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 Most makers do not publish it, so I assume 15 mm and add 6 mm to the band, which on its own is enough to hold an answer at "probably" rather than "fits".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
Planet X Tempest
Gravel · titanium · 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
- Planet X Tempest · Gravel · titanium · 5 sizes · seatpost offsets 0 / 15 / 20 / 25 mm
- Geometry
- planetx.co.uk, fetched 28 Aug 2026, not yet re-checked
- Cockpit
- two-piece (Planet X does not publish stock stem or bar), generic 70-130 stems, the maker's spec
- Solved with
- cover 15 mm (assumed), max spacers 40 mm (published), 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 |
|---|---|---|---|---|---|---|---|---|
| XS (460mm / XSM) | 532 | 373 | 70.5 | 74.5 | 100 | 440 | 1018 | |
| S (490mm / SML) | 543 | 385 | 71 | 74.5 | 110 | 440 | 1029 | |
| M (510mm / MED) | 557 | 390 | 71 | 74 | 125 | 440 | 1039 | |
| L (530mm / LRG) | 587 | 395 | 71.5 | 73.5 | 155 | 440 | 1050 | |
| XL (550mm / XL) | 599 | 407 | 72 | 73 | 165 | 440 | 1061 |
The table runs on to the right: 6 more columns after Reach. Scroll it sideways to read them.
The M (510mm / MED) 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
What each size is solved on unless you choose another bar on the sheet.Planet X two-piece (Planet X does not publish stock stem or bar), generic 70-130 stemsStockstem -6 / 6 / -7 / 7 / -8 / 8 / -10 / 10 / -12 / 12 · reach 75 · lengths 70-130
In the maker's words
Kept whole, as I read it off planetx.co.uk.Conventional two-piece bar and stem, not integrated: the official frame page states "Gear cables are routed externally", "44mm head tube", 27.2mm seatpost (https://planetx.co.uk/products/planet-x-tempest-titanium-gravel-road-frame-2).
Cockpit and seatpost, in the maker's words · 238 words
Conventional two-piece bar and stem, not integrated: the official frame page states "Gear cables are routed externally", "44mm head tube", 27.2mm seatpost (https://planetx.co.uk/products/planet-x-tempest-titanium-gravel-road-frame-2). The CURRENT official complete-bike pages (Apex XPLR 1799.99, Apex AXS 1999.99, GRX RX820 2199.99, GRX RX717 Di2 2299.99, Rival AXS XPLR E1 2399.99, Force AXS XPLR E1 2999.99 GBP) list only groupset, wheels, frame, UDH hanger and weight; they do NOT publish stem length or bar width per size, so those fields are null. Secondary sources for previous-spec builds, all showing ONE stem length and ONE bar width across all sizes: bikes.fan 2021 Force 1 build "Selcof Zeta V2 6061 Alloy Stem / 100mm / 31.8mm / 7 Degree" and "Selcof Sterrato Flared Gravel Handlebar / 42cm", seatpost "Selcof Zeta V2 6061 Alloy Seatpost / 27.2mm / 350mm" (https://bikes.fan/planetx-tempest-sram-force-1-titanium-2021/); Bike Insights V3 2018 entry: handlebar 420mm, stem 100mm, stem angle 10 deg on S-XL (https://bikeinsights.com/bikes/5d5409b56e08bc0017576cf5-planet-x-tempest-v3?version=2018&build=base); The Pro's Closet 2022 Medium as sold: "Selcof Alloy, 31.8mm x 100mm, 6 deg" stem, "Selcof Alloy, 42cm" bar (https://www.theproscloset.com/products/2022-planet-x-tempest-m); a Singletrack forum V3 Large owner: "standard 100mm" stem (https://singletrackworld.com/forum/bike-forum/planet-x-tempest-sizing-advice/). Current Planet X component listings: Selcof Sterrato V2 Flared Gravel Handlebar - drop 125mm, reach 75mm, flare 8 degrees, 30mm back extension on flats, 31.8mm clamp, widths 400/420/440mm measured at the hoods (https://planetx.co.uk/products/selcof-sterrato-v2-flared-gravel-handlebar); Selcof Zeta 6061 alloy stem - 7 degree rise/drop, 31.8mm, listed lengths 80/100/110/120mm (https://planetx.co.uk/products/selcof-zeta-6061-alloy-stem). Headset type, spacer stack and headset cover height: not stated by Planet X.
OFFICIAL CURRENT TABLE (read from HTML tables on https://planetx.co.uk/pages/tempest-size-guide-geometry, https://planetx.co.uk/collections/tempest and the Rival AXS product page, all identical, fetched 2026-08-28): rows are lettered A-K to match the diagram: A Head Angle (degrees) 70.5/71.0/71.0/71.5/72.0. Source: official manufacturer website, HTML geometry table (identical table also embedded on
How I read the maker's table
B Head Tube (mm) 100/110/125/155/165; C Top Tube Effective (mm) 520/535/550/570/590; D Seat Tube Angle (degrees) 74.5/74.5/74/73.5/73.0; E Seat Tube C-T (mm) 460/490/510/530/550; F Chainstays (mm) 440 all; G BB Drop (mm) 70 all; H Stack (mm) 532/543/557/587/599; I Reach (mm) 373/385/390/395/407; J Front Centre (mm) 588/599/610/620/630; K Wheelbase (mm) 1018/1029/1039/1050/1061 for XS/S/M/L/XL. All values already in mm and degrees, no conversion needed. Not published by Planet X and therefore null: standover, fork offset, trail, stem length, bar width. OFFICIAL RIDER HEIGHT GUIDE (same page): 5'0" to 5'5" = 460mm/XSM; 5'5" to 5'8" = 490mm/SML; 5'7" to 5'10" = 510mm/MED; 5'9" to 6'0" = 530mm/LRG; 5'11" to 6'3" = 550mm/XL (my conversion: 152-165, 165-173, 170-178, 175-183, 180-191 cm). OFFICIAL FRAME SPEC (https://planetx.co.uk/products/planet-x-tempest-titanium-gravel-road-frame-2, frame only 1099.99 GBP, SKU FRPXTEMPUDH-XSM..XLG, sizes X-Small to X-Large): "Aerospace Grade 9 3AL-2.5V Titanium" (94.5% Ti, 3% Al, 2.5% V); "71.5 degree head angle" and "70mm BB drop" quoted in copy (the 71.5 is the Large row); 44mm head tube; round-to-ovalised down tube; hourglass chainstays; 27.2mm seatpost (offset not stated; the Selcof Zeta post fitted to complete bikes is a single-bolt micro-adjust post, offset not stated); 12mm thru axle dropouts (rear 12x142 per the bikes.fan 2021 spec, not stated by Planet X); SRAM UDH hanger; BSA 68mm threaded BB; external gear cable routing; tyre clearance 700c x 48mm (45mm with mudguards); full rack (pannier) and mudguard mounts; frame weight 1550g Medium; frame is sold WITHOUT fork, "pair the frame with our Selcof Carbon Gravel Fork (available separately)" - that fork is not currently listed on planetx.co.uk (store search only returns the Selcof Road Disc fork), so fork offset is unverified: a search snippet of the unreachable selcof.co.uk page claims 400mm axle-to-crown, 50mm rake, 45mm clearance, while Bike Insights assumes 45mm offset / 395mm length - treat both as unverified. Wheel size: 700c on all five sizes (complete bikes: Mavic Allroad 700c disc or Token G23HD/G23AR 700c wheelsets). Complete bike weight approx 9.8kg Medium (GRX RX820 build). Dropper compatibility: not stated by Planet X; the 27.2 external-routed seat tube would only take an externally routed 27.2 dropper and Planet X's own Selcof Watchtower dropper is 30.9/31.6 only. Headset standard not stated beyond "44mm head tube". VERSION HISTORY (Planet X never publishes a changelog; assembled from archived URL SKUs in the Wayback CDX index and secondary reprints, Wayback page bodies were unavailable - 503 "Temporarily Offline" and 429 during this session): V1 2016-2017 SKU FRPXTIGR / ZXFRPXTIGR frameset (S/M/L/XL): Geometry Geeks "Tempest 2017" stack|reach 543|383, 579|383, 588|394, 599|406 (search snippet only; their table needs JS so other rows unread) https://geometrygeeks.bike/bike/planet-x-tempest-2017/. V2 2018 SKU FRPXTIGRV2 (bike CBPXTEMFOR1FL700): Geometry Geeks "Tempest V2 2018" 543|378, 579|383, 588|394, 599|406 https://geometrygeeks.bike/bike/planet-x-tempest-v2-2018/; forum posts say pre-V3 frames were not flat mount; same Pilo D1208 hanger for V2, V3 and Hurricane (https://www.elanusparts.com/derailleur-hangers/d1208-derailleur-hanger-for-planet-x-tempest-v2-v3-hurricane). V3 2019-2021 SKU FRPXTIGRV3 "V3 FM" (flat mount), bikes CBPXTEMV3FOR1700 (700c) and CBPXTEMV3FOR1650B (650b build option), frameset FTPXTIGRV3: Bike Insights "Tempest v3 2018" S/490 M/510 L/530 XL/550: stack 543/579/588/599, reach 378/383/394/406, ETT 535/550/570/590, HTA 71/71.5/71.5/72, STA 74.5/74/73.5/73, HT 110/125/155/165, BB drop 70, chainstay 427/430/430/432, front centre 599/602/621/632, wheelbase 1016/1022/1042/1054, standover 720/740/760/780, sizing 5'5"-5'8" / 5'7"-5'10" / 5'9"-6'0" / 5'11"-6'3" (source labelled www.planetx.co.uk) https://bikeinsights.com/bikes/5d5409b56e08bc0017576cf5-planet-x-tempest-v3?version=2018&build=base; bikes.fan "2021 Force 1" reprint (probably V3 with the Selcof Carbon Gravel+ 45mm-clearance fork): stack 548/584/593/604, reach 383/388/399/411, TT 540/555/575/595, HT 110/125/155/165, HTA 71/71.5/71.5/72, STA 74.5/74/73.5/73, chainstay 432/435/435/437, wheelbase 1021/1027/1047/1059, BB drop 70, standover 725/745/765/785, front centre 599/602/621/632, trail 66/72/66/64, rider height 158-171 / 168-180 / 178-189 / 186-199 cm, wheels Fulcrum Racing 900 disc 12mm thru / 12x142, tyres Panaracer 38mm https://bikes.fan/planetx-tempest-sram-force-1-titanium-2021/. V4 2021 SKU FRPXTIGRV4: Bike Insights "2021/V4" S-XL: stack 531/545/576/587, reach 387/394/399/411, ETT 535/550/570/590, HTA 71/71/71.5/72, STA 74.5/74/73.5/73, HT 98/113/143/153, BB drop 70, chainstay 440 (lengthened from 427-437), front centre 598/609/620/630, wheelbase 1028/1039/1050/1060, standover 720/740/760/780 https://bikeinsights.com/bikes/5ce98ff224e4f6001704b79a-planet-x-tempest?version=2021-v4&build=base; an owner describes V4 as "at the racey end of gravel bike geometry" (https://singletrackworld.com/forum/bike-forum/planet-x-titanium-gravel-bikes-experiences/). CURRENT (2023 onward, SKU FRPXTEMPUDH, Bike Insights "2023"): adds XS 460mm size, head tubes back to 100/110/125/155/165 (taller than V4 by 2-12mm, so stack up and reach down vs V4 on S-L), keeps 440mm chainstays, 48mm tyre clearance, SRAM UDH hanger; the 5-size table matches Bike Insights 2023 exactly (https://bikeinsights.com/bikes/5ce98ff224e4f6001704b79a-planet-x-tempest?build=base&version=2023). Caveat: the secondary V1-V4 tables disagree with each other in places (e.g. bikes.fan vs Bike Insights V3 stack differs by 5mm), so treat pre-2023 numbers as approximate reprints, not official. Unreachable this session: web.archive.org (503/429), 99spokes (403), matchbikes (402), on-one.co.uk and selcof.co.uk (connection refused / DNS).
Source: official manufacturer website, HTML geometry table (identical table also embedded on https://planetx.co.uk/collections/tempest and on each complete-bike product page, e.g. https://planetx.co.uk/products/planet-x-tempest-sram-rival-axs-xplr-gravel-bike); diagram image https://img-va.myshopline.com/image/store/1704903372076/TEMPEST-geometry.png (letters A-K only, no numbers)
