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Discussion Starter #1
not a new Idea,just looking for any web sites that speak of this activity of people who have done it or people that are doing it are there any current frame builders shoving big engines in small frames ?not disco volante but perhaps others like them .Just staring at a lot of bikes lately and just was thinking about this idea.or just perhaps frame builders that are still building road frames that dont have the word chopper in them. it would be nice to have a sleek frame that you slip a motor of choice into.



Edited by - LiLBull on Oct 23 2005 4:20:30 PM
 

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What do you mean by bigger engines into smaller frames? how big an engine and how small a frame?

here is a site taking about the conversion process for putting a kawasaki h1 500cc engine in an s-series frame (250-350-400). This may not seem like that much of a difference until you realize that the 750 motor shares the same mounts and dimensions. the 500 motor makes more hp than the 400 but because of the frame design was heavier and therfore only as fast as a 400, I have a friend with a h1/s3 conversion and that bike screams:

http://kawtriple.com/mraxl/khconv/400to500.htm

As for hondas it has long been a street racer's trick to get the cb650 SOHC engine and put it in an early cb500/550 frame. The early cb500s are lighter and the cb500 shares the same motor mounts with the cb650 so it is a bolt in.

As for more modern machinery, the fzr400 was imported into this country in 1988 through 1990. They are all alumnium and with lightening tricks can be brought down to under 350 lbs. The fzr600 is almost the same bike and an fzr600 motor bolts in directly to the fzr400 frame. The yzf600 motor and R6 motors fit with some minor modifications. Basically a 120 hp 328 lbs bike when you are finished. the fzr400 makes a great track day bike for a lot of people.

The cb350f four is a hideous lump of slow honda, can barely get out of it's own way, but a hot rod 400F motor fits right in. I have heard of people getting early 500 motors in there too but have yet to see one in person and don't know what is involved. the 400 four motor is a little barn burner.

The popular swaps with kz400s is to find a 440ltd cruzier style bike. Makes almost half as much more hp than the standard 400 and the mounts are the same.

As for road frames that aren't chopper, you can get a manx frame brand new but be prepared to pony up $4K. A t500 motor will fit in the manx frame since suzuki designed the tr500's frame by modifying an original manx frame. I'm trying to convince rosko to help me make some new cafe racer frames but he won't do it without a set up shop (right now anyway). I want to make slimline frames that take all the norton cafe racer bodywork but cb750/t500/h1-2/cb450/rd350 engines.
 

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Discussion Starter #3
geeto67 exactly you are on the money in what I was thinking I have a kz550 with a twisted frame,and under 700 original miles on it, thats good for not and thought why buy a salvage frame and redo the same old thing might make something more interesting....then I was looking at my other two bikes I just pulled apart a honda cb450 twin dohc and a honda cb400t twin with sohc and this all got me thinking of swaps others have done, and frames that may be out there .I know johnnyb is into frame building and that other site eurospares which has so much info but hard to navigate thru to absorb any usful info . But geeto67 this is the kind of stuff I was thinking about .....G R E A T stuff !!!



Edited by - LiLBull on Oct 23 2005 7:25:40 PM
 

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if you have to "spend money" on a frame, put the engine in a norton featherbed frame. They are one of the best handeling vintage frames by far and every manner of engine has been stuffed in there from vincent and triumph to cb750 and kz900 to harley davidson. Atlas frames are wideline and usually the cheapest featherbed style to start with. Commando frames also work well but don't have that cool factor but are a little easier to swap into since they use rear bolt in motor plates and not welded mounts.

If you have frames just kicking around the shop and just want to do a transplant keep this in mind. The kz550 is a boat anchor of a bike. Almost as heavy as a the kz750 and kz900 but down on power. If you are going to do a swap you want a really light frame setup. In that regard here is some food for thought. Most of the sport bikes of the 1980's use a lower motor cradle to mount the engine. Fzr400's and 600's are a prime canidate because they are relativley light, have a rim and tire size closer to most 1970's bikes (max 160) and have the motor cradle. the kawasaki's of the 1980's are notorously heavy and the 600's don't have the motor cradle so stay away. GSXR's are ok weight wise as are the cbr 600 f1 and f2.

If it were my engine, I would go out and find a ninja 250 (ex250) with a blown motor and use that chassis as the strarting point. The 550 engine makes a lot more torque than the 250 WC, about the same hp and you will be saving the bike water weight. It would make an awsome mini-me streetfighter with dual headlights, and a ducati tailsection. The ninja 205 as it sits is a under 350lbs motorcycle so imagine how light you can get it with some good old fashoned race tricks. A lot better than the 400lbs the kz550 is used to slugging around. just take a look at this ninja 250 with an rd350 motor and tell me it's not a good idea.

http://kawasakitriplesworldwide.com/phpBB2/viewtopic.php?t=17995

if you have ever ridden a 250 it is one of the most fun ninjas made just because it's handeling is so good you can drag a knee safely on any turn on city streets (and I have the holes in the jeans and scars to prove it). Eventually I want to put an h1 2stroke motor in one just for fun.

When doing motor swaps your best friends are the stock spec sheet and a scale. If you aren't optimizing the weight and hp from the swap, then it isn't worth the energy. Some swaps that seem like they would be close but actually aren't are the cb360 in a cb350 frame and cb750 in a cb550 frame.

You hust have to read the enthuasits sites for the bike and see what others are doing. Also read streetfighter magazine as it has a lot fo cool bikes built overseas and sometimes they are old kz550 and gpz550s or the like.
 

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Discussion Starter #5
geeto67 my friend you spend a lot of time on bikes I like your mind .I have seen the street fighter mag before seemed like its about newwer stuff which is great Im more into the old retro look but I do like the idea of the 250 ninja mod just because your thinking into its design and mods .Great stuff pure design enginuity I like that .Thanks for the fuel in this fire it has me thinking even deeper into possibilities wow is that a word?
 

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You might want to take a look at framecrafters.net Randy will make anything you want. He has lots of experience with Tritons and such. Take a look at some of the racebikes he has done. He also will do all kinds of frame mods to existing frames. He worked on my 350 race frame last summer and I am considering a takedown frame that will fit into standard sized airline luggage. He says he can do it.
Ken

AHRMA 412
Vintage racing - old guys on old bikes
 

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C&J frames out in cali is also a good source for aftermarket frame stuff, plus they used to make flat tracker frames back in the day. For the top of the line in h2 flat trackers check out Henry Hester's beast:

http://home.san.rr.com/h2hester/

LiLBull,

I do spend a lot of time tinkering with bikes. When I lived in New Orleans there was a bike only salvage yard on the west bank that I used to spend several hours in every saturday. Once you see the different iron stripped of it's body work you begin to see the potential and also what peices will fit in other bikes. Having that salvage yard at your disposal is great because you can fit stuff together and if it doesn't work out you leave it and start over. You only pay for what you take with you. If I had it to do all over again I think I would have liked to become an engineer.

Here is an idea I have been kicking around for some time. I would like to take a modern sport bike frame and copy it but in a tubular trellis style setup like ducati and made to take a vintage motor. two strokes are probably best for this because you can make modern sport bike power out of a two stroke (guys are getting 100+ rwhp out of 750 h2 street triples by reeding them and porting)but it would be cool to see a triumph 650, sohc4, or harley davidson motor hanging between the rails. set it up with a dual disc rear and front (I know overkill) and a single sided swingarm like the ducait sportclassic with one outboard shock. If ducati can build a sportclassic, what is wrong with trying to build your own version out of a real classic? I like the fact that disco volante offers spoke rim conversions for the fazer, now if I could only figure out what bikes the fazer shares a wheel size with (BTW early 916 ducatis and early 1990's fzr's share the same front wheel but with different bearings, the fzr is also one of the only bikes in that era to still have an 18" mag).
 

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Discussion Starter #8
kennessex ,framecrafters is a great resource and looks like a can do chassis shop thanks for the tip!
Geeto67 what is C&Js web address I found picture frames lol no bike frames in web search.Geeto67 looks like framecrafters can make your frame you have been looking to build.by the way Gee that ninja 250 link didnt work even after I registered is it still posted on that site thanks for the info This is a great thread in my mind .



Edited by - LiLBull on Oct 24 2005 07:15:48 AM
 

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here is the pic of it, its an ad and it still works for me. He recently sold the bike but answered a few questions for me before. For a 2 stroke parallel twin engine it is a super straight forward swap, the across the frame four bigger than 250 will stick out a little past the bodywork. The rd on the stator side stuck out so I don;t think it is a big deal. Round here you can get a nice running ninja 250 for around $1300, which means a blown motor one should be even cheaper. I see a few with blown motors since they are not fast enough for a lot of the wannabe squids that buy them.
 

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Discussion Starter #10
see its cool and its THINKING ...I just eat this stuff up .I like different the idea also is there are so many bikes out there and mixing and matching parts to come up with some thing different and still be way under the cost of a custom frame which seem to be around 2grand ...well its just PLAIN COOL to me its what cool is any one can throw money at something ...its why i like the whole cafe thing especially at ace cafe gallery just one unique build after another raw talent and not alot of money ......or is it because brits are well how should I say it ....frugal that is the catalyst for the origins of the high art of the current crop of cafe and naked bikes/ street fighters.
 

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Discussion Starter #11
not much out there on frame mild steel material whether dom or other wise or wall thicknesses used in bike building ,I know some are brazed some are aluminum I see some in chrommolly which is light but not tuff in bending .I have yet to see what the smaller tube wall thicknesses are in the majority of vintage bikes street not race because race gets very specialized in material specs .just in general are they made of DOM tubing mild steel or other mild steel tubes used .I havent seen any written material on frame material ....should just buy the books on bike chassis design and handling part one and two! See if i post long enough I answer my own questions . George
 
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