Dream bike - what would you spend?

pblakeney

bendertherobot wrote:

Dream is difficult to define. If it's lottery, then my bike garage would be like Jay Leno's car garage.

But, my dream? With my salary? A little inheritance? I'll be honest and say I'd draw the line at 5k. Probably even £4k.

I don't know WHAT bike it would be, but in terms of what LEVEL I'd like it to be than something like a Trek Domane SL7 Disc with Etap and Carbon wheels is enough of a level. Beyond that, I'd find it difficult to justify even if it is my dream.

Matthewfalle wrote:

why wait that long?

start doing it now to spread the cost - you could keel over tomorrow morning and it would never be done.

do it. do it. do it. do it now. do it.

Buy a quality frame from last year in a clearance sale. Fit it with your current bits and pieces.
Upgrade when sales allow. End up with a bargain top kit bike.

craigus89

TGOTB wrote:

Sniper68 wrote:

Shirley Basso wrote:

To me it's sad that people dream of disc breaks.

Having disc brakes break would be more of a nightmare..... :P

I'm toying with making my own carbon rotors, so it could happen!

Because the thing wrong with disc brakes is the material used on the rotors? WTF!

imposter2.0

Matthewfalle wrote:

TGOTB wrote:

Sniper68 wrote:

Shirley Basso wrote:

To me it's sad that people dream of disc breaks.

Having disc brakes break would be more of a nightmare..... :P

I'm toying with making my own carbon rotors, so it could happen!

can you video the first (and last) ride for us please.

FTFY

DeVlaeminck

I don't know if I've got one dream bike - I could spend a fortune on a top level Colnago with Super Record etc - if I had more money I probably would too - but it'd be a pretty cliched dream bike. Adding narrower bars with a traditional bend, the top San Marco Regal saddle, whatever wheels and some Vittoria Corsa tyres and whatever other stuff I happen to like doesn't really change that.

There are bikes that I just think I really fancy owning that - one would be this Sagan alloy Allez Sprint disc http://cycling.today/peter-sagan-aboard ... own-under/

I just like the colours, I like the Sagan connection, the fact it's top end of it's type and it's very much an out and out race bike.

Longshot

Perhaps some of us are happy to dream of a stock bike? We don't all have to have the same dreams.

imposter2.0

Longshot wrote:

Perhaps some of us are happy to dream of a stock bike? We don't all have to have the same dreams.

Belinda Carlisle wouldn't agree...

tgotb

Craigus89 wrote:

TGOTB wrote:

Sniper68 wrote:

Shirley Basso wrote:

To me it's sad that people dream of disc breaks.

Having disc brakes break would be more of a nightmare..... :P

I'm toying with making my own carbon rotors, so it could happen!

Because the thing wrong with disc brakes is the material used on the rotors? WTF!

Nah, just because I like trying stuff out. It's also an opportunity to get 100g of rotating mass out of the wheels, but mostly just for the fun of trying.

I can understand why a thread full of people who are too scared to assemble their own bike might not get that; that's fine...

imposter2.0

TGOTB wrote:

I can understand why a thread full of people who are too scared to assemble their own bike might not get that; that's fine...

No idea whether people on here can assemble their own bike or not - I'm guessing most probably can, so a comment like that is a little disingenuous, I think.

There's already plenty of data on carbon disc performance - or lack of it - at low temperatures, or in low system weight situations. I suspect that's what 'a load of people who can't assemble their own bikes' are getting at...

shortfall

TGOTB wrote:

Craigus89 wrote:

TGOTB wrote:

Sniper68 wrote:

Shirley Basso wrote:

To me it's sad that people dream of disc breaks.

Having disc brakes break would be more of a nightmare..... :P

I'm toying with making my own carbon rotors, so it could happen!

Because the thing wrong with disc brakes is the material used on the rotors? WTF!

Nah, just because I like trying stuff out. It's also an opportunity to get 100g of rotating mass out of the wheels, but mostly just for the fun of trying.

I can understand why a thread full of people who are too scared to assemble their own bike might not get that; that's fine...

Good luck sourcing or making a carbon disc suitable for road bicycle use. I'm not sure what performance benefits you expect to gain from (potentially) saving 100 grammes of rotating mass or at what cost, but I read the following abouting carbon brakes on F1 cars that reach speeds in excess of 200 mph.

" A carbon brake has relatively poor performance below about 400°C and has optimum braking performance above 650°C."

Have you thought this through?

tgotb

Imposter wrote:

No idea whether people on here can assemble their own bike or not - I'm guessing most probably can, so a comment like that is a little disingenuous, I think.

Erm... have you actually read the last couple of pages of this thread? There's just been a whole actual discussion on whether people have the confidence to assemble their own bike. On this thread. Scroll up.

Imposter wrote:

There's already plenty of data on carbon disc performance - or lack of it - at low temperatures, or in low system weight situations. I suspect that's what 'a load of people who can't assemble their own bikes' are getting at...

Fair enough. To me it sounded like the sort of people who are scared of carbon as a material, wouldn't consider repairing a broken carbon frame, used to avoid riding carbon frames in the rain etc, but I admit that could have been a false assumption; it's equally possible that they'd all done lots of research into how carbon brakes on aircraft and race cars work, and could see that the operating conditions on a bicycle are rather different.

I think they'll be fine for my use case; if the first one I try doesn't work, I've wasted a couple of quid's worth of materials, and I'll have to coast to a halt or use the other brake to slow down.

imposter2.0

TGOTB wrote:

it's equally possible that they'd all done lots of research into how carbon brakes on aircraft and race cars work, and could see that the operating conditions on a bicycle are rather different.

I suspect that's exactly the point that 'they' were trying to make. Weight, speed and braking force (and therefore disc temperature) are massively higher on aircraft and racing cars.

tgotb

Shortfall wrote:

Good luck sourcing or making a carbon disc suitable for road bicycle use. I'm not sure what performance benefits you expect to gain from (potentially) saving 100 grammes of rotating mass or at what cost, but I read the following abouting carbon brakes on F1 cars that reach speeds in excess of 200 mph.

" A carbon brake has relatively poor performance below about 400°C and has optimum braking performance above 650°C."

Have you thought this through?

Yeah, I have thought it through, and as I said it's not because I expect to get any measurable performance benefit, it's just for fun.

You can already buy all-carbon rotors (as opposed to metal rotors with carbon spiders) off the shelf, though I think making them will be more interesting.

They're for a CX bike, not a road bike. Because of the nature of the racing, the consequences of total brake failure aren't particularly serious (and in any case, they're obviously going to get tested out on benign terrain).

DeVlaeminck

If weight is an issue why not look at a totally different kind of braking system - I imagine you could design something lighter - maybe some kind of caliper that applies braking force to the rim ?

tgotb

DeVlaeminck wrote:

If weight is an issue why not look at a totally different kind of braking system - I imagine you could design something lighter - maybe some kind of caliper that applies braking force to the rim ?

Caliper brakes aren't especially popular on CX bikes, probably on account of all the twigs, leaves and other debris that jam in them and stop the wheel going round.

Cantilever brakes used to be popular, but they still get twigs caught in them, and rim wear was a bit of an issue (which is why many amateurs switched to disks while the pros were still on lighter cantis). For a while some of the top-level framesets were available in disk or canti options; since then disk brakes have become lighter, and top-end canti framesets have pretty much disappeared.

shortfall

TGOTB wrote:

Imposter wrote:

No idea whether people on here can assemble their own bike or not - I'm guessing most probably can, so a comment like that is a little disingenuous, I think.

Erm... have you actually read the last couple of pages of this thread? There's just been a whole actual discussion on whether people have the confidence to assemble their own bike. On this thread. Scroll up.

Imposter wrote:

There's already plenty of data on carbon disc performance - or lack of it - at low temperatures, or in low system weight situations. I suspect that's what 'a load of people who can't assemble their own bikes' are getting at...

Fair enough. To me it sounded like the sort of people who are scared of carbon as a material, wouldn't consider repairing a broken carbon frame, used to avoid riding carbon frames in the rain etc, but I admit that could have been a false assumption; it's equally possible that they'd all done lots of research into how carbon brakes on aircraft and race cars work, and could see that the operating conditions on a bicycle are rather different.

I think they'll be fine for my use case; if the first one I try doesn't work, I've wasted a couple of quid's worth of materials, and I'll have to coast to a halt or use the other brake to slow down.

Honestly I'm not having a go at you here, but do you genuinely believe that in buying a couple of quids worth of carbon and adapting it to fit your bike you can create a workable alternative to conventional braking systems? Really? For sure it will make a great topic in the Workshop or Your Bikes sections. Looking forward to the pics and vids.

Matthewfalle

as an aside, they use carbon discs on race motorbikes due to operating temperatures.

they are utterly utterly shyyyyt at low speeds so not sure how you are going to get the heat into yours to make it work.

but, as they say in my parts, fair dinkum blue for giving it a bash.

tgotb

Shortfall wrote:

Honestly I'm not having a go at you here, but do you genuinely believe that in buying a couple of quids worth of carbon and adapting it to fit your bike you can create a workable alternative to conventional braking systems? Really? For sure it will make a great topic in the Workshop or Your Bikes sections. Looking forward to the pics and vids.

I'm only replacing the rotor; the whole of the rest of the braking system is completely off the shelf. I've built quite a lot of things out of carbon, and making a flat disk of the correct thickness is about as simple as it gets.

Matthewfalle wrote:

as an aside, they use carbon discs on race motorbikes due to operating temperatures.

they are utterly utterly shyyyyt at low speeds so not sure how you are going to get the heat into yours to make it work.

I'm not, I'm intending to run it at ambient temperature. I may not have the kinetic energy of a few hundred kg of motorbike and rider travelling at 100mph to heat the brakes, but I also don't need to stop a few hundred kg of motorbike and rider travelling at 100mph; at a quarter of the weight and a fifth of the speed, I only have 1% of the kinetic energy. I also don't particularly want to ride around with glowing hot rotors, and I doubt that the rest of the braking system - particularly the hydraulics - would cope very well with that heat.
The coefficient of friction between ceramic pads and carbon is fairly similar to that between ceramic pads and stainless steel, so the performance should be ok; if not, I've wasted a couple of quid's worth of materials I had lying around anyway and learned something in the process.

This isn't anything that hasn't been done before; here's one example:
I doubt you could produce carbon rotors commercially at a price that made sense; it's going to be way more expensive than cutting them out of a sheet of steel, and any gains are going to be tiny, but as an interesting project - why not?

shortfall

TGOTB wrote:

Shortfall wrote:

Honestly I'm not having a go at you here, but do you genuinely believe that in buying a couple of quids worth of carbon and adapting it to fit your bike you can create a workable alternative to conventional braking systems? Really? For sure it will make a great topic in the Workshop or Your Bikes sections. Looking forward to the pics and vids.

I'm only replacing the rotor; the whole of the rest of the braking system is completely off the shelf. I've built quite a lot of things out of carbon, and making a flat disk of the correct thickness is about as simple as it gets.

Matthewfalle wrote:

as an aside, they use carbon discs on race motorbikes due to operating temperatures.

they are utterly utterly shyyyyt at low speeds so not sure how you are going to get the heat into yours to make it work.

I'm not, I'm intending to run it at ambient temperature. I may not have the kinetic energy of a few hundred kg of motorbike and rider travelling at 100mph to heat the brakes, but I also don't need to stop a few hundred kg of motorbike and rider travelling at 100mph; at a quarter of the weight and a fifth of the speed, I only have 1% of the kinetic energy. I also don't particularly want to ride around with glowing hot rotors, and I doubt that the rest of the braking system - particularly the hydraulics - would cope very well with that heat.
The coefficient of friction between ceramic pads and carbon is fairly similar to that between ceramic pads and stainless steel, so the performance should be ok; if not, I've wasted a couple of quid's worth of materials I had lying around anyway and learned something in the process.

This isn't anything that hasn't been done before; here's one example:
I doubt you could produce carbon rotors commercially at a price that made sense; it's going to be way more expensive than cutting them out of a sheet of steel, and any gains are going to be tiny, but as an interesting project - why not?

I googled the image you posted and it's a disc produced by Alpha. I haven't been able to find any actual reviews of their rotors but it seems from what I read that they are a carbon ceramic polymer. Are there any real world examples of these discs performing on a bicycle that we can check out? What kind of carbon do you intend to use? How are you going to machine it into shape?

bendertherobot

PBlakeney wrote:

Buy a quality frame from last year in a clearance sale. Fit it with your current bits and pieces.
Upgrade when sales allow. End up with a bargain top kit bike.

I used to love doing this. Or upgrading stock stuff on the best bike to ensure that, for example, contact points were right etc.

Now, I just go, this stem's ok isn't it? Then ride on.

(I may have fallen partially out of love with bikes as an object!)

DeVlaeminck

TGOTB wrote:

DeVlaeminck wrote:

If weight is an issue why not look at a totally different kind of braking system - I imagine you could design something lighter - maybe some kind of caliper that applies braking force to the rim ?

Caliper brakes aren't especially popular on CX bikes, probably on account of all the twigs, leaves and other debris that jam in them and stop the wheel going round.

Cantilever brakes used to be popular, but they still get twigs caught in them, and rim wear was a bit of an issue (which is why many amateurs switched to disks while the pros were still on lighter cantis). For a while some of the top-level framesets were available in disk or canti options; since then disk brakes have become lighter, and top-end canti framesets have pretty much disappeared.

Well of course a cantilever is a style of caliper that acts on the rim.

The issue with cantis for most people is/was their stopping power - if you are designing a rotor that is lighter but has less stopping power at operating temperature then effectively you may as well have stuck with cantis.

tgotb

Shortfall wrote:

I googled the image you posted and it's a disc produced by Alpha. I haven't been able to find any actual reviews of their rotors but it seems from what I read that they are a carbon ceramic polymer. Are there any real world examples of these discs performing on a bicycle that we can check out? What kind of carbon do you intend to use? How are you going to machine it into shape?

There's not a lot of substantiated real world feedback on performance, which is one of the reasons I'm interested in trying it out for myself. Plenty of stuff on forums from people who've bought various carbon rotors and said the performance was good, but that's really hearsay. I did a few tests, ages ago, to compare the coefficients of friction of carbon and stainless steel (the same experiment you probably did in school Physics), which is why I think it should work. You're not getting the benefits of running it hot, like aircraft and race cars/bikes do, but it should still be good enough.

Making them should be easy; you just impregnate each layer of carbon cloth with epoxy resin, lay them up on a flat surface, compress and (preferably) heat; although it accelerates curing, the main purpose of the heat is to reduce the resin's viscosity. An easy way to do this on the cheap is to cut out two square pieces of 18mm MDF, screw big chunks of timber to one side to provide extra stiffness, and cover the other side with parcel tape so your component doesn't stick to the mdf. You lay up the carbon between the two pieces, clamp them together with big G-clamps, and leave the whole thing on its side above a nice hot radiator, with a sheet of polythene to catch the drips. That actually gets you a better laminate than vacuum bagging, because you can apply more pressure. 2 sheets of thick glass also works, but you have to use weights rather than clamps, so you can't apply as much pressure. Once it's cured, you can drill/cut/sand using normal power tools (though the blades tend to wear quite quickly, and it's best to avoid inhaling the dust). For the purpose of this exercise I just have to cut out a circular disk, cut a big hole in the middle with a hole saw and then drill 6 more for the bolts. You can get special drill bits for carbon, but regular steel ones are fine.

I have a load of ~600g multi-axial cloth that I don't really have a use for, so I'll use some of that with a few layers of 200g woven at different orientations on the outside. The resin's the biggest potential issue at the moment; the most suitable stuff I have is only rated up to 90 degrees C, so I'll have to see how hot they get (bear in mind the intention is to run them cold). Easy enough to measure with an infra red thermometer. If they're otherwise fine but temperature is looking like an issue, I'll have to start investigating other resins (or figure out a safe way to test one to destruction - not sure about that!)

Key points:
- This is for fun, just because I enjoy making stuff and trying things out
- I don't expect the slightest discernable performance advantage; if I wanted that I'd spend the time training instead
- I'm never going to sell any, so they don't have to be cost-effective to produce
- I'm never going to go racing down an Alpine descent with these; even if they get used in anger it'll only be on a CX course where total brake failure is unlikely to result in anything worse than embarassment

mamil314

TGOTB this has been done before by certain Mr Magura who had access to carbon used in military vehicle brakes.
I was too lazy to look for the original thread but this is the fellow
https://www.pinkbike.com/forum/listcomm ... did=144947

Matthewfalle

TGOTB wrote:

Shortfall wrote:

I googled the image you posted and it's a disc produced by Alpha. I haven't been able to find any actual reviews of their rotors but it seems from what I read that they are a carbon ceramic polymer. Are there any real world examples of these discs performing on a bicycle that we can check out? What kind of carbon do you intend to use? How are you going to machine it into shape?

There's not a lot of substantiated real world feedback on performance, which is one of the reasons I'm interested in trying it out for myself. Plenty of stuff on forums from people who've bought various carbon rotors and said the performance was good, but that's really hearsay. I did a few tests, ages ago, to compare the coefficients of friction of carbon and stainless steel (the same experiment you probably did in school Physics), which is why I think it should work. You're not getting the benefits of running it hot, like aircraft and race cars/bikes do, but it should still be good enough.

Making them should be easy; you just impregnate each layer of carbon cloth with epoxy resin, lay them up on a flat surface, compress and (preferably) heat; although it accelerates curing, the main purpose of the heat is to reduce the resin's viscosity. An easy way to do this on the cheap is to cut out two square pieces of 18mm MDF, screw big chunks of timber to one side to provide extra stiffness, and cover the other side with parcel tape so your component doesn't stick to the mdf. You lay up the carbon between the two pieces, clamp them together with big G-clamps, and leave the whole thing on its side above a nice hot radiator, with a sheet of polythene to catch the drips. That actually gets you a better laminate than vacuum bagging, because you can apply more pressure. 2 sheets of thick glass also works, but you have to use weights rather than clamps, so you can't apply as much pressure. Once it's cured, you can drill/cut/sand using normal power tools (though the blades tend to wear quite quickly, and it's best to avoid inhaling the dust). For the purpose of this exercise I just have to cut out a circular disk, cut a big hole in the middle with a hole saw and then drill 6 more for the bolts. You can get special drill bits for carbon, but regular steel ones are fine.

I have a load of ~600g multi-axial cloth that I don't really have a use for, so I'll use some of that with a few layers of 200g woven at different orientations on the outside. The resin's the biggest potential issue at the moment; the most suitable stuff I have is only rated up to 90 degrees C, so I'll have to see how hot they get (bear in mind the intention is to run them cold). Easy enough to measure with an infra red thermometer. If they're otherwise fine but temperature is looking like an issue, I'll have to start investigating other resins (or figure out a safe way to test one to destruction - not sure about that!)

Key points:
- This is for fun, just because I enjoy making stuff and trying things out
- I don't expect the slightest discernable performance advantage; if I wanted that I'd spend the time training instead
- I'm never going to sell any, so they don't have to be cost-effective to produce
- I'm never going to go racing down an Alpine descent with these; even if they get used in anger it'll only be on a CX course where total brake failure is unlikely to result in anything worse than embarassment

all this sounds excellent and well interesting. Bonzer.

two things: i personally think this is worth a thread of its own - not through any "hijacking" rubbish but because its well good

2. whats your background dude?

tgotb

Matthewfalle wrote:

all this sounds excellent and well interesting. Bonzer.

two things: i personally think this is worth a thread of its own - not through any "hijacking" rubbish but because its well good

2. whats your background dude?

Thanks - I actually do think we should give the thread back; I'll start a new one if/when I get round to trying this.

I learned all this stuff in boatbuilding - friend and I built a 14' carbon sailing boat from scratch (using existing design/moulds), raced it, cut it up and modified it, and raced it some more (quite succesfully at times). We used to break carbon masts from time to time; so long as you had the right kit you could repair the mast overnight (the important bit was retaining the bend characteristics) and be out racing next day. Once you've done that, repairing something like a carbon bike frame is pretty easy; my road bike's built around a crashed frame that had a 45 degree "bend" in its head tube when I got it, one of my TT bikes had been a write-off, and I've done a few repairs for friends. At the current rate, the carbon I have left over from my sailing days will last me for decades

Mamil - thanks for the link, hadn't seen that one. He made his own carbon pads too, which seems totally obvious (and quite easy) but I completely hadn't thought of it.

Trivia - the high temperature carbon laminate that race car rotors are made from is pretty much the same stuff that was used for the leading edge of the Space Shuttle wings.

gsk82

I don't think that deciding you want an expensive bike then choosing one, qualifies as a dream bike. Its just an expensive bike. Dreaming of having any (ie not specific) expensive bike would be pretty shallow.

AlgarveCycling

Back in the 1980's and 90's when I took racing very seriously and not just for fun like now, I had to save and rely upon sponsorship for high end parts for my bike. I looked forward to the day I could afford to buy a top-of-the-range bike outright.

Well, I can do that now but find it hard to do, not sure it is worth it for the latest and greatest. That said, I have spent a lot anyway but on two bikes rather than all on one and both in sales. I spent £5400 earlier this year on an RRP £6600 MTB from my local bike shop and last week took advantage of one of the big online retailers 45% discounts on an RRP £9600 road bike for £5290.

I don't mind getting 2019 models rather than the new 2020 and paying a whole lot more for the privilege with marginal gain for my use. Both bikes are 'worth' what I paid judging by the cost of similar bikes generally but I wouldn't have wanted to pay more.