TallChop: This is a transforming TallBike to Chopper or the reverse.
I don't really know why I made it but I saw something that sparked the idea so I built it.
Step 1: Find Some 26 Inch Junker Full Suspension Bikes
1. Find 2 26inch Junker
Full Suspension bikes. Make sure one of them kind of works. The one that kind of works will be the main frame on the bike and we will call it the GOOD bike.
Step 2: Build the Rear Triangle
This was the most challenging and took the longest
because of the Air Shock I used. I think it took 2 months to get to me from Europe.
1. On your good bike, cut the rear triangle on the bottom stays just forward of the dropout.
2. Cut the Tube that Front derailleur claps around.
3. Completely remove the rear triangle from the BAD bike.
4. Cut both sides of the lower stays near the Bottom Bracket. Don't just cut... Read all the steps first and make your best guess at where to cut.
5. Now we need a piece of pipe that fits around the stays. see the Pink and Teal tubes in the pic. Take these tubes and slip them onto the the Bad bikes lower stays.
6. Now take the Lower stays on the Good bike and put them in side of the stays of the bad bikes. Jam them in there about 4 inches and then slip the tubes in step 5 over the tubes. Just like in the image above. Ok... this is the part that needs to be adjustable for right now so DO NOT weld it yet.
7. Add the part that you cut off of the good bikes triangle back. I just used some sheet metal screws to hold it for now.
Step 3: Figure Out Which Locking Gas Shocks You Need.
As you can see I have 2 shocks because
I didn't calculate the PSI right. I ordered a 600N locking shock when I needed about 1500N. I weight 170. So I added another 600N non locking shock and I can just barely get the bike to lift me if I lean all the way forward on the bike.
Notes: I think having a fast release shock would be best.
BIG NOTE: You should also build your fork in the next step to make sure all the bike angles look right before ordering your shock!
1. Find some good mounting points for your shock/s. As you can see on my bike I was able to find a bike that had an opening for the shocks to go through and bolted them to the rear shock mount. You might not be so lucky. You can bolt these anywhere. I almost mounted mine under the seat to the dropouts. You will have to move your bike up and down to figure out a good spot. You just don't want the bike to hit the shock at full compression or extension.
2. Now measure the length of the shock that you will need at full extension and full compression. If you minus the two you get travel/stroke.
3. Figure out how much PSI you need in Newtons you need for the shock. I weight 170 and 1200 Newtons barely lifts me if I learn forward over the handle bars.
4. Which Locking GAS Shock should I get? I found that there were 2 companies in the world, back in 2013 that had what I needed. Bansbach and MagnusInc One was a bit more then the other and I'm a cheap one.
The lever locking shock(FYI you do not want 600N): KK2X3-018* K0A7KK2-305-896/600N $152.17 The Locking lever: BE5.1-001* EasyTouch Bowden wire release system $44.10 2500mm
I don't recall what these were but they were needed: 1*20AKXXMXX,1*20BZ0500TAAKP,1*20ET1 Magnus Quote:
The lever locking Gas Shock: 732451 extended length of 28.7”, travel/stroke of 9.8” 1.0 GAS PRING;BOL;730M EXT;250M STR;600N $74.63 The Lever: CMA12076-10 consists of P/Ns 784575, 783234, and 012491
I don't recall what these were but they were needed: 0305BE CABLE RELEASE;$12.600 ,CMA12076-10 GAS PRING OPER;$7.50,
Double check that you have everything for it to work. Ah ya thats right you do NOT need the HAND LEVER that releases the shock. A bike brake lever works just fine with their cable end. So you need the Shock,the release thing the screws onto the shock and the cable.
5. When the shocks come in add them to the bike and run the cable to a brake lever.
Step 4: Make the Forks
Buy two 5 foot 1inch steal water pipe, Two 1 inch water pipe caps, 2 things that slid over the pipes that had screws in them, 2 New Brake cables. To make my forks, I removed the lowers tubes from the shocks. All cheap shocks can be taken apart by. (yours might be different)
1. Remove top caps
2. Use a long 6mm allen key and stick it down in the top hole where the caps were and find the allen bolt in the bottom of the tube. Undo the allen bolt.
3. Now take the lowers and slip the 5 foot pipes in to them. Drill 2 holes in each of the lowers through the steal pipe and bolt them together. I was able to find an old bike frame tube that fit perfectly around the steal pipe and fit very snug into the Lowers.
4. Add the Slip over pipes with screws and bolt them down with a strong cross brace.
5. Add a chainring for strength also. I just drilled 4 holes and screwed it to the Steal with sheet metal screws. ( Welding works also). This will help the fork to not twist when turning.
6. Put the tire back on.
7. Now slip the 5 foot pipes up through the Upper tubes and put the top caps on.
8. Extend the finished rear triangle all the way and lock it to the full length if your shocks are on it. If your like me, you will not have the shock in hand so just use a piece of 2x2 wood to hold it in place. (You can even ride it like this)
9. Adjusting the forks. YOU DO NOT WANT TO STRAIGHT (Up and Down/vertical/Plumb) OF A FORK! I think mine are at about 30 degrees. Drill 4 holes in the very hard chrome and through the steal pipe. Now put some strong screws in the holes to hold . the uppers to the steal pipe. (or just weld it) Screws have worked just fine. You want your forks to be the angle of the headtube when the bike is fully extended. You can go a little less if need be. This step should be done before ordering the shock, just in case!
Step 5: Get It Rolling
1. Dry fit it all together with sheet metal screws and bolts. Then weld it all together when you have it all aligned.
2. Extend the front and rear brake housing by taking the housing from the other bike and add the new brake cables. There are special ferrels that allow you to put housings together but I just used Black tape for now.
3. Extend the rear derailleur housing.
4. The front derailleur is gone, so remove the inside and outside chainrings and go with the middle one.
5. Extend the chain using some of the other bike chain. I found that mine was very sloppy so I used a ziptie as a chain tensioner. (See image in step 2)