Stephen Hilton Posts

Handlebars

Handlebars

I copied this handlebar from Jon Thompson, who made some in this fashion for fixies (http://tomobikes.co.uk). As such he made them quite narrow, ideal for London traffic, but maybe not ideal for hillier northern roads. His idea was that the design of most handlebars is not really anatomical and setting the handgrips at a more natural angle may be more comfortable. It also struck me that apart from being a simple design to make I may be able to accommodate some integrated lights so I decided to make my own version for my upcoming fixed wheel frame. This is in fact a project I have had on the go for some time. Realising the angle of the bars may not be exactly the same for everyone, or indeed exactly the same on both sides, I decided to start with a variable handlebar to establish the best position for me.

Oxy-Propane Brazing Update 3

Oxy-Propane Brazing Update 3

I use oxygen and propane for my brazing. I did not want the expense and extra safety concerns of storing and using acetylene, and in particular did not want to get involved in contracts given the small number of frames I am likely to build as a hobbyist. Though contract free acetylene cylinders have become available, personally I see no advantage in using acetylene for building lugged frames, but it does have advantages for fillet brazing. Propane is relatively cheap and long lasting and widely available for a small cylinder deposit. I use a 11kg cylinder. Smaller ones are OK but I have found the larger cylinder more stable, especially when using a gas fluxer, I don’t know why. Storing the smallest size cylinders of practical use of any flammable gas is common sense.
IMG_0925

Tube Mitering on a Lathe – Update 2

Tube Mitering on a Lathe – Update 2

Tube mitering is a fundamental part of custom frame building and I am sure there is always a need to be able to produce good results by hand and eye. Paper templates are a boon for speeding up the process and increasing accuracy but some time ago I decided to see how I would get on with some form of automation for the process. A milling machine, lathe or tube notcher can all be used but as I already had a lathe this seemed the way forward. Although I have since acquired a milling machine I feel the lathe is easier to set up for the process. I have described elsewhere making the tube blocks to enable this. My lathe is small with 500mm between centres.
I initially obtained several Coba-Tech hole saws from Stakesy’s metalwork machinery suppliers (https://www.stakesys.co.uk/hole-punches-hole-saws/hole-saws-arbors/coba-tech-10-tpi-fine-tooth-holesaws). These are fine tooth saws as opposed to the more usual coarse tooth saws I have used in the past. For cutting good mitres in fine tubes I would say these are essential and Stakesy’s were the only supplier I could find. Tube notchers are available, such as these: https://www.stakesys.co.uk/tube-notchers/tube-notchers. They are designed to be powered by a hand drill and are considerably cheaper than a lathe, though obviously are a one trick pony. The speed of the saws is set by the drill trigger speed and will be determined by feel rather than dials, but I am given to understand can be used quite successfully.

Coarse and fine tooth saws (fine on the right)

Coarse and fine tooth saws (fine on the right)

T47 and associated matters

T47 and associated matters

I was recently asked if I would be able to make a bike with an oversize bottom bracket and full internal cable routing, amongst other things. Although this project may come to nothing it has been on my mind for some time to use a T47 bottom bracket, my only personal reason for this would be that it gives the space to potentially run cables and cable guides right through. I have never been keen on partial internal gear cable routing which always looks untidy, and I have never been happy with the idea of drilling holes in chain stays.
I would choose T47 over press fit, do I need to say why, though I did make a press fit bottom bracket shell for a balance bike and it was OK as far as I am aware.
Ceeway do stock PF30 press fit bottom bracket shells, which appear to be the same dimensions as T47, so I presume it would be feasible to cut threads in a PF30 to make a T47. Paragon in the USA make both Stainless and Plain steel T47′s and Bear frame supplies do plain steel ones but both were out of stock at the time I looked. The upshot of this is I decided to make my own, how difficult could this be, well a lot more difficult than anticipated, but I got there.

Carbon Fibre Framebuilding – Any Interest? – UPDATED

Carbon Fibre Framebuilding – Any Interest? – UPDATED

The purpose of the first post on this subject was to try and ascertain the interest in the frame building community in constructing their own carbon fibre frames using tube to tube construction. I have only dabbled in adding carbon to my steel frames, but the techniques for building carbon tube to tube frames appears to be much the same, in as much as they can be cut and mitred and assembled and glued in a standard frame building jig. I have been put off by the subsequent wrapping of the joints to finish off and strengthen the build, feeling this has to be done properly. I am given to understand that it can be completed without the use of an oven afterwards, presumably by using the correct type of epoxy and that wrapping of the joints is not as difficult as it may appear. My own perusal of the internet has only come across projects to produce moulded frames, which as a steel frame builder, is a completely different way of working. It also would require more space than I have available. I have not found any books on the subject and there seems to be one teaching course in the USA, in Tucson, Arizona (https://www.framebuildingschool.com/carbon). There is however some useful information on several manufacturer websites, albeit rarely related to bicycle construction per se.

Custom Framebuilders Association and Public Liability Insurance – UPDATED

Custom Framebuilders Association and Public Liability Insurance – UPDATED

Several informal meetings took place between Custom Frame Builders across the UK with a view to establishing an Association. At present there is no formal organisation established but an intention existed to make it such, primarily as a talking shop for exchange of information. Additionally it had been proposed to offer a EN/ISO test of frame integrity in conjunction with Reynolds. It had been mooted it may cost around £300 for 631 tube set and test and the frame could be lugged or fillet brazed or maybe Tig welded. Regarding entry to the Association, the only clear cut criteria which was been agreed by all the participants was Public Liability Insurance. The long term structure and function of such an organisation I am sure would evolve over the years but I would like to think there may be a place for Amateur and semi-Professional builders within it. Unfortunately I have heard nothing more about this subject for some time and am under the district impression it has stalled. From my own point of view I decided I would have to investigate Liability insurance as, even though I have never sold a frame for profit, it would be nice to have the cover and indeed even making frames for friends and family it is a sad fact of life that one would be wise to have some indemnity against frame failure leading to accidents etc. I have now updated my previous post on the subject to reflect new information.

Cubic Boron Nitride – Any Use to Framebuilders?

Cubic Boron Nitride – Any Use to Framebuilders?

I have had some problems in releasing my home made seat tube heat sink from the seat tube after brazing, in as much as the heat tends to seize up the threads and cone mating surfaces making it difficult to loosen. Otherwise my simple design works very well. More sophisticated heat sinks may not suffer with the same problems.
I therefore decided to try a Cubic Boron Nitride lubricant, which is available conveniently as a spray quite widely at prices of £20-£30 a tin. Whilst expensive, a little goes along way. It is normally used as a releasing agent for stainless steel moulds for firing glass in a kiln and apparently can be used on mig welding tips to prevent spatter sticking. It is often used as lubricant for bullets in a powder form (thankfully sold only in the USA), and is the “ceramic” in ceramic lubricants.
It is supposed to be stable up to about 600 degrees centigrade or thereabouts, and still remains active for repeated use. I sprayed the components of my heat sink before use and am pleased to say it worked really well, the whole item unscrewed and removed easily and the product itself was not consumed.
IMG_4429
It is true that I was silver soldering, so the temperature would probably be well within the specification, but I doubt the internal temperature of the sink would reach brass brazing temperatures so I am optimistic it will still work. I’ve also used it to lubricate the threads on my Jig where they are exposed to heat.

Lugged Single Chainring Winter / Light Touring Bike

Lugged Single Chainring Winter / Light Touring Bike

I wanted lightweight bike with lower gears for cycling holidays and winter use. Rather than going for a mountain bike group set I thought I would try a Sram single ring road group, though I still have a healthy scepticism about it. Getting a low enough gear is not a problem with the 42 tooth inner sprocket but it does compromise the top gear because of the small front chainring. Even getting the parts was a problem as availability is sketchy and I have to thank Paul Hewitt Cycles for obtaining the components for me. However, I wanted to use caliper brakes and nobody, at present, makes a 130mm non disc rear hub to accommodate Sram’s XD cassette, which is needed to get a 10 tooth sprocket, so I have to settle for a 11 tooth.

Where do I Obtain  Bicycle Framebuilding Parts?

Where do I Obtain Bicycle Framebuilding Parts?

This is a question I am often asked. Anyone who has already built a frame outside a course will already know the answer, but it is something prospective builders may be interested in. The information is already provided in the Links page of this website but the following may clarify the options. There may be sources of cycle tubing and parts I am unaware of so I would always be grateful for further information about any other sources. I am not including suppliers in the USA with one exception. The added cost of importation to my mind is not worth it as most of the parts are available from the UK and Europe, though of course with us leaving the European Union in the near future, this balance may change.

CEEWAY
Ceeway in Erith, Kent, run by Peter Evans, is the main source of framebuilding supplies in the UK, being virtually a one stop shop.
They supply a large range of dropouts, braze-ons, bridges and bosses as well as lugs fork crowns and bottom brackets. Some of the lug sets are from Long Shen as otherwise you would have to order them from Taiwan, though the lugs do not always have their origin specifically identified on the website. Additionally they stock brazing sundries and will sell brass and silver rods in small quantities as well as a large range of frame building tools. They are constantly adding new items whilst maintaining a range of classic frame parts. Columbus carbon forks and sometimes other carbon sections are also available and these are available un-laquered at a saving over normal retail prices.
They are the main stockist of Columbus tubing and also stock a lot of older lines and obsolete tubes.
Fork blades are from both Reynolds and Columbus though you cannot buy Reynolds frame tubes from them except perhaps some non-current ones. They do however, offer Reynolds 953 stainless fork blades.
Ceeway are strictly mail order. Ordering is by email and as no prices are listed on the website you will receive a return invoice of cost and payment link which you can then pay if you accept the invoice.
There is a minimum order value of £12 (£10+vat). Delivery is pretty swift once the order is confirmed.
Website: http://www.ceeway.com      email: sales@ceeway.com

REYNOLDS
TECHNOLOGY
Reynolds sell their frame tubes direct. You have to contact them initially and they may ask you your frame building experience, though I don’t know if they ever refuse to sell to anyone. They will then forward a tube specification and price list. Most of the commonly used tubes are in stock but they have many more that can be ordered. Reynolds 953 stainless tube is often in short supply despite being a stock item. Reynolds 531 is still available only as a main triangle for lugged frames. You can then order by email and when the order is ready to despatch they will contact you for payment which can be by various methods but I use a bank transfer. Delivery after that is very rapid. They do also supply a range of dropouts, bottom brackets, steerers and lugs etc. There is a minimum order value of £150.
Website: http://www.reynoldstechnology.biz     email: toptubes@reynoldstechnology.biz

BEAR FRAME SUPPLIES
Based in Leighton Buzzard, Bear Frame Supplies morphed out of Bear Bikes and specialises in CNC machined dropouts, also making flat mount disc tabs and through axles. They will also make custom designs if you feel the need. There is a simple online shop for their stock items.
Website: http://bearframesupplies.co.uk

PARAGON MACHINE WORKS
Paragon is based in Richmond, California, and is worth a mention as it sells an extensive range of dropouts and other, often unique, frame building parts. Some of it’s products are now available from Ceeway. The parts, I think, are expensive, possibly because of the value of the dollar, but ordering is simple enough. I once ordered some rear dropouts online with no difficulty.
Website: http://www.paragonmachineworks.com

DEDACCIAI
Though only formed in 1992, Dedacciai is another Italian (as well as Columbus) company manufacturing a smaller range of steel tubing, though they also make titanium, aluminium and carbon tubes for the frame builder. Their steel tube range can be viewed at: http://www.dedacciai.com/website2016/index.php/en/serietubi17/alloy
It is possible to order direct and there is minimum order value of 250 Euros (which is £223 at the time I am writing this). Lesser value orders I think are subject to a surcharge of 12.50 Euros (£11). They also of course do a range of carbon forks which can again be obtained un-laquered at a saving. Forks and other frame components can be found on their website: http://www.dedacciai.com
Ceeway also stock some of their tubing

I could supply their 2017 price lists and an order form on request.

TIM CROSSMAN -** NOW CEASED TRADING**
I have no personal knowledge, as yet, of this manufacturer of handmade carbon fibre tubing but his products have been used by some custom builders, noteably Matt McDonough of Talbot Frameworks (http://talbotframeworks.co.uk); who has incorporated some of the tubes into steel designs which seems to be currently in vogue, especially with seat tubes. Whilst Dedacciai do sell carbon fibre tubes, they seem to be all quite large diameters intended for making full carbon frames. Crossman however supplies narrower tubing more suitable to using in steel lugged designs. He is based in the Ukraine but says he will supply worldwide.
Website: https://www.timcrossman.com

RANDOM SUPPLIERS
Our old friend EBay is of course a source, particularly of vintage tubes and lug sets. I have to say I have not been impressed with what I have seen for sale nor the price, however provide you are happy with the provenance of that which is offered, you may be lucky.
You occasionally see mainstream retailers offering frame parts. St John Street Cycles currently offers own brand Thorn Rohloff dropouts.  https://www.sjscycles.co.uk/frames/thorn-for-rohloff-stainless-steel-dropouts-per-pair/
Brick lane bikes offers vintage Zeus rear track dropouts should anyone be interested. https://www.bricklanebikes.co.uk/frame-spares-2
fullsizeoutput_6df

 

Framebuilder Tooling – Using a Milling Machine

Framebuilder Tooling – Using a Milling Machine

A Milling Machine is usually the second major machine tool any aspiring metalworker will obtain, after a lathe. More correctly known as a vertical mill as horizontal mills do exist. Whereas a lathe mainly turns objects in a circle, the milling machine will make objects square and cut slots as well as performing tasks that can also be done on a lathe such as drilling and tapping (being more flexible for this), boring holes and sawing (using a ‘slitting saw’) and mitering tubes.
 Basically it consists of a drill mounted on a column which can be moved up and down, pretty much the same as a pillar drill. The head is wound down slowly and has an accurate depth scale on the operating handle. There is also a plunge section as you would find on a pillar drill with a large handle which can be used for rapid drilling but is locked out for more subtle milling operations. The column can often be tilted from side to side to enable cutting at an angle but in practice this is not very useful and it is usually better to mount the work at an angle. The mill can be used as a drill press. Some mills are sold as mill/drills but I am not sure of the difference. Drills can be mounted in a drill chuck but other tools are best mounted in a collet chuck system which is more accurate and secure. The drill head itself can only move up and down, so the shaping of the metal is achieved by moving the table in two axes, against the milling cutters of which there are several types. Collet chucks and the like are usually attached to the mill head using a morse taper. These have a tapped hole in the top which is to further secure them in the drilling head with a threaded bar. Unfortunately a lot of potentially interchangeable lathe tools have a tang (a projecting bit of metal) which is to facilitate their ejection from the lathe tailstock. This means they will not fit into the mill head. I am mystified as to why tooling manufacturers do not make interchangeable tools.
*(Belatedly I have discovered my mill can accept tools with a tang by fully extracting the drawbar, I do not know if all mills are capable of this. I have not seen any reference to it anywhere so it may well be worth asking if you are considering a specific purchase)
fullsizeoutput_6c6 fullsizeoutput_6c4