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.

Building frames - a new series starting 22 of Dec!

Hey guys,

I'm in the process of starting up my own bicycle company.

Building frames - new series of posts, where you can join me in seeing how a bicycle frame starts from a bunch of tubes and ends up as a beautiful frame! I'll go over geometries, materials, cutting, threading and all manner of other stuff interesting and uninteresting :)

Planning to do 2 bike types - singlespeed bikes and fixie bikes. I'd love your feedback on my ideas :)

Singelspeed
Aimed to be ultrasleek and ultralight. Currently I'm trying to get it to weigh around 7.9 kg or about 17.4 pounds. Comfortable yet very agile to use. Frame size would not be variable, fixed at 60cm or 19 inches.
1-2 colors and a few other small things you could change - very basic yet very versatile.
* Light, sleek and sexy
* Easy to use, for city folk

Fixies
It would be of a similar concept to the singlespeed, but lacking a rear brake and utilizing a much more agressive parts - heavier gears, lighter(and smaller) tires, stronger spokes, a much more agressive fork/ handlebar combination. The frame would be almost completely made to order - almost anything can be changed.
* Light, svelt and agressive stance
* Customizeable frame

Frames
Custom frames and framekits for everybody! For the near future, I am limiting production to only singlespeed frames and biketrials frames. Pictures and info shall start arriving in the near future, when I've gotten a chance to get more pics!

Let me know what you think, feedback much appreciated. Pricepoints are still open, but hoping to keep the price in the 350-450 USD/  270-340 EUR range.

Thanks :)