boatbuilder

I'm new to pedal biking as we just celebrated our 25 th anniversary and the wife and I bought ourselves some comfort bikes. Really enjoying the bike rides.
I am a welder by trade and would like to build a bike or two. Does anyone have blueprints or where do you get them.
Thanks

Jim

e.din

Well I guess the point of a custom frame is that it's tailored to you. "blueprints" are geometry designs made by you to fit you. Paterek manual has pretty much everything you need to get your geometry set.

Andrew R Stewart 

https://www.bikeforest.com/CAD/index.php

Here's a link to an onlne design program. Andy.

repechage

When boatbuilder describes that he just purchased a comfort bike, the design of those is probably very different that what a manual will suggest or what bikecad will suggest too. Not a bad thing, as by comparing what is needed to create a bike that functions is applicable. Kind of like studying a lines plan of a hull, after you have been around you can tell in general how it will behave in the real world.

I would read and study things well before I took to welding anything.

boatbuilder

Funny you mention line plans of a hull. I built a 25' boat(aluminum) that we use for fishing on the west coast of Vancouver island, about 6-7 years ago. It took me 2 years of evenings and weekends. I always want to build a motorbike and even bought blueprints of a deign I liked but never got around to building one. Building a bike is something that wouldn't take long to do as I have all welding/fabrication equipment needed.( except jigs for bike). Not even sure what style I would want to build. Any decent blueprints of a comfort or road bike would do. If it doesn't fit me I could give it to someone that it does fit.
thanks for the replays.
Jim

Scooper

The point of building a bike yourself is to precisely fit it to the rider's physical dimensions, flexibility, riding style, and intended use. The first step is to measure the rider and translate those measurements and the rider's flexibility and intended use into the dimensions of a frame. Good Internet tools for converting a rider's physical dimensons into frame dimensions include Competitive Cyclist Fit Calculator and Bill Boston's Accufit. BikeCAD can then be used to design the frame and create the "blueprints" based on the rider's measurements and design parameters for the bike.

Here is my BikeCAD design for the bike I'm building for the 2013 AIDS/LifeCycle ride in June. It is based on my own physiology and riding style (I have relatively long legs and short torso).

Andrew R Stewart 

I dissagree with Scooper. The reason to build a frame is to do it. I think this is where many newbies get caught up in the passion and loose track of the result. Many think (from what i infer reading many threads) it's the cool thing to do, ride what you built. And when i first started out I felt the same. But with the help a lot of years and spending a little time with masters I see things differently. I now feel that the process is the reward. The learning, problem solving, the questions answered. After building a couple dozen for myself I still am looking for the next one and it's different aspects. Andy.

boatbuilder

I agree with Andrew. I want to build a bike to say I did it. I will research it more and build a bike that fits me. After building my boat I got real pleasure knowing I built it myself and it gets used many days during the summer. It has been on the water for 5 years now and has 4000 hours on the motors. I get lots of compliments on the boat. I just enjoy building things. I am also a hobbyist knife maker and built most of the tools myself for making knives.
I just want to build a few bikes for friends and family to enjoy.

Jim

MassiveD

I build and design boats, that was one of a couple of root things that got me into all this making stuff thing. Bikes are different from boats, sorta. There is not a big business of plans. I have boat plans that are hundreds of pages long. Though one of my favourite builds was a small catamaran that I built for fishing, sorta a green thing. What was great about it was that I knew what I wanted, and there was only one 8.5x11 sheet of instructions, plus the hull lines, which were in a simple table. It was great because I got the plan exactly as I wanted it. No material the designer liked or had access to that would drive me crazy sourcing.

Anyway, for the most part bikes are very simple, one does not need plans. essentially you need locations for the axles, the bottom bracket, a seat tube angle, and a head tube angle. The rest is pretty much connecting the dots as far as getting a bike to plan is concerned. Of course simple matters like axle position will affect one's fit to the bike.

With some oversimplification, the basics are that the head tube goes where it has to go given the wheels and tires you are using (get these first); the forks you will use (many builder do not make the forks, either because they are too challenging to make, and dangerous to screw up, or because they are specialty carbon or suspension forks); and the angle you are going to have for your head tube (steal this from an existing design, or copy listed specs, it is often 73 degrees).

The seat tube is usually 73 degrees and depends on your seat choice, and the body position your bike is set up for, and your seat post. Comfort bikes have outlier seat tube angles. One of the best ways to get seat post numbers is from a good bike you fit well. Given the correct posture on a bike, the seat tube relates you to the pedals, and does not vary much bike to bike, other than where odd postures are encountered, as with something like a time trial bike, or comfort bike.

Once you have your two verticals laid out on paper, the rest is easy. Your BB drop relative to axle height will be a range for the type of bike you are building. Again scavenge manufacturer's catalogs, and online source.

You draw in the top tube relative to torso fit needs and standover needs, you can get a number from online calculators. And the downtube, just goes where it goes.

The rear stays are the biggest build challenge, but design wise, they are mechanical. They go where the drivetrain needs them to be, wheelbase determines, drop as already mentioned, etc... You just copy what is out there.


The bad news in all this is that making bikes is a lot more difficult and uses a lot more expensive and weird tools that you may expect. Also, unless you are a welding expert, air aircraft or refrigiration, or pipe fitting, Tig or gas welder, you may have more of a learning curve than you imagine. I got into the whole chopper thing, and I can tell you bikes are way more difficult, frame wise.

ksisler

+5; Nice bike Scooper. Looks like you have done well in balancing all the design challenges. If you can, would appreciate some pix as you progress. //K

ksisler

+5 Massive for the general view; Bikes are generally rather simplistic, expecially for folks who have built a few frames. After a while a detailed plan really doesn't seem as necessary. The devil is in the details of execution though and I suspect that takes a bit longer for most.

On a humorous note; I have been quoted more than once to have said "the first recumbant bike resulted from a novice builder working from a few functional specs but no specific design or plan" while I actually did say "the first tandem, aka; the NagaCycle, probably resulted from a frame builder finally agreeing to allow his spouse to help out in the shop...and Mr Naga had no idea what he had started!"