Closed chain guard
 

Hi,
Is there a closed box for keeping all the drive system closed?
I'm talking about keeping all the moving part inside the box. This will keep them clean.
I saw something like this for single speed city bikes, but none for Shimano derailleur systems.

Thanks,
Kfir

There's no such thing as a completely closed chain guard made for full derailler set up.
I mean, you could always fabricate one, or have one fabricated, but nothing currently exists like that.
-Gene-

Its odd. It should be very practical. The Dutch like this stuff. Maybe I'm missing something?!

Kfir

Full chain cases typically come with internal gear hubs... fabricating a chain case for a derailleur system would have to take into account the derailleur and the fact it moves laterally and is deeper vertically.

A full chain case is a beautiful thing and will extend the lifespan of a drive train and chain like you would not believe... and does an amazing job of keeping it clean.

Don't be so sure- the Go-One Evolution velomobile:
http://www.kunststoff-beyss.de/assets/images/evo2.jpg

features a fully-enclosed derailleur system. This is in contrast to the previous Go-One 3:

http://www.go-one.us/images/DSC_8421.JPG

I do realize that velomobiles are outside the experience of most cyclists... but they do exist!

Yes,
I was asking that because I don't want to clean the drive chain any more! I'm like a slave of my bike ;-)
Internal gears are very pricey. This is why I'm looking for a closed box for the drive train.

Kfir

Jeff - I would so love to own a velo-mobile... with a Bionx assist. :)

Kfir - The initial cost of an internally geared system is more than that of many derailleur setups but over the long haul the decreased need for service and longer lifespan will pay for itself.

~1200$ for rohloff is just insane!
It should cost more in the 200$ range IMO.

Kfir

Full fenders with a LONG mudflap on the front will give you 80% of the benefit of a chaincase as far as keeping crud off the drivetrain and infinity% of the benefit of a chaincase as far as keeping your feet dry. One is still susceptible to the dreaded chainring tattoo though.

Wasn't there a downhill MTB made with a gearbox in the frame, which, when opened, contained a regular derailleur system?

could get belt drive, but those are limited to IGH.

couple up a belt drive with shimano nexus or alfine, that should be pretty good...

Yes, I think you right. A long mudflap will help. I have big SKS fenders, bug the flap at the end is small.
I don't think this will solve the problem. Again, closed system will be better.

Kfir

Yes, this is an improvement, but the nexus or the alfine don't have the range I need. Rohllofe does, but it is very expensive.

Kfir

have you seen about the alfine 11 speed that's supposed to be coming out soon?

http://road.cc/content/news/13981-sh...-car-park-test

You're not. When Dutch people want a derailleur system city bike, they use something like what's on this Puch. Mostly a pant-saving measure.
http://www.mammoet.nl/store/catalog/...ntry%20300.jpg
Well, that's the top of the market, isn't it?
There are several good hubs from people like Sturmey Archer and Shimano available for far less.
A fully enclosed full derailleur system would need to be massive. Tall enough at the rear to enclose the derailleur, and wide enough to accomodate the full range of lateral movement.
Yes, This Honda. That drivetrain box alone weighs many pounds.
http://static.i4u.com/images/2007/honda-rn01g.jpg

combine IGH with an sram hammershmidt?

To get a fully enclosed chain case for a front and rear derailer system you'd need to build an awfully big box, or one with a couple of protrusions. And you might encounter some interference issues between chain case and spokes up by the cassette.

Still, it's not like it's rocket science. Getting the chain reasonably well protected from above is easily doable. Start off with the biggest chain case you can find and either some thin sheet metal aluminium, or something like a sheet of Lexan from a R/C hobby store. A roll of assembly grade double sided sticky tape, some hand tools and you're all set to start crafting. You might want to use cardboard to make up templates first.

Haven't looked at the cost, but there's always Schlumpf as well. That + an IGH should give you plenty of range.

If I were to try building a custom chaincase, i'd look into getting or making a vacuum forming machine. You could use cardboard, wood, putty, whatever to build up a form to match your chainrings, cogs and space around the derailleurs and then form a single plastic sheet around it.

Shlumpfs are awesome, but outrageously expensive. I think its something like $500 for their 'two speed bottom bracket'. Yes, it is a miracle of modern engineering and all that, but it's to expensive to actually ride.

Also, many IGH have an lower torque limit, which effectively limits how low of a gear they can have. You can always ignore this at the expense of the warranty, but the risk is yours.

The Rohloff is expensive due to multiple factors. It is made in Germany in limited numbers and assembled by hand per a video that has been linked to on BF IIRC. The Schlumpf is made in Switzerland which has even higher labor rates than Germany. Even the Shimano 8 speed hub, made in much larger quantities in a lower lbor rate setting and with more automated assembly, does not meet the $200 price point mentioned. A lot of small precision parts go into a 8 speed or more complex IGH.

Commercial derailleur drivetrain full chaincases are not available for several reasons IMO. They would need to be large and due to dimensional differences between various frames it would be difficult to make one that fit more than one model of bike and chainring/cassette combination.

The 2 speed bottom brackets are expensive because they are not mass produced like Shimano's IGH hubs and perhaps Shimano will offer a 2 speed bb at some point to expand he range of their IGH hubs... I have heard rumours of this happening.

The range on the Alfine is pretty decent and is best suited for commuting and touring where you have more bottom end for climbing and might max out at about 80 gear inches at the top... unless you are racing this is a perfect top gear for most people.

I get by pretty well with a 3 speed IGH... my better half loves her 8 speed.

Fully enclosed chainsets for derailleurs are a custom/hand-made project.
I would try prototyping with some correx, ductape and wooden spacers to get the dimensions that avoid interference.
The only potential issue is that you cant see which gear combo you are in.

You may find the rear-most inside part interfering with spokes.