I have a 500 and a speed/cadence sensor. Again my 500 hasn’t dropped a signal very often when off road so I wouldn’t bother. For me cadence is more important on my road bike so i keep mine on there.

A very simple solution to such situations….

but i suppose i could pay 90p hour at the council c.p

90p? is that to much to ask to park? sounds like a pretty good deal to me. Personally I couldn’t be bothered to drive around looking for alternatives to avoid the 90p parking charge.

Next time pay the 90p, be happy that you have done the right thing. Then you will avoid getting letters and “poor little wifey” being in tears in the first place.

when i first saw a fat bike, i thought they were ridiculous.

Now i’m starting to like the look of em 8O

It will depend on the surgery type that you have had. You can either be opened up or you can have it done laproscopically.

I was snow boarding in 2 weeks after a laprascopic repair.

I noticed that someone said they had open surgery for this type of thing. If anyone else has the misfortune of needing this type of surgery insist on a laprascopic repair. They are more reliable and recovery is faster. Open surgery for this is now a bit dated.

Take it easy, hope you get up and running soon

Hed doctor every time. SFN can create an internal groove which can act as a crack propagation site.

I would certainly not, I want to hear everything when I’m out there and be as safe as i can.

Also, if something did happen to you, they might point the finger at you.

If you post on here and have a go at the OP because he is an engineer and doesn’t fix his own bike you are a complete idiot. There is no argument you are an idiot and these kinds of posts are not helpful. My advice to all those with comments about not fixing your own bike is: keep your stupid comments to yourselves, you completely miss the point.

More an more often I am seeing people post really rude and unhelpful comments on this forum which do not contribute positively to such a community.

Anyone venting or airing a complaint should be allowed to do so without fear of being shot down and abused. Maybe they are a bit upset and post in haste, perhaps they are a bit emotional and just need a reality check and to be put straight by some friendly comments.

what they don’t need is for some fool to quickly check how many posts they have made and then judge them on that basis and follow up with ridicule. More and more comments I’m seeing would have been met with a punch in the face if they had been made in a pub or face to face. Just because you are hiding behind a keyboard does not make it acceptable.

Be nice to your fellow bikers, make this a nice place to contribute to and promote a positive and respectful attitude to the posts of others.

Could try these. A bit retro but nice:

http://www.cervorosso.com/index.php?section=shop&catId=30

Got a code for 10% if you are interested

Also sound to me like you need a couple of new bikes.

Where are you riding exactly? Are you riding with others or solo?

I think that if you buy an “in between” bike you could limit yourself. A friend of mine, could not make up his mind what type of bike he wanted and bout a hybrid type city bike, with the aim of doing more commuting. He now feels a little bit left out when people go mountain biking, but also cant really keep up with guys on road bikes.

Hello,

I would just like to clarify some points here.

Mr Scar has made some points, here however I would like to add some detail as these points could be misunderstood. I’m not intending to have a pop at you Mr Scar, just filing in details.

Can’t really say CF is the best secondhand bike material either due to its limited lifespan.

This is a slightly ambiguous statement. In essence everything has a limited life span. It will depend on the application and various external factors. Aluminium and also steel could also be described as having limited life spans. So we must be clear bout this.

“It’s not a finite number, but the material composition deteriorates over time. The resin epoxy in carbon fiber will go stiff and crack or fatigue a lot faster than any metal.”

Metals too will deteriorate over time. The statement that CF will go stiff and crack faster then any metal is simply does not make sense. One of the biggest advantages of CF composites is that they have longer fatigue life in comparison to metals.

By saying that they go hard and crack you imply that there is some deterioration. Of course plastics can deteriorate, however almost all plastics today have UV inhibitors.

Even with some frames have carbon nano tubes as a resin filler you’re always face the fact that no existing resin epoxy can withstand UV and natural deterioration inherit to all resin products.

Mentioning nano tubes in the same sentence as UV and “natural degradation” implies that nano fillers are there to prevent these from happening. Nano tubes are “functional fillers” their use is aimed at improving mechanical performance, rather than environmental performance.

The surface of carbon fiber is very soft and resin will crack when bump by strong forces. Eventually all resin epoxy based reinforce materials(fiber glass and carbon fiber) will warp.

Not sure what is meant here, carbon fibre is soft or the composite surface is soft. nevertheless, this statement seems to contradict the previous which refers to hardening. Soft materials are typically more resistant to cracking (after impact) than those which are hard.

Moreover, I would like to make clear that UV or environmental issues are not a problem for composite materials. Do you think that modern aircraft would have significant amounts of primary structure made from composites if they were going to degrade in UV and fail ? not really. Aero companies have researched these materials for decades. Testing often spans decades. I worked for one company which continues its environmental assessment of composites today. About 50 years ago they started by putting test specimens round the world in extreme weather environmental. Every year coupons have been tested and compared with the control-no significant degradation of these has occurred.

Lots of riding = lots of microfractures within the epoxy carbon interfaces.

It is not clear what you are saying here. Never the less it implies that riding time is proportional to some kind of internal defect creation. Again this is not a good statement.

The majority of these won’t cause a problem, but in the high stress areas, or a sudden off angle impact they can propogate and cause either just additional flex (due to them not reaching the surface), or complete cracks through the material as in the OP’s case.

Also an unclear statement, not entirely sure what is supposed to reach the surface. I think you mean these cracks? I think you mean that if you hit the composite real hard it might crack.

This is something that also gets me going. Sadly I love cycling, so I have to just take it :-(

Steel frames are produced in china for as little as 10 dollars a piece. Carbon fibre bikes, for no more than 250. The same carbon frame will end up in a store for probably 3000.

R&D? yes they send on that. But marketing budgets vastly exceed r&d budgets. Nothing is developed or implemented unless it is highly marketable. Sad but its true. Why do you think the 29 inch mtb came out? market saturated with 26, starting to stall. The answer? a new product, does very little more than the existing product (if anything). The right marketing convinces people they are great and hey presto. Everyone is out needing to buy new bikes, frames wheel and forks to keep up with the fad. Sorry but its how it is.

Richmars,

I have seen some really crappy efforts at making carbon bikes and I have to admit that when I clicked on your link I was expecting the same.

Pleasantly surprised! well done, its a good job. I am interested to hear how it rides? I guess you used stock tubes?

Cheers

Hi,

Why not polish the crack out?

if it does not extend past the weld fillet you could polish it out. Use a finer wet and dry type paper until you have polished it out. This way you will stop it propagating further into the stay.

Hello Mikeyd,

This will certainly be an interesting project for you. It will be fun and a little challenging. It will involve a thinking side but will also test your practical skills.

I would really ask yourself how much you want to do this. If its purely as a hobby, great carry on. However, if your aim is to obtain a bike that you will be happy with and use on a regular basis, then I would think very carefully.

I would be interested in knowing what facilities you have to do this and also how much money you want to spend. At this point I could advise you the best way to do it. lets not forget that design is closely related to manufacture. With composites you are always designing with the intended manufacturing process in mind.

You should also think about what you are eating before the ride.

How long is your typical ride?
At what point do you feel energy dipping?
What are you doing for hydration?

Its going to be very difficult (or impossible) for anyone to determine whether or not this is small crack in the paint or something more serious from a picture. Some kind of non destructive testing equipment would be required. Other than that you would probably need to take the paint back to the bare frame and or course by then its going to be too late.

One method of non destructive testing used to test the integrity of composites in aero and other such applications is the tap test. Some of you may laugh at this for such a “hi-tech” material, but is is a bonafide method of non destructive testing. To how does it work ?

In this case I would take something metallic, like a 5 or 6mm drill bit. Wrap a thin layer of electrical tape round the end (the side that fits in the drill) hold the other and proceed to tap the frame. I would remove the parts which might interfere with the sound. Any way you would be looking for changes in tone in the different parts you tap.

You could start there.

My opinion is that to have a crack like that, you would probably need some quite serious damage underneath if it was immediate carbon below. However, having said that. Most bike manufactures have still not mastered moulding these more intricate parts of bikes, as a consequence they often need a fair bit of finishing so areas like this can have quite a bit of filler slapped on there. It would not surprise me if this was filler heavy and some flexing in this area would have caused the filler to burst.

“Don’t really need any press articles to prove galvanic corrosion problems. This is 1st year engineering:”

Indeed it may be 1st year engineering, however you may be surprised that not all people contributing to, or reading posts on this forum have studied engineering in any capacity. Some of these may appreciate a reference to a press article aimed at the layperson.

Check this out:

“Boeing’s 787 Dreamliner is an entirely new concept in aircraft engineering. It features a carbon-composite skin,
And there is a galvanic corrosion tendency where carbon components actually eat aluminum, particularly in the high moisture environment of aerospace.”

Its an except from a small piece about the dream liner that i took from general press.

“Can I quote you on that?”

I can probably provide you with some references more if you need.

The next challenge you face is deciding what you want and getting it. what is your desired outcome? It might take some time.

I would thoroughly recommend going alone. You will bump into people and make new friends, it will be cool.

Another though, probably the OEM will not know what it is. You would be surprised how little they know about material science :?

My guess would be galvanic corrosion. It happens when you put Al and carbon together. In all serious applications one would apply a glass surface veil to any surface in contact with aluminum. I would be surprised if there was a surface veil on the inside of your seat tube.

Njee20,

On my own! sometimes it has been more but a kg is pretty average.

Take a dump before you go out. That should make up for it. I can lose a kg that way.

I would be very wary of making a repair yourself if you don’t have the knowhow. Equally I would also be wary of sending it to one of the many people who claim to be able to repair frames. Indeed from an aesthetic point of view, a frame might be repaired, but the question is has it been done properly? How many layers were used? are they the right length? are they the right orientation? will it basically stand up to the loadings in that area. Also, in some cases, like that of the seat stay, if one has broken, its also likely that the other has also been damaged. Damage to carbon bikes can not always be seen.

There are far too many garage bodgers out there. be careful and look for one with know how, I believe there is one out there who does ultrasonic testing, and experience.

Man keep us posted of what they do for for you. I will be pleasantly surprised if you don’t end up out of pocket here.

You have 2 lots of tax that you have paid on the import and there is also the inspection fee that customs charge. Then there will be the return cost. Its all gonna turn out quite pricey.

My guess is that it would be cheaper for them to refund you the cash and call it a day. Then you could repair the had tube and maybe live with the damage on the rear.

Why is everyone so tough with this guy?

Hello,

I am a little surprised that blasting operation has increased the internal diameter of the head. I am wondering if you can see some uneven abrasion marks on the inside?

To fix it I certainly would not do any welding to the frame. I also would avoid removing any further material.

I’m not sure what workshop equipment you have access to but I would do the following. (you need access to a lathe)

Take the headset cups that you have measure the OD and then the ID of the head tube. Then work out what the difference and what you need extra on the cup.

Put some bar in the lathe and make a hole in the centre so its a super tight fit on the cup (the part that goes in the head tube). Then part of the right amount. The heat it up and insert the cup into it. Once its cool, put it all in the lathe again this time holding the headset cup and machine down the added sleeve until you have the right OD. Then bingo!

“But there is only so much raw materials, mineral resources, land to grow food, energy capacity and so on. As demand increases it will outstrip supply (I think) and the price goes up. For the people falling out the back of that process, that’s poverty.”

This is correct. I believe that it is one of the drivers for sustainability. Economics on its own does not encourage sustainability, it has to be considered with social and environmental aspects also.

I tend to find that the outside of my feet hurt a little if I have not ridden long distances for a while. After a few rides it seems to go away for me.

I certainly would not saying it is selling out to get some decent pedals and shoes. I can’t ride bike without, being able to pull as well as push on the pedals is a great advantage.

@mattjg

“@chief unfortunately (for us and our kids) I suspect the new equilibrium is going to be most of the wealth that’s historically been in “the west” is going to end up in “the east”. There was a time the west had technological, social and intellectual advantages.”

This will not be an equilibrium, but I agree that it is likely to happen, and coming closer by the day.

Teamhurtmore, I wasn’t having a pop.

I was merely stating that the the whole thing can be looked at as a system and systems eventually reach some kind of equilibrium. Right now we are discussing about economics, we talked about manufacture in china and manufacturing in the UK. These situations are not stable, and there are always shifts. Years ago we manufactured in the UK, bla bla and then china was popular, standard of living increased there and so have manufacturing costs and for some clothing manufacturers,for example, this has meant a move to another lower cost economy. So the system is constantly changing. Eventually this will reach an equilibrium, not for a long long time, but eventually. This system is linked to physical resources, fuels metals, water etc. Once these have been depleted, we start again. Probably living in caves. That’s what i meant by poor.

This question is interesting tho.

“Is it logical to ensure that you spend as much of your money as locally as possible? And the answer is no, not always”

Well of course it will depend. I think for some people, depending on their life style, interests and so on, it can be done. Whether or not it is logical is a different question and it will depend on whats right for the person asking the question.

Teamhurtmore, I got the bit that the example was simplified :(

But anyway, of course! the real situation is a lot more complex, and i guess that a study of it would need to take into account an almost endless chain of events and effects. I guess in the end, its a system and all systems try and reach some kind of equilibrium in the end. We will all end up poor 8O

JOAO3v16, I think your approach is very narrow minded and pessimistic, you are indeed part of the problem.

Now, mr teamhurtmore. I have had to read your posts again and in particular, the one with the bike production example. Just a question (I did say I was a dunce in terms of economic understanding).

So, the UK are making bikes and china are making bikes, and we trade bikes between each other. I see how we both can benefit.

My question is, what happens if in china no one wants to buy any of our bikes? Maybe they are too expensive, or maybe people just ride around on locally made bikes. What happens then?

Teamhurtmore,

Producing in low cost economies generally increases environmental impacts.

Cheers

I would like to just throw something in there. I have a limited and very simplistic view of economics so don’t blast into me :|

I think that Molgrips has a point. Perhaps we should consider relieving poverty of certain other countries. However, while this is good theory, does it actually work? Countries get trade, but they get trade because they are cheap, workers are paid low salaries while all the big money goes to just a few. Does this not create an incentive to keep salaries low and continue to exploit people?

Spending on local products I would expect stimulates local economy, jobs and hopefully everyones life quality increases a bit. what is the alternative? Spend to get cheaper goods, money goes to other countries, local jobs lost, unemployment then poverty, then crime, then drug problems, then social unrest and violence on the street. Once that has happened, taxes go up to pay for the unemployment, health service, policing and the money you saved by buying cheap is gone and, you end up living in a dump.

Is this too simplistic?

“Look I’m not say saying it’s not morally the right thing to do – that’s not my area – just don’t expect to see a return on investment thats all.”

I think return on investment is a key issue here. There was also a comment earlier about taiwanese bikes seeming like good value for money. Producing all these goods in places like China increase profit margins. I think they would also be good value for money if they were made in the UK and also sold for the same amount. Can manufactures do this, probably they can (almost certainly) its just investors etc would have a lower return on investment.

I would personally prefer to buy from a local source, knowing that I am supporting a regular bloke in having a job and a decent standard of living. This is preferable for me to paying the same price for the same item produced in china and knowing that the item has been market up 900% and that the extra is going to some fat cat. Also at the cost of the increased pollution in that region.

The way this post is turning out is quite interesting. Nice discussion. I recently heard a politician talking about UK getting ready to provide services and call centres to support the growing wealth in Asia. This is quite interesting as things obviously were different.

As for manufacture in China. All of these things could be made in the UK. If they were, it would mean jobs created in the region. These items are all made in China to increase the profit margins, this in my opinion is not so good. I would rather see companies making a little less profit and spreading some good.

Production in China creates double the CO2 emissions that production in Europe. To to increase profits companies increase impact. For those who don’t believe in climate change there are other impacts that are also higher than if stiff was produced in Europe.

So moving production to places like chine increase profit, increases impacts and has a social impact also.

I wouldn’t normally reply to a thread like this but I really think what is missing is a

++++++WARNING+++++++

in the post title.

It would probably be good if you could also ring that bell at least once during the test.