Alpha Platinum Aluminum 29+ Trail Hardtail with Massive Tyre Clearance

The Trek Stache AL Frameset is a trail hardtail frame built from Alpha Platinum Aluminum - a lightweight and trail-tough construction that Trek describes as providing a great alloy frame platform, leaving budget available for higher-specification components. The Stache is designed specifically around 29+ tyre compatibility - the 3-inch wide tyre format that delivers aggressive grip and float over rough terrain while retaining the rollover capability, momentum, and speed that 29-inch wheels are known for. The combination of 29+ tyres and a hardtail frame produces a ride that is capable on rough singletrack without the weight and complexity of a full-suspension platform.

The Stache AL Frameset is genuinely versatile across uses - equally suited to multi-day bikepacking trips where the frame's carrying capacity and tyre volume support loaded long-distance riding, and rough singletrack sessions where the 29+ tyre's grip and float handle technical terrain. This range of capability in a single hardtail platform reflects the Stache's design intent as a do-everything trail and adventure bike rather than a single-discipline machine.

This is a frameset only. Fork, drivetrain, wheels, and all other components must be sourced separately as part of the custom build.

• You get an awesome alloy frame, and can spend the money you saved on killer parts
• Stache is super versatile and equally at home on multi-day bikepacking trips as it is on rough singletrack
• The super-short chainstays make it really easy to show off your wheelie skills

420mm Chainstays, Elevated Mid-Stay, and Horizontal Sliding Dropouts

Three engineering features define the Stache AL's trail character. The first is the 420mm chainstay length - notably short for a 29+ platform where accommodating 3-inch wide tyres typically requires longer rear-end geometry. Short chainstays move the rider's weight further back relative to the rear axle, making wheelies easier and giving the bike a more playful, manoeuvrable feel on trail. Trek specifically notes the 420mm chainstays make wheelies easier - a practical indicator of the balanced, fun handling character the short rear-end creates.

The elevated mid-stay is the structural solution that makes these short chainstays possible on a 29+ frame. By routing the upper chainstay above the tyre rather than around it, the elevated mid-stay creates the tyre clearance needed for 3-inch wide tyres without requiring a longer chainstay to achieve the same clearance. This is a purpose-built design feature rather than a compromise.

Horizontal Sliding Dropouts are the third key feature. These allow the rear axle position to be adjusted forward and backward within the horizontal slot of the dropout, enabling fine-tuning of the wheelbase length to suit rider preference or terrain. They also enable singlespeed conversion without a tensioner - for riders who want to build a singlespeed mountain bike, the horizontal sliding dropout allows chain tension to be set by moving the wheel position rather than requiring a separate chain tensioner component.

29+ Tyres - Grip, Float, and 29er Benefits Combined

29+ refers to the 3-inch wide tyre format fitted to 29-inch diameter rims. The additional width compared to standard 29er tyres provides two primary benefits - increased grip through a larger contact patch and the ability to run lower pressures without the risk of pinch flats or rim strikes that limits standard-width tyres. The lower pressure capability allows the tyre to conform more closely to rough terrain, improving traction on roots, rocks, and loose surfaces in a way that a higher-pressure narrower tyre cannot match.

The float characteristic of a 29+ tyre - the sensation of rolling over loose or soft terrain rather than digging into it - is particularly useful for bikepacking on varied surface types where soil conditions cannot always be predicted. Combined with the rollover and momentum benefits inherent to a 29-inch wheel diameter, the 29+ format provides a trail riding experience that is both more capable on technical terrain and more comfortable on sustained rough surfaces than a standard 29er tyre at comparable pressures.

FAQs

What frame material is the Trek Stache AL Frameset made from?

The frameset is built from Alpha Platinum Aluminum - Trek's lightweight and trail-tough aluminium construction for hardtail trail bikes.

What tyre size is the Stache AL Frameset designed for?

The Stache AL is designed for 29+ tyres - 3-inch wide tyres on 29-inch diameter rims, providing maximum grip, float, and rollover capability on varied trail terrain.

What are Horizontal Sliding Dropouts and what do they allow?

Horizontal Sliding Dropouts allow the rear axle position to be adjusted within a horizontal slot, enabling fine-tuning of the wheelbase length and facilitating singlespeed conversion without a chain tensioner.

Can the Stache AL be built as a singlespeed mountain bike?

Yes. The horizontal sliding dropouts allow chain tension to be set by adjusting wheel position, making singlespeed conversion straightforward without a separate tensioner component.

What is the chainstay length on the Stache AL?

The chainstays measure 420mm - notably short for a 29+ platform, contributing to a playful, manoeuvrable ride feel and making wheelies easier than a longer rear-end would allow.

What is the elevated mid-stay on the Stache AL?

The elevated mid-stay routes the upper chainstay above the tyre rather than around it, creating the clearance needed for 3-inch wide 29+ tyres while maintaining the short 420mm chainstay length.

Are components included with the Stache AL Frameset?

No. This is a frameset only. The fork, drivetrain, wheels, and all other components must be sourced and purchased separately as part of your build.

Specs:

Geometry Chart