Q?: Disk brakes and hub adaptors

[Danner]

I want to construct a hub adaptor for the KC plan from two parts: the Trike Freewheel Adaptor at http://www.amazon.com/Trike-Fw-Adapter-35mm-Screws/dp/B000AO7H84/ref=sr_1_1?ie=UTF8&s=hi&qid=1244333916&sr=8-1 or similar,
and the Disk Brake Rotor Adaptor at the bottom of the page at http://www.electricscooterparts.com/brakes.html.

The Brake Rotor Adaptors come with either 4mm or 6mm threaded bolt holes. Which one do I need, if I mate this with a typical 160mm disk brake rotor, like Avid BB7?

Or any other suggestions?

Thanks, Danner

[savarin]

Hmmmm, I'm pretty sure most disk brake rotors take a 5mm bolt. Please double check.
I will look again tonight.

[Danner]

Thanks Charles,
I'm not sure about that outfit peddling the disk rotor adaptors - I spoke with them by telephone and they say both the adaptors have the same size bolt holes, adding that the web advert was incorrect. But are they 4mm? 6mm? or 5mm? They couldn't say. They did hold the adaptor up to a 160mm rotor for me and said the holes line up correctly, with the threaded holes appearing slightly smaller than those on the rotor, maybe due to the threads. I'll probably only get to the bottom of it for certain by buying and find out for myself.

[John Lewis]

Hmmmm, I'm pretty sure most disk brake rotors take a 5mm bolt. Please double check.
I will look again tonight.

Yes definitely 5mm. I just put the micrometer on some.

John Lewis

[TheKid]

I have four of those adapters, two steel, two aluminum. They take 5mm bolts. However, buy the discs from them, because the bolt circle is slightly different on their adapter than normal bike discs. The good thing about their adapters, is that they also come in steel, so you could weld them to steel rear wheel hubs for use on tadpoles and quads. When I bought the adapters, they were out of stock on discs. Every time I went back for the discs, they were out of stock, so I never used their adapters. I ened up getting the ones from bicycledesigners.com, which are aluminum. I tried several types of epoxy, including JB Weld, ans all failed to hold the adapter to the right wheel on the Fox.
I intended to use the steel ones on the Fox, so I could weld it to the left wheel to stop the adapter from unscrewing while braking. Now that the discs are in stock, I'll buy a few. They also sell left and right disc calipers, which work quite well.

[Danner]

Thanks John. I checked one at LBS today and confirmed 5mm. But TheKid raises another issue - bolt circle diameter. The guy selling the disk adapters measured one for me and arrived at roughly 48mm - not 51. I really don't care to buy disks from them for this project, as I plan to use a couple Avid BB sets. So it looks like I may be drilling and tapping my own adapters.

TK, thanks for bringing that to my attention.

What's the thread pitch I need to tap holes for these 5mm bolts? I haven't done it before, but I'm not afraid to give it a try...

[savarin]

5mm tap with a 0.8 mm pitch.
Metric threads are measured as the distance between thread tips.
The tapping drill size is 4.2mm dia or number 19 imperial.
You will need a 5mmx0.8 taper tap and kero is a reasonable cutting fluid in aluminium. (bacon fat also works)
If you need to tap a blind hole then also get a bottoming tap so you can thread to the bottom of the hole.
(Often cheaper to buy the set of three, taper, intermediate, bottoming)
Start with the taper, finish with the bottoming.
Also use grease on the tap to hold the chips and withdraw to clean regularly.
With through holes the chips should fall through.
Dont forget to back off every quarter turn to break the developing chip.
I prefer the european tap wrench over the american chuck style as in my opinion its easier to keep square. ymmv.

[SirJoey]

Charles, you sound like you are either a machinist (or ex-machinist like myself),
or you at least have some machine shop experience. Am I right? :)


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[savarin]

Charles, you sound like you are either a machinist (or ex-machinist like myself),
or you at least have some machine shop experience. Am I right? :)


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

Fraid not Sir J, I'm totally self taught.:jester:
I'm interested a zillion fields and firmly believe anyone can do anything if they would only try. "Cant" isnt in my vocabulary.
It just needs a bit of research and then dive in at the deep end.
I'm actually a professional chef by main trade, then a coded welder as secondary trade (expired 30 years ago), now a food science/basic computer and professional cookery teacher. (waiting to retire)
I facet gem stones, silver smith, cast aluminium, build bikes, grind and polish astronomical mirrors to build telescopes, build furniture.
I was in the custom m/cycle game as a hobby in the 70's where my tool collection and metal working experience started.
My only machining experience was in high school in shop when I built a double acting steam engine and boiler from scratch.
I've never forgotten what was taught and cant wait to complete my Gingery lathe.
I usually have so many projects on the go at the same time it takes ages to finish one.
My main hate are idiots who are proud of what they cannot do, you know the ones....... "Oh! I couldnt, I cant even change a light bulb" as if its something to be proud of. (Hmm, starting to rant, had a bad day at work)
All the doors in my house are wider than the norm for my head to get through:rolleyes4:
Wish I had a lathe and mill, oh what I could build.
Do you still want to marry me??????????:D:D

[SirJoey]

Do you still want to marry me? :D
Oh man, MORE THAN EVER!!! :jester:

http://img23.imageshack.us/img23/502/notworthyzb5.gif
Holy Moses, you are truly a "jack-of-all trades!"
Rarely do I encounter anyone with such a diverse range of
skills & interests, not to mention such a great attitude!

Man, you're up there with Capt. Jack & Dr. Who...
Now I know who to pester for info & advice! :jester:


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[Danner]

...kero is a reasonable cutting fluid in aluminium. (bacon fat also works)


Thanks Charles.

I'll be working with steel flat bar. All above applies except cutting fluid?

Joey,

I tell you, Sav's been a great help to me on several occasions. The Renaissance man down under. And if you are the observant type, you might pick up a hint of his wry sense of humor.

[savarin]

As a machinist you may like this one.
I always get a grin hearing machinists talking about high precision work.
tenth of a thou here hundredth of a thou there.
I have a measuring device fabricated from some aluminium scrap I made for measuring how much glass I polish off the surface of the mirrors.
It measures in angstroms (Wavelengths of light) It can tell how thick a layer of glass is removed with the wipe of a thumb.
I find it astounding that a home made bit of kit that was cobbled together from the scrap bin can be so incredibly accurate. (It does use two cheap chinese micrometers)
It is so cool, in use you can see actual air currents wafting by due to the differing densities in the temperature gradients.
I hope it doesnt sound like I'm bragging cause I'm not, I'm gob smacked at how simple it was.
Whoops, I've hijacked Danners thread.
Sorry guys

[savarin]

Thanks Charles.

I'll be working with steel flat bar. All above applies except cutting fluid?

Joey,

I tell you, Sav's been a great help to me on several occasions. The Renaissance man down under. And if you are the observant type, you might pick up a hint of his wry sense of humor.

Yep,keeping it straight is the hardest thing to learn.
If you have a drill press available hold the tap in the chuck and manually wind it into the hole to start cutting.
Once its well established remove from drill and continue by hand.
DONT TURN ON THE DRILL.
If you can find proper cutting fluid (Tap Magic is very good) use it.

And thanks for the kind words but I've never heard puns called wry before:jester:

[savarin]

Man, you're up there with Capt. Jack & Dr. Who...
Now I know who to pester for info & advice! :jester:


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

WoW! what a coincidence, I was watching Torchwood at dinner tonight.:surprised:

[jimFPU]

Do you still want to marry me??????????:D:D

You keep putting stuff like that up here you just may get a proposal!!:beatnik2:

[savarin]

You keep putting stuff like that up here you just may get a proposal!!:beatnik2:

If your wealthy, own a pub with a machine shop out the back and look like a supermodel I might even be tempted :evilgrin:

[John Lewis]

Another guy amazed by the simple foucalts sp? tester. I couldn't get over how incredibly sensitive it was. I got my mirror to 1/32 wavelength.

John Lewis.

[savarin]

The phenomenal talent and knowledge of everyone on this forum is....dare I say it......astronomical!!!!!!!!!!!!!!
Seriously though it really is.
There are creations here that would grace any top showroom.

[TheKid]

It occured to me that the KC adapter incorporates the freewheel adapter for the freewheel, and a plate to mount the disc. If you were planning on using the screw on disc adapters, then how would you attach the freewheel? there's not enough threads on the freewheel adapter for both.
I made one for the DR by simply using a piece of 3/16" thick flat bar for the disc mount, and welding it to the freewheel adapter. I couldn't find a 5mm tap, so I tapped it to 6mm, only to find that I had to drill the holes in the disk a little wider. However, 5mm is just a tad over 3/16", so you could use a 3/16" tap if you're making your own adapter. It's easy to find a tap at any hardware store, with bolts to match.
To make the disc adapter, I just put a disc on the steel, and marked the holes. Then I joined all opposite holes to determine the center. I drilled out the center to match the axle size, the slid the freewheel adapter on the axle and tightened it, followed by sliding the disc adapter, with a shaft collar to hold it tight to the freewheel adapter. The result was this:

http://i192.photobucket.com/albums/z66/edpol_photos/Disc%20Adapter/000_0384.jpg

Here's a shot of the disc adapter before the center hole was drilled all the way, and before I cut it from the flat bar with a hole saw. I threaded the holes first, to make it easier:

http://i192.photobucket.com/albums/z66/edpol_photos/Disc%20Adapter/StartCut.jpg

[SirJoey]

Excellent work, Kid!
Thanx for yet ANOTHER method! :)


http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[Danner]

.... If you were planning on using the screw on disc adapters, then how would you attach the freewheel? there's not enough threads on the freewheel adapter for both.
I made one for the DR by simply using a piece of 3/16" thick flat bar for the disc mount, and welding it to the freewheel adapter.

Thanks, Kid, I was hoping to just weld the disk adaptor to the back of the FW adaptor, not screw it on. I just liked the idea of not having to tap the bolt holes.

Actually, I got the idea from something you wrote in the old forum, where you gave some good details on this subject. I don't remember where it was, but I kept a paraphrased copy for reference:

As for the other problem, you could buy [ a free hub adaptor ] and then make a disk brake mount as I explained (from a plate or washer w/ 6 holes). Use the step drill to drill the freewheel adapter to a 3/4" bore. Then slide both on a short length of 3/4" rod, or a 3/4" bolt, clamp them together, then weld them together. Slide it off the rod, and you have your freewheel/disk brake adapter, ready to install on the KC.

It has two set screws, one over the keyway, and one on the other side. If you drill it out, the keyway will probably disappear, so once you have it in the correct place, tighten one set screw. Then in the other set screw hole, using a slightly smaller drill bit, drill part way into the axle, about 1/8", to create a dimple that will hold the set screw in place, and prevent shifting. Tighten the screw, then remove the first screw and do the same thing. When I did mine, I removed the other set screw, and drilled a 1/4" hole all the way through and installed a 1/4" bolt with a nylock nut, the way some of the cheaper trike manufacturers mount their drive wheels. It sounds like a lot of work, but it isn't. It took me only 15 minutes to drill out the FW adapter, and drill the dimples.

After drilling out the FW adapter, and making the disc brake adapter, take a 3/4" bolt and nut, and slide the disc brake adapter on the bolt. Then slide the FW adapter on the bolt, with the non threaded side against the disc brake adapter. Tighten the nut very tightly against the FW adapter, then weld the seam between the disc brake adapter and the FW adapter all the way around.

So I plan to do just that!

Danner

[TheKid]

It only took a few minutes to tap the holes. The only thin oil I had was citronella, which worked fine. In the past, I've used everything from 3-in-1 to vegetable oil, and never had a problem. I do try to keep a supply of cutting oil on hand though.
Another alternative if you don't want to tap the holes, is to use bolts and nylock washers. Works just as well, without the need for loc-tite.

[Danner]

.... Another alternative if you don't want to tap the holes, is to use bolts and nylock washers. Works just as well, without the need for loc-tite.

After all the good info from Savarin and yourself about tapping holes, there's no way I'm not going to try it. I'm off to the hardware store for a kit now. Thanks again for your inputs.

[TheKid]

After all the good info from Savarin and yourself about tapping holes, there's no way I'm not going to try it. I'm off to the hardware store for a kit now.

Now THAT'S the spirit!

[savarin]

Way to go!
I look forward to seeing the results when I get back from internet exile out whoop whoop at the weekend.

[Patrike]

Big D -- looking great!

[chainmaker]

I wish I had found this thread before I needed it...My drive sprocket arrived today which attaches to a disc brake mount got out My adapters and presto......different size mounts .............why???

[chainmaker]

I guess I should have asked if anyone knows where I can find a freewheel disc brake adapter for standard size disc rotor. Bicycle designer sells a kit, I called and He said it will fit the rotor in the kit but not sure about other sizes.
Cheers

[PeterT]

Also have a read of the post under Disc Brakes and Hub Adaptors
http://forum.atomiczombie.com/showthread.php?t=2936

I will be sending out the parts ordered within a month

PeterT

[chainmaker]

Well...thank you Peter, but that wouldnt work in this application. I need to attach a disc brake mount to My 3/4 in axel via fw adapter, in which to attach my drive sprocket to (it mounts to a disc brake mount)
Cheers

[CharlieChops]

Notwithstanding the issues of the bolt diameter or the bolt circle diameter, Has anyone taken a pair of the aluminum disc adaptors and mounted it directly to an aluminum hub? I have a pair of 20" wheels with 14mm axles and aluminum hubs. There is a generous flat area between the spoke hole circle and the bearing area in the hub on both sides of the hub.

If I were to carve out a 1/8" plate (or whatever thickness it needs to be for caliper clearance) with 6 holes spaced between the 6 holes on the disc adaptor and weld it to the adaptor, why couldn't I drill 6 matching holes through the hub face from side to side and bolt it onto the hub? The hub holes could be tapped for 10-32 screws for instance.

Comments?

Thanks,

Charlie


I want to construct a hub adaptor for the KC plan from two parts: the Trike Freewheel Adaptor at http://www.amazon.com/Trike-Fw-Adapter-35mm-Screws/dp/B000AO7H84/ref=sr_1_1?ie=UTF8&s=hi&qid=1244333916&sr=8-1 or similar,
and the Disk Brake Rotor Adaptor at the bottom of the page at http://www.electricscooterparts.com/brakes.html.

The Brake Rotor Adaptors come with either 4mm or 6mm threaded bolt holes. Which one do I need, if I mate this with a typical 160mm disk brake rotor, like Avid BB7?

Or any other suggestions?

Thanks, Danner

[savarin]

Notwithstanding the issues of the bolt diameter or the bolt circle diameter, Has anyone taken a pair of the aluminum disc adaptors and mounted it directly to an aluminum hub? I have a pair of 20" wheels with 14mm axles and aluminum hubs. There is a generous flat area between the spoke hole circle and the bearing area in the hub on both sides of the hub.

If I were to carve out a 1/8" plate (or whatever thickness it needs to be for caliper clearance) with 6 holes spaced between the 6 holes on the disc adaptor and weld it to the adaptor, why couldn't I drill 6 matching holes through the hub face from side to side and bolt it onto the hub? The hub holes could be tapped for 10-32 screws for instance.

Comments?

Thanks,

Charlie

something like this?
http://forum.atomiczombie.com/showthread.php?t=1881&page=3
(3rd post down)
So far they are working with no problems.

[CharlieChops]

something like this?
http://forum.atomiczombie.com/showthread.php?t=1881&page=3
(3rd post down)
So far they are working with no problems.

savarin,

Thanks for the link.

I've looked at a lot of threads but would probably never have found that one. Almost exactly what I came up with. I'll hold that whole thing now until i have the brake components in hand.

Charlie