Evidence map›Paper›PMID 42086807›Full record

ArticleScientific reports2026

Systematic design and analytical evaluation of a novel multi-speed bicycle rear transmission hub with a permanent magnet assisted gear shifting mechanism.

Feng-Ming Ou, Yi-Chang Wu, Jin-Yi Feng

Abstract read
In one paragraph

Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Feng-Ming OuDepartment of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan.
Yi-Chang WuDepartment of Mechanical Engineering, National Yunlin University of Science & Technology, Yunlin, Taiwan. wuyc@yuntech.edu.tw.
Jin-Yi FengDepartment of Mechanical Engineering, National Yunlin University of Science & Technology, Yunlin, Taiwan.

Funding

National Science and Technology Council 112-2222-E-006-003-MY2National Science and Technology Council 113-2221-E-224-032
6 · The paper itself

Abstract

This study presents a systematic design approach for a multi-speed bicycle rear transmission hub, which consists of a gear speed-changing mechanism and a rotary-type gear-shifting mechanism to enhance functional performance and optimize space utilization. The design process encompasses structural synthesis, gear stage arrangement, gear teeth synthesis, and clutch configuration, ensuring optimal power transmission and seamless gear shifting. A 9-speed rear transmission hub is used as an example to illustrate the design process. A compound planetary gear train with a new permanent magnet assisted gear-shifting mechanism was presented to provide nine forward gears, including four underdrive gears, a direct drive gear and four overdrive gears. The proposed design was verified through computer simulations, confirming its functional feasibility and mechanical integrity. Key performance results demonstrate that the system achieves a speed ratio ranging from 0.56 to 1.80 with a step jump no greater than 20%. Furthermore, the design maintains a compact dimension within a diameter of 200 mm and an axial length not exceeding 190 mm, while keeping the total weight under 3 kg. The results indicate that the system effectively meets performance specifications while addressing limitations associated with traditional spring-based gear shifting mechanisms. This study contributes to the advancement of multi-speed transmission hubs, providing a structured framework for next-generation bicycle transmission systems.

Indexed as

BicycleEmbodiment designGear-shifting mechanismPlanetary gear trainRear transmission hub

Identifiers

PMID42086807
PMCPMC13334002

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.