The 4130 Trail Frame & Fork Set is the perfect foundation for your next hardtail shredder. Made from double-butted 4130 Chromoly steel, this frame is built to take a beating while delivering a smooth, lively ride feel. With progressive trail geometry, UDH compatibility, and clearance for big rubber, it’s ready for anything from techy singletrack to loaded bikepacking missions. Quick Features: Progressive Trail Geometry: A slack 65° head angle, low-slung top tube, and long front-center keep things stable when the trail gets rowdy while maintaining playful agility in the corners. Universal Derailleur Hanger (UDH) Compatibility: Future-proofed for modern drivetrain tech and easier maintenance, because you don’t need to be stressing parts availability. Double-Butted 4130 Chromoly Steel Frame: Tougher than aluminum and smoother than carbon, our double-butted 4130 Chromoly frame absorbs trail chatter and takes a beating without flinching. Internal Dropper Routing: With a 31.6mm seat tube and internal cable routing, upgrading to a dropper post is hassle-free. Threaded Bottom Bracket (73mm BSA): Reliable, creak-free, and easy to service. More Mounting Points: Triple bottle cage mounts on the downtube — because adventure doesn’t come with limits. Three Forks Fit: Build it rigid with our steel or carbon MTB fork, or suspended with the RockShox Psylo Silver RC (130mm travel, 35mm stanchions). Add one above — see Choose Your Fork below for what each one does to the bike. .tfk { font-family: inherit; font-size: inherit; line-height: inherit; color: inherit; } .tfk h3 { font-size: 18px; font-weight: 700; margin: 30px 0 8px; } .tfk p { margin: 0 0 12px; } .tfk-cards { display: flex !important; flex-wrap: wrap; gap: 12px; margin: 16px 0 14px; } .tfk-card { flex: 1 1 calc(50% - 7px); min-width: 250px; border: 1px solid #ddd; border-radius: 10px; padding: 16px 18px; box-sizing: border-box; } .tfk-card .fk-badge { display: inline-block; font-size: 10px; font-weight: 800; padding: 3px 9px; border-radius: 4px; background: #111; color: #fff; margin-bottom: 8px; letter-spacing: .3px; text-transform: uppercase; } .tfk-card .fk-img { display: block; width: 100%; max-width: 340px; height: auto; aspect-ratio: 4 / 5; object-fit: cover; border-radius: 6px; margin: 0 0 10px; background: #f3f3f3; } .tfk-card .fk-name { display: block; font-size: 14.5px; font-weight: 700; margin-bottom: 4px; } .tfk-card .fk-add { display: block; font-size: 15px; font-weight: 800; color: #111; margin-bottom: 8px; } .tfk-card p { font-size: 13px; color: #555; margin: 0 0 8px; } .tfk-card ul { margin: 0; padding-left: 18px; font-size: 12.5px; color: #555; } .tfk-card li { margin-bottom: 3px; } .tfk-card a { color: #0055cc; font-size: 12.5px; font-weight: 700; } .tfk-advisory { background: #fff8e6; border: 1px solid #f0d080; border-radius: 8px; padding: 14px 20px; margin: 16px 0; font-size: 13px; color: #5a4000; line-height: 1.6; } .tfk-table { width: 100%; border-collapse: collapse; font-size: 13px; margin: 12px 0 10px; } .tfk-table th { text-align: left; padding: 8px 10px; font-size: 11px; font-weight: 700; color: #555; text-transform: uppercase; letter-spacing: .04em; border-bottom: 1px solid #e0e0e0; } .tfk-table td { padding: 8px 10px; border-bottom: 1px solid #eee; vertical-align: top; } .tfk-table tr:last-child td { border-bottom: none; } .tfk-note { font-style: italic; font-size: 12.5px; color: #555; } Choose Your Fork This is a frameset — the fork is sold separately. Add one above and it ships with the frame, or leave it off and run a fork you already have. Three forks fit, and they build into three genuinely different bikes. Option No Fork +$0.00 Frame only. For a fork you already own or one you're sourcing yourself. Tapered head tube, ZS44 / ZS56 Match 550mm axle-to-crown for stock geometry Rigid Steel Rigid MTB Fork +$179.99 Double-butted 4130 chromoly. The load-hauler — more bolt-on real estate than any fork we build. 492mm A2C · 50mm offset 29 x 3.0" max tire 5 cargo mounts per leg, plus fender and rack mounts 180mm brake adaptor included 4 lb 0 oz Full fork details ? Rigid Carbon Rigid MTB Fork +$349.99 563 grams, and it clears a 32-inch wheel — almost nothing does. 495mm A2C · 49mm offset 29 x 3.0" max tire, or 32 x 2.4" 3 cargo mounts per leg, rack mounts No fender mounts · 180mm adaptor not included 1 lb 6 oz with axle Full fork details ? Suspension RockShox Psylo Silver RC +$385.00 130mm of travel on 35mm steel uppers. The fork the frame's geometry was drawn around. 550mm A2C · 44mm offset 29 x 2.6" max tire Motion Control damper, Solo Air spring 5 lb 12 oz The rigid forks change the geometry, on purpose. Both are 55–58mm shorter axle-to-crown than the Psylo. That steepens the head angle, drops the bottom bracket and shortens the wheelbase — the bike gets quicker-steering and sits lower. It's an intentional conversion from slack trail hardtail to fast all-terrain bike, not a compromise, but go in expecting a different bike rather than the same one minus the squish. Published geometry on this page is measured with the 550mm suspension fork. Fork Axle-to-crown Offset Max tire Weight Add RockShox Psylo Silver RC 550mm 44mm 29 x 2.6" 5 lb 12 oz +$385.00 Carbon Rigid 495mm 49mm 29 x 3.0" · 32 x 2.4" 1 lb 6 oz +$349.99 Steel Rigid 492mm 50mm 29 x 3.0" 4 lb 0 oz +$179.99 No fork — — — — +$0.00 All three forks are 15 x 110mm Boost with the thru-axle included, post mount brakes, and a 300mm steerer shipped uncut on the rigid options. The steel fork's straight 1-1/8" steerer ships with a 30mm cone so it runs in this frame's tapered head tube — no reducer headset needed. Frame clearance is 29" up to 2.6" or 27.5" up to 3.0"; fork clearance is listed above and is the limit on the front. .tgeo { font-family: inherit; font-size: inherit; line-height: inherit; color: inherit; } .tgeo p { margin: 0 0 12px; } .tgeo .note { font-style: italic; font-size: 13px; color: #555; } .tgeo details { border: 1px solid #ddd; border-radius: 10px; margin: 20px 0; overflow: hidden; } .tgeo summary { list-style: none; cursor: pointer; padding: 14px 18px; background: #fafafa; } .tgeo summary::-webkit-details-marker { display: none; } .tgeo summary::marker { content: ""; } .tgeo summary:hover { background: #f1f1f1; } .tgeo details[open] summary { border-bottom: 1px solid #eaeaea; } .tgeo-chev { display: inline-block; width: 12px; color: #999; font-size: 11px; transition: transform .18s ease; } .tgeo details[open] .tgeo-chev { transform: rotate(90deg); } .tgeo-bar-t { font-size: 15px; font-weight: 700; color: #111; } .tgeo-bar-s { display: block; font-size: 12.5px; color: #777; margin: 3px 0 0 12px; line-height: 1.5; } .tgeo-body { padding: 16px 18px 18px; } .tgeo-body > p:first-child { margin-top: 0; } .tgeo h5 { font-size: 13px; font-weight: 800; margin: 22px 0 6px; letter-spacing: .02em; } .tgeo-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 0 0 14px; } .tgeo-t { width: 100%; min-width: 520px; border-collapse: collapse; font-size: 13px; } .tgeo-t th { text-align: right; padding: 7px 9px; font-size: 10.5px; font-weight: 700; color: #555; text-transform: uppercase; letter-spacing: .04em; border-bottom: 1px solid #e0e0e0; white-space: nowrap; } .tgeo-t th:first-child { text-align: left; } .tgeo-t td { padding: 8px 9px; border-bottom: 1px solid #eee; text-align: right; white-space: nowrap; } .tgeo-t td:first-child { text-align: left; font-weight: 700; } .tgeo-t tr:last-child td { border-bottom: none; } .tgeo-t caption { caption-side: top; text-align: left; font-size: 12px; font-weight: 800; color: #111; padding: 0 0 6px; } .tgeo-t caption span { font-weight: 400; color: #777; } .tgeo-sum { border-left: 3px solid #111; background: #fafafa; padding: 14px 18px; margin: 14px 0; font-size: 13px; line-height: 1.65; } .tgeo-sum b { color: #111; } .tgeo-sum ul { margin: 8px 0 0; padding-left: 20px; } .tgeo-sum li { margin-bottom: 4px; } ? See how the geo changes Head angle, stack, reach and trail for all three forks, in all four sizes This frame is drawn around the 550mm axle-to-crown of the RockShox Psylo Silver RC, and that is the build our published 65° geometry describes. Both rigid forks are shorter — 495mm carbon, 492mm steel — so the front end sits lower, the head angle steepens, and the bike turns into something quicker. Here is how far it moves. RockShox Psylo Silver RC — 550mm axle-to-crown, 44mm offset Size Head Seat Stack Reach BB height Wheelbase Trail XS/S — 38cm 65.0° 74.5° 628mm 420mm 316mm 1158mm 125mm S/M — 41cm 65.0° 74.4° 637mm 445mm 316mm 1188mm 125mm M/L — 43cm 65.0° 74.4° 647mm 465mm 316mm 1212mm 125mm XL — 46cm 65.0° 74.4° 656mm 490mm 316mm 1241mm 125mm Rigid carbon — 495mm axle-to-crown, 49mm offset Size Head Seat Stack Reach BB height Wheelbase Trail XS/S — 38cm 67.6° 77.1° 609mm 448mm 297mm 1141mm 100mm S/M — 41cm 67.5° 76.9° 617mm 473mm 297mm 1170mm 101mm M/L — 43cm 67.5° 76.9° 626mm 493mm 298mm 1194mm 101mm XL — 46cm 67.4° 76.8° 634mm 517mm 298mm 1223mm 102mm Rigid steel — 492mm axle-to-crown, 50mm offset Size Head Seat Stack Reach BB height Wheelbase Trail XS/S — 38cm 67.8° 77.3° 607mm 450mm 296mm 1140mm 98mm S/M — 41cm 67.7° 77.1° 616mm 475mm 296mm 1170mm 99mm M/L — 43cm 67.6° 77.0° 624mm 494mm 297mm 1194mm 99mm XL — 46cm 67.6° 77.0° 633mm 519mm 297mm 1223mm 99mm What actually changes Going rigid, in round numbers, whichever size you ride: Head angle steepens about 2.5° (carbon) or 2.7° (steel) — 65° becomes roughly 67.5°. Stack drops about 20mm. The front end sits lower, and you may want a spacer or two back under the stem. Reach grows about 28mm. This is the one people miss: a rigid build rides noticeably longer. If you are between sizes, it argues for the smaller one. Bottom bracket drops about 19mm , to roughly 297mm. Lower and more planted, with less pedal clearance over rocks. Trail falls from 125mm to about 100mm. The shorter fork and its longer offset work in the same direction, and this — more than the head angle — is why the rigid bike steers so much faster. Suspension geometry is quoted with the fork fully extended, as published. Geometry is measured with a 29 x 2.4" tire. Full published geometry for the suspension build is on our geometry chart . Build and Customize FRAME SIZE: XS/S: 5'1" to 5’5" S/M: 5'5" to 5'10" M/L: 5'10" to 6'1" XL: 6'1" to 6'5" Also Included: Headset Thru-Axles Front & Rear Universal Derailleur Hanger Cable Guides Quick Release Seatpost Clamp *Frame and Forks Sold Separately - be sure to add the fork as an option or a la carte to receive both* MAX TIRE CLEARANCE: Frame: 29” Wheels: Up to 2.6” / 27.5” Wheels: Up To 3.0” Fork: Depends on the fork you choose — see the comparison table above