View Full Version : starting my FrontRunner

08-06-2012, 11:20 PM
Looking for a easy first build. I will look at my pile of bikes tomorrow to see if I can find one that will work. I picked one sat. cut it up sunday then decided it won't work. A lot of my bikes are (lugged)type bikes. Are they brazed together? I have not been around bikes for 40 years. I WILL need all the help I can get . This computer will be the biggest problem.

08-07-2012, 01:34 AM
Yes lugged bikes are brazed together and that does make it a little more tricky to modify them. The important thing to remember before trying to seperate a lugged joint is that they are often pinned and these pins will need to be drilled out first.

08-07-2012, 09:26 AM
It may be best to avoid lugged and brazed frame parts for your first build. It does cause problems, and the fumes from burning braze are not really healthy, so if you do use these parts, watch the ventilation.
It can be very hard to get a good weld over brazed parts if you are using gas welding. Stick welding seems to be OK apart from the fumes.
Steve G
Steve G

08-07-2012, 09:43 AM
I think you picked a great first build. I want to build that one too and i'm gathering parts for it I bet that will be one of Brads most popular builds in the future. Have fun with it and remember every one make mistakes and there all correctable. Remember to tack weld your parts first and make sure that's where you want it. Looking forward to seeing your build. good luck with it and there's are always plenty of free advice here

08-10-2012, 01:33 AM
Will a lugged fork on a rear wheel break? I picked what looks like the strongest one I have. I Have rear fork ready to tack weld.

08-10-2012, 02:07 AM
The only problem I see with a lugged (front) fork being used onthe back of the Fontrunner is that it is the wrong shape if you are to follow the plans exactly.
There will be no problem with the steel if you cut below the "lugs" but you will have to invent a new way to join it to the main boom. It is not an insurmountable problem, but if you have what I call a BMX fork it will be much easier!
I wonder if Brad can offer some advice here?
All the best,

08-10-2012, 09:52 AM
I am not sure what you mean wrong shape. I am not cutting the fork. I made two bushings to fit on the threaded end of fork. The bushings will be welded on each end of the threaded end. The bushings adapt the threaded end to fit inside the 1-1/2 sq tubing. I will drill 8 holes in sq tubing and weld sq tubing to the 2 bushings. The bushings are welded to the threaded end of fork. The problem is will the brazed connection between the threaded tube and the fork legs be strong enough to not BREAK.

08-10-2012, 10:15 AM
I think I see what you are doing. You have got round the problem of the different fork shape. I had second thoughts about my last post , as I saw this as a possible way out. There is a short brace between the fork and the seat tube. This will virtually eliminate any bending stress on the joint at the fork crown. If you weld the forks to the end of the bottom tube, but keep the heat buildup under control (weld wait weld wait) then I see no problem . If you leave out the brace I see big problems!
In most cases with lugged forks there is a pressed metal 'Cap" over the top of the forks. It may be best to remove this as it is only thin metal.
Sounds like you have it fairly well thought out.
Used entirely on their own, the forks are incredibly strong (infact they defy logic in many ways) But you have to be careful when you start welding near a brazed joint. The brazed joint is made above red hot, but below the steel welding temperature.
With MIG or Arc welding, you can avoid a massive heat build up that could destroy then entire brazed joint.
Wth Oxy acetylene you cannot avoid this heat. The only risk to a brazed joint is where you see red heat.
I would weld the forks to the end of the tube, plus use you bushing ideas, and use the brace as per the plans.
I doubt you will break it if you do all this.
Looks like problem solved.
If you intend to use other parts of this lugged frame, take a look at my thread, "two spirit tandem build", where you will see what happens to a bottom bracket.
No useful advice about lugged head tubes except to say, based on my one attempt--don't use a lugged head set!
Great to share ideas,
Steve G

08-10-2012, 01:52 PM
Thicktock For my bottom bracket I want 3 gears. If i need to use a lugged bottom bracket I will cut tubes off 1 inch long and tack weld round headed bolt on top of hole. I may never be able to ride this bike. I have never ever saw a bike like this and I am73. I will build me a trike. This is going to be a very cheep bike.

08-10-2012, 09:51 PM
I am not too far behind at 63--and I still run rings some of the young boy racers here!
Just build and have a go! My first ride on a recumbent were a bit wobbly to say the least.
Never actually fell off, or hit anything, but came close a few times.
The front runner does not look like a high stress frame, so it should be quite forgiving to small errors.
Have fun,
Steve G

08-11-2012, 01:33 AM
I cut my square tubing today. Cut some pieces to practice welding. It might be awhile before I weld on the bike. All my welding knowledge seams to have gone on vacation. Practice-Practice-practice, I think I need a lot. Is there some supper glue I can use?

08-11-2012, 05:00 AM
Yep--white hot steel--the trick is how you apply it!
Think we have all been through this--I would still prefer to use oxy, but have to put up with the sparky stuff.
Won't take long if you have done it before. Best advice---relax.
An auto dark helmet does help a lot at the beginning.
Steve G

08-11-2012, 02:47 PM
The first thing i bought was a auto dark helmet. Had good one at work. Bought a flux wire mig welder. My helmet at work cost more than my welder that I have now. My tools are cheep junk, but they can be made to work. If I had to buy tools like I had at work I would not be trying to build bicycles as a hobby. I will try the flux wire for a while. If that don't work I will get the gas and try mig. I know mig will make a nicer weld. Tig is the best but even with a cheep welder it is to expensive.

08-11-2012, 04:34 PM
Is this an AC unit or a DC unit? Charlie_R just had a line about converting his to DC to make the Arc more Stable. That may help a bit. But the nice thing about Gas shielded Mig is the reduction of smoke so you can see your puddle and guage how fast to move the gun better. It also reduces spatter and clean up. River did a demo after I had already convert my unit to Gas shielded. I am not sure if your unit is capable to convert to gas shielded but it was definitely worth it to me. But I did flux core weld for a couple years before converting as the convertion was over $200 including the Gas bottle. Some people never upgrade an do fine. Most of it is practise practise practise on every srap you have. Good luck.

08-11-2012, 06:21 PM
It wasn't me who gave the demo, I forgot who posted that

08-12-2012, 10:54 AM
My welder is a 110 ac dc welder. I have all parts to run mig. I can barrow tank for gas, but some day I will have to give it back. I hooked a vacuum hose to remove smoke. It helps.I have never tried to get vacuum hose to close to weld. You will know when you get to close. There should be porosity in the weld. Going to Iowa state fair today. Might rain and 77 for high. GREAT weather.

Radical Brad
08-12-2012, 11:36 AM
Look forward to seeing some photos of your build.
You "can" use lugged parts, but with a lot of extra work filling holes.
Easier to scrounge up a new frame.


08-13-2012, 08:02 AM
to give you an example of using lugged parts, see my "Two Spirit Tandem Build " thread.
Can be done, but a lot of work, as Brad says. And a headtube--advice is no at any time--it's like opening a can of worms!
Steve G

08-13-2012, 09:38 PM
Intrepid I finally figured out what the pin was you were talking about. Brad I welded up a big hole today. I really need the practice. I have several mountain bikes I could cut up. If I cant make this one work I will. This is going to be a town bike. I have not welded on the bike. My granddaughter will try to show me how to post pictures. I am a very slow learner. I said I was using a vacuum to remove smoke. It really helps until You get 3 sparks in vacuum. I don't think I will try that anymore. I caught it before any damage was done. That could have been a major problem.

08-14-2012, 08:28 PM
My workshop vacuum is an old aluminium bodied monster which doesn't mind so much if it gets a fire lit in its belly. Still not a good thing to do though :oops:

08-17-2012, 01:30 PM

This is an experiment to see if this works. Hoping for the best!

08-17-2012, 01:57 PM

This is with my camera, just trying to see how it looks. This is the forks I have, and my inch and a half square tubing that I need for this build. I have to go buy more wire.

08-17-2012, 02:36 PM
My granddaughter was here helping me learn how to post photos. The last one was with my phone. I may learn. I may even learn how to make a new paragraph. I ran out of flux wire and need to get some more. I can get gas if I have to. I need to practice.

08-21-2012, 10:52 PM
I built my frame laying on a table. The wheels do not fit the in forks square . Should I get a round file and file the bottom of the dropouts so the wheels fit in the center of the forks?This seams to be the easiest way to fix the problem. My welding still sucks. I still want to use flux core. Finely realized the reason I could not see is because ,I believe people with trifocals have a hard time seeing through a helmet. At work I had glasses that I taped in my helmet, I had forgotten about them. Where do I get glasses? What are they called. How do all you Zombies handle this problem?

08-22-2012, 12:37 AM
Actually flux core smokes so it may not be your glasses at all. I have many different layers in my lens, not trifocals but 10 to 15 to see at various distances. Smoke and low light make is hard to see. I went to Gas shield mig just to reduce the smoke and splatter and it improved my welds 100 fold over the flux core as I could see the puddle form and weld in a semi straight line over the joints. Not sure if that will help you but that was my issue. Had same issue with Stick welding and why I research Tig welding a lot. But the Gas shielded mig worked out great for me.

08-22-2012, 12:51 AM
I think they are called vision correcters in the welding trade.
Any welding supply house should have them--they just clip inside the helmet in the same place the black and clear glass is already.
I would not take out the original clear glass if you manage to fit it all in.
As to the wheel--assume you mean the rear wheel.
What is the error? Without seeing it I will stick my neck out and say --bend it! (if the error is vertical)
If the error is sideways, you may have to file the dropouts to get the wheel to point in the right direction.
But as you have not altered the fork length, this should not happen unless the bike was built wrong in the first place
Steve G

08-22-2012, 01:15 AM
Steve I made cuts in the side of forks, then bent them and then welded. Front and back forks. The frame looks straight. I never checked for level.I will check before i do anything. Pretty sure the forks are level.

08-22-2012, 07:26 AM
Bear in mind I have not built this bike. Which wheel is causing the problem>
I can see a need to widen the front forks as a rear axle is wider than a front axle.
I see no need to alter the rear forks except as required to weld them into the frame.
So without seeing what you have done, I am at a loss for a better answer.
There is no problem bending forks to get alignment --just need something solid enough to resist the force you have to apply.
I would have thought that all the bending needed for the Front runner could be done cold.
I have just changed the steering geometry on the Tandem, all done by cold bending in Me Lee's bi vice on a tree stump!
I have bent 2 inch pipe in the fork of a tree --but don;t ask how accuraye it was.
With more info I may be able to help more.
If bending will work, I would bend before filing. You can always un-bend a little. You cannot un-file!
Steve G

Radical Brad
08-22-2012, 10:26 AM
Yes, you can use a round file on the one of the dropouts to adjust the wheel position. Perhaps one of the legs was altered slightly more than the other? No big deal, just adjust the dropout.