Going to be building a aggressive hardtail frame something that will fit 140mm-160mm forks. it will be single speed thou (as ss rule)
its going to be made out of steal. (don’t know exactly what grade of steal might be mild steal)

what sort of problems am I going to have. can anyone recommend me some sites with info etc.

will I be best buying the bb shell and head tube.
how hard are horizontal drop-outs to make.

also how will i make sure the frame is strong enough etc.

really appreciate any help…

cheers Alex

First, learn how to spell: STEEL.

Bit of an ambitious project! Shouldn’t you be doing ‘City and Guilds Mobile ‘Phone Texting’ or some subject like that?

Good luck; ask people like Brant on here, and I’m sure you can get loads of advice!

Build a frame? You’re braver than me!

How good are you at welding? I would imagine that frame alingment will be the main problem

Probably worth speaking to a framebuilder for advice, maybe somebody like Argos Racing Cycles or Dave Yates. Forget mild steel, won’t be strong enough, they will probably recommend 4130 chromoly.

A very ambitious GCSE Project – I wouldn’t let any but the best of my year 12/13 students anywhere near this unless it were intended as a non-rideable full scale prototype. Definitely contact a frame builder if you can but be prepared for a healthy dose of realism.
I would expect the design and manufacture of a suitable frame jig as being the most important part of the project, with a frame as almost a secondary outcome. This would allow you to work with affordable mild steel sections to test the geometry etc. and allow for development into proper butted cycle tubing later when you have used the jig to practice welding or brazing. Unless you have access to a TIG welder at your school I would recommend brazing as the way to go as it is more likely to be a success.

I’d say probably overambitious. How is your welding- i’m reasonably competent and still would not attempt to build a frame. Even the design part is hard- ok you could just copy an existing frame but then it is not a design project. I’m not sure where you would go to buy a bb shell or head tube although if you gave someone the dimensions etc then they could make it for you.

Sorry, that is actually quite demeaning, what I wrote above. I apologise. That was out of order.

As mentioned, it’s a very big task; frame materials have to be the right type, of course, but the quality of welding is vital, and you’ve got to have all your angles etc spot on. Pro frame builders use proper jigs, to hold things in place. Not just a case of welding tubes together.

But, if you’re just trying to make something that looks ok, and won’t be ridden, then go for it.

In fact, I wish you every success. frame building is a dying art, and it would be great if someone like yourself could keep the skill alive.

Couple of names to consider: Dave Yates and Chas Roberts have both been known to build mtb frames, and perhaps might be worth you getting in touch with them. If you are serious about want ing to build bike frames, then you deserve all the encouragement and support you can get.

How about going down the Pace route and going for square or rectanguler sections

Try making a front hub. A lot simpler, still bike related, and might even be usable.

I made a wheel truing jig and dishing tool for my GCSE. Won young inventor of the year for my area (yes, I did point out that the wheel truing jig had already been invented).

I might ride it I don’t know yet.

my school has just had a the whole D.t department refurbished so it has all of the state of the art equipment etc.

I know two qualified wielders how will give me points, advice etc
atm I am just doing the planning, and will be building this time next year
I am doing the frame in the style of “Jeff Jones”
So i will need to get my wielding skills up to scratch.
my product design teacher who IMO is one of the best I have had says that it’s aright if I build a bike frame.

what other materials could i use instead of [list]STEEL[/list] and 4130 chromoly??
I asked if I could use titanium but he just laughed and smiled at me for obvious reasons.

Thanks a lot guys, i know it’s a bit well a fair bit overambitious but it’s what I’ve always wanted to do…

no worry’s RudeBoy

Al

Have a read of this thread on mtbr.

And all they let us make in metalwork at school was a ashtray!

Good luck mentalalex, don’t forget to post your results.

Go for it, mate! Seriously, it’s that sort of attitude that really pushes technology, engineering and design on.

I want to see regular updates, now. This could become an STW classic!

will do. I will post regularly about it etc
and i will post a pic of the final piece and my grade.

cheers guys loving all the support and encouragement.
I really appreciate it.

I can use any type of D.T Through-out my course e.g textiles resistant materials ,graphics And systems + control.

Al

Sounds like a good idea for a project but you will surely be able to get just a good of a mark doing something simpler?

But if you really want to do it and dont mind the work load then go for it.

Use steel, easiest to weld. Straight gauge stuff would be best for something like this. You could try asking the chap who runs Curtis bikes for some advice, they make all their frames ‘in-house’

Research geometry so you know how different lengths and sizes effects how the bike rides. You’ll be able to base your design around something thats already in production

I reckon a better project would be a chain device though. Current designs all seem to have issues with them in one way or another, plus it would be much easier to make one.

If it works out and the frame is fine I might ask you for one 🙂
Seriously!

Or, even though its been done before, something out of an ‘alternative’ material??

People have made bikes out of bamboo before now, just using headtube and bb shell from a donor frame.

Why don’t people use glass reinforced plastic rather than carbon fibre? (I have a fair idea why, but if you want to go down a ‘Jeff jones’ route then it needs to be different)

Plus, anyone can glue, but there’s still a lot of work and preparation in making a mould (probably a lot of wood work or sanding dense foam like what they use on model gliders maybe) and preparing the materials, choosing the right epoxy etc.

Again, wood should be rideable if you do it right. Maybe not to huck off a building or even for trail use but it’d could be a fair demonstration of dt practical skills and something really sweet to hang on the wall when you get your own house one day (assuming a fair lady friend who understands ;-).

Or as Brant said make a hub, also what about an up/downy seatpost? Its ‘only’ the same technology as office chairs but I can’t believe it can’t be done better or differently to the current crop?

GCSE tech – I made a coin counter to count and sort all my coins for me. Never worked. Still got an A*, because pretty much all the marks were for writing up about your faliures, not making them 😀

I’ve already started the planning etc nice to hear that Minish Man make me feel better.

but i am %100 dedicated two this, i know there is going to be a lot of work involved but I know/hope it’s going to be worth it, 🙂

While fibreglass/ carbon fibre would be fun they are not the kind of materials you’re likely to get to play with very easily in school environment and they are pretty hazardous materials.

You can use fairly bog standard steel if you’re not worried about weight. Its a lot more readily available, cheaper and gives you the chance to experiment and make mistakes without running up big bills, and I’d expect the school would have all the equipment you need sitting there. If you want to learn about and develop a frame design, or even demonstrate something about the geometry then maybe you would make two or three frames.

Slotted dropouts will be the easiest bit, just jigsaw them out of flat plate. I would buy head tube and BB as these need to intersect with bought components so they need to be just so. Beyond that so long as the bike fits you, or at least so long as it isn’t far too big and the geometry is broadly in the right range (keeping in mind there are only a few degrees difference between the extremes of mountain bike geometry), then all should be good.

You want assurance that the welds/brazes are good, otherwise so long as the headtube and rear axel are in good alignment the rest should just follow, even if it ends up a bit wonky it will all still work.

The time consuming bit will be preparing the ends of the tubes – cutting the ends of the tubes so they meet at the correct angles and follow the profile of the tube they join too. Try tracing the line of the weld around where you seat tube meets your top tube onto a flat piece of paper – quite a wavy line – now look at all the tubes that meet the bottom bracket – they all need to do that.

Somewhere theres a piece of software that you can use to design a frame – put in all the sizes and angles – and from that it prints out paper templates that you can then wrap around the tubes that map out the cuts you need to make. If you’re school as the kit and the skills then you can achieve the same result with a pillar drill and a hole saw, so long as you can get the tubes clamped and supported safely at the correct angles.

If thats all a bit too labour intensive you can look at lugged and brazed frames, old school but a perfectly legit way of putting a frame together. In this case you are buying all the lugs where the joints in the frames are and buying tubes that are sized to match. It like putting together a (very elegant) piece of mechano, but the end result and the decisions about geometry will be the same.

Nick in my workshop* put this prototype together with a tube-notcher (you can get a similar result with a pillar drill and a holesaw and some careful clamping) and a tube bender. Admittedly he is an engineer, but he’d never built a bike before and it all worked out first time.

*actually its his workshop, I just take up all the space

Can I just add – when I was at school – the nearest we got to anything like this was making a coathook. 2 Pieces of metal, one square, one shaped like a lollypop stick. Bend the stick shaped bit and rivet it to the square.

But… is the square really square? Most people never got beyond the square bit. File file file -give it to the teacher to check. No file file file – check. No. file file file file file file file file file no no no no no no no no

After five years there was only me and another guy who had a finished coat hook, some people were still filing a piece of metal smaller and smaller. Legend has it there was a next ‘thing’ we could have made – a candle stick. But I would still be making it now at that rate.

When I went to university I proudly screwed my 5-year precision-made coathook to the door of my digs and when I moved out I forget to take it. If anyone in Birmingham is passing an old shop at 422 Ladypool Road could you give them a knock and ask for it back? Its screwed to the back of the door at the back of the shop, or at least it was in 1994. Its got my initials stamps on the back.

Will pay postage.

Hi Alex

As said above – very ambitious but don’t let that put you off! I’m impressed that you are planning well ahead. But Brant does make a very valid suggestion…

I made a folding bike for my degree (but that was after an apprenticeship to teach me how to cut / drill / file / machine etc), but most of the marks came for the engineering / design / CAD etc rather than actually making it (which I still did – have it in the attic somewhere). Regarding using other materials – that bike had a front “triangle” made from bonded marine plywood with steel back end / fork / seat mast. Was plenty stiff enough so anything goes!

I’ve made dropouts from flat steel plate before. Does take a lot of time…. If you have all the gear at school can they not be done on a CNC miller?

4130 tube is almost impossible to buy in the UK. T45 (as used by Curtis) is a bit easier but still hellishly expensive and better suited to brazing (brazing stuff is easier than welding anyway). Curtis might sell you some T45 if asked nicely. Or can get it here £££ http://www.elmdonmetals.co.uk/Products_BS4T45_Stock.htm

Your best bet is become a regular at the local recycling centre and harvest their scrap metal skip. Maybe write a nice letter to the council to get permission for skip diving. Scrap frames are your best source of parts for this kind of project. e.g. a large supermarket MTB frame can be trimmed down to give a suitable BB shell ready attached to a longish seat tube (for your Jones design) and a pair of chainstays (dropouts removed ready for your own). Doing this will save an awful lot of work (most complicated tube junction ready made) and not really detract from what you are trying to do – maybe even some extra marks for creative recycling? Then just buy a few specific tubes where you can’t make do with scrap. Budget on about £15 a tube for plain gauge stuff from here http://www.framebuilding.com/

Reasonable quality big lengths of cheapish seamed tube from here
http://www.hublebas.co.uk/

Plenty of inspiration for what can be achieved with scrap at http://www.atomiczombie.com

Do you definitely want to make an aggressive hardtail?

The first thing that popped into my head with regard to the complexities of welding/forming steel junctions etc. would be to make a wooden frame instead by laminating your own profiles. You could design it as a kind of ‘comfy cruiser’ as there’d be a fair bit of flex in the design.
Lamintaion jigs are really easy to make and there is something very satifying about gluing layers of wood together, squeezing it all into a funky shape and seeing the end result pop out of the mould.

Hi,

If you go to a shop that deals with the supplier ‘Whiskers’ they will be able to supply columbus tubing. Which at trade isnt too dear and if the shop were nice could sell it to you cheap (i used to Manage a bike shop but have since left and the new staff are less than helpful).

Also if you managed to find an old (80s/90’s) lugged raleigh (or simmilar)frame you will find that the lugs will be pre set at around(? dont hold me to this)67 to 69 degrees whic is about what you would want for your hardtail. If you happend to find, say, a 20 inch frame you could remove an inch or so from the top tube and down tube and reuse. You could also cut the ‘middle’ out of the headtube lug to reduce it to your size, sleeve it and reweld or braze.

Once sprayed you will have a (kind of) functional frame prototype. Once happy look at bikebiz on line and get the supplier for renoylds tubing.
When brazing you ‘tack’ weld the tubes into place, pull into the correct angles.
You can do one ‘Angle’ at a time using chocks of wood cut into shape.
A certain frame builder does this. He was voted frame builder of the year at the international awards a few years ago.

And built my own lovely frame.