Jeff Cochran Signature SpeedKing Swingarm

Maybe the most versatile custom swingarm you can find in the after-market world to create a bike where you can choose among several unique stances.

It is offered by Custom Builder Jeff Cochran and will fit all Harle Big Twin 4-speed chain drive bikes from 1973 to 1984.

Axle plates for 3/4” axle applications that not only lower your bike 1 1/2” without sacrificing comfort but also allow you to lengthen the wheelbase to a full 1/2”, giving you the “SpeedKing” stance.

This steel swingarm features a 5-position shock mount adjustment that will either raise the seat 5/8” or lower the seat 1 3/4” from the stock position. The threaded mount holes are reinforced for a secure fit.

Bearigs and races included but will require rear fork seals for final assembly (H-D part # 47519-72) Contact Jeff Cochran at SpeaKing Racing.

15 Responses to “Jeff Cochran Signature SpeedKing Swingarm”


  1. 1 chopmonster66 Oct 11th, 2017 at 9:02 am

    were do the rear fork seals go ?

  2. 2 58_pan Oct 11th, 2017 at 10:18 am

    My question is why would you want three calipers locking up your back wheel (bike in the picture) my pan has a juice drum brake in the back that is perfectly capable of locking up the rear wheel, the front mechanical drum however is almost useless…makes for a very defensive riding style

  3. 3 smithncustom Oct 11th, 2017 at 10:38 am

    very cool. Building a swingarm chopper now. Went through the trouble of getting a round tube swingarm for the axle drop, so that is a cool feature to me. Love the adjustable shock mounts too!

  4. 4 Anton Oct 11th, 2017 at 10:55 am

    @chopmonster66 swingarm bearing seals (rear fork aka swingarm).

  5. 5 Pat h Oct 11th, 2017 at 7:49 pm

    I wanna know how thick the tubing on the swingarm is for the adjustable shock mounts

  6. 6 JohnnySpeed Oct 12th, 2017 at 7:17 am

    Looks killer. I’d run it.

  7. 7 burnout Oct 12th, 2017 at 9:45 am

    I like this! peace

  8. 8 Lyle Landstrom Oct 12th, 2017 at 2:15 pm

    It looks almost exactly like an old Ness adjustable swing arm with High Pockets axle plates welded on. Neat swing arm but nothing new.

  9. 9 Kelly Oct 12th, 2017 at 4:05 pm

    Square swing arms with adjustable shock mounts have been around a long time, but if you lower the shocks too much it DEFINATELY affects the ride. Most people who have trouble with a mechanical front brake do not know how to set them up!

  10. 10 Daytona Donnie Oct 12th, 2017 at 4:09 pm

    Ya we used a bunch of these back in the middle 80″s I think Art at Santee was doing them and they we very reasonably priced I think there was one as well that allowed you to run the sturgis belt or others ( I used Phil Ross units from SuperMax ….) or a 150 tire .. something old …..New again

  11. 11 58_pan Oct 13th, 2017 at 6:01 pm

    @Kelly if you have any advice on how I can make my mechanical front drum work better please share. I don’t know everything and always have open ears for people that want to share their knowledge

  12. 12 Pat h Oct 13th, 2017 at 9:06 pm

    58 pan I think it would be to hard to put into writing you get lucky somtimes maybe Kelly could simplify most are hill holders at best

  13. 13 Eddie trotta Oct 16th, 2017 at 3:15 pm

    Jeff’s bikes are always super clean and first class
    I altered a swing arm simalar to that one last year and it worked
    Out great , I want to get one is there a phone number for Jeff ???

  14. 14 Kelly Oct 16th, 2017 at 5:04 pm

    Ok while front drum brakes will never have the stopping ability of disc brakes, if the drum brake is set up according to the manual they do work. You have to loosen the brake cable then loosen the stop nut on the backing plate, there is an adjuster that centers the brake assembly that should be turned in till you feel tension then lock it down, adjust the brake cable and if your brake shoes are good the brake should work better. All that said a drum brake is and was meant to be used in combination with the rear brake and to use when coming to a stop. Also the part number for front shoes is the same for sportster rear mechanicaI as I recall.

  15. 15 Admin Oct 17th, 2017 at 5:48 am

    Jeff Cochran 513-885-7433

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