Bike of the Week: 1990 Rocky Mountain Fusion

WARNING: This post contains tedious, bike nerd content. My feelings won’t be at all hurt if you skip the text and just look at the pictures.

Introducing the 1990 Rocky Mountain Fusion

Introducing the 1990 Rocky Mountain Fusion

This winter I retired my old winter  ride, a 2007 Iron Horse Commuter. This bike served me well as my only bike for a couple of years before it was demoted to only winter service for two more years. By this time I was looking for something a little nicer for my winter ride. Preferably an older, good quality rigid mountain bike. What I ended up using was a slightly scruffy Rocky Mountain Fusion frameset  that had been kicking around, neglected, at Bikeworks North for several months.

About the Fusion Model:

The Fusion was first introduced in 1988. This bike’s frame was made overseas and then assembled in Canada. There was nothing unusual about this for the company, however, as in the previous year  six out of nine of the Rocky Mountain models were imported. By 1990, the year my bike was made, only the Fusion was not made in Canada. The 1989 model was made in Taiwan and I’m guessing that my 1990 bike was as well.  In the following year all the bikes including the Fusion were made in Canada. Ironically, I’m pretty sure that the pendulum has swung back and most if not all of Rocky Mountain’s bikes are made in Taiwan now. During these early years, the Fusion sat close to and sometimes at the bottom of the Rocky Mountain lineup. Even so, at  $760 in 1993 this was not an inexpensive bike.

1990 Rocky Mountain Fusion

It has Ishiwata triple butted chromoly tubing. Triple butted was a marketing term from the period and functionally it’s no different from double butted. The tubing mostly has a circular cross-section, except where the seat tube joins the bottom bracket. At this point it is shaped to an oval cross section, purportedly offering better stiffness under pedaling torque.  Looking at the bike you can see the hint of a sloping top tube, something Rocky Mountain was making a big deal about at the time. It’s nothing by today’s standards, of course.

1990 Rocky Mountain Fusion

It has sturdy rear rack bosses, eyelets for rack and fender in the rear, and for just a fender in the front. There is also nice attention to detail in the form of threaded holes for accessory mounting in the chainstay bridge, the seatstay bridge, and the fork crown

There are a few details that definitely place the era  the bike was made in. Firstly, the stem is the short lived 1 1/8″ theaded size. This size was briefly used in the early nineties but was quickly swept aside by the now familiar  threadless system. This isn’t  a big deal, but it will make sourcing replacements parts a bit more inconvenient. Secondly, while it has cantilever brakes in the front, it has a seatstay mounted U-brake in the rear. U-brakes were a fad in the late 90s, initially appearing on the chainstays, but later migrating to the seat stays before disappearing from bikes in the early 90s. There will be about that stupid U-brake later in this post.

Building the Bike:

Building this bike was the first time I’d ever started from mostly just a frameset. The only original parts are the frame, fork, headset, and probably the stem. All of the other components I either transferred from the Iron Horse or scrounged from my parts bin or the ones at BWN.

Starting off, the non-driveside crank threads were stripped. As we don’t have a puller at BWN, I cut the crank off with a hacksaw. The bottom bracket parts were worn out and I discarded them. Next, checking the frame with the alignment gauge showed that the rear triangle was bent to one side. Although this was my first time using the frame bending tools, the internet helpfully instructed me and I was able to realign the tubes, dropouts and derailleur hanger.

1990 Rock Mountain Fusion

I mounted XT levers with the shifters removed. These are great short-pull levers with good braking force and modulation. I used Suntour ratcheting friction shifters. Friction shifting is much less fussy than indexed in winter conditions, when your bike is coated in sand,salt and ice. These Suntour thumbies are as good as it gets. Levers and shifters are mounted on a Zoom 170 butted aluminum handlebar.

1990 Rocky Mountain Fusion

I used a set of older LX cantis on the front. A little finicky to set up but with good braking power.

Biopace triple crankset. Some people loved the biopace chainrings, some hated them. I'm indifferent. The front derailleur is a nice,earlier Deore. Te rear derailleur is a nothing-special Alivio. Winter is tough on the drivetrain. No  sense in using anything too nice.

Biopace triple crankset. Some people loved the biopace chainrings, some hated them. I’m indifferent. The front derailleur is an earlier Deore. The rear derailleur is a nothing-special Alivio. Winter is tough on the drivetrain. No sense in using anything too nice.

Dratted U-Brake.

Dratted U-Brake.

When I started building the bike I assumed that it was supposed to have rear cantis. Posts on the seatstays equals cantilevers, right? Wrong! It wasn’t until I tried mounting a set of V-brakes that I noticed that the posts didn’t have a hole for the brake springs. I also belatedly noticed that the posts were higher than cantilever posts, above the rim in fact. What the heck was going on? U-brakes, that’s what.

U-Brakes are a sort of caliper brake on steroids.They do have plenty of stopping power, but have a few peculiarities. When bike manufacturers started using U-Brakes they placed them on the chainstays. These tubes are stronger than the seatstays, resulting in less frame flex during braking. Unfortunately it also put the brakes down near the ground where they tended to get clogged with mud and dirt. Builders, didn’t quite give up on them yet, though, and for a few years they located the U-brakes up on the seat stays. However,in this location they didn’t really have any significant advantages over cantilevers.

The geometry of the U-Brake system causes the pads to contact the rim higher and higher   as the pads wear out. Eventually, they will start rubbing on the tires with unfortunate results. This is not an endearing feature. While riding my Fusion this winter I made a special point of monitoring the pad wear to ensure my skookum studded tires were not ruined. Also, these brakes didn’t make it easy to squeeze fat tires and fenders on the bike. If you look closely at the photo you will see that I had to grind slots in the fenders to fit them inside the brake calipers. Add, a rack to the bike and it’s a real pain to make adjustments. Enough about brakes.

The front wheel is a Mavic something-or-other rim with a DT Hugi hub. I’d rolled with this wheel for two winters on the Iron Horse before using it on the Fusion. It’s continues to be great. Winter riding is one application where sealed cartridge bearings are very useful. Next year I may do something similar for the rear wheel (currently Mavic on an 8-speed LX Hub).

I wasn’t able use my DIY studded tires with this bike as the front fork clearance is quite tight. However, I lucked into some great second hand Nokian Haka WXC300 carbide studded tires. These have fantastic traction (I was down riding on the frozen river one day this winter) but are a beast to roll when you’re on bare pavement. The narrow fork clearance meant that I couldn’t fit a fender with these tires, either. I also used a set of Schwalbe Marathon Winter tires for a while, too. These 26 X 1.75″ tires were narrow enough that I could use the front fender with them. They don’t have anywhere near the grip of the Nokians but they roll much better on pavement. I used them throughout the last part of winter when there was a lot of bare pavement but still a fair number of icy patches.


Riding through the winter months on the lighter weight Fusion was much more enjoyable than on the clunky old Iron Horse Commuter. It’s stable, fast, and nimble. I churned through deep powder, ground across pits of brown sugar, climbed hills of sheer ice, and pounded across rutted hardpack. All the while whistling a jaunty tune (or maybe not).

1990 Rocky Mountain Fusion

In the autumn, after building the bike and before the first snowfall,  I had the chance to take the Fusion for a test ride on the river valley singletrack. It flowed smoothly through the twisty trails, urging me to ride faster than my terrible off-road skills would normally permit. The difference between this bike and my previous imitation mountain bikes was noticeable. When I was racing down the the long, straight stretch leading to entrance to Kinnaird ravine I felt like I was outpacing the photons carrying  the visual information to my vibrating eyeballs. Good, clean fun.

It’s worth noting that the longish stem without much rise results in a very stretched out riding position.This aggressive stance felt great  on days when I was really digging in and pedaling hard.  However, on those commuting days when I was feeling less energetic,a more upright riding position would have been nice.

1990 Rocky Mountain Fusion

The Fusion also did a fine job of hauling cargo. I’ve loaded up the bike with panniers full of groceries on a regular basis and have hauled a few large awkward packages with no problems. These older rigid mountain bikes really are great all-around bikes. As a bonus, you can still buy them for cheap as they tend to be undervalued. However, there has been a lot more internet buzz about them in recent years so that change soon. If you are the sort that absolutely MUST have drop-bars,check out this forum thread to see some  conversions. For the summer, I’m thinking of going the opposite way and temporarily transmogrifying the Fusion into an upright city bike style. Stay tuned for details.

Whichever configuration it ends up in, this bike is now one of my keepers.

There will be a caption here


17 thoughts on “Bike of the Week: 1990 Rocky Mountain Fusion

  1. “here are a few details that definitely place the era the bike was made in. Firstly, the stem is the short lived 1 1/8″ threaded size. This size was briefly used in the early nineties but was quickly swept aside by the now familiar threadless system. This isn’t a big deal, but it will make sourcing replacements parts a bit more inconvenient.”

    Ya gotta love early MTBs (1980 to, what? 1995?) for things like this. Mountain bikes were “new” so manufacturers were more willing (or just stupid) to try different or funky things. My 1984 Raleigh Crested Butte MTB came with a 21.1 stem instead of the more standard 22.2. This was because they were basing it off a balloon-tired cruiser which traditionally used that ever-so-slightly smaller stem. A pain in the ass when I wanted to switch the bullmoose bars (integrated stem and bar) for something different. Thankfully this was before the U-Brake craze so I have a nice set of Deore cantis instead.

    But I hear you on the undervaluedness of this early era of rigid mountain bikes. Snap ’em up while you can before people figure out what they are worth!


    • Ha! When I realized how tight the fork clearance I decided to try replacing it with a wider one. Unfortunately, the frame has a really long headtube and I could only find one fork at bikeworks with a steer tube long enough. Guess what the stem size was. Yep, 21.1 stem size. Dang! It was a nice old Raleigh MTB fork, too, and it’d have nice if I could’ve used it.


  2. Great read! Just stumbled across your blog. I own 2 Rocky Mountain Fusions and dearly love them! I will have to keep an eye on that rear brake now that you mentioned the ‘flaw’.


  3. Thanks for the blast from the past! I was a total bike nerd in the 90’s, went away for university without a bike and then the whole market changed in the mid-90’s.

    I bought my ’89 Fusion new and after my trail days were done I converted it to a commuter. I’m only now buying a new commuter (cyclocross) to get a bit more performance during the weekly grind and for casual weekend road rides.

    I will not part with my Fusion and will keep it for really bad weather. I am basing my purchasing decision on how close the new ride feels to my Rocky (other than weight!). I think my Fusion will be my son’s first BIG bike! 🙂

    It still has original front wheel, derailleurs, brakes (including that blasted U), fork, seatpost, stem & handle-bar!


  4. Wow, that is a huge frame. I had a 19.5 inch 88 or 89 Rocky Fusion and it was tiny compared to that frame. Definitely no sloping top tube either. I sold that bike because i hated the U-brake (it had the chainstay mounted version). FYI, I’ve heard that you can run Magura’s on U-brake studs or you can stick some cool roller cam brakes on there as well if you hate the U-brake. I thought that by the 90’s they’d given up on U-brakes on the Fusion. If I had one of the slightly later canti versions come my way at a decent price I think I’d have to get it just for old time sake. Might make a fun drop bar version.


  5. Hey good read haha even tho your humble about it. I picked up an old rocky mountain with manitou three front suspension. I had been planning to build a RM Vertex I have sitting in pieces and instead I opted to strip the fusion down and left it raw metal. I put 3 coats of 50% gloss clear lacquer and the next day I put 3 coats of liquid plastic clear on top. I rebuilt the manitou threes and set it up as a single speed with just the front brake. It was sitting at 27 pounds but after I did the ss job and swapped rims I got it down to 23…its the lightest bike I have and wonder now if the vertex might have been a better choice. Im going to stick with the fusion for now and since building it as my 4th bike im now selling my specialized hardrock sport with disc brakes because its slow and I mainly commute and its slow and fusion has a T9310 xxxx serial number and after researching it my best guess was that its a fusion. It also has “ROCKY MOUNTAIN” stamped into the rear dropouts. Does your fusion serial number start with a T ? My vertex serial number starts with a V so im guessing that stands for vertex or possibly Vancouver where it was built…and then my T code might mean Taiwan….best guess there is my fusion is a 94 model…but its all clear as mud… anyways….great blog…take care..


  6. Nice ride! I just moved from Edmonton to Vancouver and I’m trying to fit some fenders, but having a heck of a time with that narrow fork. Did you end up cutting away part of the fender to make it fit? Tips would be appreciated!


  7. love your old fusion. i recently acquired one of similar vintage (1990?) that was no longer use able to a stripped threaded headset. so took it away for 20 bucks and looked for parts. thank goodness for the 1 1/8th head tube as i found an old Iron horse parts bike, stripped out and installed the threadless headset and was then able to also install the suntour suspension forks with disk brakes. All in im 30 bucks poorer and love my retro Rocky Mountain. It is priceless.


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