Africa Twin Tech INTL - please Show and Discuss

[A-Wind]

Technical Stuff, Pictures, Q&A, R&D

To the point and WITHOUT all the Jo Momma

[Jim Davis]

I'm in! I know what you mean about the chit chat. Some is fun, but it gets to the point of being a 10 man show, a clique so to speak.

So to start off the tech talk, yesterday I was thinking my RD03 needed a fork oil change, it's diving quite a bit more than I'd like...

So before changing the oil (too bloody hot here to work right now) I got a bright idea - try some air in the front forks - hey it has air caps, why not?

Bit awkward with the air pump up on the tank but not so hard to put some in. The forks pumped up very quickly, thought I'd try 1 bar for starters. The forks definitely are a bit stiffer.

So my question is, is it necessary to have the front end unloaded: ie bike on the center stand with a prop under the engine, when putting air in?

I figure that's the way to do it, but I've never really read anything about air in forks. I'd like to hear from any RD03 users that have experimented with air in their forks.

I believe only the RD03 had the air caps on the forks - is that correct?

Well, hoping this get some discussion started in our new thread!

[Jim Davis]

I guess some photos would help this thread. Here's one of my AT in front of the shrine at the top of the pass just north of town. I took this two days ago.

[A-Wind]

Hi Jim!

I'm glad you are IN and supplied a great shot of The Original Beauty.

As far as suspension setup, I don't have any advanced tuning knowledge. However it is my understanding as well as experience, that for better handling it is best to have NO AIR in the forks. Indeed I find the air valves most useful for actually letting air out of the suspension as air can get in through the seals over time. In the past I fabricated distance rings for stiffer forks, which I added as needed. However I'm not using any of these on my current bike, since my springs are still great.

The fork air valves as well as the drain screws on the bottom of the forks were used until production end of RD07. RD07a does not have them any more.

BTW: I found some information on German Africa Twin Page, according to which Honda filled Africa Twin forks with Automotive ATF. So there is no need to buy expensive fork oil.

Andreas

[Jim Davis]

Well it's possible the air caps are just to let air out but I think likely in some cases one might want to pump some air in to assist the springs or whatever.

As to ATF, I might have to find a Ford dealer for that, might not be so easy to get in Japan as I think all the cars here us the GM type auto tranny fluid. Wonder if that would work as well.

I used to use ATF in my Norton, worked very well too.

I have some 10w fork oil here, wasn't too pricey so will likely use that and see how it goes.

Always interesting to see what comes out of the forks! Although the forks have been working very well since I've had the bike, there's a very real chance the oil has never been changed. Now at 40,000 kms would be a good time to make sure it's fresh.

You never realize how badly the forks were actually working until you put in new fluid then suddenly - wow, they're really working well now!

I'll play with adding some air too, it's easy and cheap to change. First I want to see if it actually can hold air pressure. It seems to me with fork seals etc it might leak over a few days, but I could be wrong.

[A-Wind]

Originally Posted by Jim Davis

As to ATF, I might have to find a Ford dealer for that, might not be so easy to get in Japan as I think all the cars here us the GM type auto tranny fluid. Wonder if that would work as well.

ATF used to be the same for all cars, only the current versions are tailored by manufacturers to be a bit more specific to their needs. However as far as our purpose (forks) goes: they are the same.

[psi-]

Did my forks couple of days ago. The oil was a bit milky, non-transparent and looked like a very, very abused engine oil. I've no idea how old it was, at least three years I think.

I have the RD07, so there is the flush hole on the bottom. It tends to splash&splurt the oil around when the bolt is first taken out, so keep it in and let only small amounts out at a time (wear goggles too).

I put the 10W oil in (haynes says 5W, honda dealership recommended 10W), I have stock springs. Definitely changed for the better, but I've only little experience as to what it actually should be like.

When putting the top-cap back on I found it very easy with keeping left hand closed around the fork top and its index&thumb keeping the cap in its place while turning the cap around with right hand to locate its thread.

[A-Wind]

Originally Posted by psi-

When putting the top-cap back on I found it very easy with keeping left hand closed around the fork top and its index&thumb keeping the cap in its place while turning the cap around with right hand to locate its thread.

A little tip:
Another good idea is to leave the top-cap on all together as you don't really need to take it off for adding new fluid. Instead you can just unscrew the valves only and use a syringe with a small hose to inject the fluid. Look for some high capacity (60ml and up) syringes on eBay. They are usually used in the non-medical field to apply chemicals or to feed animals. I recently got 5x 60ml units (great size for garage use) for just under $20 incl. shipping.

[Joz]

Hi all. Just finished reassembling my RD07A. Went from this:



To this:



Once the carbs had fuel she fired right up! Now comes the paperwork to make her street legal in the US....

[Jim Davis]

Hey good news, the guy Thomas, who's selling RD03 crash bars on the AT thread contacted me. He can get them white powder coated as well. Hopefully this can happen. It would be great to get them on my bike. It's about the only upgrade I want to get for it now.

I never really thought crash bars would be necessary but they'd really give it a 'real adventure bike' look I think. Plus if I drop it again it might not bugger the tank which I still have to do some repainting on. I think I'll wait until I get the crash bars before getting the tank back to spec though :-)

Not sure why anyone would want black bars on an RD03 but they are black now. He's getting his frame white powder coated as it turns out so can do the bars at the same time, yay!

[Jim Davis]

Joz your AT is looking really sweet. Good luck with the paperwork so you can get out and ride her!

[A-Wind]

Hi Joz!

That is one pristine looking bike you have there. I like your choice of tires too. X-Fingers for quick successful paperwork.
As far as crashbars fo, I'm very happy with my Africa Queens PROII Crashbars. They seem to be really heavy duty.



Andreas

[Joz]

Originally Posted by A-Wind

Very nice!

Does your speedometer cable go through the plastic plate below the lower triple clamp or around the forks? I've routed mine through the deflector plate but it doesn't seem right.

[A-Wind]

Yes. I just checked, speedocable goes through plastic plate.
The plastic plate has a curved, long oval shaped hole (like a half C) for the speedo cable to go through. The plastic plate is mounted so, that this "half C hole" is closer to the left side fork.

[Antti]

Have you lambda tested / dyno tested your AT?
Result?
Wich jets?
Have you assembled lambda sensor and meter to your AT?


I did downjet my bike from 120/118 mains to 112,5/115.
Only other mod is Leovince can. Pilots are original 40.

I think it still goes a bit rich (dark plugs),tough consumption dropped over half a litre per 100km.