Frequently Asked Questions
What is a fixed gear bike?
A fixed gear bike (fixie) is a bicycle with no freewheel mechanism — the pedals are directly connected to the rear wheel. When the wheel turns, the pedals turn too. This gives riders a direct, connected riding experience with better control and feedback. Fixed gear bikes are lighter, simpler, and require less maintenance than traditional geared bikes.
What is the difference between fixed gear and single speed?
A fixed gear bike has no freewheel, so the pedals always move when the wheel moves — you cannot coast. A single speed bike has one gear but includes a freewheel, so you can coast without pedalling. Every current Unknown complete bike comes with a flip-flop rear hub and an included single-speed freewheel, so you can switch between fixed gear and single speed by turning the rear wheel round.
Which countries do you ship to?
Unknown Bikes Europe ships to selected European countries. See our Shipping Policy for the full list of destination countries, shipping methods and costs. Standard shipping is free, with no minimum order value.
What size fixed gear bike do I need?
Frame size depends on your height. Here is a general guide:
| Frame Size | Rider Height |
|---|---|
| 52–53 | 152cm – 168cm |
| 55 | 166cm – 178cm |
| 58–59 | 176cm – 190cm |
| 61–62 | 183cm – 200cm |
Sizes vary slightly between models — check the size chart on each product page for exact measurements. Contact us if you need help choosing.
Are fixed gear bikes good for commuting?
Absolutely! Fixed gear bikes are ideal for urban commuting. They are lightweight, low maintenance, and reliable — fewer components means fewer things that can break. Our SC-1 and Bass-X are particularly popular with commuters thanks to their comfortable geometry and included brakes.
What is the difference between the SC-1, Singularity, Bass-X, and LV3?
- SC-1 — Entry-level 4130 chromoly steel fixie with a steel fork, riser bars, flip-flop hub and front and rear brakes. A good choice for beginners and daily commuting.
- Bass-X — Versatile urban bike with a 6066-T6 aluminium frame, full 12K carbon fork, flip-flop hub and a more relaxed, upright riding position than the LV3.
- Singularity — Fixed gear and single speed bike with a 6066-T6 aluminium frame, 12K carbon fork with aluminium steerer, flip-flop hub and aero seatpost. Approx. 7.5 kg in size 55, without pedals.
- LV3 — Our flagship track bike. Hardened 6066-T6 aluminium aero frame, full 12K carbon fork, sealed-bearing hubs. Approx. 8 kg in size 55.
Do your bikes come with pedals?
Yes. Every complete bike comes with free pedals and foot straps. Frames and framesets are sold without pedals.
How assembled do the bikes arrive?
Our bicycles arrive approximately 90% pre-assembled, with free pedals and foot straps included. We recommend professional assembly by a qualified bicycle shop. Professional assembly at a bike shop is also one of the conditions for activating the additional Unknown Bikes warranty, including the 5-year frame warranty. See our Warranty page for the full conditions.
Do your bikes come with brakes?
Yes. Every current complete bike comes with front and rear brakes fitted.
What is a flip flop hub?
A flip flop hub has a fixed cog on one side and a freewheel thread on the other. By removing the rear wheel and flipping it around, you can switch between fixed gear (no coasting) and single speed (coasting). Every current Unknown complete bike comes with a flip-flop hub, with the single-speed freewheel included.
What does 4130 chromoly mean?
4130 chromoly is a type of steel alloy containing chromium and molybdenum. It is stronger and lighter than standard steel, making it the preferred choice for bike frames that need to be tough and durable. Our SC-1 uses 4130 chromoly for a frame that absorbs road vibration naturally and will last for years.
What is 6066-T6 aluminium?
6066-T6 is an aluminium alloy that is heat-treated for extra strength and hardness. Aluminium frames are typically lighter and stiffer than steel frames, which suits performance-oriented fixed gear bikes. Our Singularity, Bass-X, LV3 and Paradigm use 6066-T6 aluminium frames.
What is your return policy?
As a consumer, you have a statutory 14-day right of withdrawal. Ordinary change-of-mind returns are handled according to our Return and Refund Policy. Exchanges can be arranged by prior agreement, subject to availability. Exchanges are a voluntary service and do not affect your statutory rights.
How do I contact you?
You can reach us through our contact page. We are happy to help with sizing advice, product questions, or anything else!