I have found the following for the rear bars.
I haven't taken into account changes in the bar arm lengths. I know the diameters and thickness on the vw and eibach are correct (tuv certs and a call into eibach us) the rest are based on MFG quoted increase over GTI or bar dimension calculations.
Rear | | | | | | |
Size | OD | Thickness | Stiffness | Increase over GTI | Solid dim | Stiffness |
| [mm] | [mm] | [mm^4] | [%] | [mm] | [lb/in] |
Golf | 19.6 | 3 | 104581 | -41% | 18.0 | 196 |
GTI PP | 20 | -- | 160000 | | 20.0 | 333 |
Clubsport S | 21.7 | 3.6 | 177532 | 11% | 20.5 | 369 |
22mm solid | 22 | -- | 234256 | 46% | 22.0 | 488 |
whiteline mid | 22.5 | -- | 256289 | 60% | 22.5 | 533 |
whiteline stiff | 23 | -- | 279841 | 75% | 23.0 | 582 |
eibach eu | 25 | 4.7 | 331401 | 107% | 24.0 | 690 |
Hotchkis | | | | | | 716 |
eibach us | 25 | 6.4 | 367736 | 130% | 24.6 | 765 |
034 soft | 25.4 | -- | | 153% | 25.4 | 842 |
034 mid | | | | 164% | | 877 |
034 stiff | | | | 174% | | 912 |
HR Race | 26 | | 456976 | 186% | 26.0 | 951 |
Neuspeed race | 26.42 | | 487227 | 205% | 26.4 | 1014 |