Author Topic: 70's Triumph Bobbers- How To?  (Read 20033 times)

0 Members and 1 Guest are viewing this topic.

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
70's Triumph Bobbers- How To?
« on: January 07, 2009, 12:09:21 AM »
I've have had my eyes set on the old school triumph, for my next project, and I would like to go for the bobber look. But what is involved with the process? It seems like in order for it to go from factory to the bobber style, one would have to do some fabricating on the frame, or are people just buying another frame to achieve the look???

Here is a Triumph Bonneville Before and After.







Any thoughts on the process??


Thanks JAG
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline Shenanigans

  • At making holes in walls, Im a
  • Master
  • *****
  • Posts: 1,560
  • Right turn?
Re: 70's Triumph Bobbers- How To?
« Reply #1 on: January 07, 2009, 12:13:45 AM »
I hope that was not the VERY same bike  :o


You could always weld on a hard tail, but a new hard tail frame is the way to go. I think they look a lot better.
   This pretty much sums it up.   76' CB592 cafe. 69 750 project, 03 CBR954, 75 750 super sport.

okie

  • Guest
Re: 70's Triumph Bobbers- How To?
« Reply #2 on: January 07, 2009, 04:30:48 AM »
This thread needs to be renamed.  Call it, "How to turn a $10,000 bike into a $4,000 bike in a few easy steps". :'( :'( :'( :o :o :o :o :o :o :o :o :o :o :o

Offline gerhed

  • Master
  • *****
  • Posts: 1,801
Re: 70's Triumph Bobbers- How To?
« Reply #3 on: January 07, 2009, 07:34:28 AM »
On my '67 Triumph 650, the entire rear portion of the frame
--from just in back of the gas tank--can be unbolted.
So, theoretically you can bolt on a hardtail and
later when you realize that what you did was a bad mistake,
you can take it back to stock.
Please don't cut the stock front fender--!
« Last Edit: January 07, 2009, 07:37:01 AM by gerhed »
Rides: 75 CB750F, 48 Indian Chief, 67 Triumph TR6, 63Honda CA95
          83 XL600R in CB360 Frame
          3-wheel electric tilting cycle

Offline nickjtc

  • I was numero dieci
  • Old Timer
  • ******
  • Posts: 4,210
  • Yamaha XT500 'Gromit'
Re: 70's Triumph Bobbers- How To?
« Reply #4 on: January 07, 2009, 08:21:47 AM »
This thread needs to be renamed.  Call it, "How to turn a $10,000 bike into a $4,000 bike in a few easy steps".

What he said, tripled. If the 'donor' bike is complete and in good shape it will be worth waaay more in it's original state.

Find a deserving older (mid 80s) Japanese twin and resurrect it.
Nick J. Member #3247

2008 Triumph Tiger 1050
1977 Suzuki GS750

"That which does not kill us reminds us to wear proper motorcycle clothing...."

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #5 on: January 07, 2009, 09:44:33 PM »
I completely agree that the original state of the Triumph's is the way to go, but I found a lot in some pretty bad conditions, that would make it seemingly more appropriate to alter the state of the original specs. Also, at my price range, it would unpractical for me to invest into going back to factory beauty.

So the answer is, it can be done, but only by completely changin to another frame, aside from the late 60's models? What about the 70's models?

If that IS the case, then I again agree, I should take one and make it back to original specs.

JAG
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline nickjtc

  • I was numero dieci
  • Old Timer
  • ******
  • Posts: 4,210
  • Yamaha XT500 'Gromit'
Re: 70's Triumph Bobbers- How To?
« Reply #6 on: January 07, 2009, 10:28:06 PM »
What about the 70's models?

The '70s models had a redesigned, oil-in-frame, set up. So I would guess that it would not be any easier to do a custom job on one of those.
Nick J. Member #3247

2008 Triumph Tiger 1050
1977 Suzuki GS750

"That which does not kill us reminds us to wear proper motorcycle clothing...."

Offline jreich

  • Enthusiast
  • **
  • Posts: 196
Re: 70's Triumph Bobbers- How To?
« Reply #7 on: January 09, 2009, 07:10:33 PM »
If you want to recreate what might have been considered a bobber, and do it for the least amount of money, it is best to find a decent running bike from the get-go. If you can find one where you know the sludge trap has been cleaned, and ideally, replaced, this in and of itself will save you quite a few bucks. Rebuilding the triumph motor requires quite a few special tools. Not too mention, a few whitworth tools for the earlier '60's models. If you want it to last, and don't know the history of the motor, you really need to have it stripped down and the sludge trap cleaned.

In regard to the hardtail...don't weld to the stock frame. Not only because you (or someone else) may want to put the stock rearend on, but also because quite a few builders feel that welding to cast material isn't the safest. There are quite a few really nice bolt on rear-ends out there now for around $250.

Find a nice unit construction, pre-oif bike and throw on the hardtail and a solo seat, and there ya go.

Cheers
JD


Offline nickjtc

  • I was numero dieci
  • Old Timer
  • ******
  • Posts: 4,210
  • Yamaha XT500 'Gromit'
Re: 70's Triumph Bobbers- How To?
« Reply #8 on: January 09, 2009, 08:26:38 PM »
Here is one from 1965.
Nick J. Member #3247

2008 Triumph Tiger 1050
1977 Suzuki GS750

"That which does not kill us reminds us to wear proper motorcycle clothing...."

Offline jreich

  • Enthusiast
  • **
  • Posts: 196
Re: 70's Triumph Bobbers- How To?
« Reply #9 on: January 09, 2009, 08:32:11 PM »
Here is one from 1965.

That is beautiful...love the ducktail style front fender and using the stock rear end....looks so clean

That must be pre-65 however, as it is a pre-unit engine


Offline nickjtc

  • I was numero dieci
  • Old Timer
  • ******
  • Posts: 4,210
  • Yamaha XT500 'Gromit'
Re: 70's Triumph Bobbers- How To?
« Reply #10 on: January 09, 2009, 08:35:58 PM »
You are right; the bike was featured in a '65 magazine. The front fender 'effect' was created by mounting it back to front.
Nick J. Member #3247

2008 Triumph Tiger 1050
1977 Suzuki GS750

"That which does not kill us reminds us to wear proper motorcycle clothing...."

Offline jreich

  • Enthusiast
  • **
  • Posts: 196
Re: 70's Triumph Bobbers- How To?
« Reply #11 on: January 10, 2009, 06:40:59 AM »
You are right; the bike was featured in a '65 magazine. The front fender 'effect' was created by mounting it back to front.

Oh, I'm with ya now! I appreciate you posting that picture...just a nice clean setup

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: 70's Triumph Bobbers- How To?
« Reply #12 on: January 10, 2009, 09:42:57 AM »
This thread needs to be renamed.  Call it, "How to turn a $10,000 bike into a $4,000 bike in a few easy steps".

What he said, tripled. If the 'donor' bike is complete and in good shape it will be worth waaay more in it's original state.

Find a deserving older (mid 80s) Japanese twin and resurrect it.

The Yamaha XS650 seems to be one of the best choices for a project like this.  Specifically the 78-85 Special models due to the fact that they are readily available.  It is usually frowned on to use an XS1, XS2, TX650, or 74-79 XS Standard model due to rarity of these models.  One guy on the XS650 forum did make a bobber out of a mint 77 Standard and though he did a nice job he did get a degree of guff about it.  The Yamaha 650 twin is a simple, reliable, bullet proof engine that is readily adaptable.  There is a large supply of after market stuff available, stock and custom, for virtually any part on this bike.  The exception would be certain engine parts on the XS1,XS2, and TX.   There is also a hardtail  kit available specifically made to modify the XS frame.  They even have a bit of resemblance to a Triumph.  They have sometimes been described as the best Triumph that Triumph never built. ;D
« Last Edit: January 10, 2009, 11:09:51 AM by srust58 »

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #13 on: January 10, 2009, 03:09:59 PM »
Thanks guys that is some really great info!  I didn't even stop to think about using a Yamaha. I know with going with a Triumph, the parts would probably be more expensive and harder to find. A Yamaha, like you say is more accessible, then maybe I can put one together for a few thousand dollars and make it look great.. Looks like I need to go find some pictures of the XS650, and alter my research criteria a bit to include it in the search.

Thanks again.
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #14 on: January 10, 2009, 03:47:07 PM »


Here's a yamaha I found, not sure if it's the "Special" or not, but it does look almost identical to the triumph, as far as design and engine. I don't like the forward controls, or the exhaust,  but it's a start. :Dmm

I don't know anything about Yamaha's and their power/horsepower, and all that jazz. Guess it's time to do some research ;D  What would be a good price for a decently running xs650 special, but bad on the cosmetics-since all that will change anyways?

Winter time sucks because ya can't ride, but I do love winter time cause it allows me to tinker around and start other projects!!
« Last Edit: January 10, 2009, 03:49:04 PM by JAG »
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: 70's Triumph Bobbers- How To?
« Reply #15 on: January 10, 2009, 03:54:44 PM »
A few good places to start your research:

http://www.650central.com
http://www.mikesxs.net
http://xs650temp.proboards29.com/index.cgi
http://xs650.org.au       An Australian site and one of my favorites

Have fun.  Around here an excellent running/looking 650 Special will run $900-1200.  One not running or in poor cosmetic shape under $500.  Among the Special model years the 78-79 are the same and the 80-85 are similar.  The early two years have disc brakes front and rear, points ignition,  38mm Mikuni cv carbs.  The later years had electronic ignition, rear drum brake, and 34mm Mikuni cv carbs.  If you like the classic look of spoked wheels look for a Special II or Heritage Special.   So you have some choice here too.  The 77-85 years had a little better fork than the earlier years.. The Special had a smaller sleeker gas tank so that may be a better fit than the Standard tank.  Once modified it can be hard to say what that bike was as many of the differences between Standard and Special where cosmetic.  I think it was around 52hp but like I said earlier this engine lends itself to a lot of modification.
« Last Edit: January 10, 2009, 05:51:18 PM by srust58 »

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #16 on: January 10, 2009, 05:45:28 PM »
A few good places to start your research:

http://www.650central.com
http://www.mikesxs.net
http://xs650temp.proboards29.com/index.cgi
http://xs650.org.au       An Australian site and one of my favorites

Have fun.  Around here an excellent running/looking 650 Special will run $900-1200.  One not running or in poor cosmetic shape under $500.  Among the Special model years the 78-79 are the same and the 80-85 are similar.  The early two years have disc brakes front and rear, points ignition,  38mm Mikuni cv carbs.  The later years had electronic ignition, rear drum brake, and 34mm Mikuni cv carbs.  If you like the classic look of spoked wheels look for a Special II or Heritage Special.   So you have some choice here too.  There is quite a lot of parts interchangeability between all years 1970-1985. The 77-85 years had a little better fork too. The Special had a smaller sleeker gas tank so that may be a better fit than the Standard tank.  Once modified it can be hard to say what that bike was as many of the differences between Standard and Special where cosmetic.


Thanks so much! Great Info.. That'll get me on the ground running!!  ;)
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline Soos

  • Just a butcher with a carbide hatchet, definitely not a
  • Master
  • *****
  • Posts: 2,324
Re: 70's Triumph Bobbers- How To?
« Reply #17 on: January 10, 2009, 06:00:37 PM »
I always thought a "bobber" was simply a bike you stripped EVERYTHING not needed to run off it to make it lighter, therefore accelerate quicker, and possibly higher top speed.

http://en.wikipedia.org/wiki/Bobber_(motorcycle)




l8r
-=≡ Soos ≡=-
Just think to yourself what would Alowishus Devander Abercrombie do?
"Brix will be shat by your neighbors." - schwebel
(61mm)652cc 1979 cb650

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #18 on: January 10, 2009, 06:37:14 PM »
I always thought a "bobber" was simply a bike you stripped EVERYTHING not needed to run off it to make it lighter, therefore accelerate quicker, and possibly higher top speed.

http://en.wikipedia.org/wiki/Bobber_(motorcycle)




l8r

I agree completely. And a chopper is usually designated by it's long front forks and what not.
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: 70's Triumph Bobbers- How To?
« Reply #19 on: January 11, 2009, 11:16:27 AM »
One thing to keep in mind is when I see XS650 Specials on ebay or graigslist  they are sometimes misidentified as to model year.  I don't think this is for any nefarious reason as one year is not any better or worse than another.  To many they all look alike but there are obvious visual clues to help tell them apart.  For your purpose it may not matter what year unless you want a specific feature that one year has over another.

fuzzybutt

  • Guest
Re: 70's Triumph Bobbers- How To?
« Reply #20 on: January 12, 2009, 09:19:17 AM »
the xs650 is the best motorcycle triumph never built i've heard.

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: 70's Triumph Bobbers- How To?
« Reply #21 on: January 12, 2009, 06:17:23 PM »
Sweet.
  Has the XS Special rims and the front and rear disc brakes of the 78-79 model year. 

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #22 on: January 12, 2009, 07:54:35 PM »
I like the way that one looks srust58. Simple yet effective. Are those the stock forks?

I found a website (www.650motorcycles.com) with literally thousands of pictures, and I'm getting a lot of good ideas. I'm having a difficult time trying to find anyone with their builds/projects in any detail. I'd like to know what kind of things I am getting myself into; re-wiring, engine rebuilding, what kind of frame to get, or to cut it in half and weld a hardtail, mounting battery, what kind of tank to use, foward controls, etc., etc.

I really like the more simpler ones. No long forks, or big fat rear tires. Although some of them that I have found, actually doesn't look bad with the big tire. I suppose after building my honda, it seems like there are a lot more options with this build. It's all down to personal preference and style.

Jonathan
« Last Edit: January 12, 2009, 08:00:08 PM by JAG »
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline JAG

  • Expert
  • ****
  • Posts: 907
  • '74 CB750K, '72 CB500, '76 550K
Re: 70's Triumph Bobbers- How To?
« Reply #23 on: January 12, 2009, 07:57:40 PM »
Oh, and what the heck is a rephased engine? Is that another way of saying it's been bored or something??
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures. I am a Cafe Racer myself, on some days - and it is one of my finest addictions. ~H. S. Thompson~

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: 70's Triumph Bobbers- How To?
« Reply #24 on: January 12, 2009, 09:52:04 PM »
Jag
This may not be 100% accurate but I think it's pretty close.  The XS650 has what is known as a 360 degree crankshaft.  The pistons rise and fall in unison.  The crankshaft can be modified to make the right cylinder lead the left by 90 degrees giving a 270 degree firing interval.  This reduces vibration substantially.  It requires an extra crankshaft as a donor.  The #3 flywheel is removed and replaced by the #2 flywheel  from the donor.  It also requires modification to the ignition and cam.   There is an explanation on the Australian site under the tech menu giving more detail.  The engine can also be rephased at 83 degrees with a 277 degree firing interval.  I think the stock crankshaft can be used for this but it is not as effective as the 90 degree mod.  I would assume the cam and ignition would still need to be modified but this approach may be easier for the DIY'er and still reduce vibration over the stock engine.

If you have not already checked the XS650 forum http://xstemp.proboards29.com/index.cgi  has some extensive build threads with many photos under the project heading.  Those do look like stock forks with Brit style boots.  The rotors and calipers are also stock though they look to be polished as they are normally black. 
« Last Edit: January 12, 2009, 10:38:55 PM by srust58 »