Yesterday was the first real test of the P3 and my building skills. I went with some friends to Holmbury hill for a short ride. Well that was the aim, but they met someone who offered to show them some of the less popular trails. The result a rather longer day on the hill and a test of me and the bike.
I would love to say I spent the time flowing with the terrain and catching big air, but actually I spent frantic moments of concentration learning new routes and learning the ways of a new bike. Bits fell off, the result of not be quite tight enough, I didn't although my foot slipped from the pedals. I also spent a lot of time letting my legs recover from the climbs.
First off it seems a torque wrench might be a worthwhile investment if you are building a bike that is going to be shaken by the ground. The handlebars slipped on a short downhill section, which was alarming. I also lost one of the front brake arms. It is possible that the brake boss problems are the cause or it may be the mechanic who put it together.
I also realise now that I need a few changes to improve the rideability of the bike. A 42 tooth front ring is not an ideal climbing ring for the average unfit weekend rider. It was hard work, perhaps made harder by trying to follow the lead riders up the hill in their granny rings when I needed to be going faster. I also can't push the crank round up in 9 for long enough. Perhaps one day I will be fit and trail wise enough to do this ......no I don't think so either. The other problem was that other the hardening trails as the back kick out over stones and roots I would lose my connection with the big flat (cheap) pedals . A few shin bites resulted. I am now looking for a nice pair of clip in pedals with a wide foot bed.
Am I disappointed to have the bike now? No, it is fantastic to be riding something that I have worked on. The tinkering with all the little details is, I guess, all part of the fun.
Sunday, March 27, 2011
Sunday, March 20, 2011
Well it beats washing the car
First impressions on riding out was that the bike was really comfortable. I had forgotten how much off the peg bikes are not designed round your length. So the distinct advantage of building from scratch was that I have been able to select component parts (mostly the headstem length) that factored in my body length. This also means my legs aren't cramping up under my arms, despite having a frame that is at the bottom of the size range for my height. There were two immediate issues that need some attention. The rear wheel isn't quite true, simple to fix. The gears have a habit of slipping, which isn't too serious and just needs some minor adjustment. Well at least I hope, but the worst case scenario is the shifter is more shot than it feels.
It felt odd to ride out with only 9 speed at your disposal, I kept reaching to change front rings and finding nothing on the handlebar. However, it really didn't dent my general speed over a rough, flat course. Very smooth would be my assessment of the overall ride, but I suspect it will glue itself to the ground on longer slopes. The front end did wash out in gravel on a twisty descent, but not seriously and no more than expected for a hardtail. I didn't push it downhill as there wasn't much and I had to be wary of other park users.
There is a pure joy in being able to do something and then look back and say I built that. I remember my uncle talking fondly in similar terms about a car and a motorbike he built from scratch. Its not the same sense of achievement of looking at a finished project and seeing others use it. Instead, because it is you using it there is a certain - connectedness.
Saturday, March 19, 2011
Evolution, revolution and mechanical assembly
When I started this blog I rather ambitiously likened myself as a bike builder to the blind watchmaker of Dawkin's fame. As if I can compete either with evolutionary forces or God, depending on what you believe! But then there are some serious points that can be considered from the whole process of building a bike and the creative process.
Initially, I think you need to decide if the process of life is creative or mechanical assembly. The bike building that I have just completed is essentially a mechanical assembly. You could argue that there was some creativity in determining the paint, and dealing with some of the potential problems. In reality though most of the choices were predetermined by the shape of the machine. However, in my mind whilst working there were creative processes working. I am thinking about frame geometry and sizes, wheel bases, tyres and the like. Now I am not a natural engineer and so this creative thinking is unlikely to result in a bike, but creative it is.
Think about all those bike designers who think about and have developed the geometry of the bicycle from the simple wooden horse, through the Penny farthing, and on to the modern bicycle forms we see today. Two hundred years of development and evolution. I find it all quite amazing that anyone would think of these changes to make a better machine. Then again perhaps necessity was the mother of invention. I can of course conceive that an individual would perhaps add a round "wheel" or find the addition of a pneumatic tyre beneficial. But you are left wondering how long things would take if it was left to a random stop/start process. The timescales are immense and the processes required to meet each stage complex. Understandable that we should seek a concept that describes what happens according to our own social understanding. The scientific method (often forgotten) is to formulate a hypothesis based on available evidence and to test hypothesis to destruction. So in reality all scientists are actually uncertain if any of the theories by which we build stuff and do things really works.
What about building a bike you say. Well I hardly did the work in a vacuum of knowledge. I have had a bike since I was 7 years old. So although perhaps not the most engineering of brains has managed to absorb one or two things in the intervening years. Then there are books, manufacturer's booklets and the Internet as a sources of information. Which, despite my best efforts I couldn't totally ignore. A good thing too, or I would still be trying to build the damn thing right now. My bank balance would be a lot emptier than it is now, and my shed would be full of components that did not fit. An excess of brake bosses is enough thank you very much. How long then for a blind bike builder to produce a modern bike from nothing?
Initially, I think you need to decide if the process of life is creative or mechanical assembly. The bike building that I have just completed is essentially a mechanical assembly. You could argue that there was some creativity in determining the paint, and dealing with some of the potential problems. In reality though most of the choices were predetermined by the shape of the machine. However, in my mind whilst working there were creative processes working. I am thinking about frame geometry and sizes, wheel bases, tyres and the like. Now I am not a natural engineer and so this creative thinking is unlikely to result in a bike, but creative it is.
Think about all those bike designers who think about and have developed the geometry of the bicycle from the simple wooden horse, through the Penny farthing, and on to the modern bicycle forms we see today. Two hundred years of development and evolution. I find it all quite amazing that anyone would think of these changes to make a better machine. Then again perhaps necessity was the mother of invention. I can of course conceive that an individual would perhaps add a round "wheel" or find the addition of a pneumatic tyre beneficial. But you are left wondering how long things would take if it was left to a random stop/start process. The timescales are immense and the processes required to meet each stage complex. Understandable that we should seek a concept that describes what happens according to our own social understanding. The scientific method (often forgotten) is to formulate a hypothesis based on available evidence and to test hypothesis to destruction. So in reality all scientists are actually uncertain if any of the theories by which we build stuff and do things really works.
What about building a bike you say. Well I hardly did the work in a vacuum of knowledge. I have had a bike since I was 7 years old. So although perhaps not the most engineering of brains has managed to absorb one or two things in the intervening years. Then there are books, manufacturer's booklets and the Internet as a sources of information. Which, despite my best efforts I couldn't totally ignore. A good thing too, or I would still be trying to build the damn thing right now. My bank balance would be a lot emptier than it is now, and my shed would be full of components that did not fit. An excess of brake bosses is enough thank you very much. How long then for a blind bike builder to produce a modern bike from nothing?
Saturday, March 12, 2011
Time for reflection
I promised, sometime ago, that I would pause and reflect on my experiences of constructing a bike from scratch. I think I am going to split this into sections, mechanical, philosophy and riding.
On the mechanical side of things I am surprised. OK so this wasn't a design and build a bike from bits of steel, but I did start with nothing in mind. So it was a surprise that the mechanics of assembling a bike were quite simple. True I did have to buy some extra tools that were not in my basic bike tool box. This added to the overall cost of the build so perhaps not a good idea if you don't plan to build another, but I suggest that having built one you will build another.
What you do have to be careful of is mixing and matching components. Some gear shifters don't work with some mechs. Some bottom brackets don't fit some frames and also need different tools. Wheel hubs will only accept certain sizes of cassettes. Even the frames have different capacities that affect headsets and wheel/tyre choice. All in all the idea of just picking things up in a random fashion is not a good idea. From a mechanical stand point, I'd suggest a list of choices, and a little research. Being a blind bike builder can be a slow and expensive process.
Start off with an idea of what you are going to use the bike for and develop that. There are no rules that say what you initially put on the road/trail is the finished article, so don't hold out for the ultimate kit if you can get hold of an alternative that will get you out riding sooner. Parts will always need replacing, and I missed being able to ride when I had taken both bikes off the trail.
As you develop the idea of what you need the bike for, a certain frame type and gear/wheel combinations follow on. Be guided by the price of components. Put the higher priced ones as the guide for getting the rest that are dependent on that.
Mechanical assembly is pretty straight forward. A bike is after all a bit of pre-fabricated engineering. Most bikes are developed to be relatively simple to assemble and parts in general fit a logical scheme. Whilst a generic understanding of how a bike fits together is important, either through analysis of an existing bike as a template or through experience, most of the build is suggested by location. Bolt front wheel to front axle, rear derailleur to rear stays on the right is not exactly rocket science.
Getting the tools for job is important, but a reasonable £30 bike mechanic kit will do all but fitting a headset and servicing the forks on a bike. As you can see from the blog the former needs some pretty specific tools, or which there are pro, amateur, and DIY versions. Depending on your choice of drive train you may also need a different tool for the bottom bracket. But if you stick to the taper type, you can save an awful lot of money if you are not requiring a high standard of performance.
Finally, what you don't know you can find out. I tried to do most of this build without to much reference to the internet and books, relying instead on my abilities to analyse a system and understand how it works. Having said that "Zinn and the art of mountain bike maintaince" was invaluable for checking my logic. If you get stuck and you need a practical demonstration then the Bicycle Tutor has excellent "how to " videos. Other riders were also helpful sources for ideas, although not always correct. You can find all sorts of conflicting advice on bike forums, based on conjecture and one off experience, they will give you an idea but don't take them as gospel. Instead, go to Sheldon Brown who has compiled lists of technical information in a much more rigourous manner.
What you do have to be careful of is mixing and matching components. Some gear shifters don't work with some mechs. Some bottom brackets don't fit some frames and also need different tools. Wheel hubs will only accept certain sizes of cassettes. Even the frames have different capacities that affect headsets and wheel/tyre choice. All in all the idea of just picking things up in a random fashion is not a good idea. From a mechanical stand point, I'd suggest a list of choices, and a little research. Being a blind bike builder can be a slow and expensive process.
Start off with an idea of what you are going to use the bike for and develop that. There are no rules that say what you initially put on the road/trail is the finished article, so don't hold out for the ultimate kit if you can get hold of an alternative that will get you out riding sooner. Parts will always need replacing, and I missed being able to ride when I had taken both bikes off the trail.
As you develop the idea of what you need the bike for, a certain frame type and gear/wheel combinations follow on. Be guided by the price of components. Put the higher priced ones as the guide for getting the rest that are dependent on that.Mechanical assembly is pretty straight forward. A bike is after all a bit of pre-fabricated engineering. Most bikes are developed to be relatively simple to assemble and parts in general fit a logical scheme. Whilst a generic understanding of how a bike fits together is important, either through analysis of an existing bike as a template or through experience, most of the build is suggested by location. Bolt front wheel to front axle, rear derailleur to rear stays on the right is not exactly rocket science.
Finally, what you don't know you can find out. I tried to do most of this build without to much reference to the internet and books, relying instead on my abilities to analyse a system and understand how it works. Having said that "Zinn and the art of mountain bike maintaince" was invaluable for checking my logic. If you get stuck and you need a practical demonstration then the Bicycle Tutor has excellent "how to " videos. Other riders were also helpful sources for ideas, although not always correct. You can find all sorts of conflicting advice on bike forums, based on conjecture and one off experience, they will give you an idea but don't take them as gospel. Instead, go to Sheldon Brown who has compiled lists of technical information in a much more rigourous manner.
Tuesday, February 22, 2011
let the good times roll
It is always good to get out on a bike, the feeling of freedom, speed and the pure adrenaline rush of turning the cranks are always a tonic. It is even better when you are riding the bike you have constructed from the frame up. Slightly different perhaps to riding a new bike, because generally you are certain that everything is set up correctly and all you are trying to do is determine how fast it stops and how tightly you can make the turns. So perhaps it is a good thing that I rode to our local park with the kids and so stopped myself pulling any crazy tricks before I was sure of my mechanical skills. A great leveller of ability, is when you have to stop to support and encourage your 4 year old on their bike.
So what did I find out about the mechanical soundness of the bike? Well, I need to make a small adjustment to the brake and gear lever as they aren't optimal, and I haven't quite aligned the limit screw to allow a jump on to the final cog. Apart from that everything else held together fine. The wheels go muddy, I wall rolled a few steep banks and popped a few (brief) wheelies. By the end of the trip nothing was squeaking or falling off, which is a positive. I washed the wheels off, not because they were muddy, but because of the risk that some of the brown stuff came out of dogs' bottoms, and the paint stayed on. All in all a good start to a career as an amateur bike mechanic and assembler.
Next steps, well I think after the small adjustments to be done it is time to get out on some tame trails near me, and then move out to the bigger challenges after that. I also think that now might be the time to reflect on what I have learned through this process, so I suspect the next few blog posts will carry the dos and don'tsl in bike construction.
So what did I find out about the mechanical soundness of the bike? Well, I need to make a small adjustment to the brake and gear lever as they aren't optimal, and I haven't quite aligned the limit screw to allow a jump on to the final cog. Apart from that everything else held together fine. The wheels go muddy, I wall rolled a few steep banks and popped a few (brief) wheelies. By the end of the trip nothing was squeaking or falling off, which is a positive. I washed the wheels off, not because they were muddy, but because of the risk that some of the brown stuff came out of dogs' bottoms, and the paint stayed on. All in all a good start to a career as an amateur bike mechanic and assembler.
Next steps, well I think after the small adjustments to be done it is time to get out on some tame trails near me, and then move out to the bigger challenges after that. I also think that now might be the time to reflect on what I have learned through this process, so I suspect the next few blog posts will carry the dos and don'tsl in bike construction.
Tuesday, February 15, 2011
On the road again
Swapped tyres for a thinner profile at the back, and hey presto no problems with the tyre being jammed into the frame at full inflation.. Of course now the bike just looks plain silly with a big fat free ride tyre on the front, so I will have to find a few moments to change that for a different one as well. If I had the spare cash I would buy some new ones, but as I don't I am robbing them off the old bike. A bike which will set on the work bench of the shed for awhile awaiting a new headset and a pair of forks.
The advantage of the tyre change is that suddenly I look less flashy and a little more "stealth" for riding out with all those fit young dirt jumpers. No-one will expect me to be making big air or downhilling in Scotland every summer. Certainly, not until I have invested in a full face helmet. One very bruised face from a "minor" tumble is enough thank you very much.
The advantage of the tyre change is that suddenly I look less flashy and a little more "stealth" for riding out with all those fit young dirt jumpers. No-one will expect me to be making big air or downhilling in Scotland every summer. Certainly, not until I have invested in a full face helmet. One very bruised face from a "minor" tumble is enough thank you very much.
Sunday, February 6, 2011
Cry "Havoc!" and let slip the dogs of war.
Finally, the bike is complete! There are a few niggles, like the fact that it is unrideable in its current configuration, but it is complete and I am hoping that the issues can be overcome quickly and cheaply.
Finally, I have brake bosses that at least partially work with the XT brake arms. If you look in the photograph you can see the three versions that I managed to get. Look at the different size of the lip next to the screw and if you can compare the profile of each boss fitting. Not all bosses are the same and so when you get to adding brake arms it is clearly a question of the right ones for the job. I'm keeping the others in my spares box for anyother job. The one to the right is from Tiawan and made of titanium, but is far better quality and has a better profile than the others. Even so it does not provide a perfect fit for the brake arms, with a small 3mm gap between the frame and the arm. I am hoping that this will not cause to much strain in braking, because if it does I will need to see if the adaptor kit works any better.
Confident that I would at least have some braking potential, and finding my Sunday afternoon surprisingly free, I continued on completing the last jobs on the bike. First up chain onto the bike. Simple enough, I'm not going to explain the ins and outs as it is done well enough in Zinn and in other bicycle maintance books. I had not appreciated how much you need to be an octopus though. I was most pleased that I was fixing the chain together with a powerlink and not having to force a pin into place with a chain tool. Really simple, but a little more fiddley was the task of aligning the rear derailleur (mech). Setting the high and low screws to match the limits of chain movement is simple in theory. I found that holding the derailleur over the low position and looking at where the limit screw was holding gave me more confidence that this phase was set up.
I then needed to cut the housing for both the brakes and the gears. I wish I had a proper wire cutter for this as it was hard work with the cutter on my old pliers, but they worked adequately. Fighting to not strip the wire as you thread it through the housing is also a must. Not only does it make it difficult to thread, it will also weaken the cable. Finally, I fitted the handlebar grips, (some lizardskin ones which have lock down bolts) and adjusted the shifter and brake levers into position.
I have however, created a bike that is a little overdeveloped in the tyre department. There is an alignment issue with the rear wheel which I think is easy to sort, but there is one major problem that is preventing me from riding the P3 today. The tyres are too fat. Inflated the rear tyre is one large balloon wedged between the downstays. Not so bad at lower pressures, but it still rubs the frame badly. The original tyres that came with the wheels, I seems to remember, were fine. So I will try a switch back. In the short term there is a potential to borrow some from Uncle Riotous who is storing a load of spares. The ultimate will be a rebuild of the hub on a narrower rim. Whilst I have enjoyed assembling a bike from its components and I even feel that framebuilding might one day be an option- I have visions of being an old man with a shed in the Welsh mountains building custom frames. Wheel building is an art that requires specialisr equipment, much patience and many hours. So to rebuild the wheel I think I may need to employ my local bike shop.
 |
| brake boss line up |
 |
| just a small gap |
Confident that I would at least have some braking potential, and finding my Sunday afternoon surprisingly free, I continued on completing the last jobs on the bike. First up chain onto the bike. Simple enough, I'm not going to explain the ins and outs as it is done well enough in Zinn and in other bicycle maintance books. I had not appreciated how much you need to be an octopus though. I was most pleased that I was fixing the chain together with a powerlink and not having to force a pin into place with a chain tool. Really simple, but a little more fiddley was the task of aligning the rear derailleur (mech). Setting the high and low screws to match the limits of chain movement is simple in theory. I found that holding the derailleur over the low position and looking at where the limit screw was holding gave me more confidence that this phase was set up.
 |
| powerlink |
I have however, created a bike that is a little overdeveloped in the tyre department. There is an alignment issue with the rear wheel which I think is easy to sort, but there is one major problem that is preventing me from riding the P3 today. The tyres are too fat. Inflated the rear tyre is one large balloon wedged between the downstays. Not so bad at lower pressures, but it still rubs the frame badly. The original tyres that came with the wheels, I seems to remember, were fine. So I will try a switch back. In the short term there is a potential to borrow some from Uncle Riotous who is storing a load of spares. The ultimate will be a rebuild of the hub on a narrower rim. Whilst I have enjoyed assembling a bike from its components and I even feel that framebuilding might one day be an option- I have visions of being an old man with a shed in the Welsh mountains building custom frames. Wheel building is an art that requires specialisr equipment, much patience and many hours. So to rebuild the wheel I think I may need to employ my local bike shop.
 |
| The beast nearly ready for action |
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