Disc Brakes...

jasonh

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Jun 23, 2008
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You have a couple options.

1. You could get the sickbikeparts shifter kit and keep your rear disc brake.

2. King's Sales & Service can make you a left-side sprocket that bolts to your disc brake mount. No sandwiching the spokes, but you lose your disc brake in the back.
 

~macaddict~

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Jul 29, 2008
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Ok, thanks. One last question. But if I remove the back brake can't I just install the stock sproket on there with no issues, or do I have to go with one of those two options?
 

jasonh

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Jun 23, 2008
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you should be able to install the stock sprocket on there no problems I think.

If you don't go with a shifter kit, I would highly recommend putting some type of brake on the back. Front only is baaaad.
 

~macaddict~

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Jul 29, 2008
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you should be able to install the stock sprocket on there no problems I think.

If you don't go with a shifter kit, I would highly recommend putting some type of brake on the back. Front only is baaaad.
ok, so if i remove the disk brake on the back and leave the one in the front BUT put a V brake on the back that'll work. No need for the left sided sprocket or the shifter kit.
 

jasonh

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Well the stock sprocket is a left-side sprocket :)

it's just King's will give you a sprocket that mounts to the disc brake mount instead of attaching via sandwiching the spokes.

And yeah, I think a V brake would be just dandy on the rear. Never had disc brakes, but the V brakes are my fav out of the rest.
 

~macaddict~

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Jul 29, 2008
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Ok, cause I wanted to use one with disc brakes cause I have heard that using v brakes with a motor with run the brakes down really fast. If they don't really run down like they day they do, might as well just use a bike with F & R v brakes. (^)
 

jasonh

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Jun 23, 2008
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The brakes being worn down quickly is due to stopping from higher speeds. I don't think it's anything about V brakes in particular.

Disc brakes will be safer because you will have more stopping power. Something you're going to want when doing 25-30mph.
 

~macaddict~

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Jul 29, 2008
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Oh, well yeah thats what im going to need I guess. I bought an 80cc motor kit online. And i'm planning to use it as transportation here in Seattle. So I think its best to buy a bike with back v brake and front disc brake...
 

ocscully

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Jan 6, 2008
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Oh, well yeah thats what im going to need I guess. I bought an 80cc motor kit online. And i'm planning to use it as transportation here in Seattle. So I think its best to buy a bike with back v brake and front disc brake...
That may be easier said than done, finding a bike with two different brakes. Depending upon how good you are at problem solving and fabrication skills you can have both the rear disc brake and driven sproket on the left side of the bike. Again Kings Sales and Service have a couple of new adapters for mounting the driven sprocket to a disc brake rear hub. The one you will want if you want to try this is called the Top Hat. I believe it sells for under $30.00 and should allow you to have both sprocket and rotor mounted to the rotor mount on the hub.

ocscully
 
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Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
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Scottsville, VA
HI All,

Yes, the disc hub adapter and Top Hat Adapter are currently for sale although I have not formally put ads up for them up on eBay or elsewhere.....I have been selling them informally for $29.95 each plus $12.50
shipping anywhere in the US...Ask for other locations....

If you are running a disc brake bike AND want to try to keep the disc brake you will need to use the Top Hat Adapter....the standard adapter does not
allow for retaining the use of the disc brake.

Since there are so many different frames / wheel / disc brake calipers combinations out there... it is hard to say 100% for sure if the Top Hat will allow you to mount both the sprocket and use the disc brake but here is a general descritption of things to look for to see if it is a possibility (some tinkering may be necessary but it should work in most all cases....In a worse case scenario, you will still be able to use either adapter to mount the sprocket to the hub itself but in order to have 2 brakes if yours was a disc brake bike to start with you may need to install a different rear brake system))....(I will try to make disc brake bike this weekend and include pics showing the Top Hat adapter in action...well at least on the bike....may not have enough time to put the engine on too).

The first step to seeing if your bike is a candidate for an easy install of the Top Hat Adapter is to see how much room there is between the disc brake rotor and the lower chain stay (the part of the bike frame that runs parallel with the ground and goes from the bottom bracket to where the rear wheel attaches to)....Ideally there should be about 1/2" to 5/8" gap.....the more the better....If the gap is not there or is smaller it may still work but may be a little more difficult.... all is not lost if you don't mind "tweaking" the stay or using a (gulp) ball peen hammer to make a dent so that the rotor can be moved out away from the bike hub....

Basically what you will need to do is remove the disc brake caliper from the frame and reposition it OUTSIDE the frame (the caliper assembly is normally
bolted on small tabs welded on the frame on the inside...simply remove the bolts, place the entire assembly on the other side of the tab and re-attach)...

The Top Hat adapter has a built in offset that will place disc brake rotor approximately the same distance outwards as the now relocated caliper....Minor spacing (using flat washers or specially designed Disc rotor spacers (available at bike stores) can be used to perfectly center rotor within the caliper......An alternative would be to file the mounting bracket
of the caliper itself but do this ONLY when you are SURE everything works...you don't want to possibly ruin a perfectly good caliper mount in case it does not work out.....Same thing goes for filing the frame tabs....Don't do it until you are sure everything will work...

Once you have gotten the disc brake situated, now bolt the sprocket (HD 9 bolt sprockets only (8MM) with the enlarged 2.15 center hole (available through us OR use your stock sprocket but you will have to enlarge the center hole to clear the disc hub area) onto the backside of the Top Hat Adapter (the backside is under the "brim" of the Top Hat....You can reuse the factory bolts but they will be way too long...You need to cut them down....NOTE: be sure to put the nut on the bolt BEFORE you cut the bolt because the threads will get "buggered" a bit....having the nut on the bolt BEFORE cutting allows the nut to "fix" the thread when you take the nut off....If you do it the other way you WILL have a hard time getting the nut started on the bolt unless you "fix" the threads with a file or die...

The bolt heads fit through the sprocket from behind and the nuts are to go near the top part of the top hat (the reason for this is in case the bolt head rubs against the spokes you can grind / file the bolt head a little shorter for clearance....) .

Now, place the disc rotor on the top of the Top Hat Adapter and attach the
completed assembly to the hub itself (NOTE: depending on the amount of spacing needed you may need longer M5 disc hub bolts (6 total).

NOTE: if there is not enough clearance for the disc caliper to fit between the disc rotor and the sprocket....you can either move the caliper and disc rotor outwards more through the use of spacers/ washers and/or add spacers to place the sprocket closer to the spokes....NOTE: if placing the sprocket very close to the spokes it may be necessary to file the bolt heads thinner so they will not interfere with the spokes themselves).

I hope this is fairly clear for you to understand how the Top Hat Adapter works....If not, I plan on building a disc brake bike this weekend and taking pictures along the way.

Have Fun and Ride safe!

Andrew