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English => Parts & Bikes => Topic started by: PiR products on November 19, 2009, 06:57:44 PM

Title: New concept, new frame...
Post by: PiR products on November 19, 2009, 06:57:44 PM
Hello fellow flatlanders.

I'm glad to introduce you a new design frame concept called the "chain-tunnel".

To resume this concept, it's a way to minimize the width of the rear triangle, by making different dropouts jonction.

PiR already made a similar dropout jonction for the non drive side but never for the drive side, as you can see in the following link :

http://img.photobucket.com/albums/v631/malovelo/Dropoutsjonction.jpg (http://img.photobucket.com/albums/v631/malovelo/Dropoutsjonction.jpg)

But now, it's possible with the "chain-tunnel" design.

(http://img.photobucket.com/albums/v631/malovelo/VisuelcadreSteevecopie2.jpg)

A first frame has been made for a french flatlander nammed Steeve and here is some pictures of his bike...

(http://img.photobucket.com/albums/v631/malovelo/IMG_3574.jpg)

(http://img.photobucket.com/albums/v631/malovelo/IMG_3572.jpg)

(http://img.photobucket.com/albums/v631/malovelo/IMG_3567.jpg)

(http://img.photobucket.com/albums/v631/malovelo/IMG_3542.jpg)

(http://img.photobucket.com/albums/v631/malovelo/IMG_3589.jpg)

(http://img.photobucket.com/albums/v631/malovelo/IMG_3594.jpg)

(http://img.photobucket.com/albums/v631/malovelo/IMG_3610.jpg)

For more informations, you can contact PiR products at : pir.bmx@gmail.com

The website is in progress...
Title: Re: New concept, new frame...
Post by: robpossible on November 19, 2009, 07:17:16 PM
How does a narrow rear triangle help in the design of a flat frame? I never understood St. Martin’s logic here either...
Title: Re: New concept, new frame...
Post by: flem on November 19, 2009, 07:20:39 PM
and what about the solidity? cause how i see the thing, it's that only the dropout will support your weight? or am i going wrong?
Title: Re: New concept, new frame...
Post by: cow on November 19, 2009, 07:27:06 PM
every idea is worth a try...however i do see problems with sprocket restrictions etc.........

somehow seems like the return of pacman dropouts.....soon...........
Title: Re: New concept, new frame...
Post by: SIN on November 19, 2009, 07:38:17 PM
your chain is on backwards...
Title: Re: New concept, new frame...
Post by: ollie on November 19, 2009, 07:40:52 PM
What is the point to minimize the rear triangle? Does it help in any tricks aside from tire trod bike varials?
Title: Re: New concept, new frame...
Post by: JFos on November 19, 2009, 07:50:19 PM
I dont get this advantage either. a Long rear doest exactly make backwheel easy. is this steve pokemon?
Title: Re: New concept, new frame...
Post by: robpossible on November 19, 2009, 07:51:21 PM
What are the rest of the specs on this frame? The thing looks nice and simple as well as a bit roomy for a strait tube design...
Title: Re: New concept, new frame...
Post by: rick macdonald on November 19, 2009, 08:06:38 PM
I like it..you had a thought, a drawing, a plan, and now a real prototype.

Congrats..we all wish we could create a bike of our own!


anyone who says they haven't dreamed of it is lying...

!!
Title: Re: New concept, new frame...
Post by: Levi on November 19, 2009, 08:08:10 PM
I dont get this advantage either. a Long rear doest exactly make backwheel easy. is this steve pokemon?
it's a way to minimize the width of the rear triangle,
Title: Re: New concept, new frame...
Post by: TJ Perry on November 19, 2009, 08:10:04 PM
I dont get this advantage either. a Long rear doest exactly make backwheel easy. is this steve pokemon?

Yes it does. These 12.5 rear ends coming out now make rear wheel tricks incredibly twitchy and over-responsive. 13 should be the minimum.

As for the chain through the frame design.. I don't think that hole will be able to withstand the abuse that a normal seatstay would be able to. Not to mention the fact it limits what kind of gear ratio could be run on it.
Title: Re: New concept, new frame...
Post by: JFos on November 19, 2009, 08:21:58 PM
whats the advantage of a narrower rear tri? and seriously was this meant to narrow ro shorten the rear?

Im not knocking this becasue i fully believe to each his own...im just tyring to understand where this is coming from and why.

Is a shorter rear helpfull with front wheel tricks? or narrow at that?


 i think that smore viable than helpfull for rear. i just think a rear end this short or narrow is kind of unnecessary, and actualy counter productive. I just cant think of reasons to reinvent for front when I fully understand at the same time that a short rear or narrow rear wasnt made so to assist with back wheel styles.
Title: Re: New concept, new frame...
Post by: byke on November 19, 2009, 08:31:40 PM
I Like it.


Malo, I will email you soon ... I had the swine flu the past week and a half so havent spent much time out of the bed.
Title: Re: New concept, new frame...
Post by: flt trix rider43 on November 19, 2009, 08:38:04 PM
I SEE PROBLEMS WITH SUPPORT OF THE DOWNTUBE AND
BOTTOM BRACKET AREA/SEATTUBE AND WILL THIS THING
BREAK AND WHAT IS THE WEIGHT ON THIS FRAME!

THANKS
Title: Re: New concept, new frame...
Post by: out~riding on November 19, 2009, 09:14:27 PM
I like the concept but it brings to mind some questions:
a) how strong is the "floating" dropout? It doesnt have the same support a regular dropout junction would have.
b) how strong is the tunnel? Will it withstand the lateral impacts? If it does go into production it would have to be enlarged vertically to have chain clearance with bigger sprockets and that would weaken even more the tunnel.

Anyway I wish you good luck with this idea!
Title: Re: New concept, new frame...
Post by: Evil_Lincoln on November 19, 2009, 09:27:56 PM
Yes, it's cool that somebody out there can make their own frames.  When I look at this one, I think it's cool looking but the very first thing that crossed my mind was how many people would be posting pics of it in the "broken parts" thread...

Title: Re: New concept, new frame...
Post by: NOpurpoSE on November 20, 2009, 12:05:01 AM
Very interesting "outside the box" design. It looks rather cool as well.

But as others have already said, I fail to see the benefit of it other than looks, and I personally would not want to pay more for a frame with a chain tunnel, than a frame without it.

Any idea what range of sprocket sizes you can run on this?

Other than that, I say good job. I wish I had the means to build my own frames.

Keith
Title: Re: New concept, new frame...
Post by: EZChris on November 20, 2009, 12:18:57 AM
I think the idea is silly.

But what I love here, is the whole "yeah, why the hell not?" attitude.

If you can, why ever not. It's a interesting concept and seems for the prototype to be well excecuted.

I like a good enginering challenge, well done to you.

Yeh it may not be usefull, helpful, or beneficial to flat in anyway but if people had that attitude towards things we wouldnt of ever bothered building a 763mph rocket jet car or a house constructed out of 3.3million bits of lego.

WHEN IN ROME, etc.
Title: Re: New concept, new frame...
Post by: Paradoxium on November 20, 2009, 12:20:06 AM
It makes perfect sense. The centre of gravity is in the hub centre, not only of the diameter, but across ways as well. When on one wheel, the centre of the axle is your balance point. The closer you are to it, the easier it is. This is the exact reason most forks got narrower.

As for design, major props for going through with it. I can see it can benefit not only balance points, but give extra arm clearance too as a bonus. So many times crank spindles seem almost long enough.

Due to its open design, it will no doubt flex more or even crack.
To compensate, it would be necessary to increase the thickness of all materials in that immediate vicinity, particularly the actual tunnel.  Frames are light enough.

While I have no doubts you have already tested and retested this prototype, there will be bigger, heavier riders with more aggresive styles that will ride the end result should it go into production, and thats why thicker materials should be used even if the prototype survives.

Please announce gearing limitations. For example 11/23.

Congrats on thinking of this, and having the guts to go through with it.  ;D  :beer:  :mellow: Critics will be in abundance.  ^_^
Title: Re: New concept, new frame...
Post by: TGK on November 20, 2009, 12:43:45 AM
There is a very specific point to having do have width concerns not only on frames, but on forks also. 

I had this talk with a rider in Ohio about this last week.  We both have custom odyssey forks now,(his the freestyle ,and mine being the director forks) and have had major yet very productive results in our riding by the means of having to deal with foot wedge tricks in relation to being able to control the wheel in a more stable manner. 

So with all that said, I hope a lot more companies look into this future, and consider this just as important as any functional design should be. 


Hope this helps. 
Title: Re: New concept, new frame...
Post by: fablus on November 20, 2009, 01:14:21 AM
I like the straight tubing in the rear triangles.  Keep those fresh ideas flowing! props PiR.

Title: Re: New concept, new frame...
Post by: Theory on November 20, 2009, 01:44:57 AM
I enjoy this concept.

I believe that the drop outs and corresponding tunnel can and should be reinforced without losing any visual appeal, but that's what prototypes and new iterations are for!

I would extend some reinforcement back on the drop out so that the chain is more protected and so when I'm holding the back pegs I don't end up touching a greasy chain.

I like the idea of a narrower rear end. It fits the functional trend of getting closer to the balance point (smaller diameter pegs, narrow forks).

I like the welded seat stays & chain stays. It reminds me of a custom automotive look. Although it does provide 4 more points of failure.

I like the incorporated seat post clamp below the TT. I have this on my Eastern Tramp and It gives it a really clean look as well as being functional (easily replaced nut/bolt system).

I agree with TJ that the rear end really doesn't need to be shorter than 13"...
Title: Re: New concept, new frame...
Post by: Pralex on November 20, 2009, 01:58:36 AM
Making the rear triangle more narrow won't really bring your foot/feet closer to the centre of of the hub (aka balance), as you'll still be restricted by the width of the hub forcing you to keep the dropouts a certain distance apart.

Interesting concept, but I agree with others that I can not find/understand the overall benefits.
Title: Re: New concept, new frame...
Post by: Theory on November 20, 2009, 02:14:57 AM
Making the rear triangle more narrow won't really bring your foot/feet closer to the centre of of the hub (aka balance), as you'll still be restricted by the width of the hub forcing you to keep the dropouts a certain distance apart.

Interesting concept, but I agree with others that I can not find/understand the overall benefits.

True, we are restricted by the width of the hub.

That being said my current frame has seat stays and chain stays welded on the outside of the drop out. All other things being equal, if my frame had this drop out design my feet could move closer to the center of the hub by half an inch. 

This may also be a benefit for pivoting tricks. Again all things being equal, I would have an extra half inch of clearance for my feet to pivot.

Title: Re: New concept, new frame...
Post by: rawchild on November 20, 2009, 02:26:06 AM
Looks really cool.  Like the design.
  How long has it been in testing?  Any problems yet?
Title: Re: New concept, new frame...
Post by: Pat on November 20, 2009, 02:37:59 AM
there'd obviously be a tire limitation too...
Title: Re: New concept, new frame...
Post by: Jason on November 20, 2009, 03:25:11 AM
I enjoy this concept.

I believe that the drop outs and corresponding tunnel can and should be reinforced without losing any visual appeal, but that's what prototypes and new iterations are for!

I would extend some reinforcement back on the drop out so that the chain is more protected and so when I'm holding the back pegs I don't end up touching a greasy chain.

I like the idea of a narrower rear end. It fits the functional trend of getting closer to the balance point (smaller diameter pegs, narrow forks).

I like the welded seat stays & chain stays. It reminds me of a custom automotive look. Although it does provide 4 more points of failure.

I like the incorporated seat post clamp below the TT. I have this on my Eastern Tramp and It gives it a really clean look as well as being functional (easily replaced nut/bolt system).

I agree with TJ that the rear end really doesn't need to be shorter than 13"...


A good weld is 10 times stronger than the material that it is bonding together.  I think that is is a good idea to weld them as opposed to bend the tubing.  Overall I like the look of the frame itself, minus those ugly dropouts. But I would never buy one because I agree with TJ as well, a 13" dropout would be nice on alot of these frames that we ride.  I don't like having to push my wheel back so far on the dropout just to keep it from getting all squirly on me.
Title: Re: New concept, new frame...
Post by: Jason Rideout on November 20, 2009, 03:26:41 AM
i really like this design , closer the the center of gravity . the short frame look cool. the only sugestions i have are , thicker stronger drop out and for the chain tunnel use thicker tubing in the shape of a rectangle so you can have a larger gear ratio.
Title: Re: New concept, new frame...
Post by: g-man on November 20, 2009, 03:37:26 AM
looks like another circus frame and I dont mean from twenty bikes. I'm not a fan of gimiky stuff or the wheels almost rubbing on one another, and those stupid looking short seat tubes with long posts

To each there own, I prefer a longer wheel base and normal length seat tubes

Are you sure this this wasn't built for 16" wheels?
Title: Re: New concept, new frame...
Post by: Burd on November 20, 2009, 03:38:05 AM
I would suggest that this frame is going to constantly be cracking right between the top part of that hanging bottom bracket and the downtube.  KGB had a frame with that same BB area layout, and I saw Andy Cooper crack one of those within a month of getting it.  I would seriously reconsider that portion of the design...
Title: Re: New concept, new frame...
Post by: welfaresoldierbt on November 20, 2009, 03:47:39 AM
Hats off to the innovation and progression in general. But I think my gut reaction to this bike is like looking in the mirror and finding more wrinkles and even less hair.
Forget the chain/frame design a minute. At what point does a bike end up so wacky that it doesn't look like you are doing tricks on a bike anymore?
"Hey mom, look at that guy spinning on a couple of wheels connected by a stick!"
This looks like something a yuppy would fold up and stuff into his private jet.
To each his/her own, of course, old guys like myself are often critical of new things.
I don't mean to sound harsh, that is just one ugly little bike-type thingy.

Title: Re: New concept, new frame...
Post by: Theory on November 20, 2009, 03:53:40 AM
A good weld is 10 times stronger than the material that it is bonding together.  I think that is is a good idea to weld them as opposed to bend the tubing.  Overall I like the look of the frame itself, minus those ugly dropouts. But I would never buy one because I agree with TJ as well, a 13" dropout would be nice on alot of these frames that we ride.  I don't like having to push my wheel back so far on the dropout just to keep it from getting all squirly on me.

I didn't say the welds were weaker, you are right in saying the weld itself can be stronger. I was thinking more of the heat affected zones beside the welds. Most of the pictures I have seen of broken parts, the cracks are always beside the welds.

That being said I'm not a welder, just expressing an opinion... I do believe there are more important aspects of the frame design to worry about rather then those joints.
Title: Re: New concept, new frame...
Post by: pulsar on November 20, 2009, 04:35:46 AM
wow nice looking frame there. i like it..

tough to say how that back end would hold up. there is some sh!t going on there....the tunnel which seems like you would get some side to side flex in the back, the stays are not attaching to the drop out how they normally would, so that back wheel is just hanging out there. drop outs are usually well supported by the stays normally.

i would think they went with multi tube stays to try and lessen the amount of flex in the rear.

its cool as Sh!t though..... -_-
Title: Re: New concept, new frame...
Post by: Pat on November 20, 2009, 04:40:07 AM
welds may be stronger, but the area around the welds are alot weaker. thats why they heat treat stuff  :mellow: bends are stronger  :P

i think  :rolleyes:
Title: Re: New concept, new frame...
Post by: TOflat on November 20, 2009, 04:53:47 AM
I like it, I've always liked riding narrow frames, though my sick child has a huge ass on it. I enjoy the frame but am too tired to go in depth with the description. All i'd say is clean up the welds, bend the chainstay and seatstays instead of welding them.
Title: Re: New concept, new frame...
Post by: pawnshopmike on November 20, 2009, 09:21:44 AM
Can we call it the "Chunnel"? I love the innovation. Keep it up.
Title: Re: New concept, new frame...
Post by: Revig on November 20, 2009, 12:51:42 PM
is this steve pokemon?

No, first name of Pokemon is Stephane, not Steeve.
Steeve is a guy who lives near Paris too but who cares...

Great welding job, it looks very very nice !
Title: Re: New concept, new frame...
Post by: PiR products on November 20, 2009, 02:43:31 PM
This frame is a custom frame, made to the specifications of the customer.
So, the specifications are very personal, that's why this frame will not necessarily fit other people.

Steeve who ordered this first "chain-tunnel" frame, knew exactly what he wanted, so the frame has been made exactly to the specifications of his parts (tire, gearing...)
Everything has been made to satisfy him.

The specifications of the frame are the following :

USA 4130 heat treadted CRMO tubing
Top tube : 18" ; 457.5 mm / 1-1/8" diameter
Downtube : 1-1/8" diameter
Head angle : 74 °
Chain stay : 12" ; 305 mm / 3/4" diameter
Seat stay : 5/8" diameter
Seat tube angle : 71 °
Chaintube tunnel : located for a 16 X 9 gearing ratio
Machined head tube, bottom bracket and seat tube.
Integrated seat post clamp located between the top and down tube
5 mm thick lasercut dropout
Offset seat tube tangent to the bottom bracket
Weight : 1600 g
no paint !

Every PiR frames are made to order and designed to fit the parts of your bike.
Title: Re: New concept, new frame...
Post by: PiR products on November 20, 2009, 06:43:43 PM
Quote
How much $ for custom frame ?

PiR is a french brand so, the price is in Euro.

A custom frame costs between 300 and 450 Euros.
Title: Re: New concept, new frame...
Post by: khe killah on November 20, 2009, 09:25:31 PM

PiR is a french brand so, the price is in Euro.

A custom frame costs between 300 and 450 Euros.

Very nice looking frame indeed... Probably one of the nicest i've seen in a while to be honest, only thing that im not sure about is the tunnel but i trust it's had a fair test?? What's the warranty on these then? It's a Flat specific frame so guess you can't say no if it break's mid trick.. or can you?
Title: Re: New concept, new frame...
Post by: NOpurpoSE on November 20, 2009, 11:54:38 PM
Ok so if the idea here is to make the rear end more narrow in order to help with balance, than I have one question or issue rather.

I can see how being closer to the cg can help with pivoting, but are you guys also saying that it helps with font/back and side to side balance while rolling? When I think about it, for front to back balance being closer to the cg really wouldn't matter. But when I think about side to side balance, I immediately thought of my balance board. Like this one:

http://www.indoboard.com/application/cart/index.php?main_page=product_info&products_id=187 (http://www.indoboard.com/application/cart/index.php?main_page=product_info&products_id=187)

The closer your feet come together, the harder it is to balance, as you would imagine. I've always related this to how I balance on my pegs with two feet, and have always felt that the farther I can get my feet apart, the easier it is to balance.

Keith
Title: Re: New concept, new frame...
Post by: Hugo @ Portugal on November 20, 2009, 11:57:37 PM
I have to applaud the audacity and courage but nevertheless I can't stop thinking how useless it looks to the average joe.

I mean, it looks to me as if you're trying to reinvent the wheel and that is something the world doesn't really need. A BMX frame is a simple, useful, eficient concept. It doesn't need hollow chainstays or holes in the headtube to be better.

Get those neurones working towards parts that can withstand a fair amount of abuse from a skilled rider, at a fair price, that's what flatland needs.
Title: Re: New concept, new frame...
Post by: Flatland-Cris on November 21, 2009, 12:07:26 AM
looks dope as hell man wish pir luck with the custom frames! if the french could make a good car like this id be impressed! =]
Title: Re: New concept, new frame...
Post by: thestraw on November 21, 2009, 12:31:30 AM
i can only think about a loose chain rattling around in there, one of my favorite sounds...
Title: Re: New concept, new frame...
Post by: Navid on November 21, 2009, 02:54:35 AM
Damn!, ik realy like the idea, and the inovation!!
i dont know if the tunnel would help my riding, but its original etc...
But what i realy love!!, is the  seat post clamp system!!!!! incredible!!!
Great job! let us know when it hit the market!!!
if you need a test rider let me know, i ride heavy...:D
Title: Re: New concept, new frame...
Post by: flatlandfreak66 on November 22, 2009, 10:15:39 PM
interesting concept :beer:!!!!! 

though a bigger triangle is stronger, and the welds on the stay adds more of a weak point to the backend rather than using a bend. also i would imagine using thicker material for the dropout as well. :huh:

but, i do like the look of the skinny backend, and the tube for the chain looks very sleek.

kudos :beer: :beer: :beer:
Title: Re: New concept, new frame...
Post by: sakis on November 22, 2009, 11:17:15 PM
pros:
more space for pivots.
more gap for cranks.
foot closer to balance point.


cons:
hanging bottom bracket that will probably crack sooner or later as ALL frames that did that design.
i dont like the seatpost idea,i think eastern frames cracked in that area.
needs gusset under the downtube and over the top tube if it stays like this or else they need to be more wider in between them so the frame will be stronger.
one more point:where exactly your foot will stand against if there is no actual seatstays to keep your foot steel if you do a turbine megaspin for example?
overall nice idea,congratulations,but it needs some changes as i see it.