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 Most makers do not publish it, so I assume 15 mm and add 6 mm to the band, which on its own is enough to hold an answer at "probably" rather than "fits".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 bar is than your saddle.
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
Bigrock Sohtea
Road · 5 sizes
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This is the bike I ride
No account is needed to read the table. Report a wrong number · Correct this bike
- Bike
- Bigrock Sohtea · Road · 5 sizes
- Geometry
- 43.136.68.97, fetched 29 Aug 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
- 6 September 2026 · 210 bikes, 43 makes, 1,262 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)not published |
|---|---|---|---|---|---|---|---|---|
| XXS (45) | 502.3 | 364.8 | 70.5 | 76 | 102 | 410 | 969.5 | |
| XS (49) | 513.2 | 375 | 71.75 | 75.5 | 109 | 410 | 972.9 | |
| S (52) | 526.4 | 380 | 72.5 | 74 | 120 | 410 | 974.8 | |
| M (54) | 543 | 384.3 | 73 | 74 | 137 | 410 | 978 | |
| L (56) | 563.8 | 395 | 73.5 | 73.5 | 157 | 410 | 990 |
The table runs on to the right: 6 more columns after Reach. Scroll it sideways to read them.
The S (52) 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.
In the maker's words
Kept whole, as I read it off 43.136.68.97.FRAME ONLY on the maker's page: no bar or stem is listed or pictured with the frame; the product photos show frame, fork, round seatpost with an external Bigrock seat clamp, and the maker's 'other info' tab gives only weight (frame XS(49) 730 g, fork 330 g, both without metal parts), sizes XXS(45)-XS(49)-S(52)-M(54)-L(56) and type (road).
Cockpit and seatpost, in the maker's words · 348 words
FRAME ONLY on the maker's page: no bar or stem is listed or pictured with the frame; the product photos show frame, fork, round seatpost with an external Bigrock seat clamp, and the maker's 'other info' tab gives only weight (frame XS(49) 730 g, fork 330 g, both without metal parts), sizes XXS(45)-XS(49)-S(52)-M(54)-L(56) and type (road). SEATPOST: round; the TEAM edition frame photos carry '27.2 MM SEAT POST' printed on the seat tube (http://bigrock.rjkf.top/2024-02-18-21-10-24.JPG), so 27.2 mm round post; the maker's own carbon seatpost product (id 5cb7f0a643523eec1683edc7) is offered straight or setback with a 3 degree layback, 27.2 / 30.9 / 31.6 mm, 400 or 420 mm long, 182 g; the maker's CNC seat clamp for 27.2 posts is 31.8 mm (id 60d40dbcb87b6e2aa2fa254b). ROUTING: description says the frame was changed from external to internal routing and 'is compatible with full-internal and external routing systems'; BB changed from BSA to T47. OPTIONAL BARS sold separately by the maker: 'Skyline II road integrated bar' (天际线二代公路一体把, id 64b65c5a9f35c10463e3a149, 2023-07): 45 sizes, supports OD1 and OD2 steerers, integrated computer mount, titanium bolts, 325 g, stated 35 to 40% stiffer than gen 1 (gen 1 'Skyline': 20 sizes, OD1 only, 328 g at 90x400, internal or external routing 'depending on the frame headset'); 'aero two-piece bar' (破风分体把, id 662b1453e4a38b60cdb93915): six widths 340(380) / 360(400) / 380(420) / 400(440) / 420(460) / 440(480) mm (hoods, drops in brackets, 40 mm flare-out), reach 70 mm, drop 127 mm, supports full-internal, semi-internal and external routing. Stem lengths, stem angle, bar reach/drop for the Skyline II, spacer heights, max spacer stack, headset cover height: NOT published on the maker's site. Distributor data, not maker-confirmed: Panda Podium lists the Skyline II as 'Horizon II' with widths 340/360/380/400/420 x lengths 70-150 mm in 10 mm steps (5 x 9 = 45, matching the maker's '45 sizes'), -8 deg, reach 75, drop 127, flare 25 mm, 338 g (90x400); Panda also lists the frameset contents as frame, fork, seatpost, headset (1-1/8 to 1-1/4), T47 85.5 mm, tyre clearance 700x30C, front derailleur on a bolt-on hanger, 12x100 / 12x142 thru axles.
OFFICIAL SOURCE STATUS: the URL given is the maker's site. Source: image_table (maker's own site: www.bigrock.cc is a full-page iframe of
How I read the maker's table
www.bigrock.cc (HTTP 200) is a one-line page that iframes http://43.136.68.97:85, and the site footer reads 'Copyright BIGROCK.CC'. The page fetched is 'BIGROCK公路车架-变色龙' (Bigrock road frame, Chameleon colour), product id 64711ff7b2601e7659887d10 in category 公路车架 (road frame, id 64711f2bb2601e7659887cdc). The maker never uses the name 'Sohtea' on its site; the road-frame category holds the same frame in ten colour listings (Chameleon, Meteorite Grey, Star Silver, Mist Purple, Ninja Black, Lake Blue, Transparent Red, Athens White, Sakura Pink, Raw Carbon, plus a discontinued Crystal Green) all carrying the identical description and size list, and two 'TEAM 版' listings (Anodised Blue id 65d2022ee7add67f1f1e0ecd, Coffee id 65d202dbe7add67f1f1e0ed0, dated 2024-02-18). Panda Podium sells the colour frames as 'Sohtea Superlight' and the TEAM frames as 'Sohtea Team Edition', which is the naming used here. GEOMETRY TABLE: only published as the last content image on each colour listing (same image on the Chameleon page; the Ninja Black, Lake Blue etc. pages carry their own copies). Rows in the image, in order: FRAME SIZE, SEAT TUBE (ST) mm, TOP TUBE (TT) mm, HEAD TUBE (HT) mm, SEAT ANGLE (STA) deg, HEAD ANGLE (HTA), BB DROP (BD) mm, FORK LENGTH (FL) mm, FRONT RACK (FR) mm, FRONT CENTER (FC) mm, REAR CENTER (RC) mm, WHEEL BASE (WB) mm, STACK mm, REACH mm, HUB SPEC. Values are copied exactly as printed, decimals included (CAD output). SIZE NAMES: the chart labels sizes only by the frame-size number 45 / 49 / 52 / 54 / 56; the description maps them to XXS(45) / XS(49) / S(52) / M(54) / L(56). Note the size number is NOT the seat tube length (45 has a 400 mm seat tube). STACK DATUM: not stated on the chart, but the numbers reproduce exactly (within 0.2 mm on every size) from BB drop + fork length 369 (axle to crown, along the steering axis) + head tube length x sin(HTA) minus rake x cos(HTA), so stack and reach are BB centre to the TOP OF THE HEAD TUBE (frame, no headset cover). Reach reproduces from front centre the same way (size 52: 380.1 calc vs 380 printed). SEAT ANGLE: labelled only 'SEAT ANGLE (STA)'; effective vs actual not stated (the seat tube is straight so the two should coincide), left null. TOP TUBE: labelled only 'TOP TUBE (TT) mm'; the frame has a sloping top tube so this is taken as the effective/horizontal length (assumption). 'REAR CENTER (RC)' = chainstay 410 all sizes. 'HUB SPEC.' 142 all sizes (rear axle 12x142). Standover, trail, stem and bar: not published, null. SIZES NOT IN THE CHART: the maker's TEAM listings give six sizes 'XXS XS S M L XL' with weights XXS(45) 603 g, XS(49) 615 g, S(52) 626 g, M(54) 638 g, L(56) 675 g, XL(58) 720 g (without aluminium parts; fork 285 g uncut) but publish NO geometry image at all, and the standard listings show no XL; Panda Podium's transcription adds XL(58) and (Superlight only) XXL(61) columns that do not exist on the maker's site as of 2026-08-29, so those two sizes are deliberately NOT recorded here. CROSS-CHECK: Panda Podium's table (Store API, products 5748 and 7680) matches the maker's chart on every cell for 45-56 once its rounding is allowed for (508 vs 507.73, 574 vs 574.37, 577 vs 576.72, 579 vs 578.8). MODEL YEAR: undated; product record created 2023-05-26, geometry image dated 2023-05-27, TEAM listings 2024-02-18, newest colour listings 2026-08-07 with the same description and image set; left null. FRAME FACTS from the description: frame weight reduced from 880 g to 730 g during development, Mitsubishi and Toray carbon; TEAM version Mitsubishi T1100 + T800; T47 BB; 12x142 rear.
Source: image_table (maker's own site: www.bigrock.cc is a full-page iframe of http://43.136.68.97:85, the Nuxt app whose product pages are image-only; geometry chart image http://bigrock.rjkf.top/2023-05-27-14-06-07.png, 1933x1726 PNG, CAD line drawing plus a 16-row table)
