HarleyTechTalk

Technical Forums => General => Topic started by: les on August 04, 2022, 06:58:04 AM

Title: Why is it called a trap door?
Post by: les on August 04, 2022, 06:58:04 AM
Where did the name "trap door" come from for the transmission bearing housing?
Title: Re: Why is it called a trap door?
Post by: xlfan on August 04, 2022, 07:18:22 AM
Maybe it originates from the fact that it actually trap the 2 shafts perpendicular to each other prior to installing them in case?  :scratch: 
Title: Re: Why is it called a trap door?
Post by: Deye76 on August 04, 2022, 07:33:14 AM
Or because it allows access to the inside of the trans with relative ease.
Title: Re: Why is it called a trap door?
Post by: JW113 on August 04, 2022, 08:57:10 AM
Exactly! That, and the HD crowd has always liked cute pet names for mechanical parts. Like oil bag, cow bells, mouse trap, etc. And especially the name of the engines themselves! Knucklehead, Panhead, Shovelhead, Ironhead, none of those were in any HD literature at the time. And even the term "hog" is from the public, not HD.

Can't believe they eliminated the trap door on Sportsters. Split the cases to get to the trans guts.

-JW
Title: Re: Why is it called a trap door?
Post by: david lee on August 04, 2022, 01:55:20 PM
Quote from: JW113 on August 04, 2022, 08:57:10 AMExactly! That, and the HD crowd has always liked cute pet names for mechanical parts. Like oil bag, cow bells, mouse trap, etc. And especially the name of the engines themselves! Knucklehead, Panhead, Shovelhead, Ironhead, none of those were in any HD literature at the time. And even the term "hog" is from the public, not HD.

Can't believe they eliminated the trap door on Sportsters. Split the cases to get to the trans guts.

-JW
im amazed harley didnt call evos evohead
Title: Re: Why is it called a trap door?
Post by: JW113 on August 04, 2022, 02:43:38 PM
No, they were trying to nickname it "Blockhead" in the early marketing propaganda. Fail! HD did name it Evolution engine, and the public nicknamed it Evo. Or, at the time (lots of shovelhead riders around then) "Evil".
 :hyst:

-JW
Title: Re: Why is it called a trap door?
Post by: Hossamania on August 04, 2022, 07:05:03 PM
Hear no Evo, see no Evo, ride no Evo.
T-shirts worn by friends that rode Shovels when the Evo came out.
Title: Re: Why is it called a trap door?
Post by: nibroc on August 05, 2022, 06:23:51 AM
 :scoot:

did ya forget "CHOP" and "SCOOT"

 :chop:
Title: Re: Why is it called a trap door?
Post by: IronButt70 on August 05, 2022, 03:47:09 PM
Derby cover comes to mind.
Title: Re: Why is it called a trap door?
Post by: JW113 on August 05, 2022, 03:54:50 PM
And nosecone?

-JW
Title: Re: Why is it called a trap door?
Post by: les on August 05, 2022, 07:16:48 PM
Don't get me wrong, I like the names trap door and derby cover.  In fact, no one I know calls these parts by their real names.

BTW, I still call the cruise drive mainshaft seal the "fifth gear seal".  Probably most everyone else does too.  So funny because we call these parts by their wrong names, but there is not one person out there that does not perfectly understand this invented language.
Title: Re: Why is it called a trap door?
Post by: kd on August 05, 2022, 07:30:49 PM
Quote from: IronButt70 on August 05, 2022, 03:47:09 PMDerby cover comes to mind.

 :up:   A hold-over from tin outer primary covers. About 50 years ago was the last tin and first aluminum outer so it has really stuck.
Title: Re: Why is it called a trap door?
Post by: JW113 on August 05, 2022, 08:43:37 PM
Yeah, that is an interesting one. "Derby" cover? I know what it is, but damn. What derby? Kentucky Derby?
 :SM:

Harley-Davidson... Hate the company, love the product... and the culture!

 :baby:

-JW
Title: Re: Why is it called a trap door?
Post by: Ohio HD on August 05, 2022, 08:50:48 PM
Derby


(https://isteam.wsimg.com/ip/7c9c96eb-abec-11e4-8625-14feb5d9f2e6/ols/61_original/:/rs=w:600,h:600)
Title: Re: Why is it called a trap door?
Post by: wfolarry on August 06, 2022, 05:51:54 AM
'Trap door' didn't come from HD. It's a term used in many industries to describe the access point.
 
Title: Re: Why is it called a trap door?
Post by: les on August 07, 2022, 07:38:46 PM
Quote from: wfolarry on August 06, 2022, 05:51:54 AM'Trap door' didn't come from HD. It's a term used in many industries to describe the access point.
 

Ok, cool.  Thanks!
Title: Re: Why is it called a trap door?
Post by: Dan89flstc on August 08, 2022, 12:04:55 PM
Quote from: JW113 on August 04, 2022, 02:43:38 PMNo, they were trying to nickname it "Blockhead" in the early marketing propaganda.
 :hyst:

-JW

It wasn`t the moco that tried to give the evo the stupid blockhead name, it was a motorcycle magazine writer.
Title: Re: Why is it called a trap door?
Post by: Ohio HD on August 08, 2022, 12:48:33 PM
Quote from: Dan89flstc on August 08, 2022, 12:04:55 PMIt wasn`t the moco that tried to give the evo the stupid blockhead name, it was a motorcycle magazine writer.

No, it was Harley. Here's a 1984 HD T-shirt from Eastgate HD. HD named the bike Blockhead.


Blockhead (https://www.ebay.com/itm/154953017224)


(https://i.ebayimg.com/images/g/MJkAAOSwZ4ViXDxl/s-l1600.jpg)

(https://i.ebayimg.com/images/g/bHkAAOSw2zViXDx1/s-l1600.jpg)

Title: Re: Why is it called a trap door?
Post by: Hossamania on August 08, 2022, 01:02:13 PM
I agree, I thought it was the Moco that was trying to push the Blockhead moniker. It never caught on with the riding crowd
Title: Re: Why is it called a trap door?
Post by: 98fxstc on August 08, 2022, 03:17:14 PM

The name was already used to describe an annoying mate. No wonder it didn't catch on.
Title: Re: Why is it called a trap door?
Post by: Hossamania on August 08, 2022, 03:20:35 PM
Quote from: 98fxstc on August 08, 2022, 03:17:14 PMThe name was already used to describe an annoying mate. No wonder it didn't catch on.

Now that's funny!
Title: Re: Why is it called a trap door?
Post by: Breeze on August 09, 2022, 03:38:33 AM
I remember some magazines attempting to give names to more recent HD engines, Fathead was one attempt with the Twin Cam, Showerhead for the water cooled. Thank goodness neither stuck.
Title: Re: Why is it called a trap door?
Post by: cheech on August 09, 2022, 06:37:14 AM
I vehemently can't stand when people call the Twincam's  Twinkie.  :sick:
Seems to be on a lot of other forums.

Do real men really want to ride around on motorcycles with Twinkie engines?
Title: Re: Why is it called a trap door?
Post by: david lee on August 09, 2022, 02:19:33 PM
Quote from: nibroc on August 05, 2022, 06:23:51 AM:scoot:

did ya forget "CHOP" and "SCOOT"

 :chop:
hacksaw & vespa ?
Title: Re: Why is it called a trap door?
Post by: WhipLash96 on September 02, 2022, 02:46:18 AM
Quote from: Breeze on August 09, 2022, 03:38:33 AMI remember some magazines attempting to give names to more recent HD engines, Fathead was one attempt with the Twin Cam, Showerhead for the water cooled. Thank goodness neither stuck.
Showerhead? :emoGroan:  :hyst:  :hyst:  :hyst:
Title: Re: Why is it called a trap door?
Post by: JW113 on September 02, 2022, 07:12:32 PM
Quote from: cheech on August 09, 2022, 06:37:14 AMDo real men really want to ride around on motorcycles with Twinkie engines?


I think you answered your own question.
 :hyst:

-JW