After doing my review and other videos on my LightCarbon 18, i received to this day regular inquiries for frame size recommendations.
This gets a little tedious, so I advised my AI agent on the forum dump of the huge Chinertown thread to come up with choices (So keep in mind, most of the content below is AI generated and edited by me).
It's still not a bike fit or replaces it, instead it's a status quo of what the users of the forum chose
By height
Table is sortable
Height |
Riders |
Sizes chosen |
Go with |
|---|---|---|---|
165–169 cm |
4 |
50 ×4 |
50 |
170–174 cm |
10 |
50 ×7, 52 ×3 |
50 maybe 52 |
175–179 cm |
17 |
54 ×10, 52 ×4, 56 ×2, 50 |
54 maybe 52 |
180–184 cm |
17 |
56 ×10, 54 ×3, 58 ×3, 52 |
56 |
185–189 cm |
6 |
58 ×4, 56, 52 |
58 |
190–194 cm |
12 |
58 ×12 |
58 |
By inseam
Table is sortable
Inseam |
Riders |
Sizes chosen |
Go with |
|---|---|---|---|
75–77 cm |
5 |
50 ×5 |
50 |
78–80 cm |
7 |
50 ×5, 47, 52 |
50 |
81–83 cm |
10 |
52 ×5, 54 ×3, 50, 56 |
52 |
84–86 cm |
8 |
54 ×3, 56 ×2, 58 ×2, 52 |
54 or 56 |
87–89 cm |
12 |
58 ×5, 56 ×4, 54 ×2, 52 |
56 or 58 |
90–92 cm |
11 |
58 ×10, 56 |
58 |
93–95 cm |
2 |
58 ×2 |
58 |
Use the inseam table if you have the measurement. It is tighter at both ends: 10 of 12 riders at 75–80 cm went 50, 12 of 13 at 90 cm and above went 58, while the same riders sorted by height spread across two or three sizes.
Three things the tables do not show:
Size 58 is max. Above roughly 190 cm, check the current size chart and the seatpost extension yourself before ordering, but you might probably want to look elsewhere.
84–89 cm inseam is the genuinely unclear band. Both the 56 and the 58 are well represented and both sets of owners are happy. Maybe take reach into consideration.
Two riders went a size up from what LightCarbon's own chart recommended (58 instead of 56, 580 instead of 540) and neither reported regret. Nobody in the data reported sizing up and wishing they hadn't.
Cockpit
Stem length, both frames
Table is sortable
Stem |
Riders |
|---|---|
80 mm |
2 |
90 mm |
12 |
100 mm |
14 |
110 mm |
8 |
120 mm |
6 |
Most of these are LightCarbon's own integrated bar/stem units, where the stem length is fixed at purchase. The combinations people ordered:
Table is sortable
Width × reach |
Riders |
|---|---|
380 × 90 |
2 |
380 × 100 |
5 |
380 × 110 |
4 |
380 × 120 |
1 |
400 × 80 |
1 |
400 × 90 |
2 |
400 × 100 |
2 |
420 × 110 |
1 |
440 × 120 |
1 |
Bar width
Table is sortable
Width |
Riders |
|---|---|
360 mm |
2 |
380 mm |
28 |
400 mm |
8 |
420 mm |
2 |
440 mm |
2 |
380 mm is the default at every frame size, from the 50 up to the 58, and it does not widen as the frame does: 6 of 7 at the 50, 7 of 9 at the 54, 5 of 6 at the 56, 3 of 7 at the 58. Only the 58 shows anything above 400 (two 440s). If you run a 42 on a stock bike, expect the integrated cockpit to put you narrower.
Stem length only sorts by frame size at the top: the 58 runs 110–120 mm (7 of 8 reports), everything from the 50 to the 56 sits on 90–100 mm with no clear pattern between them, on four to eight reports per size. Nobody explained why, so read it as a spread rather than a rule.
Crank length was reported by six riders only (160, 165 ×2, 170 ×3); not enough to say anything.