Optimal front / rear weight ratio What is your preferred weight ratio between front to rear wheels on your bike(s)?  I always assumed 40% front / 60% rear was &quot;normal&quot;.  I have been experimenting with tire pressure and stem length trying to improve front tire grip and steering on my trail bike which is often slipping in corners.
These are the front / rear weight ratios I measured on my bikes:
Full suspension MTB:  38% / 62%
Hardtail MTB:  39% / 61%
Cyclocross:  42% / 58%
(Methodology: me on bike with one wheel on a scale and opposite wheel slightly elevated to compensate for height of scale)
The frequently referenced Frank Berto tire pressure experiments assumed a 45%/55% ratio.  Those were road oriented tests.  I'm guessing I might get closer to 45/55 on a road frame.  But I am no where near that on my mountain bikes and was surprised to find I was slightly below 40% front weight on both bikes.
Has anyone else ever actually checked this for themselves?  What ratio do you have?  Have you tried to alter your ratio?
I have been experimenting with tire pressure and stem length trying to improve front tire grip and steering on my trail bike which is often slipping in corners.

I cannot see how tire pressure can affect weight distribution in any measurable manner. A very minor effect on the static weight distribution may perhaps be observed on a fat bike, where a severe underinflation of one tire actually changes bike's geometry (by visibly raising or lowering one of its ends). Adjusting tires' pressure may help with getting a better traction, but the involved physics do not have much with the weight distribution to do.
Changing stem length is obviously a different story, as a longer stem may force the rider to shift their center of mass forward.

I'm guessing I might get closer to 45/55 on a road frame. But I am nowhere near that on my mountain bikes

I do not see how a &quot;recommended&quot; weight distribution, if there was such a thing at all, provided for a road bike can be applied as a measure of anything for a mountain bike. These types of bicycles have different dynamics and areas of use.
If we track trends in changes of static weight distribution for mountain bikes over the last three decades, I am sure that we will see a trend of weight shifting from front to rear. MTBs of 90's were inspired by road frames, and modern MTB's tend to have rather short chainstays.
What really makes these numbers irrelevant is the fact is that under braking/acceleration the weight distribution between front/rear wheels is nowhere close to the static values.