IFS Suspension

The first thing you notice when you look at the Collosus is the suspension. The bike uses Polygon’s 6 bar setup they call Independent Floating Suspension, or IFS. In this design, a four bar linkage, including the chainstay two small counter-rotating links, and the front triangle, determine the axle path, anti-squat, and anti-rise. This leaves the seatstay to drive the shock and dictate the progression rate of the 170 mms of travel. The IFS suspension on the Polygon Collosus creates a virtual pivot point inside the front triangle that results in a rearward axle path through the first 50 mms of travel, essentially into the bike’s sag, before returning forward for the remaining 120 mms.

All of this should, in theory, maximize both pedaling and descending performance. For the most part, it does, but the platform’s benefits are definitely muted by the bike’s girth. My size large N7 (setup tubeless and with pedals installed) tipped the scale at 41.2 lbs or 18.7. To be honest, this makes me wonder if the sophisticated suspension kinematics delivered by the IFS system are worth the increased weight, not to mention long-term maintenance. Now that’s not to say that IFS is a poor design, quite the opposite in fact! It’s a high performance suspension platform that I think would really come alive on a carbon frame with higher-end (ie. lighter) components, but it does seem like an interesting choice for a line of bikes designed to push the envelope on affordability.

Frame Geo and Features

In addition to isolating suspension parameters, the pivot and linkage placement of the IFS design also allowed Polygon to fit some pretty short 435mm chainstays on the Collosus. Short chainstays are a bit out of vogue these days, but I’m personally still a big fan of them in general, as well as on this bike specifically. Together with the relatively high bottom bracket, they manage to keep the portly N7 feeling surprisingly spritely and maneuverable through tight sections of trail and on jump lines. The frame does not feature any kind of geometry adjustment to run a 27.5” wheel in the back, but I can’t help but wonder if that relatively high bottom bracket might make it possible, as long as you were willing to make it a dedicated park/shuttle bike. The rest of the numbers on the Collosus are quite on trend with comparable 170mm enduro bikes. It features a 63.5 degree head tube angle, 77 degree seat tube angle, as well as a 634 mm stack height, 480 mm reach, and 1,266 mm wheelbase on the size large I tested. Collectively, these numbers do a surprisingly good job at hiding the N7’s weight while descending both tech lines and jump trails.

The aluminum frame on the Collosus N7 includes all the features you’d expect from a modern enduro bike; ISCG-05 tabs, plenty of frame protection, and, at least on my size large, room for a full-size water bottle. It also has impressive tire clearance, especially considering the short chainstays. The bike comes with 29” x 2.6” tires, which fit with a fair bit of room in every direction, and I can’t imagine, nor would I suggest, anyone running bigger rubber than that. One slight gripe I have is the relatively minimal dropper post insertion. My size large came with a 170mm post that couldn’t be fully inserted, which essentially negates the benefit of the short 415mm seat tube.  Lastly, for those of you as vain as I am, I personally think the frame looks great. The straight top tube, shock, and seatstay all run parallel to each other for a clean, aggressive look. 

Components

The N7 comes with a 170mm RockShox Zeb Base fork and Super Deluxe Select + shock. Despite sitting at the bottom of the Zeb range, I had zero complaints with the fork and found its narrow range of settings sufficient to get the bike feeling good on a variety of terrain. My preferred settings ended up being 90 PSI (about 10 higher than recommended for my weight), one volume token, and my rebound nine clicks from open/fast and the compression fully. I left the compression open on slower techier trails and added one click on faster terrain with bigger hits. For context, I weigh about 210 pounds in full riding gear and like my fork to sit a bit higher in its travel. 

While I found the fork very easy to get along with, the Super Deluxe Select + shock was a bit of a different story. The shock doesn’t feature any compression adjustment and even while running pressures as high as 230 PSI (with 5 clicks of rebound damping) I was still easily going through all the travel on bigger hits. Thankfully though, the shock features RockShox’s Hydraulic Bottom Out technology (HBO), meaning I couldn’t feel when I ran out of travel, but nevertheless I was. I’m guessing this could have been cured by using a volume reducing spacer or two, but I didn’t get a chance to try this while testing. One thing I did like about the rear suspension was the relatively supportive midstroke, that, combined with the short chainstays and high bottom bracket, made the bike relatively easy to bunny hop and manual, especially considering its weight.

The N7 comes specced with a Shimano Deore derailleur and shift lever paired with a SunRace cassette and KMC chain worked into the mix. The shifting was smooth, but still noticeably louder and more hesitant than a full Deore setup. That said, it’s still pretty impressive that they fitted a bike at this price point with a 12 speed drivetrain at all! 

My biggest, and honestly only real complaint about the N7’s spec are the brakes. The bike comes with a four-piston HD-M735 four-piston caliper in the front and dual-piston in the rear, mated to 203 mm rotors on both ends of the bike. I found these brakes to be woefully undergunned when compared the size of the N7 and the speed that it’s capable of carrying. There’s a chance that swapping the resin pads for metallic ones may be enough, but I’m guessing you’d need to go for a bit higher end setup, like the TRP Slate EVOs, to fully remedy the problem.

Lastly, the N7 comes with a pair of 29” x 2.6” Vee Tire Co. Flow Snap tires. These provided pretty exceptional grip, even in the rainy fall conditions I regularly found myself in while testing. That said, they’re not light, with a claimed weight of 1,400 g per tire, and are mounted to some equally heavy OEM aluminum wheels. Collectively, both wheels and tires weigh nearly 12 lbs or 5.4 kgs. I’ll once again circle back to the point I made about the suspension performance on the Collosus being overshadowed by the weight of the bike. It’s hard to get too worked up about the ideal ant-squat number when you’re working to spin wheels like that up the mountain. That said, I doubt many people are buying this bike in hopes of exceptional climbing performance and I’m happy to report that both the wheels and tires appear to be very durable. I never had any flats or rim damage while testing.

Climbing

As much as I’ve talked down on the N7’s weight and how it could negatively affect climbing performance, pedaling the bike up fire roads and even single track was relatively manageable. The IFS suspension worked as promised, and there was very little pedal bob, even with the shock left open. The bike also had an impressive amount of traction over wet rocks and roots and felt surprisingly maneuverable on techier climbs. As I mentioned earlier, the drivetrain was a bit noisy, but I’m guessing that was due to the inclement weather I was riding in and would likely be mitigated by replacing the KMC chain with a Shimano one.

All in all, the Polygon punches above its price, and I guess you could say, below its weight on the climbs. It’s far from a “climber’s enduro bike,” but still manages to be surprisingly willing on the way up.

Descending

My first descent on the Collosus was shuttling a trail I’d never ridden before. On my first run down I was pretty convinced that the N7 was the antithesis of everything I love about mountain biking. It felt muted, cumbersome, and, worst of all, loud. For context, this was on a moderately technical blue trail and I’d just wrapped up testing the new 29” Marin San Quentin, a 140mm hardtail.  And while the chain slap and cable rattle didn’t change as the day went on, my understanding and appreciation of the bike definitely did. This bike actually has some pretty sporty geometry, but its weight means that it has to be ridden quite aggressively to really make that come out. The harder I pushed the bike, the more fun it became. I kept this in mind on subsequent rides, and as long as I was willing to ride the bike hard it was exponentially more fun and capable than its $2,000 price tag would suggest. 

Unsurprisingly, the bike handled high-speed rock gardens and head-height drops with ease. I mentioned earlier that I found the stock shock configuration to bottom out relatively easily, but the RockShox HBO eliminated any harshness when that would occur. What did surprise me though was how fun the bike was to ride on flow trails, as long as they were steep. As soon as the trail started to peter out, however, the slow tires paired with the 170 mms of travel zapped any attempt to pump to maintain speed.

Lastly, as I mentioned earlier, the Tektro brakes were not up to par with the rest of the bike. Most of my riding was at a comfortable pace on familiar terrain, but I would have been pretty nervous to push the bike hard in a different setting. Thankfully, brakes are a relatively inexpensive upgrade, and one that I think most riders will want to do early on.

The Goat’s Take

I’ve always hated the notion that a bike’s price should match the rider’s experience; as if everyone buying an inexpensive bike was a newb and higher end bikes were only sold to advanced riders. And I think it’s safe to say that the Polygon Collosus N7 is also at odds with this stereotype. The bike’s portly size requires some relatively aggressive riding to make the most out of the sporty geometry and highly sophisticated suspension platform. I think a new rider would be lucky to do anything more than hang on while descending the N7, and it’s definitely not going to be any more enjoyable on the climbs. 

So who is the N7 for? To me, it’s easy. Park rats. It’s a super durable frame with lively, dare I say playful geometry, and a part spec that’s not going to keep you up at night if you break a derailleur or scratch a stanchion. Obviously, the weight wouldn’t be an issue here either. Lastly, the fork’s crown clears the down tube, so you could in theory remove the dropper, route the front brake through the headset, and go full slopeduro with the N7. The Collosus frame could also make for a pretty good enduro race bike as well, but I’d imagine  the heavy, slightly unrefined part spec on the N7 would make the experiencer less than enjoyable, let alone competitive. Polygon does sell the bike with a higher tier built, called the N9, that would be more up to the task.

In the end, the Polygon Collosus N7 all comes down to priorities. Thankfully, there are dozens of options for riders who prioritize a lightweight enduro bike and are willing to pay for it. But the N7 is designed for a different person; an experienced rider who’s more worried about counting bike park laps than grams and smiles as opposed to miles.  To be completely honest, if I had the choice of purchasing a higher end bike sticker price or the N7, I’d choose the latter and use the money I saved for a trip to the holy land of Whistler. So while it might not be for everyone, the Collosus N7 is a serious contender in the value enduro mountain bike market.