Lurker's V-twin build

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cobrafreak

New Member
Feb 16, 2011
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sacramento ca
A real honest to God Board Track racer of the day that was campaigned by the factories was running around 100 mph with 4 to 8hp. If you get the right tires and do it just once and get it on video you will be immortal! Lol. It would be really cool to make something so tight that it would safely perform to the 100mph bar. Bicycle tires are totally out of the question. You would need the real Coker Tire Co. replicas on replica rims. The tires are going to be the weak point of the chain. It's a shame that as far as I know no factory makes a skinny modern motorcycle tire. I wish someone here on the forum was a Grandson of the owner of Coker tire and convinced Granddad to make modern technology skinny tires for the resto builders like Us. I am working on a V-twin build in my mind to do in the future. I need to invest some funds in new equipment so I can go in different directions.
 

rustycase

Gutter Rider
May 26, 2011
2,746
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Left coast
That's a good idea, GN.
Price is actually NOT too bad for a 'real' tire, and the 'H' speed rating is good for 130mph. That might do it!
rc
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
Cool GN....it may not be a modern looking tyre, but if you could afford it you could have a nice shiny white cokers on a wheelset for shows and have another set of wheels with similar tyres to these for riding.

Do you have any idea what motorbike would have a 26 rim or what purpose this tyre would have? Besides us of course.......Im certainly no expert but i hadnt heard of a bike with 26" wheels/tyres.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
It all started out with the custom Harley chopper craze that went *poof* dead a few years ago. The trend has now switched over to baggers instead of choppers.
Now instead of having a 14" wide rear tire as the choppers went towards, folks want 23" or 26" front wheels on their baggers. The Metric crowd is now following the big front wheel trend as well.

Edit: my Atlas has 26" rims, although they are nowhere near as wide or as heavy duty to accommodate a 26" motorcycle tire. I seriously doubt that the motorcycle tire's beads would fit into the bicycle rim, let alone have enough room for an innertube in there as well.
 
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Lurker

New Member
Jan 29, 2010
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Pittsburgh
I finished the chain stays last night. However I miscalculated the angle of the seat tube and chain stay so the bike is currently about 2.5 inches to tall, but that can be fixed with my trusty angle grinder. I'm becoming an artist with that thing. Here are some progress pics and like I said please ignore the current height of the bike.

My main goal with this bike is to make a really cool bike to ride every day. I will be getting it registered and all that jazz. As for the tires and rim I am defiantly leaning toward Coker. I still really need to sell my other bike to fund this one; but I am finding it hard to part with. Maybe once I see some serious progress it will get easier muster up the courage to get rid of it.
 

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harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
Cool man. Looking really nice. Interesting rear setup you have going there. Is that because of the lack of a barbender? I would ask if that is strong enough but im sure you have that thought out. Looking good.

Thats crazy to me that you could register this thing. sometimes i really wish i lived in the States
 

Lurker

New Member
Jan 29, 2010
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Pittsburgh
Yes and no harry76. Since I don't have a bender I had to design something that would be strong and attractive. It will also allow for maximum chain clearance and gives visual weight to the rear half of the bike. I plan on running a very small sprocket up front and didn't want to run into the same chain clearance issues that I had on my last bike. This type of joint it very strong, its the same type use for bicycle dropouts.
 

Dan

Staff
May 25, 2008
12,765
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Moosylvania
Really enjoying this thread. Lots of cool an' learning.

Lurker, I was looking at a bender at Harbor freight and almost bought one then realized I could make one for my much more simple need for one out of a car-jack. Given your talents, bet you could come up with an awesome one. Just a thought.


Dunno or have yet to really contemplate it but am sure some sort of jig could be made cheaply.

Dang it! Now am wondering where a bottle jack I got at a yard sale is.
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
Yeah Dan, ive wondered that myself when i looked at my brothers bender.... but just a question...... All your tools over in the States are so much cheaper then here (Australia), would it be worth the effort? How much are they at harbour freight? I think we can get them here for around $250. So id guess you guys get them for around $100-$150
 

Dan

Staff
May 25, 2008
12,765
115
48
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Moosylvania
Yeah Dan, ive wondered that myself when i looked at my brothers bender.... but just a question...... All your tools over in the States are so much cheaper then here (Australia), would it be worth the effort? How much are they at harbour freight? I think we can get them here for around $250. So id guess you guys get them for around $100-$150
Just as soon as I posted that, I wondered. I still don't get why Chinese tools and parts are cheaper here in the U.S. then for you guys. The ships have to sail past ya. Think they could make a quick stop or some thing. (lol, yes, larger market and all that)

But yes, around that. Search results for: 'bender'

But really, I think it can be done so much more cheaply with some tools and umph.


Sorry about the off topic. You had mentioned not having a bender and I got lost in thought.

Really enjoying your build!

auflg
 
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wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
Cool GN....it may not be a modern looking tyre, but if you could afford it you could have a nice shiny white cokers on a wheelset for shows and have another set of wheels with similar tyres to these for riding.

Do you have any idea what motorbike would have a 26 rim or what purpose this tyre would have? Besides us of course.......Im certainly no expert but i hadnt heard of a bike with 26" wheels/tyres.
How about replacement tires for the Simplex? They were 26", narrow and way heavier than bicycle tires.
 
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wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
I just checked Coker. They have some for Simplex, 2.50 x 26"s for 119 bux. Those and some Workman wheels would be an excellent upgrade for any MB, especialy the heavier 4 stroke DIY builds.
 

agk

New Member
Oct 2, 2010
151
4
0
Santa Barbara CA
My friend has the Habor Freight bender that utilizes the bottle jack. You don't get a clean bend. It just wrinkles the tubing.

I have the upright Harbor Freight bender that comes with different size dies. That bender just wrinkles the tubing too. It works well for bending round bar or flat stock. Useless for bending tubing.

Another friend of mine has this style bender...
Bender Comparison
This style bender will actually make a clean bend in the tubing. The bending dies come in different sizes for different size tubing. There is a chart that tells you what the wall thickness needs to be to bend a specific radius. This is the friend that does all my tube bending.

Just as soon as I posted that, I wondered. I still don't get why Chinese tools and parts are cheaper here in the U.S. then for you guys. The ships have to sail past ya. Think they could make a quick stop or some thing. (lol, yes, larger market and all that)

But yes, around that. Search results for: 'bender'

But really, I think it can be done so much more cheaply with some tools and umph.


Sorry about the off topic. You had mentioned not having a bender and I got lost in thought.

Really enjoying your build!

auflg
 

cobrafreak

New Member
Feb 16, 2011
1,049
9
0
sacramento ca
The Harbor Freight pipe bender is $99 and with the 20% off coupon it will be about $80. If you can do a better job with the bender get it. Curved smooth flowing bends look great on a frame.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
Remember, pipe benders are different than tubing benders.
Pipe is measured by the inside diameter.
Tubing is measured by the outside diameter.
The dies are shaped differently (width and depth of channel) to properly accommodate the size of the tube or pipe being bent.

Get it wrong and you will end up with wrinkles, dimples or kinks.
 

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
An old trick for bending tubing with less chance of kinking, is to pack it tightly with fine sand and plugs or caps on the ends. Than use a bender of your choice. I used this method on some 1 1/8 chromoly once.


I was at a machine shop once where they were making very tight bends in stainless tubing by pressurizing it with hydraulic oil at 10,000 psi then bending it.
 

tomgndallas

New Member
Sep 19, 2010
132
0
0
Dallas, TX
My friend has the Habor Freight bender that utilizes the bottle jack. You don't get a clean bend. It just wrinkles the tubing.

I have the upright Harbor Freight bender that comes with different size dies. That bender just wrinkles the tubing too. It works well for bending round bar or flat stock. Useless for bending tubing.

Another friend of mine has this style bender...
Bender Comparison
This style bender will actually make a clean bend in the tubing. The bending dies come in different sizes for different size tubing. There is a chart that tells you what the wall thickness needs to be to bend a specific radius. This is the friend that does all my tube bending.
Not sure if that link is broken or what I cannot seem to open it. I had been thinking of getting a roller or bender myself. Looking further down the thread I am curious how the HF tools would work if the tube were packed with sand. Also, any need to heat the metal? If you look on HF now they have a video for that wheel roller. When the guy shows you the copper tube, of course they use copper which is very soft, the bend looks flat to me....I started laughing when I saw it....

Tubing Roller
 

agk

New Member
Oct 2, 2010
151
4
0
Santa Barbara CA
Not sure if that link is broken or what I cannot seem to open it. I had been thinking of getting a roller or bender myself. Looking further down the thread I am curious how the HF tools would work if the tube were packed with sand. Also, any need to heat the metal? If you look on HF now they have a video for that wheel roller. When the guy shows you the copper tube, of course they use copper which is very soft, the bend looks flat to me....I started laughing when I saw it....

Tubing Roller
We use 1/16" wall thickness for exhaust and up to 1/8" for go kart chassis stuff. The HF tube bender/pipe bender does not work for this application. We tried packing the tube with sand and heating the tube. That was a long time ago and we simply didn't know much about tube bending.

Now we use a real tube bender and get nice clean bends. We have an assortment of bending dies to choose from for different size tubing and different radiuses. We follow the manufacturers recommendation for wall thickness that should be used with each die. The result is a precise bend.

It's been several years since I've priced compact tube benders. About $2500 for a hydraulic bender with a stand and some dies. Not cheap like the HF bender, but a necessity for us. They have more affordable bench top manual benders too.

Bender Comparison