U.S. Built Custom Bicycles in Titanium and Titanium-Carbon Mix
We are agnostic about component brands and the standards they try to impose. Shimano, SRAM, and Campagnolo all offer excellent derailleur systems. Each system has strengths and considerations. We offer dropouts that work with every major manufacturer's high-end and midrange derailleurs.
Both standard rear derailleur hangers and SRAM's UDH system have benefits. We offer both hangers for that reason.
Most bike brands have to go all in on one dropout system because investing in multiple dropout designs, having fixturing for more than one system, and supporting conflicting component brand pressures is expensive and time-consuming. Conversely, for Seven, partly because we build custom framesets and partly because make most of our parts in-house, we can offer multiple systems agnostically. We decide which dropout-hanger method is best for the specific application rather than decisions made from supply chain pressures.
Read on to determine which system may be better for your riding needs.
Seven's singlespeed solution does NOT require adjustable dropouts — like sliders or rockers. Instead, we use an eccentric bottom bracket tensioning system. It's a significantly improvement on the typical 14-plus-piece slider dropout.
UDH, Universal Derailleur Hanger, T-Type, and Transmission are all trademarks of SRAM Corporation. Use of those terms on this website is for identification purposes only.
We design all of our dropouts. We do extensive in-house fatigue testing on our designs. We don't use any aftermarket dropouts or small parts. We design for performance over all else. We don't have the least expensive or the lightest dropouts. We don't offer cowled dropouts with disposable hangers. We offer only high-performance lifelong dropouts that are stiffer and stronger than any other offerings.
Seven offers seven dropout types to cover every kind of riding imaginable.
| Dropout Type | Axle Type | Available on which models? | Seven's Integrated Derailleur Hanger | Seven's UDHTM Universal Derailleur HangerTM |
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| S-Type & A-Type Dropouts (Best Value & Understated) |
Thru-Axle | All S-Type and A-Frame models: gravel, mountain, road, etc. Exceptions: suspension frames |
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| Quick Release | Only S-Type and A-Frame road and randonnée frames | |
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| SL-Type Dropouts (Strongest & Stiffest) |
Thru-Axle | All SL frame models: gravel, mountain, road, etc. Exceptions: suspension frames |
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| Quick Release | Only SL-Type road and randonnée frames | |
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| XX-Type Dropouts (Light & Compact) (Seven's Asymmetric Design) |
Thru-Axle | All XX frame models: gravel, mountain, road, etc. Exceptions: suspension frames |
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| Quick Release | Only XX road and randonnée frames | |
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| Seven's AwesommetricTM Dropouts (Lightest Dropout & Lightest Rear Triangle) |
Thru-Axle | All SL & XX frame models: gravel, mountain, road, etc. Exceptions: suspension frames |
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| Suspension Frame Dropouts | Thru-Axle | Only mountain suspension frames | |
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No hanger system is perfect for all possible situations through the end of time. That's why we offer multiple solutions.
| Seven's Integrated Derailleur Hanger | SRAM UDHTM Universal Derailleur HangerTM | SRAM UDHTM T-TypeTM Full MountTM TransmissionTM | |
|---|---|---|---|
| Overview (tl;dr) |
Performance first. Faster shifting. More accurate shifting. More riding; Less service time. Compatible with more than 99.9%[1] of midrange to high-end derailleurs. | Good for carbon and aluminum frames. UDH solves a problem that Seven's titanium dropout designs do not have. The problem: Carbon and aluminum frames NEED to have replaceable hangers because those materials are not tough enough or stiff enough to withstand average riding conditions. | Compatible with less than 1%[2] of high-end to midrange drivetrains. Released in 2023, this system is designed for mountain bikes only. SRAM parts only. SRAM wireless electronics only. SRAM's highest-end drivetrains only. And optimized for e-bikes. In SRAM's own words: "The capability truly comes into focus when experienced on an EMTB. |
| Best for what kind of riding? | Any kind of riding. Anywhere. Gravel, allroads, mountain, road and fat bike riding. No need for specialty replacement parts or specialty tools. Easy-peasy. | Club rides. Riding close to home. Not ideal for traveling overseas; will you be able to find replacement parts and the proper tools readily available? Otherwise, carry multiple replacement parts with you on your ride or tire. And a 10 mm hex key. And maybe an extra lever arm. And remember that the part is reverse threads. You don't want to get stranded in the middle of nowhere without the replacement assembly or the proper tools. Your co-riders are unlikely to have the items needed. They are unique to the UDH system. Be prepared. | SRAM 1x electronic shifting mountain bikes only. And optimized for e-bikes. In SRAM's own words: "The capability truly comes into focus when experienced on an EMTB. |
| How "Universal?" | 99.9% or more. Works with any derailleur that uses a derailleur hanger. That's more than 99.9%[1] of the midrange to high-end derailleurs in the world. Primary brands include Shimano, SRAM, and Campagnolo. | 100%. When used with SRAM's universal derailleur hanger, the system is compatible with 99.9%[1] of derailleurs on the market. When the hanger is removed, the dropout is compatible with the remaining 0.1%[1] of derailleurs — SRAM's Transmission wireless electronic derailleurs for mountain bikes. | 0.1%[1] or less. Works with SRAM's Transmission derailleurs only. As of 2024, that consists of SRAM's top-end mountain bike components only. However, when used in conjunction with a UDH derailleur hanger, the system is compatible with 100% of mid to high-end derailleurs. Unfortunately, the system then suffers the shortcoming of the replaceable hanger. |
| Not compatible with... | Less than 0.1% of derailleurs. SRAM Transmission T-type wireless electronic derailleurs for mountain bikes only. This accounts for far Less than 0.1%[1] of rear derailleur sales. | 100% compatibility. When used with SRAM's universal derailleur hanger, the system is compatible with 99.9%[1] of derailleurs on the market. When the hanger is removed, the dropout is compatible with the remaining 0.1%[1] of derailleurs — SRAM's Transmission derailleurs. | |
| Shifting speed & precision | The winner: The fastest and most precise shifting because the hanger is so stiff. | The loser: By design, the hanger is very flexible and fragile (as explained below). Therefore, its shifting precision, speed, and accuracy are terrible. | The loser for speed: Transmission shifting is intentionally designed for relatively slow shifting. SRAM says this is to improve shifting performance. |
| Toughness, Strength, & Stiffness | 350% stiffer than the average replaceable UDH made of aluminum (or plastic with a steel insert). This means that the Seven hanger will not break. And it's extremely difficult to bend 400% stronger than the replaceable UDH. Again, the Seven hanger will not break. |
Designed to fail (rather than the derailleur). Meaning that the hanger is not stiff at all, and therefore, its shifting precision and consistency are terrible. | The SRAM derailleur is tough; the carbon dropout is not. Carbon T-Type dropouts are generally not strong or tough. They are light and fragile. The market is already seeing carbon dropouts getting totalled because the transmission derailleur is so stiff relative to carbon fiber dropouts. That's why disposable hangers were invented in the first place. The industry has come full circle. |
| Future-proofing | Excellent. Standard derailleur hangers have been around for decades. No brand has been able to change that standard. The most recent attempt was from Shimano (the largest derailleur brand by far) with their Direct Mount system. That lasted a few years; Shimano has mostly given up on that system becoming the industry standard. The fight for dominance continues; Shimano recently applied for numerous patents for a new hanger standard. | Excellent. This system is well future-proofed because it is compatible with every current high-end derailleur on the market. | Unlikely to become THE standard. The odds that SRAM's T-Type derailleur will become the global standard is extremely slim. SRAM is a fantastic company but it has proven impossible, to date, to change the industry's derailleur hanger standards. Most recently, Shimano (the largest component manufacturer by far) failed in its attempt to gain acceptance for its direct-mount standard. The fight for dominance continues; Shimano recently applied for numerous patents for a new hanger standard. There is no immediate contender to take over the standard derailleur hanger. |