Stack and reach
How high and how far forward the top of the head tube is, from the bottom bracket. They are the two numbers that decide whether a frame can be set up like yours.
BB, or bottom bracket
The axle your cranks turn on, in the middle of the frame. Every number on this site is measured from it, because it is the one point that sits in the same place on every bike.
Headset cover
The little cap on top of the head tube, under your spacers. Most makers do not publish it, so I assume 15 mm and add 6 mm to the band, which on its own is enough to hold an answer at "probably" rather than "fits".
Stem clamp, and its centre
The collar on the steerer that your stem bolts to. I need the middle of it. Where a maker gives only the height, I assume halfway up and say so on the answer.
Steerer
The tube coming up out of the fork. The cover, the spacers and the stem all sit on it, and it is the thing a mechanic cuts to length.
Bar reach
How far forward the hoods sit from the middle of the bar. Two bars on the same stem can put your hands 20 mm apart, which is why I ask.
Setback
How far your saddle sits behind the bottom bracket.
Drop
How much lower your hands sit than your saddle. On a riser bar I count the bar's rise, so the drop is that much less than it is to the clamp.
Rails, and the rail centre
The two rods under your saddle, and the middle of the straight part of them. That midpoint is the point I use, because it is the one you can find with a tape.
The band
How far out I could be, in millimetres, and why. It is a straight sum of everything I had to assume rather than a clever average, so it errs wide on purpose.
wb, stand, trail
Wheelbase, standover and trail: how long the bike is, how high the top tube is where you straddle it, and how steady the steering feels. I show them against your bike, and I leave them out when the maker does not publish them.
est.
Estimated: a number I worked out rather than read off the maker's table. Anything marked this way can move if the maker publishes the real one.
Close Escape closes it. The measuring guide has the pictures. Open the measuring guide
Rose Backroad AL
Gravel · 8 sizes
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This is the bike I ride
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- Bike
- Rose Backroad AL · Gravel · 8 sizes
- Geometry
- rosebikes.com, fetched 20 Oct 2026, re-checked, no differences
- Cockpit
- Generic stem and bar, assumed
- Solved with
- cover 15 mm (assumed), max spacers 40 mm (assumed), stem clamp centre 20 mm (assumed), so every verdict carries ±10 mm at the bar
- Sheet
- 22 October 2026 · 686 bikes, 74 makes, 3,984 sizes in the catalogue
Geometry, every size, from the maker's table
The tinted row is the size drawn beside it. Press a size to draw it.| Size | Stack (mm) | Reach (mm) | Head angle (deg) | Seat angle (deg) | Head tube (mm) | Chainstay (mm) | Wheelbase (mm) | Standover (mm) |
|---|---|---|---|---|---|---|---|---|
| XXS | 540.8 | 365.1 | 70 | 74.15 | 100 | 430 | 1007.5 | 763 |
| XS | 552.2 | 374.5 | 70.5 | 74 | 110 | 430 | 1016.2 | 779 |
| S | 568.2 | 387.4 | 71 | 73.75 | 125 | 430 | 1029.9 | 796 |
| M | 583.4 | 395.5 | 71.25 | 73.5 | 140 | 430 | 1040.6 | 808 |
| M/L | 602.3 | 402.3 | 71.25 | 73.3 | 160 | 430 | 1053.8 | 827 |
| L | 612.8 | 411.4 | 71.5 | 73.1 | 170 | 430 | 1063.8 | 842 |
| XL | 627 | 429.3 | 71.5 | 72.9 | 185 | 430 | 1086.5 | 861 |
| XXL | 642.3 | 437.8 | 71.75 | 72.9 | 200 | 430 | 1097.2 | 881 |
The table runs on to the right: 6 more columns after Reach. Scroll it sideways to read them.
The M/L drawn to scale from the table, with no build on it. Stack and reach run from the bottom bracket to the top of the head tube; every size is solved from those two. One square is 100 mm.
The maker's cockpit
No stock cockpit I can name, so every size is solved on a generic stem and bar unless you choose one on the sheet.Generic stem and barAssumedNo bar is listed for this frame.
Frame facts
read from the maker's words, not a table: rosebikes.com- Tyre clearance
- not recorded yet
- Bottom bracket
- not recorded yet
- Axles and brakes
- not recorded yet
- UDH
- not recorded yet
- Seatpost
- 30.9 mm round
- Frame weight
- not recorded yet
In the maker's words
Kept whole, as I read it off rosebikes.com.Two-piece on the Backroad AL GRX 400: handlebar "Rose Gravel, 40cm", stem "Rose ALR 2.0, black sand 80mm" (the size shown); per-size stems and bars are not in the geometry feed.
Cockpit and seatpost, in the maker's words · 31 words
Two-piece on the Backroad AL GRX 400: handlebar "Rose Gravel, 40cm", stem "Rose ALR 2.0, black sand 80mm" (the size shown); per-size stems and bars are not in the geometry feed.
OFFICIAL SOURCE: https://www.rosebikes.com/p/rose-backroad-al-grx-400-2725768 (product SKU 2725768). Source: html table (official Rose product page for the Backroad AL GRX 400, its Frame geometry table as the page loads it: the page's own bikeGeometry JSON for product SKU 2725768; fetched 2026-10-20
How I read the maker's table
SOURCE: Rose (rosebikes.com, the maker's own shop). The product page's "Frame geometry" section is filled in the browser from the page's own GraphQL query bikeGeometry(productSku) at https://www.rosebikes.com/api/ (query text taken from the page's JavaScript bundle, no credentials sent), which returns, per frame size, identifier, name, unit and value for every row of the table and a drawing (cdn.rosebikes.de/geometry/<id>.svg, not stored). Rows used: a seat tube length (seat_tube_length), b "Top tube length" (top_tube_effective; the drawing was not read for its datum), c head tube length, d head tube angle, e "seat angle" (seat_tube_angle unless an e2 row is noted below), f BB drop, g chainstay length, h wheelbase, j reach, k stack, m "Standover height (100 mm in front of BB)" (standover), p Fork offset, p1 Trail where printed, v front centre where printed, w3 "Stem lengh" (sic) and w1 Handlebar Width where printed (stock_stem_length, stock_bar_width). Decimal commas converted by script (73,25 = 73.25); values otherwise exactly as returned. No stack datum is stated in words (stack_datum null). No model year is printed (model_year null). Stack, reach and wheelbase are returned to one decimal, recorded as returned. Rows kept here only: a1 frame height 46/50/53/55/57/59/62/64; j1 Reach+ 516.2/526.3/549.8/558.2/565/584.3/602.1/611 and k1 Stack+ 628.7/638.7/655.7/670.2/689.1/701/715.3/729.8 (datum not stated); o stack to reach ratio; q Wheel diameter 28 in; r max. tyre width 2.0 in; r2 Max. tyre width 27.5" / 28" "53 / 50" mm; u fork length 410; w necessary seat post diameter 30.9; x recommended size (cm) 151-162/162-167/168-173/174-179/180-184/185-191/192-195/195-200; z system weight 120 kg. Fork "Rose Backroad ADV AL V2". Stock tyre "Continental Terra Adventure Trail Grip, black/transp. 700x45C". The Backroad AL EQ and AL Plus (e-bike) builds are not covered. CROSS-CHECK NOTE: the 8 seat-angle cells that differ from Bike Insights are not a disagreement about one number: Bike Insights holds Rose e row (seat angle 75/74.75/74.5/74.25/74/73.75/73.5/73.5), this file holds Rose e2 row (effective seat tube angle); Bike Insights matches the e row exactly.
Source: html table (official Rose product page for the Backroad AL GRX 400, its Frame geometry table as the page loads it: the page's own bikeGeometry JSON for product SKU 2725768; fetched 2026-10-20, HTTP 200)