Machined Aluminum Spring-Loaded Chain-Tensioner

[Prof Fate]

Ithink you may have a winner. I am about to start on a Schwinn Point Beach project and it doesn’t look like the back wheel can be adjusted. If I can’t make it work without the chain tensioner, your model will be on my wish list. I made my own for my first bike out of a rat trap spring but looked like something Jertho Bodean might have come up with. I agree with the others that a high quality bearing or sprocket is a must. Get this gismo on a site and it’ll sell. Good luck.

 

[kipharley]

Ithink you may have a winner. I am about to start on a Schwinn Point Beach project and it doesn’t look like the back wheel can be adjusted. If I can’t make it work without the chain tensioner, your model will be on my wish list. I made my own for my first bike out of a rat trap spring but looked like something Jertho Bodean might have come up with. I agree with the others that a high quality bearing or sprocket is a must. Get this gismo on a site and it’ll sell. Good luck.

Hi,Prof Fate.I mounted my first proto-type with a sprocket,on a Schwinn Point Beach worked slick!
Another plus with my set-up is the mounting plate eliminates the chain rub inside the cover.Kip.
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[killercanuck]

I'm gonna try to keep the price reasonable but you have to understand you can't get these things made for fish heads and rice!

lol, I hear that. My fingers are crossed it'll be around $20-30(without sprocket/roller). But whatever you sell them for they will sell!

Keep us posted

 

[kipharley]

Up-Date.I've gotten my prices back from the machinist and anodizing.These things are gonna look sick,aircraft quality 6061 billet aluminum.In either black or clear or polished. I have gotten quotes for my hardware from Fastenal and Grainger.Every thing is a little pricier than I was hoping for but I don't want to put out any junk with my name on it! And they will be made in the U.S.A.!!I have sent in a document disclosure to the patent office.I have talked with Justin at Pirate Cycles and he is excited about this thing.NOBODY else is offering anything that addresses this issue.Check it out!The machine shop is going to have a table opening up next week and it'll take a week or two or three to machine,anodize and put the packages together. So hopefully before Thanksiving we'll have these turkeys together.Thank-You for your interest and check back often for up-dates.Kip.
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[happycheapskate]

If you want to skip using a tensioner and you have a very true sprocket system (dedicated hub), you can have a biker garage or friend make horizontal dropouts from pieces of angle iron, and weld them to the frame. Half-links in the pedal side can help with matching chains, or just use heavy chains on both sides.

I've seen other bikes on this thread that had a brace welded or bolted across the left chain and seat stay, as a place to mount a tensioner roller or the go-cart tensioner.

 

[kipharley]

Any fix that gets the tensioner away from the wheel and tire is a better set-up than the stock location.
In my opinion!Anyone that has a tensioner in the stock location unless it's welded on the chain stay is playing Russian roulet,and they are spinning the cylinder with a bullit in it every time they hop on their bike!Reguardless if they are using the tensioner for chain tension or chain stay clearance.Kip.
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[kipharley]

A spring -loaded chain tensioner will also benifit those that choose to run NO tensioner.
If you don't have horizontal drop outs it's tough to adjust out enough slop to minimize the chain from whipping.
Whipping will pre-maturely wear your front and rear sprocket and chain and try to tug the motor side-ways.
The sloppier the chain= more whip= more tug=motor trying to take a left turn!
Eventually it'll make it happen!
Guitar string tight chain isn't good either! That's my opinion!! Kip.
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[killercanuck]

For sure. I've tried to do up a spring loaded tensioner in the past, but my spring was weak and the chain kept locking up. I didn't want to go too strong on the spring for fear it would damage things. Can't wait to get my hands on one of these!

 

[kipharley]

Good Morning,All!! Justin at Pirate Cycles is on board for a first run of 25 units they will be offered at an introductory sale price of $70.
I am going to the machine shop today and set up table time for the machining and anodizing.I am going to try to get an open end on the machining,in the event that there is more orders initially than 25 units.
If I can and we get more orders than the 25 units,I'll tell the machine shop to just keep running them untill things slow down and send small batches to the anodizer while the others are being made.
This will get the first ones to the people that get on board of the Pirate Ship first.
So basically folks, members of Motorbicycling.com are going to get first dibbs on these things!
I have not visited any other site or contacted any other vendor about these.
Look at the hits and read the posts! All this has happened since the morning of Friday before last over twelve hundred hits and 49 posts.
I have a feeling there's some interest in these things!!
At the risk of sounding partial and like I'm bragging at the same time!!
These thing's are the answer to a problem that anyone that has installed a motor on a bicycle or have owned one has wrestled with.
They're not going to help those that have difficult chain stay clearance problems,but maybe they should of seen the writing on the wall before they commited to the build!Nother Story!!
Granted $70 bucks is a lot of money to me and most of you out there!But believe me there isn't much room for a profit after you have these things machined in the U.S.A.out of Billit 6061 Aluminum,Anodized,buy the hardware,assemble the units,packaging,shop cost,ect,ect.
There's other chain tensioners out there that aren't even spring-loaded that are selling for twice our price!And they're ALL frame mount.
So if this unit is what you've been waiting for "Get on the list" and tell us you want one,black or clear anodize.Polished?Do you just want the tensioner?or do you need a new stock wheel or want to pop for a sprocket=much smoother! You don't get that bump bump bump every time a link rolls over the wheel!Thank-You for your interest!Kip.
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[happycheapskate]

I think $70 is probably fair for a first run, to get a feel for the market, satisfy the me-first crowd, and please the show-builders. I am a little disbelieving that someone sells a tensioner for $140 though, when the china motors cost $140 for a kit with tank and chainwheel.

Congratulations on making something in America though. The design seems simplified enough, you should be able to streamline production soon. Anodizing is overkill for me. These things are show-off toys for many though, so I'm sure you'll be able to sell it at that.

 

[furament]

oi kip ill build a showcace bike just cuz i want to do a straight but ill need one of those so then how is that done? pm me kool?

 

[miked]

Any updates? I am in at $70

 

[kipharley]

Hi,Miked.The Machine Shop is making the first run of 25 for me.
I gave the one pictured a good work out yesterday and it worked if I do say so myself!"FLAWLESSLY".
Very nice and smooth.
The bike pedals easy,chain stays nice and tight"but not"to tight.There isn't any slap.
The chain doesn't rub the chain stay.I couldn't be happier with the design.
Justin@ Pirate Cycles.com is going to be retailing them for me and he is going to be offering a chain sprocket that replaces the wheel and that my friend will be the cats backside!
The very first spring-loaded chain tensioner I made I used a make-shift chain sprocket and that ran verrrry smooth.
So go to Pirate Cycles.com and get on the list and when they become available you'll get one of the first ones.Thanks for the interest! Kip.
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[happycheapskate]

There are aftermarket generators available that fit in the magneto case and produce 12v. They are about $30-40 on Ebay.

 

[happycheapskate]

If you can figure out how to glue a bigger wheel to the pedal-bike dynos, they will last longer. Maybe some kind of R/c car wheel would do.

 

[kipharley]

Didn't someone post that those in mag-area generators @ e-bay were junk? or did whoever that was making them straighten out the issues?Kip.
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[kipharley]

Hi,akv4590.I wasn't sure which sprocket you were talking about.
I thought that maybe you were talking about the rear drive sprocket?
So what you are saying is mount a dynamo onto the pivot arm for the tensioner that has a drive shaft that passes through and the sprocket attaches to the drive shaft?
Anything is do-able but that would have the dynamo spinning the same speed as the sprocket which would be much faster than on the tire!
Plus the tensioner would be bouncing the dynamo up and down with the tension of the chain.Kip.
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[corgi1]

4 cycle w/added power,just a little as not to blow it up, and then how does the riding mower hydro varrable trans work?

 

[kipharley]

Here's some pics of the proto-type spring tensioner on the finished,OP Roller bike.Kip.
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[happycheapskate]

Nice build! I really like the tensioner. If the spring breaks, is it likely to derail the chain? It looks like the chain doesn't have a lot of slack in it so it should be ok till you could stop. What chain are you using? It looks heavy.