[patineto]

now that the "Boom for the crane" is finish I need to install the Pulley my idea last night was to manufacture something similar to this

and then just install the Pulley at the end of the boom. but after xy9ine posting this morning i change into a "Hanging" tension structure, but not after spinned in my head a million times.

notice the two little pendular pieces to hold the pulley on a floating mode.

it looks something like this.

i think i need to make a sliding surface in between the two green pieces so the chain moves better , chain was on the smaller cogset but maybe on the bigger one is no big deal

this is how it looks when finish

now the pulley is a little forwad from the pivot axle but hopefully since basculate with the swing arm motions is not going to be a big deal.

I'm a little worry the cranks are going to feel like "Morse code" since the swingarm will be moving up and down and on his own turn also the "crane" on a similar radius (even if minimal since the crane is so short), maybe afecting the chain tension,, well will see.

a view from the front

and then a picture of my super dupper messy house, can you beleive i need to take all that crap out just to make this little thing, actually that is a great comparation to the amount of mental work thaat goes into figuring out something like this, i contemplate at least 15 diferent ways of doing it all of then with pro's and cons, pretty much like opening a whole box just to find one little washer ..

well i hope I inspire you guys and gals again to go and follow your own dreams and ideas.

ricky

 

[lovebunny]

wow. that is truly impressive.

 

[vitox]

standing ovation!

 

[bikenweed]

Are those silver pieces from a Suntour U-brake, circa 1986-1988?

Let's hear how that thing rides now! Looks great!

 

[thaflyinfatman]

standing ovation!

Ditto that! Great work!

 

[xy9ine]

Are those silver pieces from a Suntour U-brake, circa 1986-1988?

its definately a roller cam brake. maybe a wtb, if not suntour.

thats some mad tinkering, btw.

 

[ChrisRobin]

You should be nominated for M.V.P. of Ridemonkey for 2006.

 

[OGRipper]

Ricky that is pretty cool.

Hmm, those silver arms sure look like roller cam...not a u-brake...suntour had speed holes, wtb/cunningham were more cnc style weren't they? I'm going with Dia Compe, maybe from a Raleigh, around 1988 - 90?

Thatflyingfatman, I appreciate you trying to explain but I still don't get it if we're talking about a concentric. With a concentric, once you're in a particular gear, even if the chainline is not parallel, the angle of the chainline as compared to the stay will not change as you move through travel will it? Somewhere in the fog I can see some growth or reduction as you shift from one gear to the next but I don't understand why there would be any change in one gear.

 

[OGDMFG]

I give you an a for creativity,for solving a problem using bare min tools, good job, watch to see if the forces start bending your mounting hardware.

 

[seismic]

WOW.....this is indeed awesome !!!

 

[zedro]

Wow coll, that is very smart all the loads under tensions, sadlly for the nicolai i think i can only run the puklley under Compression since the pivot is already backwards from the bottom bracket (on a vertical axis)

thanks for the picture, it makes perfect sense, hell you can even run a "Rope" that way since all the forces are pulling down into the pulley.

very cool.

i think i might have done it first

circa 2003....

ps...how do you relink attached images to appear instead of just the hyperlink?

 

[OGDMFG]

hey zedro,nice cnc work,lots of time in front of the cnc

 

[Lexx D]

If you were able to track down a BB7 pulley, that might save you some time and effort when it comes to making one that will last. All you would have to do is find a way to secure it and keep the chain on.

I may have one if someone needs it.

 

[patineto]

Ricky that is pretty cool.

Hmm, those silver arms sure look like roller cam...not a u-brake...suntour had speed holes, wtb/cunningham were more cnc style weren't they? I'm going with Dia Compe, maybe from a Raleigh, around 1988 - 90?

actually I was sure was a old suntour XC-pro rollercam brake but now you are making me re-think about it..

good job..

Thatflyingfatman, I appreciate you trying to explain but I still don't get it if we're talking about a concentric. With a concentric, once you're in a particular gear, even if the chainline is not parallel, the angle of the chainline as compared to the stay will not change as you move through travel will it? Somewhere in the fog I can see some growth or reduction as you shift from one gear to the next but I don't understand why there would be any change in one gear.

Concentric is not a Bicycle term, is a coloquial term to express two or more item that share a Comun axis,,, is something like Conmuncenter or something like that the Antonomus work is EXentric,,aka when two or more items use diferent axis but they still sorrounded on the same enviroment.

for example a "Exentric" bottom bracket on a single speed usses a Of axis mount for the bottom bracket to be able to adjust the tension on the chain, on the other hand a BMX bike usses a "COncentric" adaptor to run the bottom bracket right on the center of the BB shell.


i hope this clarified the problem.

 

[OGRipper]

Concentricis not a Bicycle term, is a coloquial term to express two or more item that share a Comun axle,,,is something like Conmuncenter or something like that the Antonomus work is EXentric,,aka when two or more items use diferent axis but they still sorrounded on the same enviroment.

or example a "Exentric" bottom bracket on a simgle speed usses a Of axis hole for the bottom bracket , on the other hand a BMX bike usses a "COncentric" adaptor to run the bottom bracket right on the center of the BB shell.


i hope this clarified the problem.

Hahahaha, no, you just got all DW on me. All I know is that concentric in this context means a swingarm that moves around the bb, like a rotec. But I am not very smart and have no engineering training...anyway keep up the good work.

 

[ChrisRobin]

i think i might have done it first

circa 2003....

ps...how do you relink attached images to appear instead of just the hyperlink?

That was from when you presented the rear end to your class eh??

 

[thaflyinfatman]

Thatflyingfatman, I appreciate you trying to explain but I still don't get it if we're talking about a concentric. With a concentric, once you're in a particular gear, even if the chainline is not parallel, the angle of the chainline as compared to the stay will not change as you move through travel will it? Somewhere in the fog I can see some growth or reduction as you shift from one gear to the next but I don't understand why there would be any change in one gear.

I'll get back to you with diagrams in a day or two. This is quite hard for me to put into words.

 

[patineto]

Hahahaha, no, you just got all DW on me. All I know is that concentric in this context means a swingarm that moves around the bb, like a rotec. But I am not very smart and have no engineering training...anyway keep up the good work.

Come On you are not going to tell me that Rotec invent a freaking word to describe how their swingarm mounts,,,
actually lets use the rotec as a example..

if you were to make a bunch of circles ussing the center of the cranks, all the circles no mather how big or small will have the same center of origen (concentric)
Yes the swingarm on the Rotec's rotates on top of the Bottom bracket shell, but to achive that, all the bushing, bearing, mounts, etc need to be on the same axis to work propertlly, if they were not the swingarm will bind or will have a progresive change in the way it moves, again the wheel travel path on a Rotec ussing Only the swing arm as reference is equidistant in reference to the bottom bracket in any point of the suspension movement, Now If you add the upper linkage into account this will change, but lets keep it simple so is easier to understand...

also is a rectangular thing ussually really heavy and thick with a million zillion black caracters all over the place call a Diccionary that is being regarded for a long long time and a fountain of wisdom and culture, if fact if i remenebr correctlly this days this heavy objects actually float on the ether of the sustance call the internet and to make it even easier is a really call portal of the light call Goggle that in fact i enjoy very much...


give it a try get your high school compass and start to make concentric circles all over the place..

now i'm going to sleep, i need to be fresh for the inagural trip of my new and hopefully improve Idler Pulley mega monster.

 

[patineto]

I may have one if someone needs it.

Me ME mE....
just let me know if you find it and how much money you want for it and i be more than happy to make it happend...

thanks

 

[patineto]

i think i might have done it first

circa 2003....

ps...how do you relink attached images to appear instead of just the hyperlink?

man Don Zedro that is some serius research work love the detail of the multi adjustment on the lower linkage, what were you trying to accomplish..!?!?
how about the results.. ?
do you have a tread adress to go with the pictures..? i want to learn more about it..

looks pretty heavy,, how much Poundage.. !?!?

I will like to say the old "Brilliant mind think alike" but i'm afraid You are way beyond my league


so were is the rest of the bike, i only see the rear end, but then again i'm kind of blind and clueless sometimes.

 

[patineto]

now that is one cool idea. from your ideas that have been posted on here from time to time, im going to assume that you have a background in mechanical engineering. let us know how it turns out.

I study Industrial Design (and i'm glad i did) but spend millions of hours doing mecanical things, from wind tunnel testing on my landluge boards to making level Five bulletproof cars out of fancy composites and ultra hightech alloys, i also have a master deggre in ergonomics and biomecanics since i was really interested in ways to harness the power of the human body, and i have another degree in human transportation & urbanistic develoment since i'm always being interested in the well being of the comunity...

actually i'm being drawing and trying to make things since i was about five years old and far early destroy them , i can still remenber the day my mother bring some plastic bowls and make the big mistake of telling me they were "indetructible",,, needless to say they were not, since then i'm being ussing my "acid for blood" destructive abilities to stress test and find the most dependable products since aything else will not cut it...

I do have a really narrow spectrum of skills, i suck at bussiness and for sure with lenguages and verbal and writen comunications.

 

[dw]

Captain Anti-Squat

EDIT: I was thinking about it and I have to ask, even though I am afraid the answer will explode my small brain - with a concentric, why does it matter if the gears are different sizes?

AHAHAHAHA Captan Anti-Squat, nice.

So consider that concentric BB pivot Rotec. lets also say for illustration purposes that both sprockets front and rear have a pitch diameter of 100mm. OK?

Now lets say that the suspension is compressed so that the swingarm moves 36 degrees.

100mm X PI = 314mm circumference of the sprocket.

360 degrees = 314mm
36 degrees = X

X=amount of chainpull from the rear sprocket for 36 degrees of swingarm angle change.

X=31.4mm

Now in the front, that angle change has also happened, but its a negative number. Add the two up and they cancel out.

If you change the front or rear sprocket in one direction or the other you get pedal feedback in either direction depending on the gear ratio.

Make sense?

Dave

 

[zedro]

so were is the rest of the bike, i only see the rear end, but then again i'm kind of blind and clueless sometimes.

i'm pretty sure you've seen the bike, there were some changes to the above pics. The bike was part of my school project and those pics were taken before the presentation. The front end had not been built yet, the shock linkage is different and the 'idler arm' concept has been dropped in favour of the non-concentric swingarm mounted version. Overall i'm quite pleased with the outcome, it pedals really well, the linkage adjustments give a nice range and feel good, the bike is heavy but feels very neutral and balanced. I have had an issue this year with the swingarm cross brace cracking so i need to do some mods for next season.

Someone will have to dig up some pics cus my hardrive where all the pics are stored is corrupted and i'm trying to recover all my documents as we speak

 

[patineto]

After about 15 hours of playing around finally i got to take some pictures during the day light..

since DW explanations are a exelent example of the "maybe known it to much is not that great after all" sindrome, i decide to take some fotos ussing reference makrs in the search of some visual aids

again I kind of think i understand the basic of david's rubic cube theories.

lets see if i did it right...

for the Un-inform the yellow thing with the ovals is as being used as a square (90 deggre angle)

Since some of you guys only understand bicycle terms I decide to utylize as Square you guys are familiar with a Downhill racing DVD

angle finder at work just for reference

now keep this in mind...
I used two aluminum Gold Tubes and allen key cover on blue masking tape, to help visualize the angles..

the Upper gold tube mimicates the possition and angle of the chain.
the lower one represents the relation ship in between the Suspension pivot point and the rear hub axle.
the blue tape gives you a reference to the angle of the vertical segment of the chain but is also "Concentric" to the swing arm pivot point

I divide the process in two parts.
1).. First the IDler Pulley project results and that segmented in 3 diferent reference.
A)...small cog
B)... middle cog.
C).. then biggest cogset.
to try to see the deviance the cogset makes into the chainline forces

Here are the Idler fotos
First the small cog, preety much paralel, if i understand the fisics correctlly this is the best possible scenario since the forces will self cancel each other, specially being on the small cog position, ussually when you have the highest rathio of leverage

then the middle cog

and this is the squematic ussing the bigest cog in this case a 32T

here are the pictures trying to duplicate the stock location (The way the bike comes from the factory) of the chain and also the other gold bar to duplicate the relationship of the Pivot to the rear hub axle, in this case Exactlly the Same as on the Idler Pulley experiment.
Sorry I think i F666 up and forgot to take the picture of the small cog, anyway the two gold bars look almost paralel.

Middle cog

32T cog...
notice the really abrupt angles of the "chain tube" and the "axle tube"

remenber the Blue line is absolutlly perpenticular to the chain line and since the idler pulley "crane" is conected to the swingarm also the relationship will keep kind of constant (the idler cog will drop down into the chainring the more the suspension is compress)
man this project came out pretty good, so much acomplish all at the same time..

The easy lissent version ussing the DVD box, the distance from the chain to the bottom bracket axis is about 3 inches, ussing a 42T chainring, ussing a smaller or bigger chainring will change this a little , but then again wehn i make a proper prototype i can build adjustments to take the size of the chainrings into account..

the Pivot point is located about one inch forward than the bottom bracket ussing the chain as a reference.
but the two points are pretty much located on the same perpenticular line.

I guess you guys can tell i have some of this work before..

I'm a total Geometric geek at heart and in the flesh


Hopefully this little diagrams help DW to present a more "coloquial" explanation.

 

[patineto]

last nigth I took the whole thing apart and perfect it, about 4 hours later i was "done' until the freaking thing breaks some time in the future.

first I gring and shave the pieces as thin as posible trying to bring to whole "crane" as close as possible to the frame so the chain line is right above the chainring the way is soppose too.

i also decide to improve rigidity by ussing a extra bolt tap into the arms and then tread a Pilot bolt at the core of the arms to make a "Key way" for the teal rectangular blocks.

the chain line still about one milimiter from perfect, will see if is a issue when i ride it a little later in the day.

actually is not bad at all, specially it you take into account the two little steel part that act as tension meneber have some amount of helpful flexibility.

I lift the chain so you can see all the details i improve, like a rounder edge for the chain and also a much more square space for the chain, (before was pretty round and restricted)

with out a load on the bike the chain is almost touching the crane, but when loaded everything is just fine.

I also install that awesome pieces of white nylon (I just got lucky, did not need to do anything to it,,, about time after all this cutting and hacking

so nice and helpful.

I'm extremlly proud and also gladlly surprise about how well it came out, In fact i send the whole foto file and tread adress to the guys i know at Nicolai. so far no answer (send friday night)

 

[patineto]

i'm pretty sure you've seen the bike, there were some changes to the above pics. The bike was part of my school project and those pics were taken before the presentation. The front end had not been built yet, the shock linkage is different and the 'idler arm' concept has been dropped in favour of the non-concentric swingarm mounted version. Overall i'm quite pleased with the outcome, it pedals really well, the linkage adjustments give a nice range and feel good, the bike is heavy but feels very neutral and balanced. I have had an issue this year with the swingarm cross brace cracking so i need to do some mods for next season.

no don zedro I never ever see you bike before, remenber i'm kind of new arounhere, but for sure the pictures bring up even more of my admiration for you acomplisment that until now were only theorical since i never see any of your fisical work..


please take some pictures, i'm extremlly intrige on your concepts

Someone will have to dig up some pics cus my hardrive where all the pics are stored is corrupted and i'm trying to recover all my documents as we speak

sorry i can not help on that part since i'm the ultimate lamme a^^ computer person..

but if you need a place to keep some fotos to be link let me know since I have pretty much the best storage service that is at my finger tips

 

[OGRipper]

Here is a pic of Zedro's rig...Patineto keep it up man...Dave, thanks for that, I will play around with it and try to understand. Once again the monkey comes through with another mind-bender for me.:love:

 

[OGRipper]

Here's another with the drive side, I realized that is probably what you are more interested in...

 

[OGRipper]

Don Zedro, these are the only two others I have.

 

[patineto]

finally I got to ride the little monster

the first few blocks i need to confess were Evil since the chain was draging far more than i spect it..

that little 2mm deviance when the was static, end up proving to be a
to much, i just felt like a was draging a whole shopping cart, i even shave a little of the inside of the E-13 bashring .

well the pain did not last long, i when to visit my friends at mike's bikes and borrow and few washers and bolts to fix the chain line at least in a temporary way..

Funny i used to dislike that whole chain of stores in a really big way, but the guys at the berkeley shop totally prove me wrong time and time again, they are super proper very honest and also pretty good when it comes to fix things...

put it this way i got them scone and muffins just because.

I did a little temporary fix ad i move the pulley about 4mm to the inside, the diference was intense.

so far i can not really tell you how well the sistem works, i don't have suffient data for it, but hopefully soon i will do a side by side test to see the advantages and possible problems.

one thing i can tell you is that is no ill feedback of anyway and the bike feels like it reacts a little faster, more crist at least, but for now is just a empirical impression.

Oh my silly fender experiement suck big time since it hits the seattube very easilly.

When i got home i took everythung apart and fine tune the few issues, tomorrw i will go into the dirt and see what happend.

much more pictures to come..

 

[patineto]

Here's another with the drive side, I realized that is probably what you are more interested in...

many thanks OGRipper.

actually my favorite is this one since you can see the intricate linkage work..

i even open a whole gallery for master Zedro's work so if anybody have more pictures post them here or send them so we make sure this awesome work is safe for posterity.

thanks again for the great fotos.

actually here are the ones i collectb(same fotos just bigger and ready to view)

 

[thaflyinfatman]

AHAHAHAHA Captan Anti-Squat, nice.

So consider that concentric BB pivot Rotec. lets also say for illustration purposes that both sprockets front and rear have a pitch diameter of 100mm. OK?

Now lets say that the suspension is compressed so that the swingarm moves 36 degrees.

100mm X PI = 314mm circumference of the sprocket.

360 degrees = 314mm
36 degrees = X

X=amount of chainpull from the rear sprocket for 36 degrees of swingarm angle change.

X=31.4mm

Now in the front, that angle change has also happened, but its a negative number. Add the two up and they cancel out.

If you change the front or rear sprocket in one direction or the other you get pedal feedback in either direction depending on the gear ratio.

Make sense?

Dave

That makes perfect sense. As far as I can tell though, that can still be reconciled with my axle-path-is-perpendicular-to-the-chain-line theory... or am I off the mark here?

 

[seismic]

Super respect for the people building this kind of stuff !

 

[ghettogt76]

I love your posts Ricky, you really are innovative. On the other hand, I feel like an idiot when I read them. I don't understand any of this, I just like to ride my bike

 

[patineto]

I love your posts Ricky, you really are innovative. On the other hand, I feel like an idiot when I read them. I don't understand any of this, I just like to ride my bike

Greg your heart is pure as gold and at least for me that is all that matters..

also i see your work before and for sure you are no Dummy, plus is all about learning and for you still have many years to do that.

i'm being working a lot collection some fonds for your little monster, hopefully soon i have a second Nicolai at my house to make company to the rest of them..

 

[patineto]

I am so FreaKing Happy...!!!!!

my spectations were not even close to the result, the little Idler pulley made a incredible diference in the way they bike felt, to me the most important factor...

maybe the only theoretic advantage is that with convencional design the chain somehow trys to keep the suspension from bobing, you know squating and bouncing when you pedal hard ,since the chain is under the pivot point, you know what i really it makes very little diference, one of the beautys of the adler is that is no pedla feedback, somehow it feel like you are on a hardtail or a unified rear triangle suspension sistem, i don't know how to expresss it exept for the fact it feels like you are pedaling a 35pound bike as oppose to a almost 50 pound bike..

okay i did a very scentific test today, even if the results are of the "Seat of the pants" type .

i when for cross country ride,, yes on a 50 pound 9' of suspension Downhill bike, preciselly because i was testing the pedaling capabilitesm and does not get much dificult to pedal with out muc h momentum and going up hill.

anyway i did the same loop two times, first with the convensional set up (so far about 4/5 minutes to change over) to have a "base reference" the pedaling on the nicolai is already exelent, at least ten time better than my old giant Dh (kind of similar single pivot design)so is kind of dificult to tell.

something that always botter me is that the pedals have this "Telegrafic feel" like the chain gets thing and losee depending on what the suspension is doing.

then i did the exact same run with the Idler pulley install.

the bike just feel so light, nimble and responsive, it was just a delight to ride.

now i know I'm going to make a "Permanent" aka a better made cnc something or other looking pro kind of deal.

but the prototype works so freaking well, maybe i keep it until it fails.

I'm toatlly convince something like this will bring a big benefit in terms of pedaling efficiency for bikes like the Giant DH and who knows whatever else is contructed with a high single pivot point...

i keep you guys posted if i encounter more developement and interesting side effects..

 

[patineto]

so what happend, i was sure DW will be all over the Squematic picutres to explain how thing work ,,well maybe they are the wrong pictures.

and the rest will be happy to know how well the experiment end up..

so yes is 3 Am at the moment, but i when riding with 3 really fast guys this afternoon and my body is so full of endorfins i can not sleep to safe my life..

let keep this going for the benefit of every single pivot point bike around and maybe others too)

see you guys soon.

 

[julian_dh]

man im dealing with the same thing right now on my 223 made a few little prototype similar to you first one and man dose the bike feel differnet i love it im gonna keep mine on the e13 guide and stabilize it with something attached to the seat tube.

have you ever downhilled without a chain on the nicolai? i did that on my 223 and my idler thing make the suspension feel somewhat like that.

 

[Echo]

Damn, I don't think I have the patience to try something like that for my M-pire... but you inspired me to think about it

 

[patineto]

man im dealing with the same thing right now on my 223 made a few little prototype similar to you first one and man dose the bike feel differnet i love it im gonna keep mine on the e13 guide and stabilize it with something attached to the seat tube.

you go Julian..

i do agree you need to reinforce it and isolate the forces, I even dream about ussing something like a skateboard wheel rolling right next to the lexan bashguard, that will contact and roll on the guide under load but i did not go that way do to the execive drag.

maybe you can use a seat collar of the same diameter the only problem is how to reatache it togheter after you cut it or bend it, to fit since the top tube will stop you from slide it down into the optimal possition.

or maybe you can make the clamp out of a block of delrin leaving 3 sides flat and the last one concave with the shape of the tube, that will be super strong and very rigid, limiting the fatigue on the guide aluminum and maybe also improving the rigidity of the Pulley axle..

actually a even better idea (O don't know you bike) but how about you make a Bridge from the suspension pivot point to the top of the chain guide or even better the bike frae, then you can locate the pulley anywere you want in that segment and assure is very rigid and well support it..
I think that will be optimal..

please post some fotos so we can figure out what is best ad also from your current work, to marvel at you creation..

have you ever downhilled without a chain on the nicolai? i did that on my 223 and my idler thing make the suspension feel somewhat like that.

Julian, that is just a great way to describe it,,,
it feels just like that, like if you did not have a chain, the great news is that you can still pedal it.

thanks for the great analogy

keep working on it, I'm sure the benefits will out run all the hard work.