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This work extends recent efforts on the force-free modeling of large fluxrope-type structures (magnetic clouds, MCs) to much smaller spatial scales. Wefirst select small flux ropes (SFRs) by eye whose duration is unambiguous andwhich were observed by the Solar Terrestrial Relations Observatory (STEREO) orWind spacecraft during solar maximum years. We inquire into which analyticaltechnique is physically most appropriate. We consider three models: (i) linearforce-free field ($\bigtriangledown\times$ B = $\alpha (r) $ B) with aspecific, prescribed constant $\alpha$ (Lundquist solution), and (ii) with$\alpha$ as a free constant parameter (Lundquist-alpha solution), (iii) uniformtwist field (Gold-Hoyle solution). We retain only those cases where the impactparameter is less than one-half the FR radius, $R$, so the results should berobust (29 cases). The SFR radii lie in the range [$\sim$ 0.003, 0.059] AU.Comparing results, we find that the Lundquist-alpha and uniform twist solutionsyielded comparable and small normalized $\chi^2$ values in most cases. We thenuse Grad-Shafranov (GS) reconstruction to analyze these events further. We thenconsidered the twist per unit length, $\tau$, both its profile through the FRand its absolute value. We find $\tau$ to lie in the range [5.6, 34] turns/AU.The GH model-derived $\tau$ values are comparable to those obtained from GSreconstruction. We find that twist unit length ($L$) is inversely proportionalto $R$, as $\tau \sim 0.17/R$. We combine MC and SFR results on $\tau (R)$ andgive a relation which is approximately valid for both sets. The axial andazimuthal fluxes, $F_z$ and $F_\phi$, vary as $\approx 2.1 B_0 R^2\times10^{21}$ Mx and $F_{\phi}/L \approx 0.36 B_0 R \times10^{21}$Mx/AU. Therelative helicity per unit length, $H/L \approx 0.75 B_0^2 R^3$$\times 10^{42}$Mx$^2$/AU.

The Magnetic Field Geometry of Small Solar Wind Flux Ropes Inferred from their Twist Distribution