Make Your Own 29er Bicycle!




Introduction: Make Your Own 29er Bicycle!

The pictures aren't the best because I never intended on making an Instructable but here goes.

I have wanted a 29er mountain bike for a while and stumbled across an old Trek 720 hybrid that I was going to just fix up to make into a commuter bike but was inspired. I had many parts around my shop and what you have will dictate where you can take this. For those of you unfamiliar with a 29er, it is a mountain bicycle with 700c wheels (like that of a hybrid) using a larger tire width making the overall tire size around 29" instead of the typical 26" found on most mountain bikes.

I am a welder with a number of years experience in making goofy creations and sculptures, this is the first really high end bicycle. Producing strong welds is crucial in this project so if your not experienced get someone who is. I used a MIG welder for this and am self taught I can't afford a TIG welder yet and have never taken formal classes but have become fairly proficient over the years.

Step 1: Strip the Frame

strip old frame down removing all parts and decals. This bike was particularly attractive because the early Hybrid bikes like the Trek 720 used higher quallity Cromoly steel and had the geometry similar to that of todays 29ers.

Step 2: Geometry and Head Tube

This bike being an older design used a 1" threaded head tube. This design is heavier and out dated so this was the biggest obstacle I faced. I had 2 forks to chose from and both were 11/8 threadless. I researched and found a great company called Nova Bicycle Supply and was able to order just the head tube and some other braze on parts from them that you will see I used later.

I measured the geometry and used the geometry from a bicycle made by Salsa as a template for how I would line everything up and weld it together.

Step 3: Remove Old V-Brake Bosses and Braze on Pieces

In this step a carefully cut off the brazed on pieces that guide the rear brake cable to mount to the rear brakes. This bike actually had Cantilever brakes so it also had a small tube that wrapped around the seat tube which I also removed. I used my dremel with a cutting disk for most of the work and my 41/2" angle grinder with a sanding disk to clean up the remains.

(you can see the sanding disk on the work bench under the frame in each picture)

Step 4: Remove Old Head Tube

I then cut the old head tube off the bike carefully using the 41/2" angle grinder with a cut off disk. I then used the Almost Jigless Frame Building design posted by drwelby

In the first picture you can see the frame chopped up in the back and the level on what will become the "Jig" for welding the new tube in place.

In the second picture I have the frame mounted to the jig and I am adjusting where the angle of the tube will end up. I had to take into consideration the length of the fork I plan to have because the fork I will be using is an inch and a half longer than the one in the photo. (hence the spacers you see under the new head tube)

I also have cut the new head tube that I purchased down to the desired length for this frame.

(FYI: I have a different fork in the photo and in the mock buildup because I was waiting on the final fork to arrive in the mail)

Step 5: Weld on Disk Brake Mount

I don't have any good pictures of this being done step by step so here is an explanation.

There are some really nice jigs that are sold normally for over $120 sometimes found on sale but I couldn't fit that into the budget and didn't expect to need it after this. (although I am reconsidering)

So I wanted to mount this brake inside the rear triangle like the Fargo is but I don't have the proper machined piece that Salsa uses to mount the brake caliper directly to the frame without the use of an adapter. With some fiddling I found using a front 6" brake adapter I could get the pads to make good contact with the rotor.

Step 1: Mount the disk to the wheel and then attach the wheel to the bike
Step 2: With the caliper mounted to the adapter in center (the caliper can slide back and forth for adjustment)
Step 3: Using a rear disk brake mount (purchased from frame builder supply) mount the caliper/adapter to the (in this case steel) brake mount.
Step 4: Place caliper over disk making sure the brake pads are in a good contact patch on the rotor and that the disk brake mount is in good contact with the chain stay.
step 5: Tack weld into place in a few spots
Step 6: Remove brake caliper/adapter and wheel
Step 7: Weld

I also welded some cable guides and an extra set of bottle cage mounts similar to what the Fargo has. I used mostly the standard style used on most mountain bikes but I did try this unique one that I thought would look cool. Unfortunately I found them to be somewhat weak and only used one on the frame. closest to the caliper.

Step 6: Paint and Logo

This is pretty straight forward, it is only a coincidence that the original color was blue I wanted that color from the begining. I chose Rustoleum's metalic blue. I first sanded everything wiped it down with acetone used a generic primer then on went the blue with some light sanding with 400 grit in between.

My hobby has been welding sculptures for some time and with some old copper lying around and running off a joke at the bike shop I began with a logo. Because I modeled the bike after the Fargo and my name is Morgan the name Morgo seemed to fit. I also wanted it to look somewhat Frankenstein after the bike so here it is below.

To mount it to the frame I removed some paint from a few points that will be covered then used a 2 part epoxy to glue it to the frame.

I then used an automotive clearcoat to clearcoat the entire bike including name badge. The name badge was polished but wiped down with acetone before gluing it onto the frame.

Step 7: Build the Bike

This bike is comprised almost completely from parts I removed from other biked I have. I invested maybe about $300 into the construction all the raw parts are very inexpensive. The only new parts I purchased were the road specific disk brakes (shorter pull for the levers used) and the Dura Ace bar end shifters (much cheaper than dual control). I also purchased new tires.

I chose the curved cyclocross handle bars because of the Fargo I was modeling it after you could easily mount flat bars more like a 29er. I also have a thinner cyclocross tire in the rear to reduce drag a little, that is another preference I went with due to where I will be riding this.

I hope this inspires more bike creativitivity!




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    34 Discussions

    This reminds me of a cyclocross bike with the drop bars and the hybrid frame. Nice job on the bike, it looks great!

    1 reply

    The main difference between this and a cyclocross bike is tire width. on my last trip my friend had his cyclocross bike and could only use 42C tires. he had a tough time when things got wet. I can use a 48C in the rear and a 2.2" 29er tire up front. this helped me a lot in the mud and crushed limestone they use to pave the multi use trails.

    thank you!

    Nice work! I've wanted to do this for a long time. How did you ensure that the head tube was vertical in the plane of the front triangle (i.e. parallel with the seat tube)? Did you have to face the top/bottom and ream the inside of the head tube for any warping due to welding?

    1 reply

    Honestly if there was one thing I would do differently it would be paying more attention to the top tube. I just used the grinder to shape the tube best I could to get it level but it isn't exactly level as you can see if you look carefully at the pics. Between April and May this year I used the bike for a week long camping trip from Pittsburgh to Washington DC along the Great Allegany Pass and the C&O Canal Trail which is all crushed limestone. The top tube is kind of high making mounting and dismounting tough especially with 30 or 40 lbs of gear strapped to the panniers. The bike has performed quite well over the years, I use it for commuting and weekend adventure touring rides. while the look of the 29er tire is cool and provides some comfort I have been running 700x45c tires almost 2 inches but not quite.early on Someone asked about weight. with the heavy duty rack I'm using and my Brooks Flyer saddle (kinda heavy but Super comfy) it weighs 33 lbs


    Awesome job, its funny I have wanted to put disc brakes on my chro mo vintage commuter for a long time but have been scared to weld on a caliper mount. I have access to everything I need at work, you may have inspired me to take the leap!

    ...But I wont blame you if I screw it up.

    1 reply

    Take the leap, I just attached the caliper on the frame mount installed the wheel with the caliper squeezed onto the disk where I needed it, then tacked the mount in place. It's not too difficult and with all the adjustments you can make on the brakes themselves it doesn't need to be perfect.

    Woe , that is quite an undertaking . think i've seen a 29er cheaply made with just adapters for disks and a fork before , but yours is all out . Beautiful re-working and reuse .

    Thank you, I have made many more things and seriously need to make a few more build threads. I have since added a table top belt sander to my collection of machines which allows me to make the notches in the tubing a lot faster and easier than before.

    I have the same frameset, and funnily enough, I was considering doing the same thing with it! I had one question though: did you do anything to the rear stays, or did you just leave the rear triangle alone? It seems like maybe a bigger tire on the rear would be more feasible for hard trail riding that a two-niner is suited for. Maybe I can build one of these guys; I was looking at a Fargo, but this mod looks a lot cheaper!

    Like the setup, but typically I see disc-brakes mounted on the upper seatstay. Why did you mount the caliper is on the chainstay? Did it preserve the ability to mount a rack and fenders? Was it difficult to find a compatible caliper given the unusual placement? Did you feel the need to reinforce the stays to resist the stress of the brake on the frame?

    3 replies

    Its commonly found on the touring bikes. It allows the user to still mount a rack without any special adapters.

    its like the salsa vaya. Theoretically the steel's strong enough to stand the force of the disc brake. It will stress it a lot and possibly lead to early frame failure but thats very unlikely.

    What about the the caliper? Did you have trouble finding one that would fit? It looks like you've got an an Avid BB5. Do you like it?

    Sorry I never responded in the past I need to keep better track of things on here.

    I mounted the caliper on the chainstay as said in the other persons comment so that it wouldn't interfere with the bike rack. Any caliper will fit you just need to have the distance from the center of the disc to the caliper correct in order to be sure the pad makes full contact. getting the angle took some playing around but once I had the right spot I clenched the brake and tacked the brake mount in place that way it was lined up as close as I could. The only difference in the caliper I used is the model. The "BB5 Road Mechanical Disc Brake" has a shorter pull allowing you to use brake levers for drop bars. They work great I have always been a fan of Avid brakes.

    Which head tube from Nova did you use? Was it this one: OS CRMO 37.0 X 200

    I'm contemplating a similar project as I'd really like to update an old bike of mine, but am limited by the 1" threaded head tube.

    1 reply

    I loved this frame build! I have a question about the head tube. Was it just a hollow tube that you cut to length, and is 1 1/8th diam.? How did the head set work? Was it pressed in?

    1 reply

    I ordered the head tube from a bicycle frame supplier called Nova Cycle Supply then cut it to the length I needed. The headset I am using is a Chris King 1 1/8 standard which is pressed in. You can order integrated head tubes from Nova and other suppliers but they are more complicated to install.

    As to my previous question concerning level. OK got it, I see you used axle center as level. Why didn't I catch that? Must be mesmerized by 29ers...LOL Again great job! Thanks!

    1 reply

    I am sorry I didn't get to your question, you are correct based off of the illustration from the Salsa diagram I made the chain stay level and measured the head tube angles from there.

    How did you determine the bicycle frame level? I assume the table and mounts are level, but what part of the bicycle did you use as the key part to determine level? Thanks and great instructable!