Roco geoLine or Roco Line: the differences side by side
Benjamin | TrackDrawer.com · published 2 November 2026
Roco geoLine is a system with a fixed roadbed and short 22.5 degree turnouts, made for building a layout quickly on a table or the floor. Roco Line has no roadbed, slimmer 15 and 10 degree turnouts, many more curve radii and flexible track, and is meant for a permanent layout. Both are H0 two-rail DC and share the same tightest curve of 358 mm, but beyond that the dimensions diverge: you cannot mix them piece by piece.
Two systems from one brand
It is a common mix-up: both are called Roco, both are H0 on 16.5 mm, and R2 is 358 mm in both. Yet they are two separate systems with their own part numbers. geoLine uses the 61xxx range, Roco Line the 42xxx range. Follow the geoLine radii outwards and you reach 434.5 and 511.1 mm. With Roco Line you reach 419.6, 481.2 and beyond.
Roco Line also exists in a version with roadbed, with the same geometry. In this article, Roco Line means the standard version without roadbed, as in our catalogue.
The differences in one table
| Feature | Roco geoLine | Roco Line |
|---|---|---|
| Roadbed | fixed roadbed, about 38.5 mm wide | no roadbed, 30 mm wide |
| Curve radii | R2 358, R3 434.5, R4 511.1 mm | R2 358, R3 419.6, R4 481.2, R5 542.8, R6 604.4, R9 826.4, R10 888, R20 1962 mm |
| Track spacing | 76.5 mm | 61.6 mm |
| Standard turnout | 61140/61141: 200 mm, 22.5 degrees, diverging radius 502.7 mm | 42442/42443: 230 mm, 15 degrees, diverging radius 873.5 mm |
| Slim turnout | none in our catalogue | 42488/42491: 345 mm, 10 degrees, diverging radius 1946 mm |
| Matching curve | 61128, 502.7 mm over 22.5 degrees | 42428 (R10), 888 mm over 15 degrees |
| Double slip | 61164, 22.5 degrees | 42451, 15 degrees |
| Crossing | none in our catalogue | K15 (42497) and K30 (42498) |
| Flexible track | none | 42400 and 42401, 920 mm |
| Longest straight | 200 mm | 230 mm, plus G4 at 920 mm |
| Items in our catalogue | 15 | 27 |
Roadbed and use
geoLine is built around its roadbed. The pieces click firmly together and stay put on a table or carpet. That makes it a logical choice for a first layout, or for one you set up now and then and put away again.
Roco Line without roadbed looks best when you fix it to a baseboard, with cork underneath and your own ballast. That is what it is made for: long flex track, wide radii, slim turnouts. If you want a permanent layout with a prototypical look, Line is the obvious choice. More on that trade-off in the comparable pair Märklin C track and K track.
Turnouts: short or slim
This is where a layout looks most different. The geoLine turnout diverges at 22.5 degrees with a radius of 502.7 mm. That is short and compact: after the turnout and matching curve, the second track is already 76.5 mm to the side, 384.75 mm further along. You make up the straight side with the 185 mm straight G185, so both sides are the same length.
The Line turnout diverges at only 15 degrees, with a radius of 873.5 mm. It runs more smoothly, especially with long coaches, but needs more length. After the turnout, the R10 matching curve and the DG1 diagonal piece (119 mm), the second track is 574.91 mm further along and 60.02 mm to the side. You make up the straight side with a G1 and a G1/2 (230 + 115 mm) to 575 mm. If you want it slimmer still, take the 10 degree turnout: 345 mm long with a diverging radius of 1946 mm.
For a passing loop this means about 0.4 m per turnout end with geoLine and about 0.6 m with Line. Read in track spacing why that distance differs from system to system.
Curves and space
The tightest curve is the same: 358 mm. A closed loop therefore needs about the same depth in both. Including the roadbed, an R2 circle is 754.5 mm wide in geoLine and 746 mm in Line.
The difference shows up with double track. Because Line spaces its curves 61.6 mm apart and geoLine 76.5 mm, double track in Line is narrower.
| Double track | Outer curve | Outside width | Baseboard with 5 cm margin |
|---|---|---|---|
| geoLine R3/R2 | 434.5 mm | 907.5 mm | 101 cm |
| Roco Line R3/R2 | 419.6 mm | 869.2 mm | 97 cm |
| geoLine R4/R3 | 511.1 mm | 1060.7 mm | 116 cm |
| Roco Line R4/R3 | 481.2 mm | 992.4 mm | 110 cm |
We had the TrackDrawer Auto-designer work on a 240 x 120 cm baseboard, with a typical stock of each system and a 5 cm margin. With Roco Line the longest variant was double track R3/R2 with two passing loops: 54 pieces and 12.27 m of track. A station with two platform roads on R4 also fitted (36 pieces, 7.19 m). With geoLine the designer came up with double track R4/R3 plus a siding and a small yard: 59 pieces and 11.48 m of track. Double track R4/R3 with a crossover, a passing loop and a siding also fitted (52 pieces, 10.94 m). Both get well over 11 m of track on this board; geoLine with its wider outer curve, Line with a narrower double track that leaves room for extra tracks.
On 180 x 90 cm, a common first baseboard, both systems produced an R2 oval with a siding and a small yard. With geoLine a station with two platform roads on R2 plus 2 sidings also fitted there (30 pieces, 5.58 m). A passing loop like that works with geoLine from 165 x 90 cm, with Roco Line only from 200 x 85 cm. What else fits there is covered in an H0 layout on 180 x 90 cm.
Which one when?
- Quick set-up, on a table or the floor, first layout: geoLine. The roadbed keeps everything in place and the turnouts are compact.
- Permanent layout with your own ballast and scenery: Roco Line. More radii, slim turnouts, crossings and flex track.
- Long coaches and a calm look through the turnouts: Roco Line with the 15 or 10 degree turnouts.
- Little room for a station: geoLine reaches its second track in a shorter length, Line is narrower as double track.
Frequently asked questions
Can I combine geoLine and Roco Line?
Not piece by piece: beyond R2 the radii, track spacing and turnout geometry differ. If you want to use both, keep them in separate parts of the layout, for example geoLine for a visible section and Line for a fiddle yard, with a transition on a straight.
Will my trains run on both?
Yes. Both are two-rail DC on 16.5 mm. A locomotive and wagons for H0 two-rail run on either system, as long as your rolling stock can handle the curve radius.
Your plan with geoLine or Line
Choose geoLine or Roco Line as the system in TrackDrawer, enter your stock and let the Auto-designer lay a plan that fits your baseboard. The designer works with the real dimensions of every piece, including the differences in this article.