One step forward, ten steps back…

[Ténéré Mike]

OK.
The forks have had a lot of foreign matter in them - usually metallic from either poor assembly or wear of other parts.

The bore of the lowers look pretty rough. The damaged bush runs from where the bore damage starts down to the bottom of the bore. It may be possible to clean this up. More later on that. If you haven't already, rinse it thoroughly and take another photo. Get a bottle brush and tape it to a stick...

The seal sits in the top of the lower and doesn't have any influence down there. The damage shown will chew up a new bush pretty quickly - it is meant to be mirror smooth.

The worn area of the staunchions is not meant to be so. The bush OD is bigger than that bit. The damage on the end has scratched the inside of the old bush during removal leading to ActionMan's question.
This can also be cleaned up easily by filing VERY lightly and sanding with very fine carborundum paper (800 grit). Don't sand the bush mount surface.

Check the seal running area of the staunchion. Get a pair of your old pantyhose ( ) in your hand and rub them along the staunchion (no evil thoughts here!!) - if they catch on anything, that damage will chew out a new seal. You might need a pro to look at any damage in this area. If the chrome is badly damaged with stone chips in the seal running area (under the lower triple clamp) I'd start looking for new legs.

What use is this bike for? Long distance stuff or mainly display? This will determine how some decisions should be made.

The photo of the damper tube shows the "oil lock piece", not the piston. The piston is on the other end and has a little piston ring on it.

The damage in these forks demonstrates why fork internals need to be impeccably clean before re-assembly.

Again, I hope this helps.

[andylarkin]

Thanks for the reply. I am back at work now so can't do your pantyhose check til later but from memory that part was ok. Unfortunately I know zip about the bike history other than the previous owner was a cretin obviously.

It looks like the lowers have got some sort of grit in there with the scratches. From a feel I had earlier I can't catch a thumb nail in the scratches but I can feel them (if you follow me?). I might be better stripping down the other set of forks I have and see what they are like. These might not be worth the effort I guess.

As for the bike, I am not planning on Paris-Dakar on it any time soon, but I am looking to build a good reliable thumper that can do a serious bit of off-roading. As I'm in the UK, I'm not up against such inhospitable territory as you have access to, but for peace of mind I would like it done to the best it can.

[Ténéré Mike]

Next: Yamaha fitted all 34L / 55W / 1VJ / 3AJ variants (and global equivalents) with SHOWA forks - these are VERY different to the KAYABA forks fitted to the normal XT600. The 34L forks are a earlier generation fork to the latter models. The Way to distinguish the Ténéré fork from the XT600, externally, is that the Ténéré fork has a 8mm Hex for the damper tube and the XT600 has a 10mm Hex.

Also, I've just seen your post under "Fork Springs" - The XT 600 KAYABA forks typically had the steel sleeve spacer in them. Correct spec for the 34L was with two springs. Which set are we working with???

Now you need to be be wary here. The previous advice of Suzuki parts substitution is for the SHOWA forks only. They WILL NOT WORK in KAYABA forks. Just triple check and ask for clarification if you don't understand the differences.

Suspension & running gear is one area where the early Ténéré and the standard XT600 differ significantly in details. Remember, the Ténéré was launched a year before the XT.

[andylarkin]

Next: Yamaha fitted all 34L / 55W / 1VJ / 3AJ variants (and global equivalents) with SHOWA forks - these are VERY different to the KAYABA forks fitted to the normal XT600. The 34L forks are a earlier generation fork to the latter models. The Way to distinguish the Ténéré fork from the XT600, externally, is that the Ténéré fork has a 8mm Hex for the damper tube and the XT600 has a 10mm Hex.

Also, I've just seen your post under "Fork Springs" - The XT 600 KAYABA forks typically had the steel sleeve spacer in them. Correct spec for the 34L was with two springs. Which set are we working with???

Now you need to be be wary here. The previous advice of Suzuki parts substitution is for the SHOWA forks only. They WILL NOT WORK in KAYABA forks. Just triple check and ask for clarification if you don't understand the differences.

Suspension & running gear is one area where the early Ténéré and the standard XT600 differ significantly in details. Remember, the Ténéré was launched a year before the XT.

I got my mates bike shop to separate the forks for me and there was definitely a metal spacer and not two springs… I'm 100% positive about that as I saw it this morning when I got the forks for photographing. And I then bought replacement Wilbers springs - one single spring per leg, thinking this would all be pretty straightforward. Wilbers listed replacement springs for the 34L/55W and 43F as the same. Bugger… this gets bloody complicated doesn't it?

You know, originally I was going to replace the forks and brake etc with the more modern XT600 4PT (Dave Lambeth, our local overland and XT600 expert recommended this) but I decided to stay with the originals as I was doing a restoration. I might have to look again at the 4PT set up.

I have got a complete set of 4PT forks and caliper but need to get a disc as it is a larger diameter then the 34L apparently. I don't suppose you happen to know if the 4PT disc has the same mounting holes as the 34L disc do you? I've got a brand new set of 34L wheels on my bike (well recon hub but new rims and spokes) and would really not want to not use them after the dough I spent on them.

I'm at that frustrated and full of questions stage… sorry!

[GeoffD]

Mike... just had to say, fantastic piece of information there... top marks mate..

[Ténéré Mike]

Andy,

Don't fret over the springs, they will fit either fork (same basic length, same diameter). Its just a matter of whether you got the right spring rate for your fork configuration, weight and riding style. When full of fuel the Ten needs more 'boing' on the front - this is where the air assist can work for you even though the springs may be a little light on.
I'm not really sure why Yamaha bothered with the 2-spring set-up. They probably weren't either - hence they dropped it on subsequent models.

I have a set of each fork (KAYABA [dismantled] and SHOWA [assembled]) in the back shed. I rarely need the use of copious photos (unless I acquire a brain injury or sudden onset alzhiemers), so I don't have any detail photos to hand.

The best indicator of the fork manufacturer is the internals - the damper tubes are very different. SHOWA are skinny, weak looking things. KAYABA are very robust looking.

Your previous "oil lock piece" photo may help me sort this out properly. I'll try to take a photo to explain.

Solution imminent.

As for the disc, mmm.... my knowledge of later models is not a patch on the 34L/55W versions. The front hub changed on some models from a disc hole spacing of six equally spaced holes (34L confirmed, the "3TB" hub) to three groups of two holes closer to each other (XT350, "34X" hub). The 4PT catalog I have shows it as a "3YF" hub, but the picture looks the same as a 3TB hub. The bolt pattern looks the same as a 34L, but can't swear on the bolt PCD (mounting diameter). I'm sure there is a disc available that will work with your 'new' wheels and any Yamaha front end you chose. That's all Yamaha do for most new models - part bin fishing (then they change the part number - same part, different bike - & charge more). You'd be amazed how many parts on current Yamahas started life 45 years ago!

Catch y'all soon.

[Ténéré Mike]

Andy,

My XT (43F) Kayaba forks have a damper tube that looks like this from the top...

This is classic KAYABA design. The hex is 27mm across face.
Also the fork lowers have a 14mm hole with a 22 mm counterbore, looking externally from the bottom.

Check these on your forks and get back to me.

[andylarkin]

Mike

Yup, thats exactly what I am looking at right now. 43F forks then. Bugger. That means your Suzi bushes aren't relevant then?

By the way, my pantyhose didn't get snagged. Is there anything I can do about those scratches do you think or are those stanchions junk?

[Ténéré Mike]

Yep,

The Suzuki bushes and seals won't fit the KAYABA (KYB) fork either. However, I recall that the 34L forks use the shorter bush (as does the TT350 with 43mm SHOWA forks) so the bushes you have will probably work in the 34L forks. It may be worth pulling those apart to check the condition of them (and the bush lengths it has) - it may be a better, quicker, cheaper strategy. The damage inside the current lower leg is also heading me to recommend rebuilding the 34L set.

As I said earlier the Staunchions can be cleaned up with light use of a fine file (then thoroughly cleaned). The surface around the Staunchion bush isn't in contact with anything. Just be very careful when doing ANYTHING in the area the bush sits in.

I had to research all this because, like you, someone before me had swapped over the front end of my bike to std XT (at that time I had no idea they were different - the KYB forks look the same on the bike). I had already purchased the Suzuki bushes & seals, just like I had for my mate's bike 2 years ago. Then I dismantled the forks and went . I didn't want to ditch them (about AU$200 worth), so I purchased (thankfully cheaply) a 80% complete '83 ZL primarily just for the forks. They were luckily in great nick and are now rebuilt and on my bike. I'm building a second bike and have confirmed SHOWA or KAYABA before ordering bits (SHOWA). I personally think the KAYABA is a stronger, better performing fork.

If you are doing a restoration, use the SHOWA fork - it is the correct one for the year. You appear to already have bushes for it anyhow.

You do know that the seals & dust wipers are different too? The KAYABA Seals are bigger and both (seal & wiper) are retained in the lower leg with the one circlip. The SHOWA has a oil seal retaining ring (just for the seal) and the wiper is just an interference fit into the top of the lower leg.

Don't be afraid to pull the SHOWA forks apart yourself. Basically, its drain the oil / remove spring / flick the wiper out with a screwdriver / remove a wire clip (under dust wiper - it's not even a 'proper' circlip) / out an 8mm Allen key and remove the lower bolt (there are tricks to holding the damper tube from rotating) / then use the lower like a slide hammer to rip the two halfs apart (2 good tugs should do it ).

The damper tube in SHOWA forks can be held from rotating with a piece of 5/8" steel rod about 2' 3" long. Bend one end to an "L" about 4" from the end. At the other (straight) end, grind it down with 4 tapered flats over the last 2" so that it ends with a point (the end should look like a very tall pointy pyramid). Stand on the "L" & jamb the pointy end up the fork staunchion into the internal end of the damper tube while trying to undo the Socket Head Capscrew at the 'bottom' of the now upside down fork. There will still be oil in there so watch your shoes... The Yamaha special tool does just this for the SHOWA forks. The KAYABA fork tool is a 24mm socket with a 24mm A/F nut (std M16 nut) dropped into it.

This will get you in far enough to confirm the contents of the fork. I can pull both forks apart quicker than I can change a bike tyre. Putting them back together is a little more fiddly.

Good Luck

[andylarkin]

How do one and all… I'm back after a few weeks of working away so I am now able to update. I guess this is mainly aimed towards Tenere Mike but it may be of use to the rest of you.

Mike, I stripped the next set of forks down and they pretty much fit with your descriptions… as follows I can confirm that:

A/ the damper bolt is very much thinner and spindlier than the one from the 43F forks
B/ The hex bolts that go in the fork leg bottoms are smaller than the 43F ones
C/ The bottom bush appears to be the same size as the very worn ones from the 43F (see pic below)
D/ The internals are all mirror finish



As you can see from the closer up photo below the bottom bush appears to be in pretty good nick, no scratches or wear at all from what I can make out:



Top one does appear to be showing some bronze through though - see pic below:



So it does appear that I do have a correct set of Tenere forks this time rather than XT600 ones. Unfortunately the genuine fork seal kit (all the parts) is for the 43F not the 34L… bummer.

Does this mean I can order those parts with the Suzuki reference numbers Mike? Are the bushes the same size as the ones from these photos in your opinion?

Thanks in advance.