Giro
Register II MIPS
Everyday adult helmet with MIPS and a simple dial fit.
Universal Adult, 54–61 cm
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Trek Hybrid frame
Trek FX Size Chart
Trek sizes the FX 2 Disc Gen 3 and FX 3 Disc Gen 3 from one published table, and both frames run XS to XXL on 700c wheels. Trek labels the tallest band 2XL on that table and XXL in its geometry table.
- Frame sizes
- XS–XXL · 6 sizes
- Rider height
- 4'10"–6'8"
- Height (cm)
- 147–203 cm
- Stack / reach · M
- 557 / 397 mm
FX size finder
Which FX size covers your height?
Height gives you one size, or two when the published height ranges overlap. Stack, reach, and standover settle the overlap.
ft
in
Enter your height and the FX size that covers it is marked in the tables below.
How to measureHeight gives the starting size. Standover and reach confirm it.
Height ranges
Where each size starts and ends
Height ranges for every FX size, 143 to 207 cm overall. XS: 147 to 155 cm. S: 155 to 165 cm. M: 165 to 175 cm. L: 175 to 186 cm. XL: 186 to 197 cm. XXL: 197 to 203 cm.
- XS147–155 cm
- S155–165 cm
- M165–175 cm
- L175–186 cm
- XL186–197 cm
- XXL197–203 cm
143 cm175 cm207 cm
Size chart
FX size by height
Rider height and inseam are Trek's published city sizing table, which the FX 2 Disc Gen 3 and FX 3 Disc Gen 3 share. Trek writes the tallest band 2XL here and XXL in its geometry table.
Size
Height
Height cm
Inseam
Fit note
XS
4'10"–5'1"
147–155 cm
69–73 cm
Shortest FX frame, with 212 mm less standover than the 2XL.
S
5'1"–5'5"
155–165 cm
72–78 cm
Reach grows 10 mm from XS while standover grows 31 mm.
M
5'5"–5'9"
165–175 cm
77–83 cm
Most riders start here. Stack and reach above are for this size.
L
5'9"–6'1"
175–186 cm
82–88 cm
Largest standover step in the table, 61 mm over M.
XL
6'1"–6'6"
186–197 cm
87–93 cm
Reach holds at 398 mm here and at L.
XXL
6'6"–6'8"
197–203 cm
92–95 cm
Tallest FX frame. Reach drops 6 mm from XL, so the front end rises without lengthening.
XS
4'10"–5'1"
147–155 cm
Inseam 69–73 cm
Shortest FX frame, with 212 mm less standover than the 2XL.
S
5'1"–5'5"
155–165 cm
Inseam 72–78 cm
Reach grows 10 mm from XS while standover grows 31 mm.
M
5'5"–5'9"
165–175 cm
Inseam 77–83 cm
Most riders start here. Stack and reach above are for this size.
L
5'9"–6'1"
175–186 cm
Inseam 82–88 cm
Largest standover step in the table, 61 mm over M.
XL
6'1"–6'6"
186–197 cm
Inseam 87–93 cm
Reach holds at 398 mm here and at L.
XXL
6'6"–6'8"
197–203 cm
Inseam 92–95 cm
Tallest FX frame. Reach drops 6 mm from XL, so the front end rises without lengthening.
Start with height. If two sizes overlap, use cycling inseam to choose.How to measure
FX trims
FX 2 and FX 3 sizing
Trek sizes both 2024 FX Disc frames from one table. The rider height and inseam bands above and the frame numbers match size for size, so the size you pick carries between the two.
ModelSizes Trek publishesWhat to know
FX 2 Disc Gen 3 35003
Sizes: XS, S, M, L, XL, 2XL
Publishes the same six bands and the same frame numbers as FX 3 Disc Gen 3. The sizing table and geometry above were read from the FX 3 page.
FX 3 Disc Gen 3 35021
Sizes: XS, S, M, L, XL, 2XL
The sizing table and geometry above come from this trim.
Trek also builds the FX Sport on a different frame: FX Sport AL 3 carries 37 mm more stack at M than FX 3 Disc, so an FX size does not carry to FX Sport.
Geometry
FX geometry by size
Stack, reach, and standover for every FX 3 Disc Gen 3 size, taken from Trek's published geometry table by column name. The FX 2 Disc Gen 3 shares these frame numbers.
Size
Height
Stack
Reach
Standover
XS
4'10"–5'1"
537 mm
383 mm
673 mm
S
5'1"–5'5"
539 mm
393 mm
704 mm
M
5'5"–5'9"
557 mm
397 mm
738 mm
L
5'9"–6'1"
586 mm
398 mm
799 mm
XL
6'1"–6'6"
618 mm
398 mm
848 mm
XXL
6'6"–6'8"
647 mm
392 mm
885 mm
XS
4'10"–5'1"
- Stack
- 537 mm
- Reach
- 383 mm
- Standover
- 673 mm
S
5'1"–5'5"
- Stack
- 539 mm
- Reach
- 393 mm
- Standover
- 704 mm
M
5'5"–5'9"
- Stack
- 557 mm
- Reach
- 397 mm
- Standover
- 738 mm
L
5'9"–6'1"
- Stack
- 586 mm
- Reach
- 398 mm
- Standover
- 799 mm
XL
6'1"–6'6"
- Stack
- 618 mm
- Reach
- 398 mm
- Standover
- 848 mm
XXL
6'6"–6'8"
- Stack
- 647 mm
- Reach
- 392 mm
- Standover
- 885 mm
XS4'10"–5'1"
Stack537 mmReach383 mmS5'1"–5'5"
Stack539 mmReach393 mmM5'5"–5'9"
Stack557 mmReach397 mmL5'9"–6'1"
Stack586 mmReach398 mmXL6'1"–6'6"
Stack618 mmReach398 mmXXL6'6"–6'8"
Stack647 mmReach392 mm
How neighboring sizes compare
If two sizes both fit, compare reach and standover rather than assuming the larger size is more comfortable.
How to measure a bike frame- Size stepStackReachStandover
- XS → S+2 mm+10 mm+31 mm
- S → M+18 mm+4 mm+34 mm
- M → L+29 mm+1 mm+61 mm
- L → XL+32 mm0 mm+49 mm
- XL → XXL+29 mm-6 mm+37 mm
Starter kit
Helmet, light, lock, bottle, and a pant-leg strap. Size the bike here; buy the complete adult bike at a shop.
NiteRider
Swift 300
Compact USB headlight for commuting and dusk rides.
Handlebar mount, 300 lumens
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Kryptonite
Evolution Mini-7 with 4′ cable
Hardened U-lock plus a cable for wheels or a locked-together pair.
Fits most road, gravel, and hybrid frames
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CamelBak
Podium Chill 21 oz
Insulated squeeze bottle for everyday rides.
Fits a standard ~73 mm cage
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Green Guru
Narrow pant-leg strap
Upcycled inner-tube strap that keeps a pant leg off the chain.
Adjustable hook-and-loop, about 16 in long
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Bike size calculator
Find your Trek FX size
Enter your height and inseam for a Trek hybrid bike, then compare the result with this FX chart.
Sizing notes
Why height alone is not enough
Riders with the same height can need different sizes because inseam, torso length, flexibility, and preferred handling differ.
3 checks
FX reach barely changes across the ladder: 383 mm at XS and 392 mm at XXL, while stack climbs 110 mm. Size an FX by standover and stack, then treat reach as the tiebreak.
Standover decides an FX. XS is 673 mm and XXL is 885 mm, a 212 mm spread, and M to L alone adds 61 mm, the largest single step in the table.
Trek publishes a height band and an inseam band for every FX size. Where the two point at different sizes, compare standover against your inseam before choosing the larger one.
Sources
Confirm the exact bike after you have a starting size
Every number on this page comes from the sources below. Check the exact model year there before you buy.
Data reviewed:
Compare
Compare before buying
A size label does not mean the same thing across brands. Compare published geometry before you choose.
Related guides
More Trek and hybrid sizing
Once you have a starting size, compare this frame against the Trek chart and the hybrid guide.
Trek bike size chart
Compare FX against broader Trek size guidance.
Hybrid bike size chart
Check hybrid sizing by height and inseam before choosing a frame.
Questions
FX size chart FAQ
Short answers for Trek FX sizing.
What size Trek FX should I ride?
Start with the Trek height band: XS for 147–155 cm, S for 155–165 cm, M for 165–175 cm, L for 175–186 cm, XL for 186–197 cm, and XXL for 197–203 cm. Then confirm inseam and standover for the size you land on.
Is the Trek FX 2 the same size as the FX 3?
Yes. The 2024 FX 2 Disc Gen 3 and FX 3 Disc Gen 3 publish the same six height and inseam bands and the same frame numbers, so an M is 165–175 cm with 557 mm of stack and 397 mm of reach on either one.
How tall is a Trek FX M for?
Trek publishes FX M for riders from 165–175 cm (5'5"–5'9") with a 77–83 cm inseam. It carries 557 mm of stack, 397 mm of reach, and 738 mm of standover.
What size Trek FX fits a 180 cm rider?
180 cm falls inside Trek's L band of 175–186 cm and above the M band, which stops at 175 cm. L adds 29 mm of stack and 1 mm of reach over M, so the front end rises without the cockpit getting longer.
Does the Trek FX come in a 2XL frame?
Yes, but only the FX Disc frames build it. Trek's sizing chart labels that band 2XL for 197–203 cm with a 92–95 cm inseam, and its geometry table spells the same size XXL with 647 mm of stack and 392 mm of reach. FX Sport stops at XL.