Columbia Convertible Commuter *FINISHED*

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Thanks everyone, I'm looking forward to getting this one done!

Mr renaissance those tanks you make are soooo cool . I have a space liner frame I would like to build next it's at my buddy's shop getting some magic powder shot on it right now . One of your custom tanks would look sweet on it do you have any more & how much are you selling them for ? Let me know when you can . P/M if you need to ..
Yes I do have them for sale! As kadillak64 pointed out, there is a link in my signature line but I'll P/M you.:)
Looking forward to this build , one of these days i am going to mount one of these tanks that i got from you on a frame but i am scared to cut into it
It's not hard, you just need to take your time and double check your marks as you go. I've seen your work, you should have no problems!
i saw two at the flee market last weekend and i wondered if they would work on those ...
Did they also have the racks? I had never seen one before Flying Zombie posted this one in the for sale section! The rack is the same as the Newsboy Specials.
 
Thanks to both of you! ;)

The timing for me has not been the best for bike building. I hope to slip in a little here and there and also use the time for ordering parts. Right now I just started a couple of signs that I'll be working on instead.:( For fun I started a 'build thread' for the signs HERE. :p

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I did start marking the tank for cutting and fitting. The masking tape on the head tube and seat tube is the first step toward finding the centers of cut outs. I'll get some step by step pictures and explain the process.
 
I got this BB converter last week and tried to install it. I don't know why but the BB opening is too small for it to go in. I tried it on a Spaceliner frame and it was just a little tight, but seemed like it would go in even though I didn't try to fully press it in.
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Are all of these converters a standard size? The ones that I have looked up online don't give the actual measurement. They usually just say something like 'for converting an American bottom bracket into a Euro bottom bracket'.

Any advise is appreciated before I try filing this one down!
 
I'm going to show the steps that I use for the frame cut-outs in the tank. I'm only getting to work on this a little each day, so it will be spread out over the next couple of posts.

The first thing I do is locate and mark the center of the head tube and seat tube. This is very simple to do. First I roughly place masking tape on the tubes. Then I take a yard stick and place it on it's edge on both tubes. Holding one end steady, I slide the other end along the length of the tube rubbing a mark onto the tape. This process is repeated on each end. I had to move the stationary end around a couple of times to clear the top tubes. My straight edge has been used a good bit for drawing lines with a pencil, so it has a build up of graphite on it. If not, you could first take a pencil and rub the lead on the edge of your yard stick so it will transfer to the tape.

I hope that makes sense.
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Next I roughly placed the tank on the frame and applied masking tape on the tank at the intersecting points. Then carefully laid the tank in place checking that all three points that intersect the frame are exactly where they need to be. This is mainly dictated by the points where the narrow ends line up with the top tubes and the seat stays but also checking where the tank crosses over the head tube.

I forgot to take a picture, but this is what it should look like (but with tape added) :blush::
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Then I took a sharpie and marked the tank at the center marks previously made on the frame.

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After that I placed tape on the second half of the tank, bolted the two halves together and transferred the marks to the other half. With both halves marked, the bolts where removed and the marks where connected from top to bottom with a ruler and a sharpie. I then used this line to lightly cut a groove with a hacksaw. The groove will serve as a drill guide. This was done on both halves at the head tube and seat tube locations.

I didn't get pictures of the seat tube end, but you get the idea:
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OK, now the tape for the marks is removed and the two halves are bolted back together. I also tightly taped the tank in three places to help insure that nothing can move around at all. I stuck a piece of tape on the outside of the tank as a rough visual guide for the angle that I'll be drilling.

Now, with the smallest drill bit in my index, I use the groove that I cut earlier with the hacksaw as a pilot hole to drill through while paying attention to the angle toward the other saw cut across from where I'm drilling. While I have the smallest bit in my drill, I drill all four saw cuts. Then I repeat this with my next larger drill bit and check each time making sure the hole stays centered between the halves and at the correct angle. After a few sizes up, I like to switch to a step drill. (You can get these for cheap from Harbor Freight). If you're careful, a regular drill will work, but a step drill doesn't tend to travel with you like a normal drill. If the hole does travel I'll just push the drill in whatever direction is needed to get it back to center. This is not very difficult with fiberglass.

Once I step up the hole size to 1/4" I stop!

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At this point I finish drilling with a larger step drill on the seat tube opening to a hole that is slightly smaller than the seat tube itself. For the head tube, I took a 1 1/2" hole saw (also slightly smaller than the head tube) and replaced the center drill with a 1/4" steel rod long enough to pass completely through the tank. This rod will keep the hole saw at the correct angle. I saw roughly 2/3 of the way through and stop. By stopping I still have the guide hole in tact. Then I switch to the other side and insert the guide all of the way through again and go ahead and cut all of the way through. At this point I switch back to the first hole and carefully line it back up and finish cutting through the last 1/3 of the hole.

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This would've been easier to explain on video (maybe next time). :rolleyes:
 
You should include these instructions with every tank you sell.:happy:
I have been wanting to do a youtube video for this, but haven't had the time to do it right.:( That's part of the reason I'm taking a little extra time here to explain it as best as I can with pictures and text.

Of course this is just how I figured out how to fit the tanks. I'm hoping as others fit theirs, they will share the methods that worked best for them.

There's not a correct way to do it, I've been making this stuff up as I go along!:21:
 
THANK YOU for those post , now it makes more since to me and I am going to try cutting one now , I was afraid to cut one because if I mess it up I cant weld a piece back in , I will let you know how it goes
 
After the holes are cut, I wrapped some 40 grit sand paper around a wooden dowel and hand sanded the hole the rest of the way until I reached the size hole to match the head tube. I'll do the seat tube the same way with a smaller dowel. I like the control of sanding it a little at a time until I get the size exactly where I want it. I don't trust a drill for that.

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Excellent ! i didnt do the tape on the frame , but it was pretty much the same method following your supplied instructions . The wooden dowel trick is cool , I used a air grinder with an extension bit . :crazy: hence yours came out a bit cleaner . I had to do a little of body work on mine LOL
 
I got this BB converter last week and tried to install it. I don't know why but the BB opening is too small for it to go in. I tried it on a Spaceliner frame and it was just a little tight, but seemed like it would go in even though I didn't try to fully press it in.
$_57.JPG


Are all of these converters a standard size? The ones that I have looked up online don't give the actual measurement. They usually just say something like 'for converting an American bottom bracket into a Euro bottom bracket'.

Any advise is appreciated before I try filing this one down!

RM....I put one of those 3-bolt cup converters in my 37 Shelby. I had no size issues. Maybe the shell is a bit small on that particular frame.... FYI, the Shelby developed a nasty creak yesterday on a long ride, and I found the three long screws holding the cups in the shell worked loose. Make sure you locktite them during the install..(post-grindoff):thumbsup:
 
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