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carbon fibre chassis??

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im just curious why i havent seen these with the factory team. Ive heard that guys in moto gp have them (i think, could be wrong). the wieght loss would be a big plus. Just had this epiphany so help me out on this!:smirk:

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Carbon fiber has been used on frame and suspension components in road racing, but as much as the power of a 200 hp engine strains the chassis of a 350 pound motorcycle, it doesn't really quite match the loads created by dropping 30 feet out of the sky on a dirt bike. I don't think CF is really up to it, or at least, not at a significant weight savings.

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Factory teams arent allowed to run cf frames even if they could/wanted to. Pretty sure that falls under the works bike category lol. Not unless the factory made it available to the public as an option on their stock bikes. right?

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jim castillo, founder of innovation sports/CTi as well as my uncle, developed a carbon fiber bike in the mid or late 80's, it raced one time and was protested and banned right after the race. it was almost 100 lbs lighter than the next lightest bike on the track. it IS possible, just not legal in the AMA

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...it was almost 100 lbs lighter than the next lightest bike on the track.

I must say I'm intrigued by the fact that there is anything at all that you could replace a 15 pound frame with that would save 100 pounds.

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Trek and GT both have carbon fiber framed downhill mountain bikes, so it can be made very strong. Whether there's much weight savings compared to an aluminum of chromoly frame when you get to that strength, I'm not sure.

As rubbersidedown said, factories have to run the same frames as sold to the public.

As for a carbon fiber bike being 100 lbs lighter...... ?!?!?!?!?!? I think just engine, wheels, fork, and shock likely totals over 100 lbs on any fullsize bike. Heck, even just wheels and engine on some bikes (I think 55-65 lbs is typical for a bike engine/trans, and 40+ lbs for both wheelsets with tires/tubes/disks, etc).

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There have been a couple carbon fiber frames tested in Europe and Japan, but they seem to drop the idea after a bit of testing. As mentioned, most major racing organizations require production frames anyways.

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we use to see alot of cool prototype stuff on the GP bikes in europe, but now its alot closer to what the production bikes are but they also can make the bike look like the current models and most people wouldnt notice a new frame or motor

most high end mountain bike companies have carbon frames and they are light but the main reason is for the flex

i dont see why using carbon fiber would be illegal as long as it meets the minimum weight

and in the US if they offered X amount to the public like KTMs 450 for Dungey

quick google search and found this...

http://www.wheelsofitaly.com/wiki/index.php/WRM_Motorcycles#.TwMzbTWvKSo

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we use to see alot of cool prototype stuff on the GP bikes in europe, but now its alot closer to what the production bikes are but they also can make the bike look like the current models and most people wouldnt notice a new frame or motor

most high end mountain bike companies have carbon frames and they are light but the main reason is for the flex

i dont see why using carbon fiber would be illegal as long as it meets the minimum weight

and in the US if they offered X amount to the public like KTMs 450 for Dungey

quick google search and found this...

http://www.wheelsofitaly.com/wiki/index.php/WRM_Motorcycles#.TwMzbTWvKSo

A carbon fiber frame is illegal in AMA racing b/c the rules state that the frame must be production and no production bike has a carbon fiber frame right now. If a manufacturer produced a bike with a carbon fiber frame then that is what the pros would have to ride, but I don't see that happening any time soon.

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Don't think there would be much point. It'd add a grand+ to a production bike and save what, 10lbs at best. I'd think they would go for carbon wheels and hubs before that, would make for better performance saving unsprung weight.

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I saw some extremely light Ducatis with titanium frames in a recent issue of Cycle World. That was intriguing to me.

Internet quote "It (titanium) is as strong as steel and twice as strong as aluminum, but is 45% lighter than steel and only 60% heavier than aluminum".

It would be a fun project to make a titanium framed dirtbike and it could be done by anyone that has the proper materials and skills. If titanium really is as strong as steel, you may be able to simply duplicate a steel frame using titanium.

Carbon Fiber would be much tougher to get right. :smirk:

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I saw some extremely light Ducatis with titanium frames in a recent issue of Cycle World. That was intriguing to me.

Internet quote "It (titanium) is as strong as steel and twice as strong as aluminum, but is 45% lighter than steel and only 60% heavier than aluminum".

It would be a fun project to make a titanium framed dirtbike and it could be done by anyone that has the proper materials and skills. If titanium really is as strong as steel, you may be able to simply duplicate a steel frame using titanium.

Carbon Fiber would be much tougher to get right. :smirk:

Welding titanium is not easy and can not just be done in a garage by any shmo. The only proper way to do it is to weld it in a vacuum chamber that has had ALL of the oxygen pumped out and inert gas pumped in as it must be 100% shielded at all times. Then it has to be heat treated after it is fully welded. Much harder of a process than carbon fiber. Many companys in the ATV market make aftermarket titanium frames for race quads. Nothing new to the motosport industry, been around for years.

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Welding titanium is not easy and can not just be done in a garage by any shmo. The only proper way to do it is to weld it in a vacuum chamber that has had ALL of the oxygen pumped out and inert gas pumped in as it must be 100% shielded at all times. Then it has to be heat treated after it is fully welded. Much harder of a process than carbon fiber. Many companys in the ATV market make aftermarket titanium frames for race quads. Nothing new to the motosport industry, been around for years.

no...it really really dosent.

you can tig weld it to perfection in a avrage joes garadge as long as you follow the three c's....clean..clean..and clean.. its a bit harder to weld then stainless...thats about it.

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no...it really really dosent.

you can tig weld it to perfection in a avrage joes garadge as long as you follow the three c's....clean..clean..and clean.. its a bit harder to weld then stainless...thats about it.

Not true, Titanium, When heated becomes highly reactive and readily combines with oxygen, nitrogen, hydrogen and carbon to form oxides which contaminate the welds. Whats everyones favorite part of titanium,? the awesome rainbow colors right, well all that means is it wasnt welded well, those colors are the contamination of o,n,h and c (see above)

The only way you should weld a tubular titanium frame is if you use purgeblocks on the end of every tube or use stainless tape dam with small holes and run pure argon to it at no less than 10cfh, but considering all the end tubes of motor mounts and alike are completely sealed there is no way to purge it without drilling at least 2 holes in each piece which most people would not find acceptable (Thus why I say vacuum chamber). You need to purge the volume of the piece enough to at least purge the air 10x over just to be sure of purity. And all that is after you have the purity of your argon tested which should test at %99.995 pure or better. Then after it is welded you must continue to purge until it self cools to below 500 degrees F. I personally would never ride any titanium framed mx bike that was welded together in someones garage. But hey what do I know, I only own a welding company. Sure mountain bikes, some street bikes and such are welded just by purging the best they can but they arent doing 150' triples either.

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Trek and GT both have carbon fiber framed downhill mountain bikes, so it can be made very strong. Whether there's much weight savings compared to an aluminum of chromoly frame when you get to that strength, I'm not sure.

The advantage that the bicycle world has using carbon fiber is they don't have an engine to take into account.

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Here is a nice picture of a Ti atv frame (I don't remember where I got the pic, or who made the frame).

Tiframe.jpg

This show some discoloring from welding.

I have always like the idea of a Ti frame, but I think this one cost aroud $10,000, when an aftermarket Chromoly frame was going for about $4,000 (this was 5-6 years ago, so the prices could be off, or my memory could be off too).

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Here is a nice picture of a Ti atv frame (I don't remember where I got the pic, or who made the frame).

Tiframe.jpg

This show some discoloring from welding.

I have always like the idea of a Ti frame, but I think this one cost aroud $10,000, when an aftermarket Chromoly frame was going for about $4,000 (this was 5-6 years ago, so the prices could be off, or my memory could be off too).

i do love some crafty metal work. :smirk: Titanium wouldnt be a bad idea but wouldnt that have to fall under the whole 'have to be made avaliable to the public? What if u used say a CF sub frame or downtube on the frame? just sections of the frame?

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You are correct, they are usually around 9-10g's for the custom ti frames. There is some bluing on some of the welds but really not too bad overall, Whoever built it did a pretty good job of controlling their purging or welded it in a 0 oxygen vacuum and just didnt leave it in the tank long enough when cooling. All looks good except for that one plate on the front of bottom rails, looks like that may have been welded on after the fact.

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i do love some crafty metal work. :smirk: Titanium wouldnt be a bad idea but wouldnt that have to fall under the whole 'have to be made avaliable to the public? What if u used say a CF sub frame or downtube on the frame? just sections of the frame?

I would imagine that would be ok because I know some of the pro atv guys run ti subframes, not sure about in ama mx though.

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Lone star racing makes Ti frames for quads and i recently emailed them about a xr50 frame that they made awhile back and the only down side with Ti is the cost!

back to the carbon fiber topic, as shown in my post on the 1st page there is already a carbon fiber framed bike, although its not all carbon fiber its shows that companys are looking at it and someone mentions its illegal in the AMA rules, now i dont know the rules but im pretty sure your basing this of the production rule so if say Honda made a Carbon fiber frame next year (2013) on the production bikes it would be legal.

carbon fiber is very expensive to made chassis so i dont think we would see it anytime soon on the main bikes on the tracks

honda stepped up back in 97 with the alloy frame and yamaha soon followed, tried a different style but followed suit as did Suzuki and kawi, just look at how far the bikes have come so i wouldnt rule a Carbon frame out of the equation

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