Bonneville America Forums Forums Technical Forums Custom Corner How difficult would it be to make a TBA Chopper?

I watched the biker build off the other night and Rick's team received their forks in a box in the mail. Could a TBa be fitted with true chopper forks? or would the frame need to be changed to accomodate the radically increased rake? Would it lose all of its handling capabilities and just be able to go straight and look good like most choppers??

it could be done. anything can be done, just matters how much money time and work you want to put in. i imagine it would kill its handeling though.

Frank

There was a shop in FLA that was making hard-tail custom Triumphs with our new motors. They looked much better than the Fairless bike and probably ran stronger to boot. They were selling them for around $20k. They used to post on the old list but haven't seen anything from them in a while. (can't remember the shop name!)

If your talking about putting a springger front end on our frame the right length and geomitry could be figured out. But the ride of a springger front end will never be as plush as a teloscopick fork set up.

it was the little chopper shop

Little Chopper Shop
Uh,oh. Maybe they went @it's-up, the link is dead.

Quote:

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They looked much better than the Fairless bike and probably ran stronger to boot.

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Probably? Holy crap, when did you ride your last 650 vertical twin? I'm glad I have an 03 America to go fast on when I'm done putting around on my '72 Tiger, there is no comparison. Looking cool is fun, but getting out of Dodge quick just might be funner.

Well I'm sure that big fat rear tire adds valuable HP! Dispappointing they didn't go with a classic skinny rear.

Little Chopper Shop picture at a south Florida bike show.
NewBonnevilleChopper
And another: PalmBeachBikeShow

Dennis

I have looked into this as well. Your best off getting a new frame than using the stock BA frame. It would be cheaper in the long run. The neck is cast on the BA's and it would be more time consuming in the long run. The neck is different as well. I actually talked to Ozzie at QPD who makes springer front end's for Triumphs. He can do it for the BA. The cost would be between $1700-$2000 for a Front-end. He makes well-engineered old school springers. I imagined if you wanted an American Engineering Front-end like the one Rick Fairless used I would say it would cost you between $2500-$4000. Their front-ends are awesome.


Fryguy

I've got some pictures of some TBA/SM choppers in Cool Triumphs gallery.

I doubt it would be all that hard. If uou are working with a tight budget, drop your frontend and measure the fork strm very carefully, then go shopping at the bike swapmeets. There are 2 sorts of factory HD springers readily available for the 45 and big twin, and 2 sizes and 3 styles Indian Girders for the Scout and Chief that are not so plentiful, but you see them once in a while. There is a decent chance one of these may fit without too much trouble. Avoid the Indian forks with the 1/4 eliptical spring, those would be hard to adapt and put wierd stresses on a frame that isn't designed for it.
If you find something with a stem that is the right length but a different diameter, check with your local equivalent of the Breaing Mart. They may have a bearing set that will make up the difference.
Another thing worth considering, the stock forks with the shrouds removed and the gaters from newspeedmaster.com have a destinctively late 40's Triumph look.

Cool, I'd never seen the Street Chopper bike. Any word on where it ended up?
The Bruiser also always brings a smile to my face. Probably the easiest and most cost effective way to a Hinckley chopper.

Anyone remember what the Little Chopper Shop was asking for their bikes?

I really am digging on those bikes by the Little Chopper Shop

Hi Jack,
Boy, I bet that greeting will raise some eyebrows in the national security circles.
I can't stand my own fat rear tire. My last replacement was with a size smaller which made my BA handle a lot better in the twisties. I am following "piper" with getting a larger front tire soon. He did it to get whitewalls I think, but I want it for handling. I am a flattracker at heart, but love the way I sit in my BA. That's a trade off, I know but all my old well handling bikes had equal or near equal size tires. Most winning flat trackers actually have larger front tires.
What am I talking about? I am 51 years old and thinking about draggin a knee!!!
I guess the fatter back tire lifts the rear of the bike up enough in a corner to enable you to turn your head to watch the sparks flying off your bike. A fatter rear tire surely will not last any longer. I hated throwing away my rear tire with 50,000 miles of tread left on the sides.
Dennis

I've never ridden a 650 vertical twin. I understand they're around 40 horses. That "jack drive" that Fairless installed to handle the huge rear tire cost 10 horses. Do the math, that bike had to be a bit sluggish.
The new 790cc power plant in a hardtail frame (3.5" stretch, standard rake)with a standard length springer front end (low profile with a tight front end)would be ideal.... I'll let you know when I'm done.
www.bruisercustomcycle.com

Case:
If anyone could tempt me to chop my bike, you are the guy! Can't wait to see your efforts in a rigid frame.

Boy, it would be fun to pick that up and finish! Maybe it will resurface some day.

The thing that disappoints me the most about that project not being finished is its potential for easy duplication. They built it around the stock frame without changing the driveline configuration or geometry at all and they preserved the stock frame's feature of unbolting from the engine section (for maintenance, I gather). They all but could've made a kit out of it that only required one weld - where the stretched front frame section attaches to the stock spine, just in front of the seat pan. What a shame that won't be available, at least for the foreseeable future.

That would be a cool biker buildoff project. Take a stock america or speedy and in 10 days strip it down, throw that chopper "kit" on it, fab up the tank, fenders and pipes, and maybe throw a boostisgood turbo system on it. That would be bada$$.

That does sound interesting. I'm not familiar with that magazine and missed it completely. I'll have to dig around some swap meets. What year were the issues out? I assume they covered the build monthly?

Coverage was sporatic. I'll have to dig through my collection, but I only bought the mag when there was something Triumph-related in it. I'm pretty sure they started the project back in '02.

Gotcha. I'd love to see what you have. I'll be up to the various Carlisle PA swap meets a few times this year and will keep my eye open for copies.

I wonder if getting taller shocks that would raise the back end 1" would help in the handling department? I went to the Metzler 880 on the front which is a taller tire than the stock ME33 on the Speedmaster. I thought maybe raising the back end might help in the twisties.

As far as a chopper goes, I would think going to a local frame builder would be the best route. At the least just picking their brains for ideas would be a benefit even if you didn't end up getting a frame built from them.

One of the benefits that is coming out of the AMA Grand National flat track bike that Bill Gately of Bonneville Performance built to race, is that sometime in the near future you'll be able to get a flat track frame, or a complete street tracker build, for our engines. No word yet on when this is going to be on the market.

I leaarned this from his post on the Delphi Cafe Ace forum where he posts from time to time.:

"The street tracker plan is in motion just waiting on the build for the mile bike before getting into the finances necessary to prototype a street version. This bike will also be a frame up build with a 989 stroker but your choice on a 270 or 360 crank."

Mecatwin in France does a great looking street tracker, but they won't sell the parts and ship them here. Mule Motorcycles did a street tracker for Triumph that's been touring the industry bike shows.

Of course all of the above costs a bunch of money, but I can dream.

Long story? You just going to tease me with that?

Yep.

i believe they can get the proper rake and trail with the tree's these days. i am told(and you know how that is) that they have figured a way to tip the trees in the stock yoke to get the rake look without any mods. i havnt looked close at any since i was told that so, i aint positive but i am gonna start lookin now.hahahaha And trust me here cuz i know this...that fat rear tire in a ridgid is a good thing, i had a couple hard tail chop's yrs ago when we used stock tires and that hurt, i rode a chop with a 250 rear that they run a little lower psi and the ride wasnt that bad. it wasnt a good ride by any stretch but it was better than that skinny little tire i had back then. the skinnier tire handled better i think, but the fat tire was easier on the back side.

FYI: I just started a new thread with a list of the issues (that I am aware of) of Street Chopper magazine that have something on the TBA Chopper project. I included a brief description of what was going on in each issue and even found a link for one of them.

http://www.bonnevilleamerica.com/forums/...mp;page=0#14401

I had a '61 Sportster in a rigid frame, skinny rear tire - that ride was punishing! They say these big tire choppers do offer some compliance, guess it makes sense.

You have to be careful with the trees on a stock Bike. A lot of custom guys use the rake trees to bring in the trail to an acceptable measure after they cut and stretch the neck, downtubes, etc. It you put raked trees on a stock neck you will offset the trail to unsafe levels if you go too far of a rake. Just be careful with the raked tree setup is all I am saying.

I know Bob Scogins has gone over the Springer front issue a few times here on the boards. He tried a few springers before realizing that it would take a custom made springer to fit. I think he ended up going with a stock Harley narrow glide front-end that he customized to fit.(correct me if I am wrong, Bob, if you are still lurking.


Fryguy

While searching in the old archives(what a great resource!), I came across this:

QPD, who makes the belt drive conversions, also has custom springer front ends listed. Hmmm, I wonder if they could adapt one?

Here's Bob Scogins reply in that same thread:

"The springer looks great for sure, but make sure the fabricator/ supplier has properly fitted and tested it on a BA. I tried fitting a Paughco Harley stock style springer to my 2002 BA and there were several issues that made it impractical. Tank clearance is an issue. The springer has no offset in the triple trees as it gets it’s trail from the axle being mounted forward in the rockers. This puts the legs extremely close to the tank and can reduce the fork turning angle considerably. If not done by the fabricator, you’ll need to work out fork stops and adapt the front wheel, speedo drive, and brakes. I’m not trying to disuade anyone from going the springer route. Just make sure what you get is a turn key / bolt on installation and not just an adaptation of neck bearings on a "universal" springer to get it to fit the BA frame."

FWIW, also came across a post by Bob saying it was a Sportster front end that he put on his salvaged America.

Sal, QPD is Bob 'Ozzie' Oswalt. I stopped by his shop last fall in regards to building me a Springer front end for my BA. He can do and the cost is between $1500-$2000. If anybody is interested I would recommend contacting him directly through the QPD website. He does lurk on this board at times. He would need the bike on-site to build as well.


Fryguy

As an old friend if mine once said, "With enough gas for the torch and enough cash in the pocket, you can do anything."

You hit that nail on the head!!!