Brakes On A Jack Shaft?

[kaw]

I got another kart project I am in the middle of and and finally working out the logistics of the last few things.

One of 2 remaining parts i'm trying to resolve is on the brake system.

I want to install a disk break onto my jack shaft and not onto my wheels directly.

My jack shaft was used to get a high torque ratio for the rock mover I'm building, and also turn my non-live rear axle set up into 2 wheel drive. (There is a chain from the engine to the live jack shaft then 2 chains, one on each side, to each rear tire)

My hope is by installing a single disk brake on my jack shaft, I brake both unconnected (axle wise) tires at the same time and also leave a clean set up (as far as clearance wise) on my tires by not having brakes on them.

Has anyone done this before? My only worry is putting to much strain on the chains?

Any related advice is welcome.

 

[kaw]

Should probably add, this is a very low speed application (Less then 10MPH) buy a high weight application, with a total cart weight including load of around 300-400lbs.

 

[DirtyDamage]

I don't have input on the brakes but I would love to see a pic of this kart...

 

[kaw]

Its not going to be pretty...lol ...its for moving rocks and stumps on my property. There's a picture of the frame laying in on my kitchen floor if you look at my profile. Those are 17" tires for reference of the size.

 

[kaw]

The jack shaft is located above the actual frame (in the rear) giving me a lot more clearance below my kart and allowing me to use smaller sprockets on my rear wheels too..

Please ignore the poor quality model here as I wasn't planning on sharing it... but just so you have an idea.

 

[Bladerunner]

I would do research on minibike band brakes. I wanted to put one on my JS but realized I don't have the space with my current setup, not to mention all the brake kits are for 7/8" or 1" jackshafts (mine is 5/8"). I will eventually go with a small maybe 4" disc brake and mechanical caliper.

 

[kaw]

My jack-shaft is 5/8" dia too, I've looked into the band brakes but likewise wasn't find the sizing. Plus I like the ease of replacement for pads which are beyond cheap on eBay.

 

[mckutzy]

I'd say do it. Upgrade the chains so they are heavier. I had similar ideas when I started my bike. I ended up going without... Cause I have such a big rear tire..

 

[kaw]

I'd say do it. Upgrade the chains so they are heavier. I had similar ideas when I started my bike. I ended up going without... Cause I have such a big rear tire..

Nice build!

 

[machinist@large]

If you have the room width wise, going to double row sprockets and chain would most likely be the easiest way to double your safety factor's. You could also switch to a larger single row chain/sprocket combo, but sprockets with the correct bore sizes become much more a grab bag issue.

Also, if possible, switch to taper lock hub/sprockets.They most definitely cost more up front, price wise, but offer over three+ time's the connection strength of a set screw joint.

As long as your chain sizing/shaft sizing/framework sizing is up to the task, the brakes being mounted on the J/S is a total non issue. There's been many custom designed farm machines that were factory made in the after market where they took the tractor, pulled all the tire's and rim's off, replaced the drive wheels with chain sprockets, slapped the tractor into what ever they had designed.

The stock tractor brake's were still just that: stock. The original tractor's final drive set up had become the machines J/S, with the factory brakes where they were intended to be......

Short and sweet; it can be done safely, because it has been done safely.....

 

[Bladerunner]

My jack-shaft is 5/8" dia too, I've looked into the band brakes but likewise wasn't find the sizing. Plus I like the ease of replacement for pads which are beyond cheap on eBay.

To go the disc brake route, the method I've found is to get a 6-bolt adapter to put a disc on a flipped threaded bicycle hub, then put that adapter on a freewheel to 5/8" shaft adapter from staton-inc, one of which I have on my bike. The ID of their machined aluminum adapters is a little tight sometimes and I would just to in there with some sandpaper since they are not hardened like the sprockets.

However this setup is for me, which is a total weight of not more than 250lbs including rider. So possibly look into a heavier duty adapter for a different kind of disc-- like one designed for a kart or minibike. My current front (and only) brake is a hayes stroker hydraulic with a 203mm disc. Under 30mph it's great but I'm not confident with hard stops from 45.

Also there is a thread on motorbicycling.com with photos of jackshaft disc brakes... Don't have link sorry.

Disc adapter
http://www.bicycledesigner.com/bike...sc-brake-adapter---free-or-flip-flip-hub.html

 

[kaw]

Thanks machinist and milfhunter, Thats the info I was looking for

 

[Wtf]

Just an update ... kart is up and running... still working on some minor things but this little beast seems to be working as needed.

I would have posted sooner but my account got deleted... wtf? Any way ill post some pics in a bit

Oh and as far as the brakes on the jackshaft... they work great but im using them at low speeds... they lock up really easy (which is what I needed for what im doing) but I have a feeling this would not be good at all when really moving. It really does put a lot of strain on your chain, and will blow any cheap chain tensioners off in the first run.

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[DirtyDamage]

That kart looks like a mule! What do you plan on doing with it?

 

[Wtf]

Thats exaclty why I built it, for moving rocks and tree stumps on one of my properties. Three of us guys all sat on the thing and rode it around the court trying it out... were each big guys about 200Lbs and the cart itself is about 220. It had no problem at all moving us.

 

[DirtyDamage]

What stage is that pred?

 

[Wtf]

The predator is just a 212,
however it has the governor removed, and I added new performance valves and valves springs, larger jet and upgraded emulsion tube, swapped out the intake for a K&N style filter. and added a three stage open pipe.. it sounds and runs great.

The thing really gets going, however alot of that has to do with how I geared it.

Its essentially running 12 to 120 from the engine to the rear by going from 12 to 24 on the jack-shaft then 24 back to 12 then 12 up to 60. Plus its 2 wheel rear drive...Super Torque =)

 

[Iron John]

The main drive chain looks hella loose. Can you lose a link or slide the motor forward?

 

[Wtf]

It is loose, there is still work being done on that. I'll try to post pics when its actually done... whats remaining so far is removing the plate that is being used to steer and adding handlebars, with the throttle/ kill switch/ and brake lines installed... getting the chains tightened, replacing all the wheel bearings for higher strength ones. Spray paint it more nasty looking, and add chainsaw holsters.... Then it should be good to go

 

[Poboy kartman]

What? No billet connecting rod? Bye bye Predator....