My Lahars Rohloff with mounting plates(Lahar) measures 135mm accross,with the carbon frame added,it measures 146 from outside to outside. It runs an 83mm BB shell.
the gearbox thread
- Thread starter xy9ine
- Start date
If only it had a Horst link.
Still,nice low weight,the swingarm looks heavy,it'll loose a lot of the unsprung advantage.I'm guessing that's some type of gearbox,being in this thread and all,doesn't look like a G-Boxx,is it?
Still,nice low weight,the swingarm looks heavy,it'll loose a lot of the unsprung advantage.I'm guessing that's some type of gearbox,being in this thread and all,doesn't look like a G-Boxx,is it?
im working on something that does replace both parts you mentioned, integrating them into the gearbox structure to get a better q factor.
the two parts are 118 mm apart as measured from my speedhub (measured from the edges of the main shell)
for details on q factors try the truvativ site, they have details on all their crank arms/BBs there and from memory i think it gives you the q factor.. also i believe theres a good wikipedia article with links at the bottom that may give you the info you need
Anyone ever try splitting a Rohloff? From the breif glance I've gotten of the internals it looks like you may be able to take half of the internals and use them as a standalone.
i've also been curious as to what it would take (if possible) to pull the gear doubling mechanism & run it as a 7 spd. now if rohloff were produce a (i assume cheaper & lighter) variation like this, it could be a killer wheel mounted tranny solution. makes me wonder - if there was a robust gearhub that was adequately light, would there be no need for frame mounted gearboxes? i've ridden rear wheel mounted rohloff bikes & found the weight detrimental in that application, but at what weight would the simplicity of that solution trump the added weight & complexity of frame mounted designs? i suppose its possible that a gearhub could never be feasibly light enough in terms of maximum suspension performance in regards to unsprung weight.
You know high pivots ideal for DH,what's wrong with a hub as an idler? I guess a roller and rear(light)gearbox would weigh less than a gearbox hub(as idler) and rear hub. A Rohloff cut in half with the doubler still there(narrow Rolhloff),I'm going for the hacksaw now 
C'mon Rohloff FFS,bring out a light seven speed.Sachs hubs might be the go.Anyone using one?
C'mon Rohloff FFS,bring out a light seven speed.Sachs hubs might be the go.Anyone using one?
there is a 'lightweight' rohloff in development, but it's still a ways out from production. last i heard, they were hoping to have it ready for eurobike, and into production for '09. it's reported to be smaller diameter & ~300g lighter, but will still have 14spds.
Looks to me like it has the g-box standart mounting points at the bottom of both the down an seat tubes...maybe the big ol hunk of alloy that makes up the b/b area is just a dummy g-box???
Also looks like the main pivot is in the right place to be concentric with a g-box
Well, it looks like the cat's outta the bag, Yes it is true that we're playing with the idea of producing a gearbox of sorts for the future.
Rotec's been keen on these for sometime as others have I am sure.
I'll tell ya, its not the cheapest thing to do and though the technology is improving its still a hard sell to the general public because everyone has an opinion as to why it works, why it doesn't, why we should or shouldn't produce it.
My take on that is "Hell" why not! The only way to ever know if its ever going to catch on is to do it, right??
Look, the fact of the matter is that most transmission gearbox designs have only so many way's they can work. And for the most part its a single pivot.....period.
Yeah, I might be foolhardy in wanting to bring to market an RL9 inspired GB but the reality is that its going to take a lot of dough and design effort to bring forth something that will meet both weight reduction and strength criteria for manufacturing and marketability.
You know the saying: I want it cheap and dependable, oh and it has to be Lite and strong and oh yeah, be really cheap....did I say that already?
The key here is not to focus on what the fanciest way is but to just find a solid, proven solution and build upon it to meet the goals and expectations of bringing to market a workable product that all can enjoy.
Gearboxs won't be for everybody at first......but that will change. There is a strong growing need for a product like this in segments defined by Downhill, Freeride, Bikepark.....you get my drift, right?
Over the next several years you'll be seeing some new and exciting things happening in the bike industry and we want to be apart of it!
And that goes for the KVR, even though its still just a prototype I'm stoked to see that its creating conversation!
I'll attach some more pics of the rear suspension, dropouts and GB weldin.
Remember Monkeys
, this is an on going process, those who know me know I can't never leave things alone but every one made brings us that much closer..........Don't you think?Oh and btw, this is a V-boxx (suntour) gearbox. Already working on a version for the G-boxx2, diff layout though.....man just for the mear joy of holding and getting to playing with a one of the new G-boxx2's brings me great gearbox joy!
Let the testing begin!!
Sully
Roteccycles USA
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nice work, js & welcome to the thread. great to see some industry feedback & more builders committed to the cause. nice progression from the 1st proto; this one looks production worthy. is this using a standard g-boxx 2 tranny?
i have used in teh past the 100mm shell 145 isis FSA bb. gives plenty of room but makes clipping pedals more easy.
i want to get mine as narrow as possible. @ 150 i think i can use a
73 shell, but arms vary so i will not know till i get the ones i will run
in to measure assembled.
Suntour's V-boxx is pretty nice, its a compact setup and a true gear-box in every sense of that meaning......
G-boxx2 is also exciting, no doubt these systems do the same thing yet its the excution that defines them.
I'am looking forward to an interesting summer to say the least.
And Alex, you know its just a matter of time till that happens, wink, wink.
G-boxx2 is also exciting, no doubt these systems do the same thing yet its the excution that defines them.
I'am looking forward to an interesting summer to say the least.
And Alex, you know its just a matter of time till that happens, wink, wink.
Dunno if this has been posted yet, but just seen it and I wasn't aware of it's existance:
http://www.solidbikes.de/eng/bikes_speed.html
http://www.solidbikes.de/eng/bikes_speed.html
could someone please give BCD a full machine shop and 7 figure expense account so he can build the bikes of tomorrow. all this gearbox talk is soo 1990's.
As soon as I win the 200 million dollar lottery...
Hey Monkeys!
Well here's the latest pic of our very first Rotec KVR Gearbox.
As soon as its arrives and gets built up I'll post updates.
Regards,
John Sullivan
Well here's the latest pic of our very first Rotec KVR Gearbox.
As soon as its arrives and gets built up I'll post updates.
Regards,
John Sullivan
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Did the lawwill gear box proto not work out? This one looks like a single pivot (still looks killer)
Awesome work Sully.
Can't wait to see it in the flesh.
Can you tell us about the build spec?
Can't wait to see it in the flesh.
Can you tell us about the build spec?
As they say in the industry, its on the back burner!
But I'am still tinkering with that one though. Sorta got side tracked
with other projects......you know how that goes.
The big issue is trying to make it compact enough so it can work as a floater (shock). Thats a key setup for the Lawwill to work correctly.
As for this one, well to be honest its come down to making a frame that was easy to produce and ease of function.
The point here with these prototypes as to keep it simple (no over-enginnering).
This is already a pretty solid design, simple to do and the beauty of it its quite close to production as it is. I've been tweeking this for almost a year so its almost there.
But I'am still tinkering with that one though. Sorta got side tracked
with other projects......you know how that goes.
The big issue is trying to make it compact enough so it can work as a floater (shock). Thats a key setup for the Lawwill to work correctly.
As for this one, well to be honest its come down to making a frame that was easy to produce and ease of function.
The point here with these prototypes as to keep it simple (no over-enginnering).
This is already a pretty solid design, simple to do and the beauty of it its quite close to production as it is. I've been tweeking this for almost a year so its almost there.
Thanks for Sharing Sully! Very Nice looking. I love that color!
Couldn't the swingarm be virtually upside down and run a shorter seat stay?
Sorry to be a critic, It just looks so chunky back there.
Look forward to the Lawhill one.
Sorry to be a critic, It just looks so chunky back there.
Look forward to the Lawhill one.
Yes, and it should be in structural efficiency terms.
that thing is friggin beautiful!
kinda weird to see a Rotec built under Sully that isnt Lawwill... but has linkage... awesome! but hey, Lawwill is the way to go though:biggrin:
and the crazy thing is that it can be built up under 44lbs.!!!
kinda weird to see a Rotec built under Sully that isnt Lawwill... but has linkage... awesome! but hey, Lawwill is the way to go though
:biggrin:and the crazy thing is that it can be built up under 44lbs.!!!
The limiting factor for chainstay length is the bridge behind the main pivot. I'm sure it's as tight as practical. The lower arm on the non-drive side would be no more structurally efficient to have above the main beam of the swingarm. This way gives a lower cofg and lets the struts (seatstays) be lower as well. I'd say he's done it the right way in all regards.
Maybe you misread my intentions but I wasnt saying to flip the thing and keep all 3 strut sections. I was more referencing the fact that the extra tubing on the bottom is not adding as much stiffness (or strength) to the swingarm for the huge weight penalty. Yes it may stiffen it up a bit, but not enough for what it adds in weight, hence structural efficiency. I do understand the limiting factor in chainstay length is the bridge and was not refering to this in any way.
OK, agreed. I also do have concerns that whatever stiffness gains are achieved, even if minimal, will be lopsided, so at say, full bottom-out, there would be an extra off center load corking the wheel off axis.
It would however possibly gain some slight stiffness from a shorter seat stay(or whatever you want to call it).Either way,good job for getting the job done,and like the man said,it's a first attempt.
Well Monkeys,
Heres one in Silver ano.......sweet!
Boy funny how new ideas always seem to spark conversation
Heres one in Silver ano.......sweet!
Boy funny how new ideas always seem to spark conversation
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I was thinking the same thing about bottom out loads. Also with high chain loads you may get some assymetric deflection, though I doubt anyone will be sprinting for the line at the TDF with this thing
so it shouldnt really matter.
Ahh that's a better pic. I didn't notice in the other pic that the swingarm wasn't the same on both sides.
The bend in the top tube and it mounting so high make me think there will be issues with strength of the down tube junction. A bent tube wil flex more than a straight one.
Anyone for more worms?
Silver looks good.
The bend in the top tube and it mounting so high make me think there will be issues with strength of the down tube junction. A bent tube wil flex more than a straight one.
Anyone for more worms?
Silver looks good.
ha ha NSM, you're a funnie aussie aren't you.
No seriously Monkeys,
I understand whats being said, but regardless it's incounselquencal, its a prototype.
Proto's change, they develop, they improve.
Remember these are intended to be the first of several coming down the pipeline and each one of these test boundaries, both in conceptual theory and in physical manufacturing.
I can appreciate that everyone has an opinion and I value that constructive criticism but really folks cut me some slack, they got built they're going to get used and eventually they change....period.
Man, some sure know how to take the fun out of someone's parade.
I understand whats being said, but regardless it's incounselquencal, its a prototype.
Proto's change, they develop, they improve.
Remember these are intended to be the first of several coming down the pipeline and each one of these test boundaries, both in conceptual theory and in physical manufacturing.
I can appreciate that everyone has an opinion and I value that constructive criticism but really folks cut me some slack, they got built they're going to get used and eventually they change....period.
Man, some sure know how to take the fun out of someone's parade.
Like you said, its natural for someone to have an opinion. That was my first knee jerk reaction to the bike, but I can say that I honestly thought that the build looks great and it should be an excellent bike. Plus the ano silver looks pretty bad-ass. Protos evolve and change, and just think, you are getting all of this constructive criticism for free!
proto looks sick sully!....can't wait to see how this pans out!!!
Well HaveFaith its like they say, opinions are like assholes...everyone has one and I am very cool with that...........to an extent, that is.
You know, without criticism, good or bad there would be no change..good or bad.
So for that alone I'am all for it.
Nothing but love to all my monkeys in the house!
You know, without criticism, good or bad there would be no change..good or bad.
So for that alone I'am all for it.
Nothing but love to all my monkeys in the house!
Boy Ian, me too.