TA to AT conversion

[ladder106]

Greetings All,

I've been neglecting most of my responsibilities for the past week to work on converting my 90 Transalp to RD04 specs.

The body work is finished and suspension work about to begin (after more bits arrive from Germany)

This has been a very easy - almost "bolt-up" change. I have many photos to share if anyone wants to give it a go.

Looks like this so far

[Von Short Hausen]

Hi Ray

I've been neglecting most of my responsibilities for the past week to work on converting my 90 Transalp to RD04 specs.

I guess if you leave the fire long enough it'ill burn itself out, LOL

The body work is finished and suspension work about to begin (after more bits arrive from Germany)

I love the AT colo(u)r scheme, and the twin headlamps really suit it. Can you send us some close-up photos of the changes you've made ?

Cheers.
VSH

[Gavino]

That's gorgeous Ray. I'm curious about the nose cone; what was involved in fitting that? If it's not too hard I'd like to do it to mine.

[ladder106]

Unfortunately, the RD04 nose will not mate with the Transalp side panels - the curves are different. If you were good with fiberglass you might make this work.

Changing the nose requires the RD04 bracket (the bit that mounts to the steering head and supports the front fairing), the RD04 headlight bracket and lights.

Once this is done only the RD04 side panels will mate up and those don't mate well with the Transalp tank. I'm afraid it's rather an "all or nothing" mod. Unless you get more creative than I am.

I took this on the first real test ride. A few minor things required adjustment and rethinking but I've just about got it done to this stage. Waiting for suspension bits.

[ladder106]

This is the RD04 bracket before 2 hours of sanding and a repaint. This is the key part necessary for the alteration.

This is the Transalp front bracket before removing it. The RD04 side fairing is just on for fit.

The lower Transalp bracket (the one holding the upper bashplate mounts is removed along with the black front screen. The RD04 parts bolt right up. I think it's important to change this lower bracket since it provides a lower mount for the huge fuel tank. Without this the tank is only supported at the top and the rear.


This is the nose bracket in place with the clocks installed. It is possible to do this retaining the Transalp clocks. I was able to get the RD04 bits for a fair price. The Transalp ignition switch and fuse box is retained

The Transalp instrument wiring was transmogrified to fit the RD04 clocks. It wasn't really too difficult. Only 5 solder joints were required. It did take two tries to get the temp gauge to run right but was only a matter of reversing two wires.

I didn't think the stock Transalp headlight wiring could handle the load from two 55/60 W H4s. I purchased this very nicely done relay setup from a yank in Japan who makes them. http://www.easternbeaver.com/
Nicely done and worth every penny.

The next challenge came because the RD04 uses two fuel sensors to provide low fuel warning (a light illuminates on the instrument panel). Unfortunately I did not get the sensors. After some research I found the appropriate plugs (18mm X1.5) from a Toyota transfer case.

The RD04 left fuel petcock (tap, valve, dunno the UK term) is required due to very small clearance between it and the Transalp left side coolant pipe. I found that the part from the NT650 Hawk (US model) was the same and ordered one.

This is a very busy area. The fuel pump is vacuum operated from the Translp vacuum port that previously opened the fuel tap. I didn't want to have to wire in an electrical pump and this one seems to work fine. It's a Mikuni part and easily available (at least here). The flow is adequate and I have not found fuel starvation or lean running a problem.

That's all the photos I have. I'll be happy to share what I've learned.

[Von Short Hausen]

Blimey mate, when you start a project you really get stuck in.

Some people might wonder why you've done this, but as a munchkin who can only just reach the floor on a TA - for me riding the AT is an impossibility. I think it's beautiful. Good on ya!

[Dilbert]

Unfortunately, the RD04 nose will not mate with the Transalp side panels - the curves are different. If you were good with fiberglass you might make this work.

Changing the nose requires the RD04 bracket (the bit that mounts to the steering head and supports the front fairing), the RD04 headlight bracket and lights.

Once this is done only the RD04 side panels will mate up and those don't mate well with the Transalp tank. I'm afraid it's rather an "all or nothing" mod. Unless you get more creative than I am.

I took this on the first real test ride. A few minor things required adjustment and rethinking but I've just about got it done to this stage. Waiting for suspension bits.

This looks really good Ray, I've gotta say if I didn't know I would say this was an AT and I guess I can't give you any higher praise than that, well done dude, that's one excellent bike you've ended up with

[Mudwiz]

I'd love to hear what you're going to do with the suspension! I'd love to get a more "off-roady" set up on mine, will an @ front end bolt to a 650TA?
Cheers.

[ladder106]

Thanks for the "well dones" lads.

Plans for the suspension are going in 2 directions.

First are front forks from a XR250. They are enroute from the right side of the US and will probably arrive after Christmas. These are 41 mm and have 10 in. (260mm) of travel. Standard RD04 forks are 220mm. These should (if I've done my homework well) slide right into the stock TA triple clamps and the front axle should be the same as the TA. I'll have to modify the right leg for the TA disc brake a bit and respring.

The rear involves fitting the RD04 aluminum swingarm. I could not find out if the RD04 rear suspension linkage is different from that on the TA or not, so I have the RD04 bits coming from Germany. With the stock RD04 damper I'll have 214mm in the back.

If that works satifactorily, I'll leave it there. This combination I hope will work well since it just increases the travel of the standard RD04 a bit and I don't plan on riding Dakar or motocrossing this beast. In future I may opt for a Wilbers rear damper....slightly longer with a bit more travel to get the rear even with the front.

Plan B is to go to "full dirt bike mode". This involves fitting the triple clamps and forks from a 1992 XR600. Just about 12 inches of travel and compression/rebound adjusters. This will involve fabricating a bracket for the TA ignition key and fuses but is not too difficult. The rear will have to be a custom Wilbers with increased travel on the RD04 swingarm to match ride height and travel.

I'm not too sure about this method since the chain will always be in contact with the "rub blocks" on the swingarm with this much of an increase and the seat height will become just about all I can handle (I'm 6'2" with long legs) on the street and I don't want to think what will happen if I have to get off on an off camber slope. There are almost too many negatives here to make this a reasonable plan, but there you have it.

Dunno about the newer TAs...sorry. I don't know if the XR600 clamps can be stuck on the new steering head or not. Also dunno about the fork diameter or if the front suspension was changed at all from the old US spec TA. Since the newer ones get dual discs, changing fork legs with other Honda dirt bikes will involved moding the front braking as well.

I'll post more photos as I work on this part of the bike.

Happy Christmas to All,

[koks]

first thing - let me know when this afalp is for sale. I'm first to buy it !!!
and my question is - do I really have to replace clocks if I want to put rd04 tank and fairings?