Mon-Sat 8am-5pm PT
Sign Up
Serving cyclists
since 2002
Surly ExtraTerrestrial 27.5 Inch Adventure Tire Surly ExtraTerrestrial 27.5 Inch Adventure Tire
Surly ExtraTerrestrial 27.5 Inch Adventure Tire 27.5 x 2.5 - Black
Click Here for Larger Image
Surly ExtraTerrestrial 27.5 Inch Adventure Tire Surly ExtraTerrestrial 27.5 Inch Adventure Tire
Surly ExtraTerrestrial 27.5 Inch Adventure Tire 27.5 x 2.5 - Black

Surly ExtraTerrestrial 27.5 Inch Adventure Tire

Mfg PartNum:
In Stock Now
Ships Free!
Earn $7.50 in VIP credit. Click to Learn More.
This color is not eligible for VIP points
Please Confirm Color

Ride without limits with high volume, kick-ass adventure tires

When you're out on a ride the last thing you want is to be held back by your tires in any way.

Surly's ExtraTerrestrial Tires were designed to let you ride without limits by simply following the only tenets the brands has for tire design: they're high volume and they kick ass.

The ExtraTerrestrial tire was meant to serve as a heavy-duty off-road touring tire that shines on hardpack surfaces. It uses a nylon breaker in the sidewalls for cut protection, a molded pattern for anti-cut propagation, and a Kevlar cap under the tread to protect against flats.

The ET Tire uses a distinctly directional tread pattern and its width yields more traction than you might expect from a tire with such little rolling resistance. The tread is low profile with a file tread in between tread blocks.

The ExtraTerrestrial tire has enough width and traction for the soft stuff and won't bog you down on smooth or hard surfaces.

The finishing touch is a slate sidewall that brings an understated element of flair to any frame or kit.


  • Measures 27.5x2.5"
  • 60 TPI casing
  • Tubeless ready

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.

The product weight specified is an approximate weight based on the manufacturer's specifications (if available) or our measurement of one or two examples. For most products, the weight will typically vary by 5% to 10%.

Weight: 990 grams

Wheel Size: 650B (ISO 584) 

Tire Width: 64mm (2.5in) 

Tire Type: Tubeless Ready 

Threads Per Inch: 60 

27.5 x 2.5 - Slate Grey

Mfg PartNum: TR7506 

27.5 x 2.5 - Black

Mfg PartNum: TR7505 

Ordered by Most Relevant First
5 stars
4 stars
3 stars
2 stars
1 stars
Reviewed 2/25/2021
by Anonymous
Overall Rating
Good tire, mounts easily

No problems with setup. Tire is sturdy and rolls well, looks good too. Nice for commuting and groomed trail riding.

Was this review useful to you? Yes/No
Thank you for your feedback.

Articles will open in new tab.

A guide to bicycle tire sizes, both standard on newer bikes and common on older bikes.
Understanding older bicycle tire sizes.
A useful chart for determining the tire size you need for your bicycle.
Tire Tips   
Tips for proper bicycle tire mounting and tire safety.
A guide to understanding tire width.
A guide to understanding bicycle tire tread patterns and what you should look for.

We are committed to delivering outstanding value and service to our customers, every day.
Try us today to see why so many of our customers come back again and again.

*Orders received before 3:00PM Pacific time are shipped the same day (Mon-Sat). Orders over $50
are shipped free (USA only, excluding AK and HI). Some exceptions apply. See Shipping for details. 50


Want to save on all your Bike Tires Direct purchases? Sign up here for exclusive discount offers.

BikeTiresDirect on Facebook BikeTiresDirect on Instagram BikeTiresDirect on Strava
5741 NE 87th Ave (I-205 exit 23B) Portland, OR 97220 | 800-682-0570 | [email protected]