Illegal modification of electric bicycles into devices that resemble motorcycles remains a problem despite stricter rules put in place by the Land Transport Authority (LTA) last December.
E-bike shops report receiving requests for such work, while some riders - young men on a budget - appear to be doing the tinkering themselves.
The devices came under greater scrutiny this week after the deaths of Mr Ang Yee Fong, 25, and Mr Ong Zi Quan, 18, on Thursday night. The pair died after being hit by a trailer near the junction of Pandan Crescent along West Coast Highway while riding their e-bikes .
A third rider, 17-year-old Marcus Loke, survived. He was hospitalised with injuries, and was discharged yesterday. Mr Ang was cremated yesterdayat the Mandai Crematorium, while Mr Ong was cremated on Friday afternoon. The 34-year-old trailer driver was arrested for causing death by negligence.
Mr Ong Beng Teng, owner of e-bike shop Esibike in Ubi, said illegally modified e-bikes appeal to those who cannot afford motorcycles. "They don't need a licence, they don't need to go through tests, but they can ride it like a motorcycle," he said, adding that he gets requests for illegal e-bike modifications from people of all ages, but he rejects them.
E-bikes are allowed only on the roads and must meet a number of regulations, including a weight limit of 20kg and a maximum speed of 25kmh.
Illegal modifications of e-bikes include the installation of more powerful motors that allow the bikes to go faster than 25kmh, as well as throttles, which allow users to control their speed. Some modifications allow a bike to reach speeds of up to 120kmh.
Earlier this month, the LTA announced that three retailers had been charged with selling illegally modified e-bikes.
E-bike retailers The Sunday Times spoke to said they do not carry out such work but are aware of shops that do. They declined to give names but said a number were located in Geylang.
More than 20 e-bikes were seen on the roads in Geylang when The Sunday Times visited the area yesterday evening. Some riders were seen going against the flow of traffic.
While a number of the e-bikes bore the orange or blue tags that identify them as LTA-approved devices, they had also been heavily modified. None of the riders spotted wore helmets.
A 24-year-old shop assistant, who wanted to be known only as Mr Lee, was seen riding an e-bike without an LTA tag. When asked, he said he did not realise it was required, adding that he had bought the bike online for about $400 and used it to make deliveries.
Modified e-bikes have also been seen in other areas, with some netizens saying that they have seen riders speeding along relatively deserted stretches of road at night.
Graphic artist Shahrizal Ismail said he regularly sees young e-bike riders at night near his home in Marsiling. They ride in the middle of the road at speeds of about 50kmh.
"I used to see them at the void decks tinkering with their bikes," said the 34-year-old, adding that the men appeared to be in their late teens or early 20s.
Mr Ifrey Lai, owner of mobility device retailer Mobot, said current regulations are stringent enough but that greater enforcement is needed.
Stricter regulations and greater enforcement by the LTA have reduced the number of errant e-bike riders, said Mr Swen Einhaus, founder of e-bike community Power Assisted Cyclists SG.
However, he added that more well-organised e-bike communities could help in educating users on the dos and don'ts when riding.
"Many still don't know the rules," he said.