Frame ideas

[redryderaus]

I remember the Over Racing Supermono from back in the early 90's. The frame was considered a brilliant example of stiff, lightweight engineering for a single-cylinder roadrace bike. Anyone, like me, considering building their own frame could do worse than base their design on Over's frame. I did see one in person back then (Philip Island) and the quality of the engineering along with their signature oval aluminium tube was a sight to behold. It made the Yamaha TZ250 GP chassis we were using for our Supermono look like cheap rubbish in comparison. And it was awesomely fast!!

Cheers,

red

[Blitz$M.Inc.$]

well red im pretty sure frame building is beyond most of us, lol
so we will be placing orders with you to be done at your earliest convenience :)
cheers

[The Nutty Professor]

What do you plan to do use an existing frame as a base and work from that? If so I don't think anyone has put up any numbers on their bike. I've asked before but yeah silence. Red do you have template of a chassis that would show people were and how to take measurements. Then anyone who wanted to help could measure their bike and sent it to you and you'd have an idea of what's out there. I always wondered if the standard numbers from a 125 GP or 600 would translate over? What I mean are degrees of rake that sort of thing?

The picture is the X22 the bike I'm working to get.

[redryderaus]

well red im pretty sure frame building is beyond most of us, lol
so we will be placing orders with you to be done at your earliest convenience :)
cheers

LOL!

You never know, it might happen. I don't see any reason why I couldn't design and build my own frame. I can tell you though, it wouldn't be cheap to buy from me. The cost of R&D, building an accurate jig then manufacturing the frame/swingarm/etc would be considerable, keeping in mind you're buying handbuilt craftsmanship. But if there was a market...... :)

We still need some decent tires, though. Everything else is either available (forks/shock/etc) or within our ability to design and build. But we can't make tires!

Cheers,

red

[The Nutty Professor]

LOL!
We still need some decent tires, though. Everything else is either available (forks/shock/etc) or within our ability to design and build. But we can't make tires!
Cheers,
red

Man you get to the heart of it don't youboxing. Those damn tires again! I've been so frustrated with that I even looked into Kosman weldup's. They take you rim cut the lip off and widen the tire by welding on a wider one. That would allow me to find a 12 rim and have it sized to fit whatever slick is available out there. $400 for one rim changed that deal.

[The Nutty Professor]

Question has anyone seen a stripped Avanti. It looks like it has a beam frame like a 1:1 bike. Anyone got a picture?

[redryderaus]

What do you plan to do use an existing frame as a base and work from that? If so I don't think anyone has put up any numbers on their bike. I've asked before but yeah silence. Red do you have template of a chassis that would show people were and how to take measurements. Then anyone who wanted to help could measure their bike and sent it to you and you'd have an idea of what's out there. I always wondered if the standard numbers from a 125 GP or 600 would translate over? What I mean are degrees of rake that sort of thing?

The picture is the X22 the bike I'm working to get.

I can't see any reason why you couldn't use numbers from an existing racebike as a base. Of course, then you'd be fiddling with the fine tuning. But if you look at most modern sportsbikes/racebikes they are pretty similar in ratios, angles, etc.

I could create a template if people are willing to do some measurements. It would be great to get an idea of what is currently out there. I'll even start with figures from my VTR1000 if we go for it, and I'm fairly sure I've still got the numbers from the TZ250. :)

Cheers,

red

[redryderaus]

As an example of using existing numbers. When we built the Supermono, we were fortunate in being able to use two bathroom scales under the front & rear wheels of a complete TZ250 bike (we used the "W" model, last of the parallel twins). From that we calculated the weight bias. When determining the location of the 600cc fourstroke motor we strived to maintain that weight bias. The bike handled very well as a result.

Cheers,

red

[The Nutty Professor]

I was wondering about moving the motor mounts after Swheels told me about the problem he was having with the 125 motor and his intake. His intake faces to the rear. If the motor could be moved front to rear up or down that would allow for major intake modification and fine tune weight bias as Red says.

[The Nutty Professor]

At this point, there are no aftermarket frames for midbikes.

[The Nutty Professor]

Over Racing's newest babies and they're cute as button's

[The Nutty Professor]

And more family photo's

[redryderaus]

Aluminum, over could and would do it for you, if you had the $$$.

Any frame I build will be steel to start with simply due to cost. But I'd love to go all the way and do a twin-spar aluminium frame. Lightweight, very stiff and VERY expensive! lol

Those pics you posted almost made me cry, TNP. There is beauty in engineering :)

Cheers,

red

[schofell84]

why couldnt you use a pitbike frame and modify the fairings to fit?

[redryderaus]

why couldnt you use a pitbike frame and modify the fairings to fit?

The geometry would probably be wrong for road racing.

Cheers,

red

[schofell84]

change the rear shock sag, they have too much travel for road racing anyways.

[swheels]

Here ya go red also there is a midbike with this frame.I've mentioned it in another thread.I think it's called the ducati monster AKA aluminum frame watercooled 49cc 2stroker xbike.But this frame in the pics is for monkey bikes i'm pretty sure they would work for us.But we all know the down fall to that the price tag!

[Blitz$M.Inc.$]

man those welds look like huge caterpillars!

[redryderaus]

man those welds look like huge caterpillars!

That's aluminium welding for you. It's a different technique to steel welding. Though using a modern pulse welder can improve the finish of alloy welds.

Cheers,

red

[The Nutty Professor]

Red why is it so much more difficult to put together an aluminum frame than a steel one. To me a tube is a tube. I realize the strength differents in the two materials but why can't you copy a steel frame tube for tube angle for angle taking into account that your aluminum tube may have to be a little larger but basically your frame is the same except for what it's made from:confused:

[redryderaus]

Red why is it so much more difficult to put together an aluminum frame than a steel one. To me a tube is a tube. I realize the strength differents in the two materials but why can't you copy a steel frame tube for tube angle for angle taking into account that your aluminum tube may have to be a little larger but basically your frame is the same except for what it's made from:confused:

Several reasons.

1/ Aluminium work-hardens at a faster rate than steel. This means that when you bend ally tube, it quickly hardens and therefore will crack.

2/ Aluminium does not like being stretched. This means that equipment for bending ally is different to that used for steel. Ally is also typically bent with a larger radius than you can with steel. You also must anneal ally before bending to prevent micro-fractures in the metal on the outside of the bend.

3/ Aluminium fatigues faster than steel. It will crack if flexed too much. Your design must take this into account to spread flexing rather than concentrating it.

4/ The temper of ally changes dramatically when subjected to heat (ie welding). This results in a tendency to crack at the edge of welds. To correct this, the entire structure should be re-tempered by heat treatment once fabrication is complete. You'll find that 1:1 sport bikes with ally frames are treated in this way, especially as they often use a combination of castings and extrusions which have significantly different properties.

5/ Aluminium is more expensive than steel, both to buy and to weld. For best results a pulse welder should be used on aluminium which increases the cost of the welder 4-5 times. The pulse welders I have used in my work cost in the region of $10,000AUD .

All of these problems apply to steel as well, but at a much reduced level.

Cheers,

red

[redryderaus]

What do you plan to do use an existing frame as a base and work from that? If so I don't think anyone has put up any numbers on their bike. I've asked before but yeah silence. Red do you have template of a chassis that would show people were and how to take measurements. Then anyone who wanted to help could measure their bike and sent it to you and you'd have an idea of what's out there. I always wondered if the standard numbers from a 125 GP or 600 would translate over? What I mean are degrees of rake that sort of thing?

Ask and it shall be done (time permitting, of course) :)

Useful measurements would be:

1/ Wheelbase = Axle to axle
2/ Swingarm length = Rear axle to swingarm pivot
3/ Headstem height = Ground to top of headstem
4/ Headstem rake = Angle of headstem wrt vertical line
5/ Ground clearance = Ground to lowest part of frame
6/ Seat height = Ground to centre of seat
7/ Seat location = Top of headstem to centre of seat
8/ Fork length = Front axle to top of fork (not including fork cap)
9/ Engine height = Ground to centre of clutch cover
10/ Engine location = Front axle to centre of clutch cover

A fair bit of this will be eyeballing the tapemeasure as it is hard to run it directly point to point. But "near enough" will be good enough.

When I get time I'll post measurements of the VTR1000 and the X1. I'm busy writing another How-To (with pictures :) ) on Hydraulic Brakes

Cheers,

red

[redryderaus]

Doh!! Forgot the picture.

Cheers,

red

[The Nutty Professor]

To keep cost down I'm planning to fabricate some of the outer parts of the frame like I described in my Rich Guy thread. Looking at some of the frames for 1:1 I can see that the Mid frame's aren't to far off just old tech.

[The Nutty Professor]

Oh I forgot to list this site Red don't know if you've seen it.

http://www.geocities.com/MotorCity/Speedway/3472/

[redryderaus]

Cool site. Some useful looking software downloads, articles and links. I'll peruse it later :)

Back in the early 90's there was an aerospace engineering student who was also a keen 125GP punter. As part of his degree he designed and built a 125GP chassis completely molded from carbon-fibre. It won races as well as looked absolutely gorgeous!! I wish I could find the photos I took of it.

This is another option I'm considering. Carving the frame from blue styrene foam and covering it with CF.

Cheers,

red

[The Nutty Professor]

Cool site. Some useful looking software downloads, articles and links. I'll peruse it later :)

Back in the early 90's there was an aerospace engineering student who was also a keen 125GP punter. As part of his degree he designed and built a 125GP chassis completely molded from carbon-fibre. It won races as well as looked absolutely gorgeous!! I wish I could find the photos I took of it.

This is another option I'm considering. Carving the frame from blue styrene foam and covering it with CF.

Cheers,

red

I've read probably a dozen articles about bicycle build-up from carbon fiber and they had a time with them. Luck to you on that one. But if you can get it done it would be magnificentchief_rocka

[redryderaus]

Yeah, it's a whole different ball game when you start into molding. But I've got a mate who's a pattern maker by trade, so if I go that route I'll be picking his brains for sure.

Cheers,

red

[swheels]

Hey Red checkout the chassis on this bike.I think i'm gonna try to track this one down.Then transfer everything from the my x18 to this chassis.If the price is reasonable.It's there stock chassis.Hwich i'm pretty sure is better than the current midbike chassis.

[redryderaus]

Nice. Twin spar, headstem is well braced. The swingarm appears to be a bit light but it wouldn't be hard to brace it. The footpegs look like they bolt on which would allow you to make up different mounts if you needed to change their position. USD's would be nice, shouldn't be too hard to fit some.

Cheers,

red

[swheels]

They make rearsets for this frame usd's.So far my search has brought up nothing local.But i shall continue!

[Tblank9]

Sorry to bump an old thread, just caught wind of these little bikes recently. I do not own one..yet. However I have done a fair amount of research on them. First I would like to start with a question, I have my own assumption of the answer simply because of the lack of quality put in these cool little machines. How rigid are the frames? I assume flexing is an issue? In this thread somebody said that the geometry of a Pitbike wouldnt suit road racing at all. Most recently, a group has a converted a 450cc MX bike into a full blown road racer. They infact say that MX bikes do have similar geometry. You would have to change the suspension around, simply because the road bikes dont need the travel. While I understand the frame is a issue, for you hardcore racers..can you add X like bracing in the main frame to prevent twisiting. The flexing issues to me would be in the swingarm (they look cheesy IMO) and the Front forks, which seem to be a issue for handling anyhow. I am going to getting one of these bikes, and tearing it down just to see what I can do. Building a new frame, may not be the answer.

Does anybody have a Xbike bare frame pic they can post? I would be curious to see it. What about rake a trail measurements, does anybody have them by chance?

Oh yea, the 450 MX bike converted. 450moto.com they are pretty frickin awesome.

[The Nutty Professor]

The difference is that the MX chassis are developed to a smokingly high degree. The pit bikes have very good frames but they're designed for a different use and not to the degree of their bigger brother's. I think the problem you will find is the twisting of the frame when the bike is leaned on it's side. Our frames leave a lot to be desired but they have the twin beam base that can be braced very easy, if not after a lot of testing to find the right points. Seems like you've been readin Road Racing World and Sup Planet or am I mistaken thinking_smilie If you want to run a converted pit bike frame go for it thumbsup2 Show us what can and can't be done. I'm knee deep in a non-compatible engine build so I think hanging it all out and proving something shows how big the family jewels really are rock2

[doug@xmr]

Where is Jagspeed once he gets ahold of this thread he's gonna flip. All I got to say is just wait and see..bluelaugh Don't even ask cause I ain't sayin nothin!! lol oh lolmoon1

[swheels]

After seeing this thread again made me resume the search.Well i'm getting closer now,i've found places that sells the bike.(GREAT)Now it's just a matter of contacting them and getting some info.thumbsup2

[The Nutty Professor]

Where is Jagspeed once he gets ahold of this thread he's gonna flip. All I got to say is just wait and see.. Don't even ask cause I ain't sayin nothin!! lol oh lol

bluelaugh tears2 bluelaugh tears2 Laughing so hard I'm tearing up LOLOLOL Jag my man sometimes I think people forget where they are. This isn't that other site with the stagnate way of thinking and a million juvenile question. THIS IS THE NATION! Guys in here have heard of Computrak and Elka among some of the more obscure names in racing. If we haven't tried it yet that's because of resources or money. We all have our stash of secrets or hope they're secrets. That little deal has been kicked back and forth a couple times. Some with the cro-moly single backcone frame (Cost is great) and the perimeter cro-moly or ally frame. I think we even went over that as a part of the rulebook. You could mod the frame but it had to start out as a OEM. I was thinking about a percentage change like they had in FX for awhile. Now we see what we're fighting. Thank Tblank you made my day LOLOLOLOLOLOLOLOLOLOL

[JAGspeed@XMR]

bluelaugh tears2 bluelaugh tears2 Laughing so hard I'm tearing up LOLOLOL Jag my man sometimes I think people forget where they are. This isn't that other site with the stagnate way of thinking and a million juvenile question. THIS IS THE NATION! Guys in here have heard of Computrak and Elka among some of the more obscure names in racing. If we haven't tried it yet that's because of resources or money. We all have our stash of secrets or hope they're secrets. That little deal has been kicked back and forth a couple times. Some with the cro-moly single backcone frame (Cost is great) and the perimeter cro-moly or ally frame. I think we even went over that as a part of the rulebook. You could mod the frame but it had to start out as a OEM. I was thinking about a percentage change like they had in FX for awhile. Now we see what we're fighting. Thank Tblank you made my day LOLOLOLOLOLOLOLOLOLOL

Hey Nut , I agree that this site has a more knowledgeable crew than most. I am aware that there are lots of great ideas here and that most every angle of technical know how has been or will be discussed. As far as frames are concerned I had brought up the idea with Doug a while back about using stronger or better frame than the stock frame that comes on the X18-22s. There are lots of frames out there, the thing is to find an existing one that has all of the right dimensions , strength and will be cost effective to buy or build. I have not built anything yet with a different frame , but I will be soon. I believe if all of the guys on this site had unlimited funds that we would see some of the trickest bikes on the planet. I have plenty of great ideas of my own and have found many others on this site. I just what to get a chance to actually make them real. You have to admit after seeing some of the bikes that I have been building at XMR that we have the resources to make our ideas become a reality. I will try and do a better job in the future of keeping you guys updated on my projects.

[The Nutty Professor]

Jag man you "Da Man" thumbsup2

[Tblank9]

The difference is that the MX chassis are developed to a smokingly high degree. The pit bikes have very good frames but they're designed for a different use and not to the degree of their bigger brother's. I think the problem you will find is the twisting of the frame when the bike is leaned on it's side. Our frames leave a lot to be desired but they have the twin beam base that can be braced very easy, if not after a lot of testing to find the right points. Seems like you've been readin Road Racing World and Sup Planet or am I mistaken thinking_smilie If you want to run a converted pit bike frame go for it thumbsup2 Show us what can and can't be done. I'm knee deep in a non-compatible engine build so I think hanging it all out and proving something shows how big the family jewels really are rock2

Oh no, certainly didnt mean I was going to be the guy to try a converted pit bike. Again, I am not familar with the pitbike frame either. I am aware of what a pit bike is suppose to be, a scaled down MX bike....or so i thought. Again! I assumed the pitbike frame is a twin spar, more then likely aluminum frame. Very similar to there big MX brothers...My guess I was wrong. I was PM'd with info of where to find photos of a X bikes frame. Really they dont look bad at all from a racing geometry standpoint. These are steel frames right? Maybe somebody can take some measurements for me. How long is the swing arm? From the mount points to the frame, to the mount points for the axel? How about degree of rake? I am really curious as to what I could draw up in the CAD, using a X bike frame as a base?

To me these Midbikes, seem to be a great inexpensive way of entry into road bike racing. However, the word just simply isnt out there, and the bike just isnt even remotely close to race ready from the factory. Curiousity kills the cat for me. Thanks for any info you guys can provide.

[The Nutty Professor]

The problem with the X-bikes is quality control. The frames are seriously none standard. They make have a good beginning design but the execution fell short. In the chassis department anyway.

[schofell84]

why dont you guys believe a nice perimeter frame designed for a pit bike is not as strong as your $600 midbike? nice pit bikes are going for 2500 + now and the quality control is much better seeing how they pay people to go across the pond to regulate quality control. (SGR, Pitster, etc.)

its nice to see someone finally catches on to my point ^^^ (tbalnk9). but yeah, frames are designed to have a certain amount of flex ... blah blah blah. im sure youve heard all of it. all im saying is that a $300 perimeter pit bike frame has to be better than a midbikes stocker, in every way shape and form. i could be wrong but common sense says otherwise.

then theres the geometry argument. geometry is adjustable! change fork lengths, sag, preload ... it all changes angles! the rear shock can be adjusted to affect the same things. heres the plan: get a nice pit bike frame, lower your forks and shocks to the height where you get the right head tube angle, etc. play with compression, rebound to make it work for now. once you think you have the geometry right, send out the forks to be shortened and re-valved! it doesnt take much to shorten a fork, a spacer and maybe a new spring is about it. the rear shock options are also endless. im willing to imagine for under a grand you can have the frame, forks, and shock and possibly have them revalved / shortened.

[Tblank9]

why dont you guys believe a nice perimeter frame designed for a pit bike is not as strong as your $600 midbike? nice pit bikes are going for 2500 + now and the quality control is much better seeing how they pay people to go across the pond to regulate quality control. (SGR, Pitster, etc.)

its nice to see someone finally catches on to my point ^^^ (tbalnk9). but yeah, frames are designed to have a certain amount of flex ... blah blah blah. im sure youve heard all of it. all im saying is that a $300 perimeter pit bike frame has to be better than a midbikes stocker, in every way shape and form. i could be wrong but common sense says otherwise.

then theres the geometry argument. geometry is adjustable! change fork lengths, sag, preload ... it all changes angles! the rear shock can be adjusted to affect the same things. heres the plan: get a nice pit bike frame, lower your forks and shocks to the height where you get the right head tube angle, etc. play with compression, rebound to make it work for now. once you think you have the geometry right, send out the forks to be shortened and re-valved! it doesnt take much to shorten a fork, a spacer and maybe a new spring is about it. the rear shock options are also endless. im willing to imagine for under a grand you can have the frame, forks, and shock and possibly have them revalved / shortened.

Pretty much what I thought... The only difference here though...who really wants to spend a couple grand to build one? For a couple grand we can all go and buy NSR's...really. I mean what I am already learning to love about these $600 bikes...ingenuity...I mean think that some of the more well respected posters around here dont have a couple grand wrapped into there bike.

If there was a great following, racing this type of bike...a modified pitbike frame would be the a way to go. At this point, a couple grand just really isnt worth it. Not for the average person at least.

Just my 2cents, good post though schofell