Full Suspension, Unsprung Mass

[Stefan Mikes]

In a totally rigid bike (hardtail, rigid fork), the unsprung mass is 100% of the bike plus the riders weight. Has anyone wondered what the unsprung mass percentage might be in the full suspension e-bike? Also, Does applying the shock fork but keeping the hardtail part reduce the unsprung mass? (I guess the shock fork + suspension seat post reduce the unsprung mass to some level).

Any mechanical engineer here? Is quantitative analysis doable?

1. Unsuspended e-bike
2. Shock fork only
3. Shock fork plus good suspension seat-post
4. Full suspension e-bike.

 

[Mike_V]

Hi Stefan
Well yea, but, to what end, determining that having real suspension is better than none?

Many , many variables - & you need detail information to determine:
Where is the center of mass for the bike - and for the sprung assemblies - whole rear wheel assy and motor,
1/2 the front shock and wheel? (Or for each detail assy to combine them)
Measured weights: with many length measurements, the details could be digitally measured

Then determining the effects of the various virtual bike models to each other:
Add rotational torque, gyroscopic effect, when adding motion over terrain with 'features'.
Add variable rates of acceleration and deceleration.

( Resembles "work" )
Mike

 

[Stefan Mikes]

Hi Stefan
Well yea, but, to what end, determining that having real suspension is better than none?

Many , many variables - & you need detail information to determine:
Where is the center of mass for the bike - and for the sprung assemblies - whole rear wheel assy and motor,
1/2 the front shock and wheel? (Or for each detail assy to combine them)
Measured weights: with many length measurements, the details could be digitally measured

Then determining the effects of the various virtual bike models to each other:
Add rotational torque, gyroscopic effect, when adding motion over terrain with 'features'.
Add variable rates of acceleration and deceleration.

( Resembles "work" )
Mike

Out of curiosity Looks like a tough stuff.

Thank you, Mike!

 

[smorgasbord]

Here's Court's video from 2014:

 

[Stefan Mikes]

Thank you @smorgasbord!

 

[Stefan Mikes]

That's very interesting @Timpo !