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socialtalker
05-19-2010, 02:20 PM
i really love the look of recumbent bike, but a part of the design that really stresses me out is the long chain! i am building the loderunner and it has an absolutely terrifying long chain! and it has some kind of pulley thingy midway. i absolutely must have some kind of chain guard at least at the top like the classic beach cruisers
http://www.abikestore.com/Merchant2/graphics/00000003/eldorado-cruiser-women8.jpg
i LOVE those bikes with the fenders, chain guards, lots of curves, white wall tires. i want my trike to have as many of those elements as possible
from what i have read chain guards are for 1 to 3 speeds, isnt it possible to build a chain guard for an 8 speed like my trike?

mark barker
05-19-2010, 02:29 PM
If you make guard wide enough to cover the full sideways travel of the chain then I can't see why it'd be a problem, although it will be quite wide at the back of the bike....

socialtalker
05-19-2010, 03:46 PM
will it? i cant picture that, i guess i will to study the issue more, and see how they installed, and get to that stage before i understand your point.
thanks

although it will be quite wide at the back of the bike....

mark barker
05-19-2010, 04:36 PM
will it? i cant picture that, i guess i will to study the issue more, and see how they installed, and get to that stage before i understand your point.
thanks

Maybe its me that wrong, but if you've got an eight speed set up then you've got eight gears at the rear of the bike? If so, the space these take up is far wider than a single as would be found on the hub gears used on the beach cruiser style bikes. I'm guessing the chain moves around 1.5 inches so the top of the chain guard would ideally need to be wider than that.

MarcusPHagen
05-19-2010, 05:15 PM
I'm guessing the chain moves around 1.5 inches so the top of the chain guard would ideally need to be wider than that.

The back of the chain will need to move as far as the distance from the outside sprocket to the inside one. Any chain guard would need to add enough width to that, to allow for the chain to overlap beyond the sprockets, and then a bit of "airspace" so it doesn't hit the guard. That's why commuters frequently put chain tubes on their HPVs. It keeps dirt and water (mostly) off the chain, even better than a guard, and the tube will move with the chain, so it doesn't have to be as wide as a rigid guard.

If you'd like, I can post a picture of how I setup my chain tubes on the quad I ride with my wife. [Will have to take pictures first, though.]

Marcus

vrooom3440
05-19-2010, 08:17 PM
Actually it may not be so bad as folks are making it out to be.

If you have a mid-point idler point, and it is not a floating idler, then the chain will be relatively stationary at that point. So for a guard from the idler forward, you only need to accomodate the sideways movement of the front derailer on the chain rings with a guard. And even there if you cover the outside/largest chain ring you have 80% of the problem solved.

Not too much need for a guard from idler back as that portion of chain is often underneath the seat.

MarcusPHagen
05-20-2010, 03:53 AM
Not too much need for a guard from idler back as that portion of chain is often underneath the seat.

Not trying to discourage anyone. I guess it depends on whether you are primarily trying to protect your leg, or the chain.

Marcus

TheKid
05-21-2010, 05:02 AM
Or, you could use a mid drive, with all the gear changing done from the mid drive back. The front could just be a single chain ring to a single cog, or for lower gearing, another chain ring. If you put the front drive on the left side like I did on the original Fox, you could make a reverse chain guard for the left side. If you like the look of chain guards, this may be the way to go.

socialtalker
05-21-2010, 06:10 PM
yes, my leg, chain and hair. sure i put the hair up, but sometimes a lock of hair escapes and if i were to bend over at the wrong time, something might happen.

Not trying to discourage anyone. I guess it depends on whether you are primarily trying to protect your leg, or the chain.

Marcus

socialtalker
05-21-2010, 06:12 PM
but the back of the loderunner is wider than a bike and the gearing is under the cargo bed and not on the wheel


Maybe its me that wrong, but if you've got an eight speed set up then you've got eight gears at the rear of the bike? If so, the space these take up is far wider than a single as would be found on the hub gears used on the beach cruiser style bikes. I'm guessing the chain moves around 1.5 inches so the top of the chain guard would ideally need to be wider than that.

TheKid
05-21-2010, 06:29 PM
but the back of the loderunner is wider than a bike and the gearing is under the cargo bed and not on the wheel

Right. So if you have a double or triple ring up front, you could go to a single cog or chainring to a mid drive, on the right side. Then a chainring on the left side of the mid drive, going to the 8 speed cluster on the left rear axle. You'll need to make a chainguard that covers the rings up front, and high enough to clear the derailler. A bottom feed derailler would have an advantage to doing this. It's a fairly easy project, much less involved than a completely enclosed chain drive, which is found on some velomobiles.
It's your trike, you can build it any way you see fit. If you prefer a chain guard, build it, but show some pics. I'll bet you're not the only member who'd like to have a chain guard instead of tubes.

socialtalker
05-21-2010, 06:46 PM
do you have a link to show how that is set up? it sounds very complicated. you think it would work on the loderunner? i will be hauling loads of stuff


Or, you could use a mid drive, with all the gear changing done from the mid drive back. The front could just be a single chain ring to a single cog, or for lower gearing, another chain ring. If you put the front drive on the left side like I did on the original Fox, you could make a reverse chain guard for the left side. If you like the look of chain guards, this may be the way to go.

socialtalker
05-21-2010, 11:13 PM
sure i would love to see your tubes, i did take a look at some chain tubes set up on some other site and its a good idea. i think i could maybe add some tubes that that the guard wont cover. okay, so it has to be wide enough for chain clearance plus airspace, that makes sense.
i dont see how fractions of an inch will matter much unless i use some really thick steel to make it. i may have to use some spacers


The back of the chain will need to move as far as the distance from the outside sprocket to the inside one. Any chain guard would need to add enough width to that, to allow for the chain to overlap beyond the sprockets, and then a bit of "airspace" so it doesn't hit the guard. That's why commuters frequently put chain tubes on their HPVs. It keeps dirt and water (mostly) off the chain, even better than a guard, and the tube will move with the chain, so it doesn't have to be as wide as a rigid guard.

If you'd like, I can post a picture of how I setup my chain tubes on the quad I ride with my wife. [Will have to take pictures first, though.]

Marcus

socialtalker
05-21-2010, 11:53 PM
i guess this is the time to say i am going to have underseat steering...lol!
seriously double sided gear system sounds great, but i only understood 80% of how it would work exactly, i mean in how it would be hooked up. i would need 3 derailleurs? do you have any pictures and instructions in more detail like a link showing this? i wouldnt know how to google it, i am not getting anything.


Right. So if you have a double or triple ring up front, you could go to a single cog or chainring to a mid drive, on the right side. Then a chainring on the left side of the mid drive, going to the 8 speed cluster on the left rear axle. You'll need to make a chainguard that covers the rings up front, and high enough to clear the derailler. A bottom feed derailler would have an advantage to doing this. It's a fairly easy project, much less involved than a completely enclosed chain drive, which is found on some velomobiles.
It's your trike, you can build it any way you see fit. If you prefer a chain guard, build it, but show some pics. I'll bet you're not the only member who'd like to have a chain guard instead of tubes.

John Lewis
05-22-2010, 03:45 AM
Link to Jackshaft ideas.

http://www.wisil.recumbents.com/wisil/jackshaft/jackshaft.htm

john

socialtalker
05-25-2010, 01:00 AM
thanks for posing. i have been studying this page you linked to the whole weekend and i understand 90% of the concept now. its easy to understand for the mechanically inclined, but i may have to wait until the book "jackshafts for dummies" comes out. i really do like the idea of having something on the left and the right and there might be less interference with the underseat steering. i think there is a shaft, two cogs and some spacers involved, but i not sure how the other stuff is involved. i dont know what the heck that in in the 13th picture, where do the chains go? anyway the freewheel method looks much more familiar. i think i am supposed to have more spacing between the wheel things, but not sure are the supposed to go in the same or different directions.

Link to Jackshaft ideas.

http://www.wisil.recumbents.com/wisil/jackshaft/jackshaft.htm

john

socialtalker
06-02-2010, 03:49 AM
well, i went directly to the forum of the link posted for the jackshaft
http://www.wisil.recumbents.com/wisil/jackshaft/jackshaft.htm
i wanted to ask the writer directly
to get clarification on how to do a jackshaft with the cranks right,/ freewheel left.
although i did get one poster to give me an idea how to do it. others were not enthusiatic about jackshafts including the writer of the jackshaft article. and couldnt understand why i had any interest in chainguards, chaintubes were recommended. had no idea chainguards were so unpopular.
one tangential discovery that distressed me is gear inch calculator i came across. with my 13 sprocket, 48t crank and my max peddle speed (60rpm) , my top speed will be 12-15 miles/hr!
a 60 tooth ring was recommended for higher speed. cant seem to find 60 teeth for an 8 speed.

MarcusPHagen
06-02-2010, 05:03 AM
While 60-tooth rings are available (if somewhat rare), my recommendation would be to work on raising your cadence. At a maximum of 60 rpm, it's quite likely that you are doing most of your riding at an even lower rate. That's a recipe for ruined knees. I'm a former "masher" (low rpm) myself, and can testify that it's quite possible to raise your rpm to levels you did not think possible. I currently ride at 80-90 rpm, and am working on raising my cadence. I'll probably switch to shorter cranks next, which also helps.

I notice that this is for use on a Loderunner. 15 mph is a perfectly respectable speed for a hauling machine. I'd be most concerned to ensure that you have low enough gears so that you don't injure your knees with heavy loads or hills. If you go above 15 mph, it's probably on a downhill, so enjoy the rest!

Marcus

socialtalker
06-02-2010, 09:58 AM
my concern is for cars becoming impatient driving around such a slow bike, although i am not planning to ride the main streets that often. when you say low gears, you mean higher number sprocket? i was thinking about getting an eight speed freewheel that has the 34t instead of the 28t freewheel i have now. i must say however, that the detroit area is fairly flat, except for the some of the free way underpasses.
what do you mean by shorter cranks, exactly? you mean teeth under 48t?
yes, i do have knee problems and that has been on my concerns in planning to build a recumbent. i really appreciate the advice, i didnt know slow rpm is hard on the knees. thanks, i will try to improve my cadence when i start to ride.



While 60-tooth rings are available (if somewhat rare), my recommendation would be to work on raising your cadence. At a maximum of 60 rpm, it's quite likely that you are doing most of your riding at an even lower rate. That's a recipe for ruined knees. I'm a former "masher" (low rpm) myself, and can testify that it's quite possible to raise your rpm to levels you did not think possible. I currently ride at 80-90 rpm, and am working on raising my cadence. I'll probably switch to shorter cranks next, which also helps.

I notice that this is for use on a Loderunner. 15 mph is a perfectly respectable speed for a hauling machine. I'd be most concerned to ensure that you have low enough gears so that you don't injure your knees with heavy loads or hills. If you go above 15 mph, it's probably on a downhill, so enjoy the rest!

Marcus

vrooom3440
06-02-2010, 01:06 PM
Marcus was referring to shorter pedal cranks. These reduce the amount of leg movement with a smaller circle. They also reduce leverage from your pedalling pressure so you have less torque going into your HPV. So they are a tradeoff.

Short of adding a power assist, you are only going to get so much speed in an HPV. Especially if you are hauling a load.

Another suggestion is that metal may likely be the most difficult medium to use for a chain guard. I would personally be thinking of using something relatively good at compound corners and conforming to shape. Examples that come to mind include fiberglass, vacuum formed plastic, and even paper mache'. Don't laugh but brown shipping paper or old fashioned paper bags can be built into some very functional shapes. The magic is in what kind of glue you use. You can even use epoxy with a credit card squeegee (which allows use of a throw away foam core mold).

MarcusPHagen
06-02-2010, 03:35 PM
my concern is for cars becoming impatient driving around such a slow bike, although i am not planning to ride the main streets that often. when you say low gears, you mean higher number sprocket? i was thinking about getting an eight speed freewheel that has the 34t instead of the 28t freewheel i have now. i must say however, that the detroit area is fairly flat, except for the some of the free way underpasses.
what do you mean by shorter cranks, exactly? you mean teeth under 48t?
yes, i do have knee problems and that has been on my concerns in planning to build a recumbent. i really appreciate the advice, i didnt know slow rpm is hard on the knees. thanks, i will try to improve my cadence when i start to ride.

When I'm hauling something in my trailer, I seldom exceed 8 mph average. An 8-speed cluster (perhaps 12-34 or 11-34, depending on what is available) would give you some better torque at slow speeds, and have a higher top speed than the 13-28. There would be bigger gaps between the sprockets, though, and some people find that annoying.

When you go up the other side of the underpass, you'll be happy to have low gears available, especially if hauling a couple hundred pounds of cargo.

Since you can't stand up on the cranks, using lower gears and pedaling faster puts less strain on the knees. Shortening the pedal cranks (thanks, vrooom3440) will reduce the amount that your knees bend. This will speed up your cadence, and most people also report that it reduces knee strain. A few have said that they need lower gears than when using longer pedal cranks, but many keep the gearing the same. It's one of those discussions like "chain lube" that sometimes brings out more heat than light. However, if (like me) you have problem knees, you might want to give it a try. There are relatively inexpensive short cranks available, and custom ones can be produced for a reasonable price as well.

Marcus

savarin
06-02-2010, 09:56 PM
Having made a couple of short cranks myself I am a convert and so are those I've made them for.
Well worth a try.
And definitely up your cadence else you knees will eventually collapse.

socialtalker
06-05-2010, 07:04 AM
thanks guys!

will have to test run the shorter cranksets
great idea to make the chain guard out of something other than steel!
i once built 4-6 foot high figures in paper mache, and a 4 foot child in paper mache. so i know a little about it, but i have been looking at this site,

http://bikerodnkustom3.homestead.com
and folks are making the most gorgeous chain guards and wheel coverings out of fiberglass.
there must have been like 10 bikes with chain guards.

http://bikerodnkustom3.homestead.com/gallery147.html
http://bikerodnkustom3.homestead.com/2muchbuild.html
http://bikerodnkustom3.homestead.com/kandirubuild.html
http://bikerodnkustom3.homestead.com/gallery213.html

i would love to do wheel coverings, but my bike would be dragging at 2mph with all the stuff

i was just reading how fiberglass takes 20 times longer than the metal, that wont do, need a faster alternative.

stormbird
06-05-2010, 08:05 AM
When I'm hauling something in my trailer, I seldom exceed 8 mph average. An 8-speed cluster (perhaps 12-34 or 11-34, depending on what is available) would give you some better torque at slow speeds, and have a higher top speed than the 13-28. There would be bigger gaps between the sprockets, though, and some people find that annoying.
Marcus

Hi there

The simple answer is build your own cassette ? that is what I did.

The 34 teeth clusters are usually called megarange [ well the Shimano one's are ! ] I took a 8 speed megarange apart , separated the rings and added some rings from a 7 or 6 speed [ can't remember exactly ] with the nearest correct numbers of teeth so I had even steps between 11 & 34.

I have this written down somewhere as to what I chose and which cassette they came from.

The only think to remember is to use the 8 speed spacers and not 9-10 speed spacers or the wider chain may foul adjacent sprockets.

All the 5,6,7 and 8 speed stuff is interchangeable to a degree and you can even use 9 and 10 speed sprockets and chainrings ,with 5 - 8 speed chain it is just if you want 9 or 10 speeds you need to use 9-10 speed chain as it is narrower.

regards Paul

socialtalker
06-05-2010, 01:22 PM
actually i am using a freewheel, not a cassette (all of these bike terms are still very new to me) i would like to do just that have an 11-34 freewheel, i was going to get a 13-34 8sp freewheel and find a 11 sprocket but i have not been able to find....
wait a minute, i just found a 8 Speed Freewheel 11-34t on ebay!


Hi there

The simple answer is build your own cassette ? that is what I did.

The 34 teeth clusters are usually called megarange [ well the Shimano one's are ! ] I took a 8 speed megarange apart , separated the rings and added some rings from a 7 or 6 speed [ can't remember exactly ] with the nearest correct numbers of teeth so I had even steps between 11 & 34.

I have this written down somewhere as to what I chose and which cassette they came from.

The only think to remember is to use the 8 speed spacers and not 9-10 speed spacers or the wider chain may foul adjacent sprockets.

All the 5,6,7 and 8 speed stuff is interchangeable to a degree and you can even use 9 and 10 speed sprockets and chainrings ,with 5 - 8 speed chain it is just if you want 9 or 10 speeds you need to use 9-10 speed chain as it is narrower.

regards Paul

stormbird
06-06-2010, 02:33 AM
Hi there

I think you can rebuild either ?

I maybe misused the term cassette to mean the clump of sprockets as a whole , IIRC one only goes up to 6 speed and the other all the way to 10 speed.

http://www.sheldonbrown.com/gearing/index.html

Start by looking at this ..............

Report back when you have read it all :-).

regards Paul

MarcusPHagen
06-06-2010, 03:03 AM
... folks are making the most gorgeous chain guards and wheel coverings out of fiberglass...

I've just GOT to link a few images from that site, to whet people's appetites. Well worth drooling over at some length. Thanks for the site links! There are some excellent construction tips on those pages, as well as the gallery shots for those who just like to look at some real eye-candy.

Marcus

http://bikerodnkustom3.homestead.com/files/best_black05A.jpg
http://mywilson.homestead.com/files/2muchlprofile_lrz.jpg
http://bikerodnkustom3.homestead.com/files/dark_garageA.jpg
http://bikerodnkustom3.homestead.com/files/Tcadman_bike_01A.jpg

MarcusPHagen
06-06-2010, 03:12 AM
I think you can rebuild either?

True. Different tools and procedures, but both can be reconfigured.


I maybe misused the term cassette to mean the clump of sprockets as a whole , IIRC one only goes up to 6 speed and the other all the way to 10 speed.

The older type is the freewheel, with sprockets screwed on. You'll probably need a chain whip or two to remove sprockets. The newer type is the freehub, with sprockets held onto a set of splines using a retainer. The freehub has wider bearing spacing, which makes bent axles less likely. As a result, there are higher numbers of gears available on a freehub.

On a freewheel, one bearing is located at the base of the freewheel.

|:|:|:|B===B

On the freehub, the bearings are both located on the ends.

B|:|:|:|:|===B

While there are 8-speed freewheels available, they are more problematic than an 8-speed freehub. I'm not aware of any 9- or 10-speed freewheels, and I'd not want to use one if found. There are actually some 11-speed freehubs being produced for road bikes, but they are insanely expensive for now.

Brad has some good reasons for using freewheels on his designs -- if I understand correctly, cost and ease of modification for use on custom axles or as mid-drives being among them. However, I'd stick to 5-, 6-, or 7-speed freewheels due to reliability issues. I don't want to bend or break an axle. If you are using one of the 3/4" axle designs, then perhaps going higher would not be a bad idea.

I've got an 8-speed freehub on my trike. It has been very reliable, and 8-speed freehubs/chains have the reputation of lasting longer than 9- or 10-speed freehub/chain combos before they need to be replaced. If you don't need the extra gear combinations, then it seems that 8-speed is the current sweet spot for economy and longevity. As you go thinner and lighter, things get more expensive and break more easily.

Marcus

socialtalker
06-07-2010, 03:56 PM
I read the sheldon brown article
http://www.sheldonbrown.com/free-k7.html
the way i was understanding it and looking at the pictures, the reason the 8sp freewheel would break off is because the 8 gear freewheel is hanging off the hub of the bike on the side by an 1/2 inch. a cassette has a bigger and deeper part that connect to the hub.
for the loderunner, the freewheel is impaled like a roast chicken on a 3/4 shaft of cold rolled steel between pillow block bearings, its not hanging off the side of the hub of the wheel. i cant see how it would break off and since 5,6,7, and 8 freewheels all use the same chains, i dont understand how it would be less reliable in this instance.
besides which, i paid 80 dollars to get my brake adapters done so they could screw into my freewheel, i shall run amok if i need to use it.
actually i had a hard time finding good parts for a 5/6 speed freewheel like the book says at the time.
they are going to have to start making these parts again if people are building bikes.



True. Different tools and procedures, but both can be reconfigured.
While there are 8-speed freewheels available, they are more problematic than an 8-speed freehub. I'm not aware of any 9- or 10-speed freewheels, and I'd not want to use one if found. There are actually some 11-speed freehubs being produced for road bikes, but they are insanely expensive for now.

Brad has some good reasons for using freewheels on his designs -- if I understand correctly, cost and ease of modification for use on custom axles or as mid-drives being among them. However, I'd stick to 5-, 6-, or 7-speed freewheels due to reliability issues. I don't want to bend or break an axle. If you are using one of the 3/4" axle designs, then perhaps going higher would not be a bad idea.

Marcus



Thanks for the site links!
your are welcome,i admit i got that site from someone else in another thread, but cant remember which one.
btw,i am looking at the hyperfiber product as a fiberglass replacement, but it annoys me they have no pictures or videos on their website or anywhere on the internet that shows their product.