Alto TR1 - Shelters & Tents
Sea to Summit

Alto TR1

Specs checked by Brian Williams · 6 years bikepacking
$380USD1050g / 37.0oz
Search REI

This opens a search on REI rather than a product page — we haven't verified a direct link for this one, and the results may include other brands.

We may earn a commission if you buy through this link, at no extra cost to you.

Sea to Summit Alto TR1 — shelter drawn to scale. Inner floor 214.6 by 106.7 cm. Packed poles 45 cm, inferred from packed length: overhangs a 40 cm drop bar.
Sea to Summit Alto TR1, drawn from the maker's published figures. Inner floor 214.6 × 106.7 cm, with a 183 cm sleeper drawn in for scale. The packed poles are 45 cm, inferred from the packed bag rather than published by the maker.

Will it go on your bars?

The folded pole set is 450mm, which is the 24th shortest of the 29 shelters we hold a pole length for. At 936g it is 17th lightest of 37.

On the two weights. The 1050g at the top of this page is the figure we hold on the product record. Sea to Summit also publish a minimum (trail) weight of 936g and a packed weight of 1106g. Minimum weight leaves out stakes, guys and the stuff sack; packed weight is everything in the bag. We show all three rather than picking one and calling it “the” weight.

On drop bars
450mm poles — too long for drop bars

Beyond the usable span on drop bars. Carry it on the frame, in a seat pack, or strapped to a fork cage instead. This figure is the packed bag's long dimension, not a pole length the maker publishes — for this style of tent the two are the same thing, but measure before you commit.

On flat bars
450mm poles — fits flat bars

Comfortably inside the usable span on flat bars, with room for cables and a harness. This figure is the packed bag's long dimension, not a pole length the maker publishes — for this style of tent the two are the same thing, but measure before you commit.

3 shelters here are both shorter-poled and lighter: Nordisk Lofoten 1 ULW (220mm, 490g), NEMO Hornet OSMO Ultralight 1P (320mm, 822g), Big Agnes Tiger Wall UL1 (430mm, 822g). Anything not on that list is a trade rather than a straight win.

Only 29 of the 43 shelters we track publish a figure we can compare, which is why this question is so hard to answer anywhere else. The figure above is the packed bag's long dimension rather than a pole length the maker publishes — for this style of tent the two are the same thing, but measure before you commit.

Compare every shelter by pole length
Weight
1050g
37.0 oz
Price
$380
$36 per 100g
Packed Size
5 x 16 in
Score
Not scored
verified specs, no editorial score

Sea to Summit Alto TR1 — Specs & Analysis

Manufacturer specifications, compared against every other shelters & tents in our database. We do not test gear in the field — we measure, verify, and compare.

The Alto TR1 uses Sea to Summit's Tension Ridge architecture to create steep, vertical walls that maximize headroom and livable space without adding weight. The ridge pole lifts the canopy away from your face, and the 15D fabrics keep total weight just over a kilogram.

Who Is the Sea to Summit Alto TR1 Best For?

Solo bikepackers who prioritize interior livability and headroom over absolute minimum weight. If that describes your riding style, the Alto TR1 should be at the top of your shortlist. It sits in the Shelters & Tents category alongside 17 other products we track.

How It Compares

At 1050g and $380, the Alto TR1 is 900g heavier than the lightest option in this category (the Borah Gear Cuben Fiber Tarp at 150g). The most budget-friendly option is the MSR Thru-Hiker Mesh House 1 at $150.

The price-to-weight ratio comes in at $36 per 100g — a premium price point, but you're paying for quality, materials, and design that justify the investment for serious bikepackers.

What We Like

  • +Tension Ridge creates exceptional interior volume
  • +Very livable for a solo tent with near-vertical walls
  • +High-quality DAC press-fit poles
  • +Fair weather mode with fly partially rolled back

Watch Out For

  • Heavier than minimalist trekking pole shelters
  • Single door limits entry options
  • Packed size is larger than trekking pole alternatives

The Bottom Line

We haven't scored the Sea to Summit Alto TR1, and neither has anyone else we can cite. It's here for its verified specifications and dimensions, which is what the fit tools run on — a score is an editorial judgement, and we don't hand one out until someone has a basis for it. What this page can tell you is measured: 1050g, $380, and how both sit against every other shelters & tents product we track.

The price and weight above have not yet been checked against the manufacturer's own page. We are working through the catalogue and saying so as we go, rather than letting silence imply otherwise.

Specifications and dimensions come from the sources listed above. Where a page draws on first-hand riding, it says so.

What it packs down to

Sea to Summit publishes a packed size of 5 x 16 in, which is 5.1 litres as a stuff sack. Of the 55 bags we track that publish a capacity, 29 have room for it and 26 do not.

Volume is computed from Sea to Summit's own packed size, treating a two-dimension figure as a stuff sack. Bag capacities are the makers' published figures, not ours — 12 of the bags we hold dimensions for publish no capacity and are left out of the count rather than assumed. A stuff sack does not reshape itself, so read the headroom as room to spare rather than a guarantee it goes in easily.

How the Alto TR1 compares

Against the bags people cross-shop it with, measured rather than reviewed — including how many real frames each one fits.

How it compares

Against the 18 shelters & tents we hold published specs for.

At 1050g the Alto TR1 is lighter than 2 of 17 alternatives we track, which makes it among the heaviest we track. The category median is 822g.

At $380 it undercuts 7 of 17 of them, against a median of $360. That works out at $36 per 100gbelow the $50 median for shelters & tents.

Weight in category1050g
150g1559g
Price in category$380
$150$720
Lightest we track: Borah Gear Cuben Fiber Tarp · 150gCheapest we track: MSR Thru-Hiker Mesh House 1 · $150

Weight and price come from published specifications. Cost per 100g is a blunt measure — it rewards light gear and says nothing about durability or whether the thing works — so treat it as one input, not a verdict.

More in Shelters & Tents

Ultralight tents, tarps, and bivvies designed for minimalist overnight adventures.