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Discussion Starter · #1 ·
Hi I'm suba. Some might know me. Most probably don't. I recently rejoined because I didn't have my old email any longer to retrieve my password so I couldn't post for awhile. While I'm at it I'd like to apologize for any argumentative/unrelated posts I might have made in the past. It seems when I have few beers I can get a little Surly :)

I started researching chain cases a while ago and liked the concept but there are virtually no products like that for our fatbikes so I decided to try and make my own. After trying a few different designs I found what works for me. It had to be reasonably fully enclosed, not too heavy, easy to disassemble and be pretty bombproof. I went with fabric like the Dutch for weight reduction and simplicity. The fabric is thin and stretchy. It's also very light/water proof/resistant. There weren't a lot of colors to choose from.

The chaincase isn't finished but I thought someone might be interested. I'll be happy to post a final pic or two when it's done. The fabric will have more of a polished/ finished look, and be velcro'd in front for a good seal. Maybe a different color. The fabric is held in place with sticky velcro on the bottom portion and it works quite well. I still need to figure out how to enclose the rear cog. That shouldn't be too hard. Anyway here it is and I know what you're thinking. Sure she ain't pretty...but she really is solid:)
 

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Not gonna lie, I'm intrigued. I like the one in the third pic. Small and simple. Kind of double duty as a chainring case/bashguard. Have you thought about doing the frame in metal barstock of some sort and bending a frame around? It might be lighter, and you could still do the fabric thing. I like the plexiglass look myself though. :)
 

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Discussion Starter · #4 ·
^^ Yes just to help keep out the crud. The cardboard version is nice but I wouldn't take it out in the rain :) I did make the cardboard version in .062 ( 1/16) aluminum. Not only was it heavy but it vibrated and rattled and flexed. Would have needed to brace more which would have added more weight. The final version is .125 ( 1/8 ) aluminum and .250 ( 1/4 ) plexiglass. Super sturdy and the fabric keeps the weight down.

I wanted to post this mainly to encourage others to try their hand at making their fatbike not only functionally better but truly unique. If you have an idea just keep trying and don't give up. You can make neat stuff with simple tools if you think it through. btw, the chain case looks better than the pictures show :)

delete....I also like the small version. It would be better than having nothing but I really wanted a fully enclosed case. The Dutch traditionally use a metal frame covered by cloth. That's a great way to go. I wanted a hard enclosure for the front. Plexiglass works because it's easy to work with and you can see when the chain/ring gets dirty enough to clean.
 

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The most exposed parts of a chain are where it passes the tyre at the 2 to 4 o'clock position, and the lower front part of the chainring exposed to front tyre spray.

Protect those parts and the life of the chain will be extended even without full coverage.

Good innovative thread Suba :)
 

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Looks kinda janke, but i'm a engineer and kinda sassy right now. I think it would serve as a great prototype for testing. I liked where you were going with the sheetmetal concept, and think a two piece design would work great.

Could you not just run a belt instead of a chain and eliminate this altogether?
 

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The most exposed parts of a chain are where it passes the tyre at the 2 to 4 o'clock position, and the lower front part of the chainring exposed to front tyre spray.

Protect those parts and the life of the chain will be extended even without full coverage.

Good innovative thread Suba :)
I've been mulling over this chain case idea and have come to a similar conclusion. I think it comes down to two separate components to take care of the spray of slurry and drenching of the chain/front derailleur.

I've got solutions in mind. Thanks "I'm Suba" for the inspiration. I actually first got inspired on this idea by what I saw Geoff Apps doing with regard to this same issue.
 

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Discussion Starter · #12 ·
Thanks for all the positive comments :) Like Velo and Ted said much of the stuff that gets on chains could be mitigated/eliminated by a partial ring guard. Something could be made so light it wouldn't be noticeable. Think of it as preventive maintenance. Not as something that gets in the way. Obviously a full chain case would work best with SS/IGH. With derailleur(s) a front inclosure/modified would work best with a second and smaller one for the front derailleur. It can be done.

Some might say chains are cheap so why go through the trouble. My thought is I see more people using custom cogs and rings. Even if you don't chains might be cheap but the others aren't. In my case I have a Phil cog, HBC ring, and Izumi chain. I also plan extensively using my Pugs in multiple environments in the future. I really like the simplicity of my third picture down. It worked well in dusty conditions but I wanted a full enclosure ( as best I can ) so I could heavily oil my chain but keep dirt/stuff from sticking. That way I always have a well oiled chain with none of the drawbacks including oil flying off. The cloth cover is considered a consumable and could be replaced if needed. The front section can be easily cleaned.

I think we'll see more examples of others putting together different ideas like this. Hopefully those who do will share what they've learned because we all learn from each other. If you want to weld aluminum but can't ( I can't ) there's a really good product that will braze aluminum using Map gas. It works really well after you practice a bit. I wouldn't build a frame using this technique ( for sure ) but for a chain inclosure it's very strong.

buddhak...those are Penthouse Flats.
 

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Discussion Starter · #14 ·
Burgtec. Forged by dwarves out of mithral, I hear. Boss.
.... but they must have some big feet :)

ok, I slapped more fabric together because I want to get out and ride. It's all put together with velcro even the front section sealing it against the plexiglass and the aluminum plate on the other side. I'm happy with my first attempt with the fabric. I'll test things out for a while before making a cover that's hopefully aesthetically pleasing but it doesn't look that bad now looking at the bike. I'll no doubt look for something in a different color. The only place debris could realistically get in is between the plexiglass case and the plexiglass circle that's bolted to the spider. Not much room there for too much infiltration so I'm not really worried. Maybe I can use it as an oil port :)

Here's a few last pictures for now, and it's time to clean up the mess. I've had a lot of strange looks and comments with my Pugs in the past. Can't wait to hear what people might say now. Thanks for everyone's interest and comments.
 

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...Some might say chains are cheap so why go through the trouble...
I hate the filth that comes with owning a chain. I'm not greatly concerned by the cost.

Some pics from the Museum of Transport







Those are all 1897 Sunbeam parts. (Note the epicyclic 2 speed front chainring). The chaincase is actually part of the frame on a Sunbeam.

When I used to oddjob in a bike shop in my youth, I saw Sunbeams and Raleighs with well over 50,000 miles on the original chains.
 

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Discussion Starter · #16 ·
You gave a few more ideas. While I can't build a true oil bath ( I could but don't think I need it and too complex ) I've got possibly the next best thing. If you look at the picture you'll see oil sitting on the bottom. I'm going to drill and tap a small hole at the lowest point. Then drill and tap a small hole over the top of the chain. Then I can add oil over the chain and flush contaminants out through the hole below. I could even add enough oil so the chain passes through it before opening the drain plug but would need to raise the back tire a little first ( easy enough ) I would need a small tube attached to an oil bottle which could also be carried with me on longer excursions. I would recycle the oil :)

I can see finding the best solution for the case skin is going to take a while. I need to find a material that's not affected by oils. I poured some on the fabric and nothing yet so we'll see. I'm going to look for something similar maybe in black. I've already put the velcro on top to keep it from getting oily. This is really the fun part. Figuring out what skin is best and how to make it all work.
 

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A great and fresh thread to read weither you want or do not want/need a chain case :thumbsup:
Some good shed engineering going on there...

MZ (East German) motorbikes have a fully enclosed chaincase to increase chain life, makes sense to try it Suba :)

Velobike they Sunbeam cases have to leak if their British! :D ;)
just like all our old motorcycles did :D

I love all the early pioneering cycling ideas and designs :)

If someone is looking for a chain gaurd (not fully enclosed) these are available from SKS are avaiable in the UK on ebay...

SKS cycle chain guard HUB gear FIXIE 36-38t singlespeed | eBay
 

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Maybe it's just because I am knee deep in epoxy and carbon fiber for my fender project, but I can't help but think that a composite construction is the way to go here. I am seeing it as a clam shell design, one piece behind the chain that is bolted to the bike and one half that snaps on from the outside that seals everything up.

Of course you could take the time to make it pretty, but this could also be done pretty quickly if you weren't worried about looks. All you would have to do is coat that metal frame with wax, stretch a fleece material over it, and paint it with your resin of choice (similar to what is shown here starting at about 2:40). Now that I think of it, even if you wanted to keep that frame, a nice coat of resin on that fabric would be one way to make it oil-proof.

Anyway, good luck with it, seems like a really cool project.
 

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...Velobike they Sunbeam cases have to leak if their British! :D ;)
just like all our old motorcycles did :D
Actually really oiltight unless you turned the bike upside down the wrong way.

The biggest problem with trying to make a full coverage chaincase these days is that you need to have a chainset designed for it and also a rear cog that has a sealling surface.

My Velocettes never leaked, nor did my RE, Plumstead singles, Nortons, Panthers or Ariels. BSA & Triumph were a different story though, or maybe it was an automatic boot waterproofing feature. :)
 
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