Rear brake anti-torque mod for D404 Dunlops


Information and questions on GL1100 Goldwings (1980-1983)
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Lone Eagle
Posts: 4
Joined: Sun Mar 20, 2011 10:47 am
Location: Missoula, MT
Motorcycle: 1982 Goldwing GL1100 Interstate

Rear brake anti-torque mod for D404 Dunlops

Postby Lone Eagle » Fri Jul 01, 2011 11:33 pm



When I got my bike(see my other thread for pics), the previous owner had put a brand new set of Dunlop D404 tires on it before I picked it up. Nice....new rubber for free. 8-) On the way home, I noticed a burning rubber odor, and pulled over. The tire was rubbing the anti-torque brace. Drat...not good. I limped it home, and hit the net. I found that clearance was an issue for this tire on this bike because of the sidewall dimensions. Solution? Replace the tire or modify the brace with a hammer. No $$ for a tire, and I hate whacking braces with hammers. I called a friend who does custom choppers, and here's what we did.

I found an extra brace on ebay for $12 shipped. Easy enough. Spare parts on a job like this can be a lifesaver. Next, he figured how much we needed to mod the brace for a minimum of 1/4" sidewall clearance without affecting the centerline of the brace too much. Next, we stripped the worse painted brace of the two down to bare metal. He then used a hydraulic press and a jig to tweak the frame end very slowly. This is tempered steel, so the slower the better. After an hour of tweaking and measuring, we had moved the frame end head over almost 1/4" from it's original position. We powder coated it, and put it back on the bike, and the bolt holes lined up perfectly. I now have about 9/32" sidewall clearance, and can safely run the D404 tires. I plan on upgrading to a heavier load-rated tire later this winter, as the Mrs will be joining me next summer on it.



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eklimek
Posts: 307
Joined: Tue Feb 15, 2011 1:55 pm
Location: St Catharines Ontario Canada
Motorcycle: 81 GL1100 (Widowmaker not in service), 83GL1100, CB350f x 6, CB400f x2, CB550f sold, CL350 (seized engine), plus enough donors to take me through retirement.

Re: Rear brake anti-torque mod for D404 Dunlops

Postby eklimek » Sat Jul 02, 2011 11:50 am

To avoid work hardening a critical item one should reheat and anneal. To do this heat the entire piece above the Curie point and then cool very slowly. If the piece is small and heat loss is rapid placing in an insulated container with a larger piece also at high heat to further slow the rate of cooling is effective. If the item has sufficient carbon content air cooling will harden.

In blacksmithing terms, tools are heated to a dull red glow (above magnetic threshold) and immersed in vermiculite with a large item at same temperature. Allow to cool slowly. For some items it is convenient to leave it in the forge and simply turn off the fire pot and let it cool over lunch. In any event if the iron item has the ability to be tempered it should not be cooled rapidly. The Farrier quenches horseshoes in the slackwater tub because they lack carbon and won't.

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littlebeaver
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Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Rear brake anti-torque mod for D404 Dunlops

Postby littlebeaver » Sat Jul 02, 2011 5:33 pm

I have to wonder about this problem you had, I have a 81 with 404"s [dunlops] and I have no issues at all it hitting anything, did it have both spacers in place, one on the inside of the brake caliper holder and one on the outside.. I know yours is a 82 but I think the swingarms are the same, I could be wrong...Here's a blow up of the spacer's...
1_1[2].png

Lone Eagle
Posts: 4
Joined: Sun Mar 20, 2011 10:47 am
Location: Missoula, MT
Motorcycle: 1982 Goldwing GL1100 Interstate

Re: Rear brake anti-torque mod for D404 Dunlops

Postby Lone Eagle » Sat Jul 02, 2011 7:14 pm

Yes, both spacers in place, and the braces/swingarms are the same '80 to mid-83(verified by local Honda shop). Honda shop told me this was a problem on some models, but not on others. Even they scratch their heads when confronted with this one.

Elkimek, we thought about doing it that way, and went the slow and steady route he uses to reshape frame tubes on his choppers. I've seen him spend days doing tubes with a press and mandrels.

DragonRider
Posts: 136
Joined: Thu May 19, 2011 11:11 am
Location: Ocala, FL
Motorcycle: 1982 and 1983 GL1100 Aspencades

Re: Rear brake anti-torque mod for D404 Dunlops

Postby DragonRider » Sun Jul 03, 2011 2:10 am

Both my '82 and '83 have had Dunlap D404 on them in size 140/90-16 and have had tires very close but never touching. currently the '82 has a Dunlap D404 size 130/90-16 and the '83 has a Shinko 230 tour master in size 130/90-16 both have lots of room and have the same ratings (shinko costs a lot less).

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eklimek
Posts: 307
Joined: Tue Feb 15, 2011 1:55 pm
Location: St Catharines Ontario Canada
Motorcycle: 81 GL1100 (Widowmaker not in service), 83GL1100, CB350f x 6, CB400f x2, CB550f sold, CL350 (seized engine), plus enough donors to take me through retirement.

Re: Rear brake anti-torque mod for D404 Dunlops

Postby eklimek » Sun Jul 03, 2011 7:17 am

Glad it worked for you.

To be clear "slow and steady" or the rate of plastic deformation does not alter the alteration to the metal once it has past the point of elastic deformation. Rapid deformation increases material temperature by heat dissipation. For many purposes work hardening and stress crack formation are not critical. Even material intended for recoil absorption such as your garage door spring will eventually fail when used as intended, usually after 10,000 cycles.




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