Random Tandem

I originally posted this as a thread on the Tandem Cycling forum, but it was suggested that the insight I am hoping to find may reside at this forum:

I have bought a wheel that has the non-drive side threading to install an Arai drag brake drum, but I am stuck on how to separate its axle spacers to install the drag brake, because this hub's axle has no wrench flats for cone wrenches. I also checked and can confirm that the interior of the axle hole does not have a socket to accept an allen key (the interior, like the exterior, is round). My local bike co-op (which had the wheel as a donation) did not know. I am assuming it is some sort of press fit axle, but I am not sure how the nuts and spacers are removed (nor reinstalled). Help would be gratefully received.

Tandem Specific additional information: I have two tandems (with different wheel sizes) and only one Arai drag brake. This kind of drag brake has the drum threaded onto the non-drive side of the hub and the brake shoes and arm are attached to a plate that gets installed on the axle between the spacers. The drag brake came installed on my Kuwahara Adventurer road tandem that has 27" wheels, but I also want to use it to tour with my 12-year-old son who is too short for the Kuwahara, so we ride around on a Miyata Duplicross that has 26" wheels.


Top in this picture is the side threaded for the drag brake (non-drive side)


Closer look at the non-drive side


For completeness, the drive side

fietsbob

Notice the sealed bearing cartridge? Likely it's not adjustable.

could all be pressed together at factory, so not user serviceable..

Random Tandem

I do not need to adjust the bearings, I just need to install the brake plate between the spacers on the non-drive side, otherwise I am unable to use the drag brake for which this hub was specifically manufactured.

CliffordK

If it was installed in the factory, they could well have had a tool that matches the lock ring, and can use the knurling of the lock ring to tighten them.

Check the full length of the axle for an Allen wrench socket. It could be in the middle (still, there should be a way to get to the lock nuts). Also feel with a piece spoke or something whether the axle is solid, or uses end caps.

I'd try to find two lock nuts that would match the knurling, and lock in tight with a quick release. Then perhaps add moderate heat in case a threadlock was used, and see if I could unscrew the lock nuts.

It is unlikely I would reassemble without having an easy way to disassemble. So, if one knew what the parts were like, then a semi-destructive disassembly might not be bad. Or, perhaps filing flats onto the lock rings.

Andrew R Stewart 

Many cartridge bearinged hubs have axle end caps that are meant to have a slight interference fit, sometimes with an "O" ring acting as a clip or spring. Over time this type of assembly, if not maintained, can become somewhat stuck. First thing I would try is to pull the LH side end cap off the axle gripping the cap with a channel lock or vice grip pliers, sometimes a slight shock helps to break free sticky fits while a pulling force is applied.

The hub shell has a familiar look but I don't remember the brand from this. Perhaps image searching will turn up a matching hub shell shape that can then reveal the brand and thus a trail to instructions. Brands I would check out are Hadley and Velocity, that's no Phil, White or Shimano that I have seen.

BTW these snug fitting end caps, if that's what you have, are not thought of as being a frequently repeated remove/reinstall design. If you'll be swapping the drum back and forth get another drum for the other wheel. Arai drums come up on eBay often enough. Andy

Random Tandem

The axle is hollow to have a skewer through for quick release attachment to the tandem bicycle. I am pretty sure that it does not have a socket to twist it apart.

Thanks for your comment, Andy. Your analysis seems right to what I have observed (axle does not appear to be threaded, and no obvious way to separate the press-fit parts), leading me to agree with your conclusion noted above that perhaps it was not a wheel that was suitable for my plan of using a single drag brake on my two tandems. I will keep an eye out for another drag brake, but I am pretty cost sensitive for this because I am not yet sure how much serious touring my son will want to do before he is tall enough to ride the road tandem (which I prefer for longer rides by no small measure). Thanks to all for your thoughts. I am a little surprised to find that I am preferring cup and cone bearings...

-Will

AnkleWork

First determine if any of that stuff on the NDS threaded. If not then it seems not compatible with your brake.

fietsbob

Classic Arai Drum Drag brakes* did not need things on the axle,
just a torque transfer to the frame.

Now, new gear .. go look fir a Screw on Disc Brake adapter..

Random Tandem

I think my Arai drag brake is the same as all the others I have seen in that the aluminum drum threads onto the wheel (and rotates with the wheel) and the steel plate that holds the brake shoes, the torque arm and the braking activator arm stays stationary (unable to rotate by the torque arm attached to the frame, like a coaster brake torque arm). My brake has a hole in the plate that needs to have the axle run through it and the depth the shoes sit in the drum is determined by the positioning of the spacers on the axle. Seems "classic" to me.

fietsbob

Can't open the hub axle , enlarge the hole.. till it slips over ..

Build a different wheel around a Steel axle Shimano Tandem Hub?

Andrew R Stewart 

Only issue with enlargening the Arai's backing plate hole is that it is what keeps the whole thing together. Without keeping the shoe backing plate in place the shoes might migrate out from the drum. Sure the reaction arm is attached to the chainstay but not always with a bolt, many have a stud allowing the wheel's QR removal. Andy

fietsbob

OK, (never owned a tandem , helped put a few together 30 years ago @ Burly)
Machine a spacer set to go over the existing axle.
Wheel in the bike Will hold it on , maybe, Add a tiny setscrew to keep it there
with the wheel out ..
(I have Bullseye hubs that's how they work, setscrews just there for when the wheel is out of the frame,
spacer sleeve compression in the frame is actually how it works , with QR tightened..

otherwise..
I go back to suggesting converting to a disc brake...
And, getting the fittings attached to the frame

or Shimano hubs , last I saw they could be dis assembled..

[OP did say the hub /wheel was free @ his CoOp..]


I Run, S-A Drum brake, 36 spoke wheels on my solo Winter Bike..




...

mrrabbit 

Have you taken this to the ClassicRendezvous list?

groups.google.com

=8-)

CliffordK

One thing to keep in mind, if you have to have a "serviceable hub", then it may be worth it to just cut the thing apart and put in a good threaded axle.

Although, personally, I'd at least want to see what I was working with.

Random Tandem

Thanks to all for many ideas to consider. I am leaning away from using this wheel given what seems to be the fact that it has press-fit spacers that are not designed to be opened and closed repeatedly. I can return it to the CoOp (and they will refund my modest investment in it - sadly they will likely have it sit in inventory as few tandems visit). Changing out the axle to a threaded axel may work, but may render a working wheel non-working. Building a wheel with a Shimano Tandem hub will allow me to go with my original plan of using my single drag brake on two tandems, at least until all of my stokers are able to ride the larger Kuwahara. Another generous forum member offered me a Shimano tandem hub that he is not using, so that seems to be the best path for me to follow.

-Will

base2 

On my Phil Wood a 5mm allen wrench inserts into the end of the axle as if it were a skewer. insert 1 on 1 side, one on the other. Twist counter clockwise in relation to eachother. The end cap is a very fancy nut. remove the spacer, thread on the drum. install brake plate. Hold brake actuation lever tight to center plate in drum. Replace end cap nut.

If the brake plate rubs on the back of the drum, a very, very thin washer can move the plate outboard.

Jeff Wills

I'm pretty sure it's a Hügi hub. I'm not 100% sure, but I think the spacer is supposed to come apart at the cut lines, the thin spacer removed and the brake backing plate put in its place, and everything pressed back together. Maybe... I'm not sure the spacing is right.

OP, have you consulted Precision Tandems or Santana Tandems? It seems to me that you need to consult a tandem maker that's been around for a while.

Andrew R Stewart 

Hugi, I think this is correct. I never dealt much with the brand but have seen them before. The LH thin axle spacer is exactly what I, too, feel is where the drum's backing plate would fit. I would hope that seeking info from tandem specific sources is just an assumed part of basic research methods. Andy

fietsbob

DT, took over the Hugi company, did it not?