How to fix bicycles - chain slip / skip tutorial on how to fix bicycle gear change issues

I created a simple video to show how to troubleshoot different issues when dealing with gears, chain and derailleurs. Look at this video to see what could be wrong with your bicycle gearing system.

How to repair bicycles - how to set up/fix v-brakes on your bicycle

 

Fixing up v-brakes can be challenging. I created a very simple video to explain how to

repair, service and set up v-brakes on a regular bicycle. 



 

 

 

 

 

 

 

Frame building basics #2.2 - Steel

Good quality and affordable steel has really transformed our world. In addition to being used for cars and motorcycles, quality materials have found their way onto bicycles aswell.

There are so many different steels (alloyed and non-alloyed) that I am going to try to describe three main types of steel and bring out a few examples.

• low carbon steel. Very affordable, average strength and fairly workable (cutting and machining). Very weldable and does not need artificial aging and hardening. Main alloying elements are Manganese and Carbon. For example 1010 steel.
• Alloyed steel. Fairly expensive, can be extremely strong. Difficult to work (cutting and machining). Fairly weldable, does need aging, but not tempering/hardening post welding. Main alloying elements are Chromium, Molybdenum, Carbon and Manganese. For example 4140 low alloy steel.
• Corrosion resistant steel. Fairly expensive, can be very strong. Difficult to work (cutting and machining). Fairly weldable (needs purging gas). Main alloying elements are Chromium and Nickel. For example 304 stainless steel.

Frame building basics #2.1 Aluminium (Aluminum)

Aluminium rose into the world arena after they developed a way to separate it from the ore using electricity .

There are numerous alloys used in frames and related parts and each have specific characteristics that suit specific needs. I will list below a few common alloys used in parts and what their properties are:

• 6061/6063 – a very very common alloy which is used to make bicycle frames and parts. It is very weldable and very workable. Has very good corrosion resistance and can be artificially aged and precipitation hardened. Can be extruded very well. Main alloying element is Silicon.
• 6105/6106 – a very common alloy used for rims. Has similar properties to 6061(has higher tensile strength), has a little bit more silicon in it, can be aged and precipitation hardened. Can be extruded very well. Slightly inferior workability compared to 6061. Main alloying element is Silicon.
• 7005 – used in bicycle frame prodction. Very strong (high tensile strength), also expensive and moderatly easy to weld. Inferior manufacturability compared to 6000 series alloys. Does not need to be precipitation hardened after welding. Average corrosion resistance. Main alloying element is Zinc and Magnesium.
• 7075 – used in parts production, very strong(comparable to steels), very expensive and hard material to machine. Used in places where weight is important, but loss in strength is not allowable. Should be artificially aged and precipitation hardened after welding. Main alloying element is Zinc and Magnesium.

This covers some of the aluminium alloys used in todays bicycles. 7005 series aluminium frames are a lot less frequent, since most companies have migrated to 6061-6063 aluminium. Those two are also most commonly found at different metal tubing resellers /warehouses.

Since 6061-6063 are the most common alloys out there, I am going to assume that you are interested in using them to make a custom frame. I would recommend using 6061-T6 aluminium (slightly higher tensile strength compared to 6063-T6). It is available in many different tube sizes/shapes, is easy to manipulate even with basic tools and can be polished very well.

But before embarking on a frame building adventure (which involved 6061-T6 aluminium), there are three very important questions to answer:

• Do I have somebody nearby who can Tig weld 6000 series aluminium really well?
• Do I have access to tubes that have similar sidewall thicknesses ?
• Do I have access to somebody who specializes in heat-treating /aging /precipitation hardening aluminium alloys?

- Question nr 1 is relatively easy to answer and people can usually recommend a good welder nearby. An average bicycle frame takes around 1-1.5 hours to weld up (personal experience).

 - Question nr 2 is also relatively easy – having tubes with similar sidewall thicknesses helps the welder. Having a tube which is 2mm and other which is 1.5mm does not seem like a big issue, but there is a thickness difference of 33%. In amperage that means 85-90 ampers for the 2mm tube, but 65-70 ampers for the 1.5mm tube. Easier to burn through tubes and also extends the HAZ (heat affected zone) outwards more than needed.

 - Question 3 is the biggest decider in my opinion. If you have somebody nearby who can help you and can do the whole process for 50-100 usd, I'd say go for it. The reason why I had to drop aluminium as a frame material was the high cost (was quoted around 500 usd) of post-welding processing.

Frame building basics #2.0 - materials, utilization and ease of manufacture

Bicycle frames these days are mainly made from steel and aluminium. There are advantages and disadvantages for both, but either are used extensively.

- Aluminium

There are different alloys available for both aluminium and steel. For example an aluminium frame can be made from 6061 aluminium, but handlebars are made from 7021 and rims made from 6106 series alloy. Different alloys have different properties that work for very well for certain applications, but not overly well in others. Some areas need extraordinary stiffness, others need to be flexible to make sure the parts don't shatter under load.

Aluminium frames are considered stiff, light but having shorter „lives“, due to the fact that the material/alloy has a limited number of cycles of use(1 million for aluminium, 7-10 million for steel, 12 million+ for titanium etc).

 

- Steel

For steel, it's a bit more tricky – there are many different alloyed and non-alloyed materials available + proprietary materials.

For example, most frames might have a marking of „HI-TEN“ steel – this basically means it is made out of a material that has high tensile strength. It does not certify/quantify what is considered high.

Some of the more common steel based materials can be classified as low-carbon steel (none to very little alloying elements), low-/alloyed steel (cr-mo steel) and corrosion resistant steels ( stainless, 304 or 316 series). Low carbon steel is the weakest of the bunch but also the cheapest to use (and easiest to manufacture with), while stainless steel frames take a lot more work to make them - tougher material and while welding the frame needs to be purged (cleaned out, argon is flooded in to replace regular air mixture to avoid cracks, porosity and poor weld beads).

- Excotic materials

There are also more exotic materials available – titanium, carbon fibre and bamboo/fibreglass.

Titanium is the most expensive of the bunch, where custom frames start from 800 usd / 720 eur upward with wait times of months. The most commonly used alloy is TI6AL4V, where titanium is alloyed with aluminium and vanadium.

Carbon fibre has become a lot more prevalent is the bicycle world and even rather cheap bikes have full carbon frames. Carbon can be a finnicky material, but if you take good care of your bicycle, it will be just as strong as a steel frame.
Carbon fibre frames can be built at home, but you need some specialized equipment for best results - a low pressure capable vessel, availability of good epoxy (West system) and good quality carbon fibre cloth. I will always recommend using unidirectional twill cloth. There are also videos on youtube that show how to lay up layers for areas that need it more.
 

Last but not least, there are frame made from bamboo and fibreglass. I have not first-hand experience with them, but from what I've understood, they are fun to ride and pretty durable.

Frame building basics #1 - common threads found on bicycles

 - Introduction

Bicycles that were built in the last 20-30 years have a set of common threads that are used for parts and accessories. While many manufacturers use common bottom bracket threads, children's bicycles and BMX bicycles have a different bottom bracket size and thread.

 - Bottom bracket (Please note that these threads are cut to 55 degrees (included angle)):

Imperial – 1-3/8-24 TPI . Meaning that the diameter of the thread is 1 inch and 3/8ths with a thread pitch of 24.

Metric – 34.80x1.05mm. Rarely used in metric standard, since all taps and dies are according to Imperial standard.

Please note I am not including French, Italian bottom bracket sizes as they are less common these days.

 - Accessory lugs (bottle cages etc):

 

Imperial – 3/16-24 TPI. Thread is 3/16ths in diameter with a thread pitch of 24.

Metric – M5x0.8. Thread is 5mm in diameter with a pitch of 0.8mm.

 - Rear derailleur hanger(that connects the derailleur to the hanger):

Imperial – none as far as I know(please email me if you have this info)

Metric – M10x1.0. Thread diameter is 10mm with a pitch of 1mm.

 - Rear hub axle threads (for cone nuts and locking nuts. While the sizes are similar, they are not interchangeable):

 

Imperial – 3/8-24 TPI.

Metric – M10x1.0.

 - Quick release sqewers:

 

Imperial – 3/16-24 TPI. Thread is 3/16ths in diameter with a thread pitch of 24.

Metric – M5x0.8. Thread is 5mm in diameter with a pitch of 0.8mm.

 - Thru-axle sizes (double check before buying replacements):

Metric: M12x1, M12x1.25 and M12x1.75mm. While the diameter is the same, the thread pitch is completely different (1mm is fine thread, 1.75mm is coarse thread and are NOT combatible).

 

Please note - all articles will be updated every few weeks with new and available information.

How to build a bicycle frame - welding jig special part 1

Hello all,

I had planned to write this post after the 24th, but because many people were curious and contacted me to get more information regarding welding jig's and how they were made, how much did it cost and if it actually worked. I'll try to answer as many questions below, if I leave something useful out then just give me a hoot and i'll add it in there :)

MDF/Plywood welding jig
If you are planning to build between 1-3 frames for your own use, I'd suggest using the following jig. While it is only meant to last the welding of a few frames, the cost and simplicity of manufacturing offsets the short lifespan. After about 3 frames, the jig is too soft to use. The main issue was that due to the softness of wood, the frames would come out crooked.

Manufacturing/machining the jig:
Cutting files and model can be found here: bicycle frame welding jig
As for machining the jig itself, I reccommend contacting a local wood working shop, furniture building company or a metal company with a CNC router or a waterjet cutting aparatus(note that plywood can be cut by a waterjet, MDF cannot, as it will absorb too much water and become distorted after a few days as it dries out).
Drawings: please send me an email or message here or reddit, to get the drawings - can't attach them to the blog directly :(

Cost and bill of materials:
 - 1 sheet of 18/20mm plywood or MDF. 0.7 to 0.8 inch thick to our american friends :)
 - M10 and M6 screws, 40 mm lenght. Unfortunately i have no idea about inch thread sizes, its about 0.35 inches of bolt thickness for M10 and 0.22 inches of bolt thickness for M6. lenght would be 1.5inches. if you want better results, you can buy a few washers too.
 - 2 quick releases, 1 front wheel and 1 rear wheel. The front wheel one is used to secure the bottom bracket, rear wheel one is used to secure he headtube(allows a maximum height of abot 145mm)
 - a jar of good wood glue
 - some wood screws(make sure you drill atleast a 2.5mm or 0.1 inch lead hole to reduce material splitting)
 - about 1-1.5 hours of your time and a good mood
Since I had all of this lying around the house, it cost me roughly 30bucks/20 euros to get the parts CNC cut by a local wood shop. If you have to buy everything from skratch, I'd estimate the cost to be around 75 bucks/55 euros. Works fine for first prototypes and gives you a good sense of how difficult building these things really is - (its not :) ).

Build order:
 - start by finding the material to cut the jig blanks out of. Plywood or MDF will do fine.
 - after you have gotten your material, take it to a place that will cut the blanks out for you. after accomplishing this, give yourself a pat on the back and have a break, this is the hardest part.
 - go buy your bolts, washers(if needed), wood screws and some good wood glue
 - start preparing your parts for assembly - sand rough edges, clear holes and give them a gentle sand to remove any collected particles.
 - drill lead holes into the headtube and seat tube (detail B-01, B-03 and B-04) and into 1 B-02 spacer block. after drilling is done, line the blocks up, add some wood glue in between and drive the screws in. wipe excess glue to make it look nice and make sure to check that you have a 90 degree angle(+/- 1 degree is fine).
 - with M10 bolts, the thread is quite coarse, so i decided to forgo any anchors and just threaded the bolts into the MDF. If you dont overtighten the bolts, it should hold adequately to complete a few frames.
 - you may have noticed that the rear axle block is missing completely -  that was substituted by a M10 thread rod with some nuts and bolts spaced at strategic positons. When i needed to change chainstay length i just unsecured one bolt and slid the thread rod/nut assembly up or down the slide - easy peasy.
- When using quick releases to secure either bottom bracket or headtube, use an anchor ( picture) - thread is too small to drive it directly into the material. In europe, the quick release thread is M5 - not sure if its the same for the US and CA.
- After getting everything secured and bolted togeather, make sure you check all angles before welding - this will avoid getting crooked frames.

I'm sure I left something out, so if you start the build and hit trouble, just send me a hoot and I'll give you a helping hand.

As an added bonus to the people who made it to the end - a singlespeed frame design I've been working on - feedback much appreciated :)

How to build a frame part 1: materials, welding and tube sizes(+ welding jig)

Hey all.

The point of this series is to show how we plan to build some nice Roadside Designs bicycles and frames.

All the info i'm putting up here will be OPEN SOURCE  - email me if you want any drawings to technical knowledge, i'd be happy to oblige. Unless its personal or difficult to explain, everything in the following series of posts should be information enough on how to manufacture your own singlespeed/fixie frame!

1) Materials
Bicycle frames are usually made from 4 common materials - steel, aluminium, titanium or carbon. More exotig materials are available, but difficult to source and difficult to manufacture with. Shortlist:
 - steel: heavy yet very strong. since thin walled tubes are difficult to acquire in Estonia, I will steer clear
 - aluminium: 3x lighter than steel, stiff but prone to strain induced cracks. at same strenght, it is 35-40% lighter than steel (my material of choice)
 - titanium: 2x lighter than steel, very stiff, very strong. difficult to source materials and very tricky to weld. will stay away right now
- carbon: 3-5x lighter than steel, extremely stiff, does not like scratches or dings. can be produced, but needs specialized tools, which are difficult to acquire. will stay away, but considering for future purposes.

I'm setteling with aluminium alloy, 6063-T6 and 6082-T6, because a good supply is available and its highly weldable and relatively easily machineable. It has very good material properties and nice tube sizes.

A quick pic of a frame I designed for a friend:

2)  Welding
Bicycle frames are usually welded, brazed or bonded. Welding works well with steel, titanium and aluminium, bonding with carbon and if you have a flare for nostalgia and beautiful and hidden welds, then brazing is the way to go for steel.

Welding has 2 main subtypes used with steel/aluminium/titanium - TIG(tungsten inert gas) and MIG ( metal inert gas). MIG welding is done with an automatic filler rod feed(think robots), TIG welding is done by hand, and filler added as needed(MIG can also be done very well by hand, but welding round tubes with MIG welders is best done with robots).
TIG welding produces very nice welds with a wide weld pool - ensuring good quality of the frame(for example, an aluminium frame can have a 5mm wide weld pool, while titanium frames have used 2mm and less).

Welding 6000 series aluminium yields usually very good results and thusfar has not produced any frames that have cracked(thanks to the good welders too).

3) Tube sizes

When looking for tubes, its generally a good idea to scout out what the importer has to offer. First - to get the lightest yet stiffest frame possible, second - to make sure that your bottom bracket threads and headset cups fit nicely. If you can get your hands on some oval/elliptical tubes, then go for it, at the very moment i'm limited to completely circular tubes. Or rectangular.

General sizes:

Headtube/bottom bracket - 34mm inner diameter, 2-3mm wall thickness(for inches, its 1.34 inner diameter, and 0.075-0.100 inch wall thickness)
Toptube/downtube - anything starting from 30mm up to 45mm, wall thickness 1.5-2.0mm(for inches, its 1.2 to 1.75 inches for outer diameter with 0.060 to 0.075 wall thickness.
Chainstays - between 16 and 22mm, wall thickness generally 1.5mm(or 1.0mm if you are feeling adventurous. For inches, thats between 0.6 and 0.85, with a wall thickness of 0.060 inches.

4) Welding jig

 A picture is worth a thousand words :).

More information regarding the project will come in a short while, probably on the 24th or 25th, depending how much food I consume.

Happy holidays :)