With helmets on, standing astride their rides at a stop light, Amy and Ahmad look like any other motorcyclists. But a closer look reveals that the married couple are not on motorcycles, but souped-up electric bikes.
The duo, who work as cleaning supervisors, have spent close to $10,000 illegally modifying the bikes to allow them to travel up to 70kmh - far beyond the 25kmh allowed by law.
But as more turn to modified electric bicycles, or e-bikes, for a cheaper alternative to motorcycles, their presence on the roads has heightened worries about safety.
Yesterday, an 81-year-old man died on the scene after the e-bike he was riding was involved in an accident with a trailer along Lower Delta Road at around 10.15am. The 62-year-old driver was arrested, said police.
More than 11,600 e-bicycles have been approved by the Land Transport Authority (LTA). This means they have undergone tests to make sure they meet requirements such as speed limits, and are affixed with an LTA seal.
E-bikes covered by strict LTA rules
There are strict rules governing electric bicycles.
Only LTA-approved models are allowed on the roads - these will be affixed with a blue seal.
E-bicycles also cannot be ridden on the pavement, and have a speed limit of 25kmh.
The maximum power output also cannot exceed 200 watts.
The electric motor can cut in only when the rider starts to pedal, and it must cut off when the bicycle reaches 25kmh or when pedalling stops. Using a throttle to activate the motor is forbidden.
Anyone found using or keeping an unapproved e-bicycle could be charged in court.
If found guilty, they can be fined up to $1,000 or jailed up to three months. For illegally modifying an e-bike, those found guilty could be fined $2,000 or jailed up to three months.
Amy and Ahmad said their bikes also have the seal and were checked by the LTA before they were bought and then illegally modified.
Their bikes now have larger batteries, more powerful motors and throttles. They told The Sunday Times that they knew they were flouting the rules, but the prices of motorcycles and certificates of entitlement (COEs) were beyond their reach. "We're using them to go to work, and make deliveries, not for racing," said Amy, 28, pointing out that while their bikes were fast, they were still slower than motorbikes. "For people like us, who don't earn a lot, these are our 'cars'."
Ahmad, 44, added: "We don't need to pay for petrol, ERP, COE or road tax. We spend only about $50 to $60 a month on electricity to charge both the bikes."
Even with stiff fines and the risk of confiscation, the number of errant riders fined for illegal modifications has held steady, according to LTA figures. In the first five months of this year, 459 summons were issued. Last year, the number was 1,042. In 2013 and 2012, it was 978 and 1,250 respectively.
Ship chandler Bobby Seah, 60, said: "I told my friends, if they see LTA officers or the police, start pedalling and stop using the throttle."
The e-bike that Mr Seah uses to run errands around the Toh Guan industrial estate where he works is legal, but he said a throttle can make riding these bikes easier. "Some e-bikes are heavy, and without a throttle, it's hard to stand up and move off," he said.
Adding a throttle is one of the most common modifications that people make to their e-bikes.
The LTA allows only pedal-assist motors. This means the motor can kick in only when the rider starts pedalling. But a throttle activates the motor without pedalling, transforming what is essentially a bicycle into a motorcycle. Some throttles take the form of a button on the handlebar, but others mimic the twist-grip found on motorcycles.
Amy and Ahmad have installed a hidden switch on their e-bikes that cuts off the throttle - so that, in the event that they are stopped, enforcement officers will not be able to activate it. This "switch insertion" cost them $40 apiece.
But e-bike shops point out that this illegal throttle could potentially make the vehicles safer.
Mr Ong Beng Teng of Esibike in Ubi said: "For elderly riders, they use the throttle, but not for speed. It can help them go up slopes that even young people would find difficult."
He added that a strict stance regulated by fines will not cow riders into compliance. Instead, he feels that users should be educated on how to ride safely, adding that retailers could provide lessons.
Mr Royston Teo, who runs MKP Bikes, agrees. He said: "If there's a need for an orientation, we are in the best position to offer advice."
He explained that a throttle does not increase a bike's power output, which hinges on the size of the motor. Instead of an outright ban on throttles, he suggested taking a cue from countries abroad.
"In Europe, they have a 'walk-assist' device; it functions like a throttle, but the power is limited to only 6kmh," said Mr Teo.
But others believe rules and checks are still needed. Indeed, videos have recently surfaced online of e-bikers beating stop lights, colliding with cars, and even carrying pillion riders without helmets.
Readers have also written in to this newspaper expressing safety concerns as cyclists, pedestrians and e-bikers jostle for space on the pavement.
They prompted the LTA to respond with a letter published yesterday appealing for "greater consideration".
Experts said a blase attitude towards safety cannot be condoned, especially since some modified e-bikes travel as fast as motorcycles.
"Both power and speed is something that definitely needs to be controlled, because if it's too powerful, it's potentially much more dangerous," says Mr Francis Chu, co-founder of cycling group Love Cycling SG. He suggested that e-bikers be made to get a licence or insurance if they decide to power up their vehicles.
Mr Denis Koh, who heads interest group Big Wheel Scooters Singapore, added that there should be stricter enforcement on the kinds of modifications that retailers can do.
Both Mr Chu and Mr Koh are on an LTA advisory panel looking into the rules governing personal mobility devices. The panel will release its recommendations next year.