As I have seen you are incorrect the chain line is constant:
G-BOXX 2 is born !
- Thread starter EVRAC
- Start date
I only get it if the above picture also included a bike with a derailleur and that would not make sense as the idea is to get rid of the dereailleur. What you see on the pictures is the same shifting action as found on the back of you bike today.
jimmydean said:
I think giant made one like that, only it was mounted in the frame and you could slide it in and out to replace it. Might not be giants idea but someone did it like that
CBJ said:As I have seen you are incorrect the chain line is constant:
On that one the chainline is constant, the Derailer in a box is a different setup. Its quite literally a short cage derailer and a cassette Inside a box. Works well because of a really short chain so minimal slap, and its all covered and concealed
I was under the Impression with articles i have read that was part of the idea, that the output gear of the box was going to be the same as what was at the wheel. Might just have been outdated material i had but thats what i got from itdw said:
this is what i consider to be a proper 'derailler in a box', because the function is basically the same. As long as it doesnt take a hydrolic actuator to shift that cog, i see this as the superior system.DirtyMike said:
dw said:
ok, party is officially over
I still have no idea about what you are talking about?
The chain line stays the same inside the box as the derailleur slides to the side.
The chain line stays the same inside the box as the derailleur slides to the side.
Yeah I don't understand either - one slides on a shaft, the other has a derailleur but either way the chain is lined up inside the box and doesn't effect the external set up...whatchoo talkin' 'bout Willis?CBJ said:
The derailer in a box idea looks like your bike does now. Literally crammed into a smaller area. You have your drive gear, a chain, and a Shorcage derailer. Cable goes in and Moves teh derailer Exactly the way it works on a standard setup.
The chainline on the one above stays straight, Slides the gear on teh shaft. The Derailer in a box doesnt move the drivegear. It works just like bikes do now, just compacted. Externally the chain line never changes, but your chain inside will change on teh "Derailer in a box" system everytime you shift. I like the idea better from the picture above, just need someone to find an econimical way to do it is all
Also the Derailer in a box is easy to work on
I agree the one shown in the picture is a supier setup, wasnt argueing that the Derailer in a box was better, just someone asked what it was is all.zedro said:
OGRipper said:
The chainline on the one above stays straight, Slides the gear on teh shaft. The Derailer in a box doesnt move the drivegear. It works just like bikes do now, just compacted. Externally the chain line never changes, but your chain inside will change on teh "Derailer in a box" system everytime you shift. I like the idea better from the picture above, just need someone to find an econimical way to do it is all
Also the Derailer in a box is easy to work on
whats the confusion? The secondary drive (ie. to the rear wheel) wont move on any of the systems. You guys have to specify if you're talking about the primary or secondary drive.
The pic on top, the primary drive chainline moves with each gear change, so it effectively has a perfect chainline in each gear. You could still call this system a 'derailler in a box' IMO (i know i've been refering it that way), it simply has a moving drive sprocket.
edit: maybe we could have a 'static-chainline' derailler in a box, and a 'dynamic-chainline' setup....just to add more goofy tech terms :redX:
The pic on top, the primary drive chainline moves with each gear change, so it effectively has a perfect chainline in each gear. You could still call this system a 'derailler in a box' IMO (i know i've been refering it that way), it simply has a moving drive sprocket.
edit: maybe we could have a 'static-chainline' derailler in a box, and a 'dynamic-chainline' setup....just to add more goofy tech terms :redX:
zedro said:
Your right, you could call this a cerailer in a box. But what is Known as a derailer in a box is Literally a Derailer as known today in a box
Dave do you have a link or more information about this Gearbox..!?!?dw said:
It sounds pretty bad ass. 9 speed but whats the ratio spread and is this a 135 mm hub crammed in casing? Anyone know the weight and availabilty?
Nicolai's interpretation of "affordable" is a whole lot different then mine, at least with the current bikes.
I'll wait and see what they cost. Its if crazy like the rest of thier stuff, its not exactly viable is it?
I'll wait and see what they cost. Its if crazy like the rest of thier stuff, its not exactly viable is it?
uhh, thats a prototype...notice it's not connected to a bike?THEDUDE said:
and too many bolts?...
my biggest gripe is the huge bulk of these systems.zedro said:
Would a fully hydraulic actuation be so bad?
the sliding primary drive is a good step, but there's a ways to go.
Has hayes been saying anything lately?
DW, why'd you drop off the project?
yeah, i was doing some layouts of that type of design (and another variation) but that was the key problem, the geartrain can only be so small and using smaller drive sprockets creates slower shifting. Luckily i like high pivots tho :love: .CreeP said:
I was actually thinking a servo-actuated system would be cool as it could be programmed to shift in different modes, would always maintain alignment etc.
I am talking about chain tension. The Honda is a single pivot but has no problems with chain tension. How? Concentric? Why would that then make it any "worse" than the DW link? Works the same but lighter and less pivots to worry about.jimmydean said:
In theory you could have an internally geared bike and have the necessary amount of anti-squat..dw said:
all you need is a third hub and a dw-link type suspension..
Your third hub(or inter. drive axle) would be mounted concentric to the lower rear triangle pivot.
so power is transmitted from your crank to the internally geared hub(rohloff), the power is then transmitted to inter. drive axle and finaly to the rear hub.
Zero chain growth and because its a linkage suspension the viruel pivot or CC can be tuned just like a normal geared bike.
Interesting idea. Wouldn't that extra small loop of chain between the drive axle and the "third hub" need it's own tensioner to account for growth? Not just a pulley to take out the slack, wouldn't there be growth as the lower link moved away from the drive axle?rbx said:
No because every drive axle would be cocentric to their own pivotOGRipper said:Interesting idea. Wouldn't that extra small loop of chain between the drive axle and the "third hub" need it's own tensioner to account for growth? Not just a pulley to take out the slack, wouldn't there be growth as the lower link moved away from the drive axle?
So lets say the first lower link/frame pivot(IH SUNDAY) would cocentric to the gboxx then would have an axle with an output/input sprocket that would be cocentric with the lower link rear triangle pivot, so you see every drive axle is cocentric so no chain growth.
Why not just put a rohloff chain tensioner on? With one of those, you could probably run the chain slack necessary for a more exotic suspension system that way.
The original question and the surprising lack of observation is this-
ALL MOTO bikes have single pivots-ALL. Yet they have no chain problems. Honda obviously used this information to build their mountain bike-I don't want extra pivots, i don't want the newest and hypest linkage system. I want simplicity, function, and form. That's it. So how did they=honda, do it?
ALL MOTO bikes have single pivots-ALL. Yet they have no chain problems. Honda obviously used this information to build their mountain bike-I don't want extra pivots, i don't want the newest and hypest linkage system. I want simplicity, function, and form. That's it. So how did they=honda, do it?
they do what motos do and let the chain have alot of slack in the begining of travel and be almost too tight at full bottom...all motos have the chain resting on the swingarm when static. as soon as you sit..it tightens up. but the size and strength of a moto chain lets it be able to have slack before taking load. MTBs arent that strong for repeated use..hence why MTBs snap more chains in gate starts than DH on heavier bikes.Heath Sherratt said:The original question and the surprising lack of observation is this-
i'm surprised at your surprising lack of observation that bikes and motorcycles are completly different vehicles, and that a person pedalling a bike one third his weight is a tad different from a smooth and powerfull engine driving a moto almost twice the riders weight. Ever since designers stopped 'observing' moto design, suspension designs have been getting better.Heath Sherratt said:The original question and the surprising lack of observation is this-
Hell, even Honda does have their pivot remotely in the same location, nor bothers with shock linkages etc...their bike is nothing like their moto designs.
every so often someone has to bring up MX like it's a huge revelation know one yet noticed after all these years.
when is it up for sale
My thoughts on concentric pivots:
I think it's a little misleading to call this a concentric pivot, in that it shouldn't be compared with designs that pivot around the BB, like the Rotec or Lenzsport. This is more like the BMW racelink, which I've never heard anyone complaining about.
With a BB pivot, when the rear swingarm moves through it's travel, the cranks move the same amount. If your upper chain is tight (ie: you are putting pressure on the pedals) and if your swingarm moves, say, 10 degrees, the cranks will want to rotate forward the same amount. When the swingarm rebounds the cranks get pulled back up. This is one cause of the dreaded "pedal feedback".
With the Race link's dual chain there is a gear reduction which reduces this effect by the ratio of the upper over the lower chainring size. The different pivot location helps as well.
Bottom line: Rotecs are famous for bobbing, Racelinks are famous for not bobbing.
The new g-boxx will give us the same basic layout as a Racelink, with a gear reduction and an upper secondary drive-pivot.
I think it's going to be dope.
I'm mega-stoked.
I think it's a little misleading to call this a concentric pivot, in that it shouldn't be compared with designs that pivot around the BB, like the Rotec or Lenzsport. This is more like the BMW racelink, which I've never heard anyone complaining about.
With a BB pivot, when the rear swingarm moves through it's travel, the cranks move the same amount. If your upper chain is tight (ie: you are putting pressure on the pedals) and if your swingarm moves, say, 10 degrees, the cranks will want to rotate forward the same amount. When the swingarm rebounds the cranks get pulled back up. This is one cause of the dreaded "pedal feedback".
With the Race link's dual chain there is a gear reduction which reduces this effect by the ratio of the upper over the lower chainring size. The different pivot location helps as well.
Bottom line: Rotecs are famous for bobbing, Racelinks are famous for not bobbing.
The new g-boxx will give us the same basic layout as a Racelink, with a gear reduction and an upper secondary drive-pivot.
I think it's going to be dope.
I'm mega-stoked.
you mean old (moto-link) rotecs are famous for bobbing, correct?
But then again most if not all concentric BB designs are bobbing machines. Thats the nature of those beasts including mine before we did the RL9 (Rotec/Lawwill).
The design I did (2002/2003) right after I bought rotec was still a concentric bb design but use platform technolgy to calm the bob monster but you are correct EVRAC in your statements.
The RL9 though a concentric bb design, it is a 4-bar rear end, not a single swingarm system like the earlier designs.
The design I did (2002/2003) right after I bought rotec was still a concentric bb design but use platform technolgy to calm the bob monster but you are correct EVRAC in your statements.
The RL9 though a concentric bb design, it is a 4-bar rear end, not a single swingarm system like the earlier designs.
I'am stoked to see the G-Boxx-2 both in design and function work. The G-Con standard is whats needed to make it easier for mfgs to comply and its the only way Karl can make the system work cost wise.
The fact that Suntour is getting onboard shows that their are overeseas mfgs interested in producing the gearbox itself for mass consumpution so mfgs like myself can actually build one with some degree of standards.
I can't wait to see whats ahead!
The fact that Suntour is getting onboard shows that their are overeseas mfgs interested in producing the gearbox itself for mass consumpution so mfgs like myself can actually build one with some degree of standards.
I can't wait to see whats ahead!
Sounds great. Im glad it has trigger support, the grips shift would have keept plenty of riders away.
I'm working on a G-Boxx type Full suspension tandem design with independent(ad/or constant) pedaling cadence that works exactlly that way, i'm glad to know i'm not totally crazy..rbx said:
for chain tensioning from the bottom brackets I'm just going to use exantric bottom brackets shells since the tension is always consistend and concentric
thanks for the vote of confidence RBX
yeah, all gear box's suffer from a small amount of teeth on the cranks.zedro said:
for those who don't know the larger amount of teeth the faster
the gearbox/casette is spinning and you get quicker shifts.
also if the drive teeth don't move with the shifting you get bad chainline issues.
32t is about the min seems to me after trying it all.
the cofin had a 26t seems like and was a bit slow.
well, there are a lot of us making concentric pivot bikes out theredw said:
so i will type some words in our defense.
you are right, they do have pedal bob. BUT! not nearly the amount you are saying. the closer the drive chain is to the pivot the less leverage it has. the less bob you will have. a roller of 18T at a pivot
point is unperceptive when riding a dh bike. we are talking dh bike performance here. no XC. i don't recommend CP for xc at all.
that is exactly how a good gearbox is geared. bb to gears has all thedw said:
ratio change.
then from a CP to rear use as small as you can with a 1-1 ratio. like a 18-18.
we make different bikes but some people like to know both sides.
its give and take. your bike pedal the best that is possible. that is the way you designed them.
gearbox bikes are more concerned about the QUALITY of the rear suspension. less about pedaling.
Alex
This one uses something like that, or like RBX was saying:patineto said:
http://www.dw-cycles.com/product_1.html