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The New Beast?


By Little-Ditty - Posted on 28 May 2007

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

Not sure how much it costs, but check this Beast out. Could be a Tank disguised as a mountain bike. No derailleur on this, so no broken mechanicals! Never seen mechanicals designed like this before. Not sure if you can also buy the riding skill to properly use it! Eye-wink

Specs:
http://www.gtbicycles.com/mountain/catalog/detai...

Large pic:
http://www.gtbicycles.com/mountain/catalog/lg_po...

Mmmmm, gotta get me one of those.

(Lee and Bruce - does this fit the bill?)

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That's pretty interesting. The G-Boxx gears look a lot larger than this, so at first I thought it looked pretty handy.

Then I see it's a Nexus 8 speed internal hub gearbox (like your granny commuter would have) stuffed in the frame.

Hmmmm... not sure, I know SFA about downhill bikes but would initially think, 'run away!'

That said, http://www.g-boxx.org/ looks pretty lacking right now too!

Retail for the GT is a little over $7000 I think. GT have been working with this design for a few years now,

Mountain bike australia mag had a one page article on the internal gear box

Northside cyclery at chatswood had some internal gear boxes on their specialized hybrid bikes. But these IGB's were located on the rear hub. They were adamant that there sealed 10x better than an XT Hub and also they rode 10,000 km's on them without fault. Can't wait to see one on the mountain bike just imagine how much less $$ you would have to pay for maintenance? less bits to wear and tear and get snapped off!

The talk is internal gear boxes (rear hub or integrated at the crank) will be the next big thing in Mountain Biking. It will probably come in for DH where weight isn't as important and feed on down to XC.

Imagine no more broken derailleurs, no more chain suck, no more chain slap - Nirvana

I spoke to a guy on St.Helenas that had a Rolhoff 14sp rear hub and he raved about it,
the range of gears is about the same as a 27sp bike and the increments are even. I think your bike ends up 1kg heavier

Yeah, I've thought long and hard about Rohloff hubs, but in the end it came down to expense (was quoted $2K for the conversion!) and weight. Think the design has been around for a while and was just hoping in the next few years it would lighten up and get cheaper.

These hubs sound most suited for a long distance touring bike where you will be in the wilderness away from parts (think cycling across continents) so reliability is king. That said, have seen guys riding them at various races. The other Rob posted pics yesterday from the 8 hours of mud where a Rohloff was pictured - that has to be a great idea in those conditions.

If you want to know more, probably the best resource for these I found was Sheldon Brown:

http://www.sheldonbrown.com/harris/rohloff.html

Or visit Rohloff home page in English.

If I remember my High School Physics properly (it was over 30 years ago), it would be better to have that extra kilo on the frame like the GT bike, than at the hub. The greater the weight of the rotating mass (the wheels), the more energy it takes to turn them.

New here.

I had a shimano nexus hub a few years back when I was a bike courier and it was not very efficient. They are clean and tidy and mostly maintenance free but it was like riding with your back brake on which is not really an issue for a downhill bike. the problem was always on any slight incline where it always felt more slugish than my regular normal bike. Also getting the rear wheel off to fix a flat in a hurry was out of the question the gear cables were attatched directly to the hub.

Initially expensive yes, but over a lifetime of derailluers and hangers depending on your riding style it could be paid back in 5 years

Yeah, but it's a downhill bike. So the size and weight of the gearbox is probably negligable on a 20kg bike. But you have to agree that a system like this that prevents your hanger / derailleur from tearing off has to be useful. Well, I think its pretty cool... I wonder if they put those onto all-mountain models. Where's my credit card?

I've a mate that swears by Rohloff. He is a complete weight weenie, to the point that he was running a soft ride with rigid forks. He still swore by the roholff hub and would run anything else.

As for expense. It's not that much more than a full xrt setup and I think would pay for itself in the end. In almost 35000KM Snowie replaced the 25mmm of oil once. He is on the same chain and chain rings and i think he changed the cables once.

As for weight by the time you take off the derailleurs, extra sprockets and hooha there's not much in it.

Working that sort of system into the centre of the frame where the weight isn't as crucial as it is in the unsprung, spinning wheel would only be a good thing.

Nicholia have been doing a G box bike for a couple of years now they are nice bikes and ride very nicely. The Lahar is another one, it's a bit of a love it or hate in terms of looks but people say they ride like nothing else.
This year at interbike just about every one had a proto gearbox bike.

Thanks for the links Flynny... I checked out the websites for those bikes. Man, they look like real weapons. I could ALMOST kill for one of those. I will keep dreaming to get one another day.

An interesting point that some have made here about the cost/benefit analysis of these g-boxes. i.e. the g-box that runs longer with minimal maintanence, compared to a derailleur / hanger that would need replacing a few times over the lifetime of a bike (plus all the degreasing, cleaning, re-oiling - plus the personal time you spend doing this... what's that worth to you?).

Can anyone provide a guess as to how this would work out over the lifetime of a current bike? Say you were going to use it for 5 years. Price of a g-box compared to a derailleur?

Look forward to hearing from you. Eye-wink

As I said, snowie changed the 25mm of oil once in 35000km and I'm pretty sure he changed the cables once in that time. That was it for maintenance. He didn't even adjust the cables in that time.

If you take that to a standard set up. Another mate gets 5000km out of his chains and about 20000km out of his chain rings and sprockets. He is completely anal about cleaing and lubing the chain after every ride and constantly monitors the wear.

So you go through 7 x the chains in a standard set up (it's the side forces of the deraileur forcing the chain over the gears that caused the most wear) and almost 2 sets of rings and cassettes and the rolhoff is still going strong... This is assuming you haven't torn your deraileur off or broken your hanger in the mean time

yes you also should put in a cost of labour and Lube etc to carry out all the servicing
DIY is $32.00 per hour and shop labour is around $40.00 per hour

another question that should also come into the equation as it was stated before the difficulty in replacing flat tyres do you include that in the equation

Kurt

Can't see why there would be a different in the difficulty in changing flats? The internal gear boxs would have no effect on that.

it is a beast of a bike, the local bike store where I used to live in Vic had a similar one on display - this was back in late 05; from memory it retailed for about $7000. i dont think they ever sold it..

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