Topic: Race frames...

[bubbafun101]

does any member have the spec/plans to build one of these vintage frames? Bimota, Seely, Rickman?  I am gonna have a work slow down this winter, thought I might look into building a custom frame. Since the 750 bug has  bitten me, no point in trying to cure it. Just go deeper into the illness. This is  my deepest. So far.

[turboguzzi]

Check memeber MEC Egli build thread in the projects section

[Ecosse]

there may be a little bit of helpful info/leads here:  http://forums.sohc4.net/index.php?topic=58870.0

... and here: http://www.tonyfoale.com/

there are a couple (#?) of people who can reproduce some of the old frames but i can't recall just now. if i dig anything up i'll of course post it.

[DresdaHonda]

Dont have plans, but here is a rickmann frame for cb750

http://www.dba.dk/staerkt-projekt-saelges-til/id-63708373/

-but it is in Denmark, Europa.
I don´t know the price
Regards
DresdaHonda

[Yoshi823]

I found this a useful site....
http://www.satanicmechanic.org/north.shtml

[cavebear]

www.framecrafters in illinois reproduce racing frames.

Cavebear

[azuredesign]

I'm not sure that link works.
It's www.framecrafters.net

[Howell]

Builder of classic raceframes:
http://www.jwmotorcycles.com/classic-motorcycle-frames.html

[Retro Rocket]

Does anyone know if you had a Honda frame built out of chrome moly tubing, the same specs as stock, would it be much stronger/better?

Mick

[paulages]

i believe the guy said he was looking to make a frame guys, though your sources are good. i've looked all over the net for frame blueprints that aren't for cheesy "customs" and haven't even turned up a featherbed, so if anyone has any ideas i'm eagerly watching as well. i have foale's book as well as the suspension setup program he sells, but i'd still like to find some blueprints for tested designs.

i love how some of the honda factory manuals have very detailed frame specs and blueprints in them. it would be great to find these for featherbed. dresda, egli, drixton, etc. i'm particularly looking for the drixton honda 450 blueprints, so please somebody share!

[paulages]

Does anyone know if you had a Honda frame built out of chrome moly tubing, the same specs as stock, would it be much stronger/better?

Mick

the primary benefit of chrome-moly is that it is stronger, and thus thinner wall tubing can be used and it will be lighter. the heat affected zone from welding will be brittle, and the entire piece will need to be "normalized" or uniformly heat-treated then re-hardened. bicycle frames are commonly brazed and TIGed without heat treatment, but i wouldn't trust a motorcycle frame not to develop fractures form the heat affected zones.

[Retro Rocket]

Thanks Paul, i understand the benifits of cromo but i was wondering how much better the frame would be built from it,especially using Honda's original design.  I know a frame builder in Brisbane that could build one for me and was just toying with the idea.

Mick

[paulages]

Thanks Paul, i understand the benifits of cromo but i was wondering how much better the frame would be built from it,especially using Honda's original design.  I know a frame builder in Brisbane that could build one for me and was just toying with the idea.

Mick

have you ever looked at the factory welds?  it wouldn't take much to produce a better version if attention was payed to quality, but it still would probably be a waste of money and time unless you added gusseting and triangulation in the right places.

[turboguzzi]

interesting topic... the young modulus of any steel, from mild to cro-mo is the same, so essentially, build two frames, using the same tube gauge, one in mild steel, one in cro-mo, they will have the same stiffness and that's the main criteria for handling.

cro-mo has an advantage in ultimate strength but the confusing thing is that the frame should be designed so you will never enter stress levels that get near to ultimate strength, (that's when plastic deformation sets in), but rather stay in the elastic range where all steel perform basically the same.

cro-mo is more resistant then to bend forces but if you desing a frame that acts mostly on push-pull forces like a ducati's triangular ones, there's not going to be much iof an advantage.

Michael Moore from eurospares recomends indeed to use mild steel for home frame building, a lot less headaches with the welding process creating internal strees than with cro-mo's.

TG





 

[simon#42]

i very much doubt you will find an original blue print , if indeed they ever existed . frames from this period where not designed then built , the frame was was made by experience around the engine then a jig was built . when it came to the later replica frames they just made a jig from an original frame.
paul  forget the foal book [ although it is interesting ] if you want to make a frame that works get the two bradley books you will find these much more helpful
the idea of building a standard frame from t45 or similar is interesting and i have thought about this myself , i think it would be far better than the honda frame , it would certainly be half the weight and you could build it more accurately [ production tolerances are quite high on frames ]    although its normally the poor suspension that lets the standard bike down , even with the 17 inch tyres you are planning mick you would have to ride very very hard for frame flex to be a big problem . interesting what tg said about using ordinary mild steel tubing , i read an article about the krauser bmw frames once and mike krauser said they had made the frame out or mild steel because none of the test riders could tell the difference between that and cro moly

[voxonda]

I copy the Krauser story, you will have to have a very, very good rider that will tell the difference. Think there are just very few people who can 'stretch' the frame to its max. The difference in geometry is 'easier' to feel.

Rob

[Yoshi823]

I seem to remember reading that the Gordon Pantall Kawasaki that New Zealander Grahame Crosby rode was an exact replica of the original but made from Reynolds 531...

[turboguzzi]

i very much doubt you will find an original blue print , if indeed they ever existed . frames from this period where not designed then built , the frame was was made by experience around the engine then a jig was built . when it came to the later replica frames they just made a jig from an original frame.
paul  forget the foal book [ although it is interesting ] if you want to make a frame that works get the two bradley books you will find these much more helpful
the idea of building a standard frame from t45 or similar is interesting and i have thought about this myself , i think it would be far better than the honda frame , it would certainly be half the weight and you could build it more accurately [ production tolerances are quite high on frames ]    although its normally the poor suspension that lets the standard bike down , even with the 17 inch tyres you are planning mick you would have to ride very very hard for frame flex to be a big problem . interesting what tg said about using ordinary mild steel tubing , i read an article about the krauser bmw frames once and mike krauser said they had made the frame out or mild steel because none of the test riders could tell the difference between that and cro moly

Simon, the point of my comment is that at the end of the day, in order to make a frame that weights half of stock all the wall thicknesses will have to be half of stock, (specific weight of mild steel and cro-mo are same) and at that point, the stiffness of the cro-mo frame would be lower than stock.

When yamaha went on to produce the RD350 based GP racers like the TD1  and TD2 , the frames were just lighter cro-mo copies of the road frames and they broke with alarming frequency. Yamaha had to make the cro-mo racer frames heavier to stop this and at that point, they were lighter than the road frames by just a few kilo.  

[simon#42]

yes tg i understand what you are saying but i still recon you could make a stock designed frame half the weight of standard , if only by fabricating all the mounts and brackets rather than using great lumps of cast steel [ and although they where a different design thats what seeley did and there frames where half the weight of stock ]
you are right about the yamaha frames as well the early ones did break all the time [ and the f models as well ] but a tz g or h,j k, or l frame is much much lighter than an rd frame [ probably less than half ]  when i get back to work i will dig a few out and weigh them

that pantall kawasaki brings back a few memories , people forget just how good a racer crosby was

[voxonda]

yes.......................................................................

that pantall kawasaki brings back a few memories , people forget just how good a racer crosby was

I will never forget how good he was/is. Saw him the first time back in '78 on Brands, think it was the Anglo -American. Riding against Cooley, Pierce etc.
Just kept wheeliing that big thing. Promised myself that I would name my first born after him, and in '84 Graeme was born.
IMHO he paved way for Gardner, who had a better Moriwaki then Graeme ever did. Crosby did win the Suzuka eight hour and in Daytona the Superbikes '79 and later the 200 miler, won the Imola 200 the same year, became 2nd in the 500 that year, did not feel happy and went home.

Rob

[azuredesign]

interesting topic... the young modulus of any steel, from mild to cro-mo is the same, so essentially, build two frames, using the same tube gauge, one in mild steel, one in cro-mo, they will have the same stiffness and that's the main criteria for handling.

cro-mo has an advantage in ultimate strength but the confusing thing is that the frame should be designed so you will never enter stress levels that get near to ultimate strength, (that's when plastic deformation sets in), but rather stay in the elastic range where all steel perform basically the same.

cro-mo is more resistant then to bend forces but if you desing a frame that acts mostly on push-pull forces like a ducati's triangular ones, there's not going to be much iof an advantage.

Michael Moore from eurospares recomends indeed to use mild steel for home frame building, a lot less headaches with the welding process creating internal strees than with cro-mo's.

TG

Is the young modulus you refer to the same as the modulus of elasticity? I'm not an engineer, but am interested. This thread started me thinking about using carbon fiber reinforced polymers to construct a frame. Would this be a durable alternative to steel alloys for frame making? I've read that carbon fiber is very stiff, but breaks quickly once it starts to deform irreversibly.

[turboguzzi]

yes, the two concepts are the same

The MotoGP ducati that nicky and stoner have been using this year had a carbon frame and its not the first ever.

Cagiva had a carbon 500 gp bike in the 90's and uk based skoal bandit suzuki ran their own carbon kevlar frames in 500 gp in the 80's .later the britten made use of a carbon frame, fork and wheels too.

Making structural carbon fiber components is a very different story compared to using fiberglass. Just cutting carbon fiber pre-preg requires tungsten knives or other exotic cutting methods and to obtain deffect free componenets, curing is done in huge autoclaves. add also milled aluminum tooling to form the parts.....

not that I want to discourage you, but its quite an endeavor

TG





 

 

[simon#42]

yes.......................................................................

that pantall kawasaki brings back a few memories , people forget just how good a racer crosby was

I will never forget how good he was/is. Saw him the first time back in '78 on Brands, think it was the Anglo -American. Riding against Cooley, Pierce etc.
Just kept wheeliing that big thing. Promised myself that I would name my first born after him, and in '84 Graeme was born.
IMHO he paved way for Gardner, who had a better Moriwaki then Graeme ever did. Crosby did win the Suzuka eight hour and in Daytona the Superbikes '79 and later the 200 miler, won the Imola 200 the same year, became 2nd in the 500 that year, did not feel happy and went home.


yes that yamaha team was not a happy one at all , he retired far to early , it would be nice to get him back to europe to have a ride at spa or one of the other classic meetings , especially as harris have started  making xr69 replicas   oh and he was also pretty quick around the isle of man

]

[754]

You guys are forgetting one component in building a lighter frame.
 You do not necessarily have to 1/2the tubing thickness IF you can trim off certain unneeded parts and bracketry.. altho, that weight saving should probably go into gusseting and stiffening existing design..

[scunny]

not to threadjack but I am. heres Crosbys website http://www.graemecrosby.com/index.htm