The syllabic fricatives, traditionally known as apical vowels in Standard Mandarin, share the place of articulation with their sibilant onsets, exhibiting a narrow tongue tip constriction at the dental/alveolar or postalveolar region. We hypothesize that, like voiced fricatives, they face aerodynamic constraints where voicing and frication cannot be fully optimized simultaneously. The narrow constriction may delay intra-oral pressure release, leading to unstable and delayed voicing onset and consequently shorter acoustic durations. To test this hypothesis while minimizing segmentation errors, we applied forced alignment to a large-scale, style-comparable corpus to analyze their durational differences. The results show that in both spontaneous and read speech, the syllabic fricatives are significantly shorter compared to regular vocalic nuclei. The findings join previous articulatory and acoustic evidence and provide further evidence on the fricative nature of these syllabic segments.