, etc), and it still affects the handling.
Basically the rotational mass has increased and the CG has moved down a bit, both of which should increase stability. However the opposite is true.

I'm considering lowering the fork to move the CG down and to the front a bit. Hopefully that'll sort it out.

 

[highlandsflyer]

In general, lighter is said to be better, and there's some truth in that. it'll accelerate quicker, handle lighter and be better uphill. However for off-road riding or cobblestones, I reckon 30lbs is just about perfect. In those circumstances I'll take a 30lbs bike over a 20lbs one any time.

In my experience lighter is always better anywhere, uphill or downhill, regardless of the surface. Same goes for the rider too.
I only have one bike that falls into the "light" category (sub 20lbs/9.0kgs) but after riding that, getting on any of my other bikes initially feels like I'm dragging a boat anchor around. Of course, as I'm far from light at 68kgs, it would be a lot easier for me to lose a few kgs than to shave it off the bikes.

Bang on.

 

[Andy R]

Of course, as I'm far from light at 68kgs

I am 87kg and when kitted up a bit more, hwat does make me?

But I am only 5' 9", and I'm about 4 kilos heavier than when I was doing a fair bit of racing. It's my goal to be that weight again before May.
We'll see........