Author Topic: Drag Bike / The Big 4 Express.  (Read 66427 times)

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Online Don R

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Drag Bike / The Big 4 Express.
« on: December 06, 2013, 12:49:13 PM »
I thought I'd show a couple pictures of the drag bike as it gets straightened up. 

 Edit- I replaced a few of the pics to get rid of photobuckets watermark on my photos.
« Last Edit: February 15, 2023, 09:59:45 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
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Online Don R

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Re: Drag Bike resto
« Reply #1 on: December 06, 2013, 12:59:31 PM »
So far I've rebuilt the handlebar mounted equipment and replaced the small bits that were robbed as it sat in the back of a bike shop. More pictures to come as I find time.
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Offline dusterdude

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Re: Drag Bike resto
« Reply #2 on: December 06, 2013, 03:11:07 PM »
Cool


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Online Don R

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Re: Drag Bike resto
« Reply #3 on: December 06, 2013, 07:42:38 PM »
This F tank makes it look road racey. I could use it and move the seat back a little!
« Last Edit: February 23, 2022, 08:13:57 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
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 You don't need a weatherman to know which way the wind blows.

Offline Stev-o

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Re: Drag Bike resto
« Reply #4 on: December 06, 2013, 07:51:21 PM »
Cool project Don...subscribed. 
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Tews19

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Re: Drag Bike resto
« Reply #5 on: December 06, 2013, 08:23:53 PM »
Diggin the F tank look! Slap on a Daytona seat and call it a day!
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Offline Retro Rocket

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Re: Drag Bike resto
« Reply #6 on: December 06, 2013, 09:07:56 PM »
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Greggo

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Re: Drag Bike resto
« Reply #7 on: December 07, 2013, 07:46:14 AM »
I love those magnetos on a purpose built bike.  Sweet project Don!

Offline BPellerine

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Re: Drag Bike resto
« Reply #8 on: December 07, 2013, 11:52:52 AM »
on the mag thing Don saw a photo of a shovel hd with TWO morris mags on it one for each cyl kick only and run on the street so one should be easy peasy .haha cycleboyz in Canada built it bikes name is Lucille if you google it.bill
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Online Don R

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Re: Drag Bike resto
« Reply #9 on: December 07, 2013, 11:20:09 PM »
The old fender, it flops around and is dented up pretty bad.
« Last Edit: February 23, 2022, 08:15:22 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #10 on: December 07, 2013, 11:22:25 PM »
 Structure cut from junky fender.
  The light's mounted a little high but it needed to cover the welds and the holes in  the fender.
« Last Edit: February 23, 2022, 08:22:53 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline dragracer

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Re: Drag Bike resto
« Reply #11 on: December 08, 2013, 01:56:46 AM »
Looking good Don. One question about the fender location, I noticed in one of  your posts that mentioned using the 16" wheel off another bike temporarily. Can i assume you made allowances for it to clear the 18" tire??

Online Don R

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Re: Drag Bike resto
« Reply #12 on: December 08, 2013, 09:03:56 AM »
Yes, the fender is in the same location as the old one which worked with the 18". I haven't measured but the 16"  is very close to the same height as the 18". The bar stock struts have their charm but a set of tig welded moly struts may take their place.

I'm looking at making a removable chrome moly frame kit to replace the hacked two lower rails. Something simple. I was going to telescope it into the rear frame but paint would foil that plan.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #13 on: December 28, 2013, 12:41:46 PM »
I was checking out  vintage drag bikes on facebook and they posted the pic of my dragbike. I also found a picture of a twin cam bike with the wheelie bar brackets I deduced must have been used on my bike. I'm not sure how to move the pic to here but I saved it for reference. Now off to the batshop to look for T6 plate to saw them from.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Greg H

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Re: Drag Bike resto
« Reply #14 on: December 28, 2013, 02:58:28 PM »
Cool project this . You're restoration of a vintage drag bike , which it has to be said is a much more sensible way of doing things than doing what I'm doing, which is  building one from scratch, has provided me with a certain amount of inspiration .One thing in particular that I've decided on after looking at your bike, is to go with a mag for that truly authentic period engine look . Regards Greg "H".
p.s I'm with you on scraping the ally struts in favour of a pair of tig-welded tubular ones  8).

Offline Stev-o

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Re: Drag Bike resto
« Reply #15 on: December 28, 2013, 07:55:19 PM »
I was checking out  vintage drag bikes on facebook and they posted the pic of my dragbike. I'm not sure how to move the pic to here but I saved it for reference.

Save it to your computer. Then upload to Photobucket.com and copy and paste to your post. 
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Online Don R

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Re: Drag Bike resto
« Reply #16 on: December 29, 2013, 01:22:50 PM »


Similar wheelie bar brackets, I hadn't considered the slot where the footpeg is. That will allow chain adjustment and help locate the axle too. My axle protrudes through the swingarm about 3/4" on both sides and is threaded on both ends. I'm still looking for nuts that match the threads. They appear to be 18 tpi and close to 5/8 but also could be metric.
« Last Edit: December 29, 2013, 01:27:16 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #17 on: December 29, 2013, 01:31:15 PM »
Cool project this . You're restoration of a vintage drag bike , which it has to be said is a much more sensible way of doing things than doing what I'm doing, which is  building one from scratch, has provided me with a certain amount of inspiration .One thing in particular that I've decided on after looking at your bike, is to go with a mag for that truly authentic period engine look . Regards Greg "H".
p.s I'm with you on scraping the ally struts in favour of a pair of tig-welded tubular ones  8).
Maybe we can inspire each other to build a pair of cool dragbikes. The PO said mine ran within .02 of a national record in whatever class it ran at that time.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #18 on: December 30, 2013, 09:47:52 PM »
I made the wheelie bar brackets from T6 1/4" plate. Similar to the picture above but I angled the rear of the legs back and made the lower one longer and a slightly different angle. Gives them an art deco look. Pictures when I get back to the shop.
« Last Edit: January 01, 2014, 07:17:31 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #19 on: January 06, 2014, 03:54:27 PM »
Well, I have the alleged 1180cc engine on a table and I'm gathering the courage to split the cases. I think I'll pull the head and cylinder too to check the bore and stroke and have a look at the condition of things. Pictures as it comes apart.
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 You don't need a weatherman to know which way the wind blows.

Offline BPellerine

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Re: Drag Bike resto
« Reply #20 on: January 06, 2014, 05:01:10 PM »
should be interesting !bill
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Re: Drag Bike resto
« Reply #21 on: January 06, 2014, 07:32:13 PM »
I'm glad I pulled the head. The nickel washers were puckered and there was a wayward o ring under the copper head gasket. I'll check to see if it warped anything. It appears to be approx 72mm bore x 69mm stroke.
« Last Edit: January 06, 2014, 08:08:07 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #22 on: January 06, 2014, 08:07:19 PM »


« Last Edit: January 06, 2014, 08:09:08 PM by Don R »
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #23 on: January 06, 2014, 09:09:17 PM »
 I'm surprised the port ceiling is raised so high. I read there was a formula in the days when this was built that called for raising the port to make a straighter shot to the valve.
 I would think that would hurt velocity but I'm an amateur porter. The 5 hp briggs flathead was my speciality.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Online Don R

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Re: Drag Bike resto
« Reply #24 on: January 08, 2014, 01:33:23 PM »


No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.