Nappy
08-09-2005, 12:44 PM
Well, I'm no expert but I've been thru this twice now and found out a lot of information along the way, so I guess I'll throw this out as a starting point for anyone wanting to hardtail a bike. Obviously if you have a Triumph the easy way is to buy a bolt-on, so I guess I should say that this is for anyone wanting to hardtail a Japanese bike.
Ingredients-
1 cheap XS650. Can substitute another bike.
A Grinder saftey glasses, and an assload of cutoff discs. The grinder will be your new best friend.
1 Good Welder or substitute a cheap welder to tack stuff together and a buddy that can do your finish welding
1 Tubing Bender (on sale now at HF for $70) or a buddy with a bender or two trees that are growing close together or anything else that will work to bend tubing.
Axle Plates- you can use the stock ones, buy a set at http://www.cyclexchange.net/ or if your welding buddy also has a plasma cutter (thanks, Clark!) make your own.
Tubing- 4 sections, each 4 or 5' long. I used probably 7/8"od that I got at a scrap yard. My buddy got 1" at Lowes (for probably 3X the price). Obviously don't use cheap thin shit like electrical conduit or something. And breathing Galvanized smoke isn't so cool, so avoid that.
Step 1- Cut it.
Strip that bitch down to the nekkid frame. But as you do, get some ziplock bags and label shit like you're at some sort of archelogical dig. It helps things go back together. Set up an Ebay box for stuff you know you're not gonna need. Once the frame is bare (you can leave the front and rear on), start cutting (photo #1). EXCEPT for the backbone, cut pretty much everything above the swingarm off. You can leave the swingarm attached, but basically you should end up with what's shown in photo #2.
Step 2- Stretch?
If you're keeping the stock wheelbase, skip this step. If you're going to stretch it or use axle plates other than the stock ones, you'll need to unbolt and remove the swingarm. Here's the plagurism portion of the Tech- I swiped photo 3 from an article by Lunatic on the Milk Barn board called 'How to Chop a Jap Bike'. Here's the link, it's a good tech piece...
http://www.network54.com/Forum/message?forumid=152868&messageid=1062039794
With the swingarm removed, cut across both sides evenly (a chopsaw works much better than a grinder here. Add metal evenly in the amount of stretch you want, weld it up, and put the swingarm back on.
Step 3- The Top Half.
Now with the wheels on mock up your bike to get the stance right. Either tack the swingarm or block up the frame well at the height you want. Now bend 2 pieces of tubing evenly and build the top of your hardtail by connecting the top of the backbone with the top of the axle plate.
I'm going to plagurize another time for photo #4 (I didn't take photos here on my build) this pic is from a guy named frogboy on the XS650-Garage board.
That's what ya need to do. Looks easy so far, doesn't it?
Step 4- Jig Thingys.
I built some cheezy little jig out of scrap metal to keep the bottom motor mounts from springing. I'll upload a photo of it, but don't make fun of my popcorn welds, I've gotten a little better since then. I also cut a piece of tubing the width of the rear wheel assembly. I slid out the rear wheel and put the axle thru this piece to keep me from doing something stupid like cutting thru my tire.
Step 5- The Ugly Half.
Now bend the two bottom tubing pieces, connecting the lower tubes to the bottom of the axle plates. The lower frame tubes get cut as you can see in the 'jig' photo. It's probably safest to do it one side at a time. Tack one side up then cut the other. This should keep your axle plates squared up. Eventually you'll have to cut off the bottom of the backbone, this is where having the jig is important so you don't spring the frame, which will make it ugly to get your motor re-mounted. After you get both sides connected, you'll have to bend a piece to connect the bottom of the backbone to the sides. Bend that puppy and tack it in there.
Step 6- Make it sturdy, make sure all's square.
Since I was only tacking my frame together for finish welding by a professional (Clark- are you professional?) this is the point where I made sure things were square and then sent it off for finish weld. If you're a decent welder, you can skip this step and take out the jig.
Step 7- Reassembly (not final).
Now start putting things back on it. You'll have to make up exhaust mounts, battery mounts, light, fender, and seat mounts, etc. so don't go sending the frame out for powdercoat quite yet. Plan out your controls, all that other fun crap. This is where I'm at on the 2 chops I'm building right now. Ideally someday there's such a thing as a teardown for final paint and assembly but I wouldn't know.
Again, I'm not professing to be some sort of expert. If the real bike builders have stuff to throw in here, it's certainly welcomed as I'm sure I forgot stuff or did some things the hard way. This is mostly stuff I found in tech pieces and just hacked thru myself. You can do it too, it's not that difficult.
Another option would be to just do steps 1 thru 3 and weld the swingarm in place, keeping the stock bottom back end. I thought about doing this, but it seemed a little cheezy after being into it that far already.
Happy Building-
~ Rob Napp 'Nappy'
Ingredients-
1 cheap XS650. Can substitute another bike.
A Grinder saftey glasses, and an assload of cutoff discs. The grinder will be your new best friend.
1 Good Welder or substitute a cheap welder to tack stuff together and a buddy that can do your finish welding
1 Tubing Bender (on sale now at HF for $70) or a buddy with a bender or two trees that are growing close together or anything else that will work to bend tubing.
Axle Plates- you can use the stock ones, buy a set at http://www.cyclexchange.net/ or if your welding buddy also has a plasma cutter (thanks, Clark!) make your own.
Tubing- 4 sections, each 4 or 5' long. I used probably 7/8"od that I got at a scrap yard. My buddy got 1" at Lowes (for probably 3X the price). Obviously don't use cheap thin shit like electrical conduit or something. And breathing Galvanized smoke isn't so cool, so avoid that.
Step 1- Cut it.
Strip that bitch down to the nekkid frame. But as you do, get some ziplock bags and label shit like you're at some sort of archelogical dig. It helps things go back together. Set up an Ebay box for stuff you know you're not gonna need. Once the frame is bare (you can leave the front and rear on), start cutting (photo #1). EXCEPT for the backbone, cut pretty much everything above the swingarm off. You can leave the swingarm attached, but basically you should end up with what's shown in photo #2.
Step 2- Stretch?
If you're keeping the stock wheelbase, skip this step. If you're going to stretch it or use axle plates other than the stock ones, you'll need to unbolt and remove the swingarm. Here's the plagurism portion of the Tech- I swiped photo 3 from an article by Lunatic on the Milk Barn board called 'How to Chop a Jap Bike'. Here's the link, it's a good tech piece...
http://www.network54.com/Forum/message?forumid=152868&messageid=1062039794
With the swingarm removed, cut across both sides evenly (a chopsaw works much better than a grinder here. Add metal evenly in the amount of stretch you want, weld it up, and put the swingarm back on.
Step 3- The Top Half.
Now with the wheels on mock up your bike to get the stance right. Either tack the swingarm or block up the frame well at the height you want. Now bend 2 pieces of tubing evenly and build the top of your hardtail by connecting the top of the backbone with the top of the axle plate.
I'm going to plagurize another time for photo #4 (I didn't take photos here on my build) this pic is from a guy named frogboy on the XS650-Garage board.
That's what ya need to do. Looks easy so far, doesn't it?
Step 4- Jig Thingys.
I built some cheezy little jig out of scrap metal to keep the bottom motor mounts from springing. I'll upload a photo of it, but don't make fun of my popcorn welds, I've gotten a little better since then. I also cut a piece of tubing the width of the rear wheel assembly. I slid out the rear wheel and put the axle thru this piece to keep me from doing something stupid like cutting thru my tire.
Step 5- The Ugly Half.
Now bend the two bottom tubing pieces, connecting the lower tubes to the bottom of the axle plates. The lower frame tubes get cut as you can see in the 'jig' photo. It's probably safest to do it one side at a time. Tack one side up then cut the other. This should keep your axle plates squared up. Eventually you'll have to cut off the bottom of the backbone, this is where having the jig is important so you don't spring the frame, which will make it ugly to get your motor re-mounted. After you get both sides connected, you'll have to bend a piece to connect the bottom of the backbone to the sides. Bend that puppy and tack it in there.
Step 6- Make it sturdy, make sure all's square.
Since I was only tacking my frame together for finish welding by a professional (Clark- are you professional?) this is the point where I made sure things were square and then sent it off for finish weld. If you're a decent welder, you can skip this step and take out the jig.
Step 7- Reassembly (not final).
Now start putting things back on it. You'll have to make up exhaust mounts, battery mounts, light, fender, and seat mounts, etc. so don't go sending the frame out for powdercoat quite yet. Plan out your controls, all that other fun crap. This is where I'm at on the 2 chops I'm building right now. Ideally someday there's such a thing as a teardown for final paint and assembly but I wouldn't know.
Again, I'm not professing to be some sort of expert. If the real bike builders have stuff to throw in here, it's certainly welcomed as I'm sure I forgot stuff or did some things the hard way. This is mostly stuff I found in tech pieces and just hacked thru myself. You can do it too, it's not that difficult.
Another option would be to just do steps 1 thru 3 and weld the swingarm in place, keeping the stock bottom back end. I thought about doing this, but it seemed a little cheezy after being into it that far already.
Happy Building-
~ Rob Napp 'Nappy'