850T fork tube for ambassador/eldorado

[harrytief]

I am converting my drum brake eldo to disc and have on hand an 850T front end. I want to save the eldo for tube if ever I want the bike back to stock so I will use the 850T tubes. Do I need to alter the length of the T fork tube? I have not dismantled the eldo forks yet...what is the eldo fork tube length? Should I cut down the short extension at the top of the T tubes to allow the eldo fork caps to catch the T tube thread sooner? Has any tried to machine a taper into the T fork tops to match the eldo top T-clamp and keep both forks parallel and perpendicular to the T-clamp? What are the problems?
Any wisdom is of much value.
Harry

[rodekyll]

I got nuttin.

But if you have a complete T front end, why not investigate using it in toto -- just changing neck bearings or adding a spacer for post height might be enough to modernize.  There could also be some UJM trees and forks that could get you modernized for less hassle.  I'm looking to replace my front end entirely as soon as a donor presents itself.  Once you're done with what OEM provided, you can go any direction you want.  IIRC, Greg Field has some fancy big-4 front suspension on his eldo.  He spanks the WA crew with it regularly.

I don't know.  Just spitballing. 

[Idontwantapickle]

There are tubes for the disk brake on a loop. They are tapered to fit upper tree plate on a loop and the lower is machined for a cartridge type leg like the one on the 850-T.
If you change out the whole tree it would be cheaper maybe as you could use the tubes you have, but the change in width might be too narrow for the Loop front fender.  And the shrouds would probably not work either. The bearings are the same on a loop and a tonti frame for the steering head.
Hunter

[Hahnda]

Lots of info here-

http://www.thisoldtractor.com/moto_guzzi_loopframe_disc_brake_installation_on_a_non-disc_brake_loop.html

[canuck750]

I converted my Eldorado 2LS drum to a pair of discs, you can get new tubes from MG Cycle

http://www.mgcycle.com/index.php?main_page=product_info&cPath=197_199&products_id=276

I went for new Brembo calipers and the EBC floater discs plus I added progressive springs and FAC dampers. It takes some lathe work to modify the dampers and fork top tube nuts. MG also supplied the master cylinder and the brake line fittings and hoses. It ain't cheap but is transforms the bikes ride and stopping. By the time you get the right front fender (you can modify a drum brake fender as well) and the deeper fork shrouds I had dropped $1700.00.

[Antietam Classic Cycle]

I converted my Eldorado 2LS drum to a pair of discs, you can get new tubes from MG Cycle

http://www.mgcycle.com/index.php?main_page=product_info&cPath=197_199&products_id=276

For $10 more each, the "Italian" fork tubes are much better quality.
http://www.mgcycle.com/index.php?main_page=product_info&cPath=197_199&products_id=4556

[harrytief]

I've had GREAT success converting my cx100's to USD forks from GSXR's. The process got me outstanding suspension and great brakes and a pair of bikes that get milk and honey each bedtime. They are not going anywhere. As full disclosure, I have a GSXR front end on the bench now that I prepped to install on the eldo. I am having second thoughts as I am not going to ride the eldo like I do the cx100's and I want a more authentic look for that bike. I still want good (to great) brakes and suspension but now the eldo look as well. I have a number of tonti forks on hand from prior experiments and hoped to use a good set of 850T tubes along with FAC cartridges as GB describes or...a set of cartridges I have from a CBR600 that may be made to fit.
I am uncertain as to which tubes to choose...the 850T's or the disc type eldo tubes from MG cycle.
Thanks for the help so far guys!
Has anyone tried adapting the aftermarket fork cartridge kits to tonti forks?
Harry

[rodekyll]

Harry -- what is involved with adapting the gsxr front end to the tonti?

[harrytief]

Hey RK
I hope you are enjoying your time on the road.
Attaching a gsxr fork to a tonti frame was surprisingly easy and the results very gratifying. Later model (2006 and up) showa forks are world class and and you get radial brakes to boot. I added 13.25 inch ohlins at the back end and the griso I wanted to buy can't find room in the garage. The engine, frame , and suspension resonance that I got from this combination is quite satisfying to ride. An Ohlins steering damper ensures stability at any speed but the bike is agile in the city.
The only downside is that the reduced fork offset causes the fork tubes to slam the gas tank at full lock. You need to fashion your own steering stops.
I did a write up for the archives that included listing steering head bearings that allowed you to use the gsxr steering stem and triple trees.
Let me know if you find it.
Harry