[patineto]

first this is kind of strange, I'm sure I start this same tread about four hours ago,, now i can not find it anywere...

anyway here is my question...?
after looking and hearing the great benefits about the Balfa BB7's idler pulley design

and the more recent Appalache encarnation

i was wondering if a similar concept will bring any kind of benefits to the already great Nicolai M-Pire.

anyway that question was kind of valid and important four hours ago when i made the posting for the first time,, actuallly after i few minutes of finishing the posting i keep thinking,,well I don't have a place to go or a girlfriend to visit so lets play a little and see what happend.

I drop the bike from the rack and I study the diferent options for a second or two, also since i have very little equipment at home i decide to make a very simple working prototype out of My favorite material Delrin plastic.

since the E-13 guide and the main pivot point are almost on the same axis I decide to use the upper arm of the guide as the mount for the Pulley..

Ummm... DW is going to be Mad...

first i look into my scrap box and I found this piece that kind of fit what i need.

I will use this old blue bullseye
pulley

also since i need a very rigid back plate I decide to use two sets of SPD cleat mounts as oppose to the nylon nuts to improve on stifness and also instalation (much easier to hold)

since i don't really have the proper tools, i used a variaty of Holesaws with diferent diameters to comform the pocket require for the pulley and the chain to be house in.

the delrin Piece is about 10mm thick and i need to make a poket of about 7mm at the deepest for the chain and about 6mm for the pulley

after i remove all the material I possibly can ussing the diferent holesaws, i use a "Diamont wire" mount in on a hack-saw to make a few paralel cuts to the surface and carve the rest of the material, what apain...!!

by now I spend about two maybe 2 1/2 hours making this little piece, is for sure a pain when you don't have the proper tools, but for sure that little impediment is not going to stop me, at least after some time i got a little easier because now i can use the famous "two spinning drills" technic

the second chapter will come in a minute after i make sure i can load this whole tread...


see you guys soon

 

[patineto]

this are the main powertools I use.
a small dremmel with a sanding drum and two drills to spin the big blocks and the holesaw and grinder tips.

incredible,, i got to see (well hear) one chapter of Mith busters (My favorite program) and two shows about big ships in the time it took me to finish this piece

the four 4mm counter sunk holes that will attache to the E-13 plate and then a 6mm hole for the pulley axle.

here is the back with the counter sunk 6mm bolt.

now with the pulley almost ready to be install

half the bolts in

idler pulley mount it just to measure

full view of the drive train

to really complete the "circuit" i still need to make the outhershell so the pulley axle can be propertlly supported, for that i use another scrap of delrin.

i used the holesaw again to make the pocket for the chain.

and then i cut a straight slot for the chain ussing a hacksaw and then a file (Picture before I use the file)

I drill and tap a 4mm hole (No more material left for something stronger) for the upper bolt of the outside plate.

finally i'm finish.

i use a 6mm V-brake nut with a allen head to hold the axle for the pulley in place

end up far more rigid that I spect it, at least pushing with my bare feet i will know better tomorrow when i test ride it..

I'm very happy with the results, the chainline is spot on with the pulley so i don't spect derreilings or execive loads on the E-13 bomerang (I totally know is not made for this type of loads and I assume the consequences of my actions.

for sure I don't spect for this setup to last more than a few milles (even if i get lucky) but i don't think i waste my time, since i learn a lot about the pivot locations and the possible alternatives

I think for the next version i'm going to use 3 diferent mounting points.
* take advantage of the hollow tube that reinforce the swingarm as a leverage to hold the mount align.

*a axle extension from the main pivot bolt as the main axle for the pulley

* the E-13 bash plate as a Intermediate reinforcement to improve on rigidity.

I think i also need to find a taller (bigger) "pulley" maybe one of the super chessy ones from a alivio derreileur or even better a single casette cog mount it on a bearing (to much work maybe, the clearance with the current chainring is kind of minimal at the moment so i don't think i can use anything bigger than a 12T

again, I have no idea what i'm doing in terms of "Idler pulleys" so if you guys see any possible problem or have sugestions to improve the concept please let me know..

oh the most important question,,,

I assume the pulley needs to be coaxial (on the same axis) as the single suspension pivot so the chain rolls in a eforless manner no matter were the suspension is doing,, if i'm wrong or missing something please let me know..

hopefully you enjoy my little project, for sure i have a lot fo fun making it even if is going to fail the first time i pedal it...

Oh mIster DW if you think you can use this concept for any comercial aplications as a way to provide better chainline and suspension reaction for single pivot bikes you are more than welcome to take advantage of it.

 

[lovebunny]

pretty spiffy. im interested to see how it turns out

 

[dump]

great work there! that bike probably should always have had an idler! (chainstay clearance issues, etc)

 

[Strakar]

Holy crap man, that's some great work you've done, it's good to see people being inventive and resourceful.

I assume the pulley needs to be coaxial (on the same axis) as the single suspension pivot so the chain rolls in a eforless manner no matter were the suspension is doing,, if i'm wrong or missing something please let me know..

To be independent, the chain should line exactly over the pivot axle, so the pulley axle wouldn't line up but instead would have to be located below the swingarm pivot axle. Looking at the photos I'd say that you might have a pretty good location.

 

[thaflyinfatman]

That's sick! What's that pulley made of? If it's plastic it'll probably crap the bed pretty quickly (looks like ano aluminium though). If you plan to re-do this at some stage, I'd highly recommend using an 11t SS cog (or even just the 11t cog off a cassette, they're usually separate anyway). Those pulleys are under a LOT of stress when you pedal; chain tension forces are surprisingly high (not hard at all to exceed 2000N). The radial load on the bearing is also going to be very high as a result, so you might want to look into some really high-quality bearings.

The pulley doesn't need to be concentric/coaxial with the pivot, in fact it's probably better (estimation here) that it's slightly below the pivot axis. This will give you a very small amount of chain extension (which should give you pretty well zero pedal feedback) and slightly more anti-squat than you would otherwise have had. Not a huge issue however, I'd bet that you would have a hard time telling the difference between a concentric pulley mount and one that was 5mm lower.

 

[dw]

Holy crap man, that's some great work you've done, it's good to see people being inventive and resourceful.

To be independent, the chain should line exactly over the pivot axle, so the pulley axle wouldn't line up but instead would have to be located below the swingarm pivot axle. Looking at the photos I'd say that you might have a pretty good location.

I agree, its awesome to see people tinkering and trying new things.

The second part is not really spot on though. Its a somewhat common (but dying I hope) misconception that placing a chainline through a pivot location gives a performance benefit. There is a lot more in the archives on this, search for my username circa 2001-2002.

Dave

 

[dw]

This will give you a very small amount of chain extension (which should give you pretty well zero pedal feedback)

Pedal feedback is a combination of chain center length growth and gearing choice. Zero pedal feedback can only occur if one has a concentric pivot with two identical gears, or a linkage system that increases or decreases chainstay length at a rate exactly negative of whatever the gearing effect is.

In my opinion, it is important to note 2 additional things.

1) A concentric pivot with 2 identical gears can never achieve anything other than a rapidly decreasing anti-squat curve. I.E. the bike will be a slug to pedal (Like my Nucleon was).
2) Pedal feedback and its existence is blown way out of proportion. The perception of pedal feedback is the area that is really important to consider.

Dave

 

[dw]

I drop the bike from the rack and I study the diferent options for a second or two, also since i have very little equipment at home i decide to make a very simple working prototype out of My favorite material Delrin plastic.

Nice work man, keep messing around! You will learn a lot from this I bet.

Dave

 

[binary visions]

Well, even if it falls apart and/or gives no performance benefit whatsoever, it's awesome that you actually went through and did all that. Thanks for the great pictures and let us know what you think after you get to ride it.

 

[Strakar]

I agree, its awesome to see people tinkering and trying new things.

The second part is not really spot on though. Its a somewhat common (but dying I hope) misconception that placing a chainline through a pivot location gives a performance benefit. There is a lot more in the archives on this, search for my username circa 2001-2002.

Dave

I stand corrected... oh well my intentions were good

I didn't want to spread misinformation, in fact I don't even recall reading about it before, I just looked at it and thought about the momentum created by the chain on the swingarm pivot. Without repeating yourself too much, when you say it's not optimal, you're saying it because of momentums created or because some degree of chain interaction is desirable?

I know, I know, I should probably find this info buried somewhere, I off to search it now

edit: just noticed your latest answers.

 

[vitox]

youd have to search for "f1moto" as username i guess.

remember dw`s new middle name is "anti-squat", that should give you a pointer to which of the options you mentioned in your post, is coincident with the dw philosophy.

 

[Strakar]

youd have to search for "f1moto" as username i guess.

remember dw`s new middle name is "anti-squat", that should give you a pointer to which of the options you mentioned in your post, is coincident with the dw philosophy.

Thanks man, will do

 

[vitox]

anyway here is my question...?
after looking and hearing the great benefits about the Balfa BB7's idler pulley design

anyway that question was kind of valid and important four hours ago when i made the posting for the first time,, actuallly after i few minutes of finishing the posting i keep thinking,,well I don't have a place to go or a girlfriend to visit so lets play a little and see what happend.

I drop the bike from the rack and I study the diferent options for a second or two, also since i have very little equipment at home i decide to make a very simple working prototype out of My favorite material Delrin plastic.

since the E-13 guide and the main pivot point are almost on the same axis I decide to use the upper arm of the guide as the mount for the Pulley..


I will use this old blue bullseye
pulley

see you guys soon

first of all, you have an impressive ability of doing "idea to reality", so heres a "surely you must do this for a living" right back at you!

i think we have to award lots of style points for the use of that bullseye (ano blue even!) pulley.

i guess you wanted less chain interference on the empire ? if so that attachment point looks really well placed, i have found that the chain routed through the pivot like on the bb7 is superb for climbing stairs and rockgardens but it tends to make the bike wallow a lot under power, so your chain route looks even better.

 

[patineto]

That's sick! What's that pulley made of?

the Pulley is a Old Bulllseye pulley made of Aluminum with a really nice bearing on it,, lets say that I have a "Endless supply" of similar pulleys if I need to

If it's plastic it'll probably crap the bed pretty quickly (looks like ano aluminium though). If you plan to re-do this at some stage, I'd highly recommend using an 11t SS cog (or even just the 11t cog off a cassette, they're usually separate anyway). Those pulleys are under a LOT of stress when you pedal; chain tension forces are surprisingly high (not hard at all to exceed 2000N). The radial load on the bearing is also going to be very high as a result, so you might want to look into some really high-quality bearings.

Come on Mister thaflyinfatman is my Ingles that bad that you only look at the Pictures...

My own words from the second posting

I think i also need to find a taller (bigger) "pulley" maybe one of the super chessy ones from a alivio derreileur or even better a single casette cog mount it on a bearing (to much work maybe, the clearance with the current chainring is kind of minimal at the moment so i don't think i can use anything bigger than a 12T

Here Is a little paragraf about my concerns Structural and a possible way to fix them.

for sure I don't spect for this setup to last more than a few milles (even if i get lucky) but i don't think i waste my time, since i learn a lot about the pivot locations and the possible alternatives

I think for the next version i'm going to use 3 diferent mounting points.
* take advantage of the hollow tube that reinforce the swingarm as a leverage to hold the mount align.

*a axle extension from the main pivot bolt as the main axle for the pulley

* the E-13 bash plate as a Intermediate reinforcement to improve on rigidity.

actually was way to late last night to be making noise but i think i'm going to make a small exentric mount for the Pulley, somehow like this

so i can still have good clearence as oppose to something like this "a la Karpiel" since I don't really have the space for the external adjusment methods.

and here is a little trick From the "Tricky Ricky Gekky days" from the time I was making some very adjustable measuring devices for the Ergonomics lab at my university.

The pulley doesn't need to be concentric/coaxial with the pivot, in fact it's probably better (estimation here) that it's slightly below the pivot axis. This will give you a very small amount of chain extension (which should give you pretty well zero pedal feedback) and slightly more anti-squat than you would otherwise have had. Not a huge issue however, I'd bet that you would have a hard time telling the difference between a concentric pulley mount and one that was 5mm lower.

The reason that I opt to mount the pulley setup on the E-13 bomerang and not into the Suspension pivot point or even easier just drill and tap a 6mm tread right into the bomerang and I when with something so complicated and some how fragile like this little "Elevator" is because i plan to take advantage of the sliding capavilities of the slots to adjust (as much as clearances let me) the idler pulley so i can experiment with diferent axle locations as i possibly can.

 

[dw]

thats a nice sketch above. I love sketching.

Dave

 

[patineto]

I agree, its awesome to see people tinkering and trying new things.

Well coming from "The man" himself that is a really big complement..

thanks Dave

The second part is not really spot on though. Its a somewhat common (but dying I hope) misconception that placing a chainline through a pivot location gives a performance benefit. There is a lot more in the archives on this, search for my username circa 2001-2002.

Dave

Oh beleive me I'm going to search for it too.

 

[patineto]

Pedal feedback is a combination of chain center length growth and gearing choice. Zero pedal feedback can only occur if one has a concentric pivot with two identical gears, or a linkage system that increases or decreases chainstay length at a rate exactly negative of whatever the gearing effect is.

In my opinion, it is important to note 2 additional things.

1) A concentric pivot with 2 identical gears can never achieve anything other than a rapidly decreasing anti-squat curve. I.E. the bike will be a slug to pedal (Like my Nucleon was).
2) Pedal feedback and its existence is blown way out of proportion. The perception of pedal feedback is the area that is really important to consider.

Dave

Oh man I think i need to go to the Hospital and get my self a "Intercooler" install so my neurons do not fry trying to understand what you have to say.

i'm sure is really smart but also far beyond my level of comprehension

 

[patineto]

Well, even if it falls apart and/or gives no performance benefit whatsoever, it's awesome that you actually went through and did all that. Thanks for the great pictures and let us know what you think after you get to ride it.

thanks amigo..

that is pretty much the way i see it...
if gets busted on the first pedal stroke at least I will become aware of the extreme loads the chain need to perform under.

like somebody say long time ago..
"The only lost battle is the one you did not fight" (i'm sure was not exactlly like that but hopefully you get the idea.

 

[patineto]

first of all, you have an impressive ability of doing "idea to reality", so heres a "surely you must do this for a living" right back at you!

Gracias,, Yes I design for a living but more than anything To be Alive

i think we have to award lots of style points for the use of that bullseye (ano blue even!) pulley.

thanks again..
well I'm glad somebody still remeneber them so i don't feel so much like a "Old fart"

i guess you wanted less chain interference on the empire ? if so that attachment point looks really well placed, i have found that the chain routed through the pivot like on the bb7 is superb for climbing stairs and rockgardens but it tends to make the bike wallow a lot under power, so your chain route looks even better.

well I will find that out when i get to ride the monster, i'm just going to ride it around and not even go on to the trail because i'm afraid will not last that long.

 

[patineto]

thats a nice sketch above. I love sketching.

Dave

Oh you want to see drawings Of that for sure I have "a few"

actually one thing that really hurt me business whise is my lack of computer skills, even if what is really important is the concept more than the execution

Rendering of a old bike rack concept

a little equematic about the diferent mounting posivilities

Enjoy.

 

[xy9ine]

here's a neat proto idler morewood was testing (bolted through the main pivot):

 

[patineto]

here's a neat proto idler morewood was testing (bolted through the main pivot):

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.

 

[ChrisRobin]

All of this is really awesome!

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.

This thread makes me want to go cut into something.

 

[dropmachine]

When Dave Weagle craps, he never squats.



Its a fact.

 

[dw]

When Dave Weagle craps, he never squats.



Its a fact.

Everyone squats in China.

 

[MOTODH]

cool write up

 

[renegade999]

would any other bikes benefit from running a high idler?

 

[xy9ine]

1) A concentric pivot with 2 identical gears can never achieve anything other than a rapidly decreasing anti-squat curve. I.E. the bike will be a slug to pedal (Like my Nucleon was).
2) Pedal feedback and its existence is blown way out of proportion. The perception of pedal feedback is the area that is really important to consider.
Dave

interesting stuff. i've always presumed that pedal feedback / chain growth / suspension lockout under torque was a bad thing - especially noticeable on high pivots without unmodified chainlines (like my old super8). however the inherent anti-squat characteristics (ie, swingarm extension under torque) can make for decent acceleration. my jackshaft tmx (not unlike the nucleon), has negligible drivetrain feedback in the rough stuff, but is a lazy sprinter. i'm curious as to which drivetrain scenario (in the context of a simple high pivot suspension design) is quantifiably more efficient. i'm curious to hear an a/b comparison from patineto.

 

[ChrisRobin]

interesting stuff. i've always presumed that pedal feedback / chain growth / suspension lockout under torque was a bad thing - especially noticeable on high pivots without unmodified chainlines (like my old super8). however the inherent anti-squat characteristics (ie, swingarm extension under torque) can make for decent acceleration. my jackshaft tmx (not unlike the nucleon), has negligible drivetrain feedback in the rough stuff, but is a lazy sprinter. i'm curious as to which drivetrain scenario (in the context of a simple high pivot suspension design) is quantifiably more efficient. i'm curious to hear an a/b comparison from patineto.

Which is why I've been toying with the idea of going with a platform-type shock like a Swinger or 5E for my Nuke. Like you said, mashing down on the pedals doesn't do much. Of course, I chickened out and picked up a Romic.

 

[buildyourown]

Wow. I think you win the ghetto fab award. Your stuff comes out good but you have a crazy way of getting there.
You really should get yourself a mill. They aren't that expensive. Seeing what bikes you have in your stable, you could easily afford one.

 

[wingman24]

Patineto.......man I love your crazy posts, but for gods sake, sell one of your 30,000 bikes and buy a small benchtop Mill/lathe, come on already, you can get one for like $1500 new, who knows how much used. Dear Santa........................

But I do love how you make us all think.

 

[dump]

All the old posts/archives from 4-5 years ago (damn, has it been that long?!) are long gone.

 

[zedro]

very cool, but some advice from someone who has done a few pulleys: both the pulley design and support has to be very sturdy. The first one imploded in minutes, the others tended to fall apart. Lots of force goes into those so only the finest ghetto-engineering and craftsmanship will do

 

[thaflyinfatman]

Pedal feedback is a combination of chain center length growth and gearing choice. Zero pedal feedback can only occur if one has a concentric pivot with two identical gears, or a linkage system that increases or decreases chainstay length at a rate exactly negative of whatever the gearing effect is.

In my opinion, it is important to note 2 additional things.

1) A concentric pivot with 2 identical gears can never achieve anything other than a rapidly decreasing anti-squat curve. I.E. the bike will be a slug to pedal (Like my Nucleon was).
2) Pedal feedback and its existence is blown way out of proportion. The perception of pedal feedback is the area that is really important to consider.

Dave

Yeah I remember having this discussion with you like a week ago, that's why I said not to put it concentric... although for zero feedback perhaps it should have actually been above the pivot given that the front cog is smaller than the rear (which is a fairly uncommon situation for a DH bike)? Anyway I agree that pedal feedback is a bit of a wank really. The only time I've ever actually noticed it has been on a 222, and that thing has ****loads of chain extension.

 

[skinny mike]

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.

 

[OGRipper]

Once again Patineto comes through with another great DIY project!! You are a superstar among the rest of us e-nerds. Lots of people have good ideas but never follow up - props to you for actually getting your hands dirty and not being discouraged.

Oh man I think i need to go to the Hospital and get my self a "Intercooler" install so my neurons do not fry trying to understand what you have to say.

i'm sure is really smart but also far beyond my level of comprehension

Yeah Dave has that effect on people...take your time and think about what he's saying and it might make more sense. Forgive me if I am telling you things you already know. By "concentric" he means a swingarm that pivots around the BB (like a rotec). If you have one of those and front and rear gears that are exactly the same size you can get zero chain growth - the distance between the axle and the bb center will not change as the swingarm arcs through its travel. But even with a concentric, as soon as you add different gears to the mix you are going to get some growth (I think), which theoretically translates into feedback. But like Captain Anti-Squat ) ) said, people exaggerate the actual effect of chain growth and pedal feedback.

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?

 

[thaflyinfatman]

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?

I think it's to do with the axle path relative to the chainline (which is also related to chaingrowth, ie change of distance from BB to axle). If you consider a concentric pivot with identical size gears at both ends, the axle path is always perpendicular to the chainline. So when the wheel moves up and down, it always moves perpendicular to the chainline and never pulls on it (or slackens off). But if you consider the common situation of having a front gear that's larger than the rear one, the tangent to the chainline isn't perpendicular to the axle path. So when the axle moves (say at the instant we're considering, that it moves directly upwards) it's moving in a direction that has a (smallish) component in the same direction as the chainline. So in this case, you need to angle the axle path backwards a bit (which means raising the pivot above the BB somewhat) to combat this gearing effect - this produces some amount of chaingrowth but the positive (arbitrarily speaking) chaingrowth and the negative gearing effect cancel out. I'm not 100% sure that my explanation is on the money here (DW said that wasn't the case a few days ago but I'm not sure if he misunderstood what I was trying to say or whether I've just got it wrong) but it makes sense in my head. With anything non-concentric though, you do have to take into account that to get a perfect setup you'd need a linkage which constantly alters its centre of curvature to keep it in the right place relative to the chainline/BB. But like DW said, I think for all intents and purposes, insigificant (ie imperceptible) pedal feedback can be achieved without having to go to that kind of extreme.

 

[patineto]

Okay I spend the whole day working on a Freelance job waiting for the minute I can come back home to keep working on the bike...

I think I have a idea that is going to blow you of the water,, see you later or now I have Date with my Dremmel

 

[patineto]

Okay I ussually don't like people calling me "genius" but tonight I make and exeption...


I'm so really proud of this one..

Remenber this morning when xy9ine post this Note...!?!?

here's a neat proto idler morewood was testing (bolted through the main pivot):

and remenber how I say it can not be Install on the Nicolai....


well It can Be , in fact i did.

all last night i was thinking of ussing a "arm" that will hold the PUlley, the Pivot Axle and then the "Useless" hole on the swing arm, but i was also worry because the loads will be all on compression, well thanks to xy9ine posting I have a revelation this morning when i was riding my motorcycle on my way to work...

well lets start...
the first night I was lolly gaging around, today the gloves were off and the shirt slives all rolled up and ready for action, in short this time It was for real

first a price to the person that tells me what the silver pieces are, who was the maker and from what era...

well i was looking for a really strong structure that will let me transfar all the loads into the frame with out any deflexion, so i unite a pair of them, to make the ultimate "Crane"

you think this is messy, you wait, it gets way wrost, before it gets better.

to make the pieces fit, i need to make a extension, so i adapt the little green pieces to the task

after that problem was solve, i focus on the mount for the Big A^^ hole on the swing arm

basically i made something similar to the starnut on a fork, but with out any permanent damage to the frame (since i have no idea if this is going to work)

I place a sleave made out of old polietilene from a Manitou II bushing.

this time i was not lazzy and I took the E-13 guide off, specially to reach the scrub bolt, that holds the main pivot on the Nicolai from moving and i replaced with a much longer version of the same 4mm x 1.0 bolt (Cut the head off)

this is kind of how it works, on the left the cut bolt, after that a bunch of really thin and super wide area washers to serve as spacers to hold everything togheter some really long crank arm bolts.

the blind bolt install, also the washers, one of the little tricks this time is that I tap the male crank bolt to recibe the blind bolt in search of a really strong and durable conection.

all the parts ready to install

this time I decide to drill a hole on the guide, so the whole thing becomes a single unit with the axle

here is there the real magic starts to happend.

I keep posting in a minute..