Frame Builders Advice!

[The Renaissance Man]

I am looking into wading into the water of frame building and need the advice from you experienced builders (and anyone else who might have any insights) so that I can learn from your mistakes and successes.

Please feel free to think out loud about anything as it pertains to a scratch built frame even if you think it's obvious!

Things that I have been considering so far include:
What type bottom bracket (American or threaded)?
What type head tube?
What seat tube diameter?
What drop out spacing?
BB width?
Etc. Etc.

There is a lot of info on the internet (e.g. Sheldon Brown), so post any good links also!

Thank you in advance!!!

 

[fordsnake]

What type of frame; road, mountain, fixed will determine tube size and metal choices; steel, titanium, stainless steel, or aluminum? BB shells are offered in multiple widths and OD's. Dropouts are also offered in numerous styles. Most parts you can source from Paragon...http://www.paragonmachineworks.com/ Really good guys to deal with.
Nova Cycle, another frame builder source http://www.cycle-frames.com/bicycle-frame-tubing/home.php

 

[Bicycle808]

Totally not experienced here, but I'm thinking of doing the same thing, Renaissance Man. I've been pricing out straight gauge tubing, flat rectangular bar for dropouts, and basic info like what the ID of certain tubes are, to make reaming for seatposts and headsets easier for me. Specifics, as Fordsnake said, will be determined, to a large extent, by what style of frame you're building. I want to start by building a frame that I like, and I'm leaning towards the American BB shell b/c it offers a lot of "real estate" to weld on...But I'd look at a BSC shell if I were building a road bike.

You can buy pre-fab headtubes, but I'm looking at some straight tubes with IDs close enough to finish off with these things:
http://www.parktool.com/product/head-tube-reaming-and-facing-set-htr-1 A pricey tool, but one you're apprently s'posed to use, even on a pre-fabbed headtube, plus I'd like the flexibility of building bikes with longer-than-standard headtubes.

Places to find raw materials, beyond fordsnake's excellent links, would be Pacenti's site: https://www.bikelugs.com/
S&M has some good dropouts and stuff: http://www.sandmbikes.com/products/custom/d-i-y/
ONlinemetals.com has affordable steel and aluminum tube, bar, and plate, with no minimum order. I got some 7/8" 316L stainless for seatpost duty; they shipped super quick, and I intend to order again, once i get some torch-practice in on some scrap frames.

Rear spacing? 120mm is a good number; it will allow use of BMX hubs, track hubs, most 3 speeds, 2 speed kickbacks, singlespeed coaster hubs, and even derailer setups with 5 speed clusters.

Like I said, I haven't built a frame yet, but i'm feeling the itch. I'm mostly looking for ideas on how to build a jig that's reasonably adaptable to some variation in geometry and size.

Lastly, if you haven't yet, play around on http://www.bikecad.ca/ It's geared towards road and mtb applications, but it does a LOT of math for you, and a creative designer can figure out how to apply the info and data to other styles....

HTH. I'm subscribing to this thread, b/c I'm looking for a lot of ideas on the exact same topics.

Good luck with your plans, Renaissance Man!

 

[patman73]

you will need a tool for making fish mouths for joing the tubes together

 

[The Renaissance Man]

My early thoughts right now are toward building a custom cruiser with a little stretch and a mild rake. Not so radical that it's hard to turn or clear a speed bump. Also wide enough for modern hubs and good tire clearance. That's about all I've got at this point. I've been playing with designs but until I get deeper into the real world limitations, it's just 2D sketches.

 

[LukeTheJoker]

For your first couple of frames may I suggest getting some old junk frames and cutting the headtube and bottom brackets out of them to use? You will make mistakes for sure on the first couple and using second hand parts reduces the costs involved.

Luke.

 

[patman73]

size of wheels, rake of forks are good points to think about!

 

[barnbikes]

If you are going to do look into making an adjustable frame jig. That way you can set your head tube, crank tube and wheels in place and work from there. There are plenty on the web (everything from wood to slotted metal). Helps keep everything straight and in place.

Have to agree with Luke on cutting up cheap bikes for parts.

 

[KEMPRACING]

The biggest thing I have found no matter the frame size , stretch , rake or anything else is frame alignment , if you don't get that right your in trouble from the start , spend the time building a cheap fixture to get those three items in line and the rest is easy , And like luke said cut up old bikes first to save the money for other things you will need first , it takes a little to clean up old used parts but the savings is worth the effort , If I was you I wouldn't worry about it to much as we have all seen what kind of work you do and I don't think your going to have much trouble building frames

 

[Ichoptop]

Most of my early builds were based on the stretched Dyno. I made a template of the important locations (neck, seat, axles, and BB). This was because I had one and it was set up for my size and was the most comfortable thing I had ridden. I would go (and sometimes still do) to the police bike auction and buy clapped out old Huffys from back when they were still using steel of a good thickness for 5-10$ a piece then run them through the chop saw taking the bottom bracket and head tube. I built a few frames on the welding table but keeping everything straight and centered is difficult. Your best bet is to fabricate a jig to keep everything lined up while setting the frame up and tacking everything in place. Google motorcycle frame jigs to see what I am talking about.

 

[LukeTheJoker]

If I was you I wouldn't worry about it to much as we have all seen what kind of work you do and I don't think your going to have much trouble building frames

+1!

Luke.

 

[deven_science]

My $.02...

A jig is only needed if you're going to build several of the same frame. I have yet to invest in one. I usually just use the same sized tubing for the frame, and if it's all down on the work bench flat, then it's square.

BB, go American. You can always adapt to use Euro cranks, but you can't really adapt it the other way. There's also three piece crank options for the American BB that are nice. This is why Ruff Cycles, Basman, and others use American.

Head tube, if I'm using vintage forks, I'll cut one off of an old frame, otherwise, buy and use 1 1/8" (I buy from NOVA Cycles, which someone else linked to). If you use 1 1/8", same as with the American BB, you can adapt down to 1", but you can't fit 1 1/8" into a 1". 1" shims are cheap.

If I know which wheels I'm going to use, I use that axle to weld in the drops. If I don't know or don't have them, I use the 120mm standard.

Drops, I make my own out of 3/16" flat bar. I drill a 3/8" hole where I want the slot to end, and cut up to the hole with a cutting disk on my grinder.

The most important dimension is the one from seat to BB. Find your perfect amount of stretch, and determine the rest from there. My frames only have about 10" of stretch, because that's all I need to get the 30" I want from seat to BB. No need to make your bike as long as a Dyno limo if you don't need to. It won't fit on most bike racks, and it takes up more garage space.

I use EOM .065" wall steel tubing. Some use seemless or chromoly, but I figure if EOM is good enough for bicycle manufactures, then it's good enough for me. Plus it's only about a buck a foot for 1", which is my most used size tubing.

Take all this as you will, and good luck.

 

[sensor]

http://www.chopperhandbook.com/tubing.htm
Good stuff on tubing. Don't waste a ton of cash on something you don't need.
As for fitting parts, Get them, measure them,fit them to the frame you are building(also goes the same for you for fitment). Don't forget to check you chain line. Lots of people don't think about that till after the fact. Nothing says "AFTER THOUGH!" like a cog, chain wheel, derailleur or skateboard wheel to re-route the chain. As for the rest, trial and error. You seem like a smart guy, you'll figure it out quickly.
I could share more, but not online. You want that knowledge you have to come work with me, side by side.

 

[jerrykr]

I can't believe that no one has suggested you search for member Uncle Stretch yet. He has built some fantastic frames/bikes and offered up tremendous amounts of advice and how-tos about his projects on this site.

 

[sensor]

I have bent tubing around trees before. You must be some kind of elitist CeeBee.

 

[Rat Rod]

Yes...Uncle Stretch's post are all very informative.

Rumor has it he recently moved to a new house after living in the same place for over 37 years.

He's been busy setting up his new garage....that came with VERY TALL ceilings.

 

[ifitsfreeitsforme]

He just got that shed/workshop set up right.


Sent from my iPhone using Tapatalk

 

[The Renaissance Man]

Good information from everyone, keep it coming!!!

I can't believe that no one has suggested you search for member Uncle Stretch yet. He has built some fantastic frames/bikes and offered up tremendous amounts of advice and how-tos about his projects on this site.

Yep, I've followed several of his builds over the last couple of years that I've been here. He sure makes it look easy!

 

[The Renaissance Man]

For your first couple of frames may I suggest getting some old junk frames and cutting the headtube and bottom brackets out of them to use? You will make mistakes for sure on the first couple and using second hand parts reduces the costs involved.

Luke.

I think this is a good idea. I can probably pick up a Huffy Cranbrook cruiser for cheap and have everything that I'd need for a complete build to practice with.

 

[us56456712]

There is a book in our library that has all scratch built bike projects. The author uses a 220 volt AC stick welder and thick walled tubing. I think a lot of people on this site use his ideas because I see some of them quite often here. The book is called something like "Bike, Scooter and Chopper Projects for the Evil Genius". He basically gets a bunch of old bike frames, cuts them up and reassembles it into a new frame. I feel an American bottom bracket would be easier to use and can always be converted to a 3 piece. One of my friends made custom BMX and Mountain Bike frames in the 80s, but he sold his bike shop and moved away. He made is own universal jig table out of plate steel. He said to do it right you needed a planed and leveled slab of marble but thick plate steel was close enough. He used a drop dial gauge to take measurements off of his level jig table and could lightly tap everything into alignment. Any thing that is perfectly flat, even Melamine would probably work. He had slots and tabs welded onto the frame table. If you were only going to make one bike you could weld up the adjustable taps to hold everything on plate steel. Plate steel to hold everything really solid is probably a good idea. For a first project using recycled thick walled tubing is also probably a good idea. He had a homemade something that looked like an old press with holders welded on it that held the fork parts in place. That looked hard to build. He brazed everything. He was an amazing guy, he did all this while he was getting his university degree in I guess it would be "shop". He sold out about two years after graduation. I never built a frame, but I used to hang out as his shop and watch. Using existing recycled bike parts would be beneficial as you would not have to ream the head tube or bottom bracket. Perhaps you can buy these pieces that are already reamed? It would take me quite awhile to get the skills to just build the frame.