Hi guys
I'm nearing the end of my 7 week trip through Central Asia, Altai-Russia and Mongolia.


I have a problem, I think, and would be really grateful for suggestions/ comments/ possible solutions. It is also urgent as I fly home to England next weekend (today Sat 25th Aug, flight Sat 1st September). I was hoping to leave the bike in Mongolia to continue my trip into eastern Siberia next summer, 2013 (preferred choice). If necessary, however, I can freight the bike back to the UK from Mongolia, but would need to set things in motion very quickly.


The bike: 1988 pd06 XL600v Honda Transalp, unknown mileage (I'm the 12th owner!), but anywhere above 50/80 thousand miles/kms. On this trip the bike has done 8500km/5000miles, about 50/50 pavement/gravelMudSand. The front sprocket is OEM Honda 15 tooth, rear steel aftermarket and chain expensive DID 525 118 link vx. All 3 are still in good condition, I believe. Please see images below.


I reached my destination Ulaan Baatar, the capial of Mongolia a week ahead of schedule, so decided to take a ride south to visit the Gobi desert. Yesterday morning (8300km/5000miles into this trip), just before setting off I noticed the damage to the sprocket cover (see image: I removed the plastic centre circle, it was still 2/3 attached to the cover). This damage would have happened very recently as I definitely would have noticed a gradual issue.


Before leaving for the Gobi, I replaced the sprocket retainer (number 1) with a new spare (number 2). It last precisely 200km/120miles! See image.


I rode as carefully as I could back to Ulaan Baatar today. Before setting off I also loosened the chain a bit more too. Retainer number 3 is already half worn after this further 200km/120 miles!


The front sprocket does “wobble” a little on the shaft.


How/why did this happen? I believe the chain tension wasn't too tight. The output shaft is IMHO in good condition (much better than the one on my 1995 Africa Twin...).


What's the solution?


1. Weld the sprocket onto the shaft? (not a problem, the bike is cosmetically very nasty and only really worth gbp600/us$1000/euro700, if that). This can be done locally, if I can find a competent Mongolian welder who understands English or German.


2. Replace the output shaft? The would require a full engine rebuild, for which I don't have the expertise. Finding a competent English/German speaking mechanic in Mongolia will be a challenge! Also the parts would have to be sourced and imported. I can ship the bike back to England where I know a very reliable mechanic, but I can't justify the cost (it would be 1500euro shipping for a 700euro bike and that is before paying parts and labour.)


3. Just put on a new front sprocket? I don't have one with me, but could easily bring one with me when I would return to Mongolia in 2013 for my Siberia trip. I'd also bring a job lot of new retainers with me.


4. Or? Over to you!


FWIW, I am sending this email using the wifi at the Oasis Guesthouse. Rene and Sybille, the owners, are currently out of town, but back on Wednesday. I'm hoping to be pro-active from Monday (27th August) morning onwards.


Several images are below that will hopefully help solve my problem.



Retainers from left to right
1 lasted 8000km
2 lasted 200km!!
3 is half worn after 200km!!
4 is new (for comparison)





Chain tension





Chain tension





Chain pulled off rear sprocket, still v good condition, IMHO





Retainer number 3 on sprocket, before setting off this morning.





Output shaft looks Ok to me, I've seen a lot worse on my Af Twin that has about 1/3 missing off each tooth





See above comment





When I pulled over for a pee, a quick glance revealed this shocking image (of the sprocket/retainer/shaft, not my manliness!)





See above comment





Sprocket looks fine, but does wobble a little on the shaft





See above comment





Sprocket cover after removing the worn central section


Any input is very gratefully received! Thanks in advance! If we meet, payment in s. If not, good Karma all round!


Ride safely,


Chris

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CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective

I'll offer some thoughts, having run loads of Hondas over loads of years.
Plus some questions.

There must be some force pushing the sprocket longitudinally along the gearbox shaft, away from the gearbox.
Normally in my experience there's very little sideways force, which is why the retaining washer isn't particulary substantial.
As you've no doubt experienced they last a long time, tens of 1000s of miles, and maybe become a little thinner on the internal lugs.
Also, I'd say the sideways force must have some 'hammer' effect to destroy your latest washer so quickly.

So what could be doing that? My first thoughts are: rear wheel bearings, or swing arm bearings.
Have you noticed any change in handling at all?
Maybe even a swingarm that's broken somewhere. (Sounds like you've done a lot of off-road. Particularly fast or heavy-going?)
With rear wheel off the ground, apply a strong arm to the tyre and see if you can make any side-to-side movement.

If handling is definitely OK, does the chain have any seized links? (Although not very likely to cause this). Check with rear wheel off the ground (see below).

Rear sprocket carrier bearing?
Don't know the cush-hub arrangement on the TA, if it has one, but is it OK?

Is there any longitudinal free play on the gearbox shaft? (In-and-out). There should be none (or maybe very little).

Put everything together, but leave off the retaining washer. Adjust the chain to the correct up-and-down play.
Set the rear wheel off the ground with bike vertical.
Start engine and select 1st gear. Watch what happens. With no drive force being transmitted through the chain (just enough to rotate the wheel) the sprocket should stay in place. At least for quite a while.

If not, the way it behaves may give a clue.
Does the chain bounce a lot forcing the sprocket off?
Does the gearbox shaft move in-and-out noticeably?
Watch the chain in motion. Is there a single link badly damaged and out of line? Or a pair or three links together?

As another test, try winding a length of mild-steel wire around the shaft in the groove, enough to fill the groove and leave a turn or so raised above the level of the splines. Wind it quite tightly and twist the ends together firmly.
That should be enough to hold the sprocket on for quite a few miles. In Turkey we did that to a fellow-traveller's Honda after he lost the two retaining bolts and the washer. It got him to Iran OK, quite a few hundred miles.
You could try solid copper wire if no steel, should be just as good.
So, if you go only a few miles before the whole lot comes off, there's definitely something wrong with the whole alignment of the two sprockets (a frame/swingarm/bearing thing), or the bearings of the gearbox shaft.

That's about all I can think of for now.
Hopefully others will have more to offer.

Best of luck!

__________________
TTR250 - London to Cape Town

Interesting! Especially as I only ever change the retainers every third or fourth chain and sprockets (50,000 km plus and even after that I have never seen wear that bad)

The only way I can see the retainers wearing out out that quickly are impact loads due to the sprocket continually belting into it. After trying to think of all the possibilities I think the answer is in your statement that the sprocket "wobbles" a bit on the shaft. I suspect that wobble is enough to provide the necessary continual impact - especially when you think it is revolving something like 1500 times a kilometre. This would be worse if there was any form of misalignement - have you checked your rear wheel bearings? Also looking at the photo's the front sprocket looks reasonably worn with a lot of wear on the side flanks and this may be one of those occassions where wear has reached a critical point, as material wears of the side flanks of the teeth and the teeth deform the sprocket can move a bit more within the chain, the retainer sees more impact - seemingly suddenly you are at the point where retainers last no time.

So my guess is a new front sprocket and retainer will fix everything. I know its a pain when you can't prove it but I would be fairly confident. You also at the end of the day have the fall back option next year that if it does keep failing going to the welding solution - but I'd safe that until you've proven the other doesn't work.

Another possibility is you were unlucky and the spare retainers you bought were from a bad batch - it happens but frankly I think its extremely unlikely.

So in your situation I'd stick to your original plan leave bike and return next year with a complete new chain and sprocket set plus a good handful of retainers and then hope like hell you have enough of those good karma points for it all to work out.

Enjoy UB.

__________________
Martin

finally back on the road again


http://awayonmybike.blogspot.com/

The only thing I can add to everyone else's suggestions (which are excellent) would be to question the chain tension. I keep my V-Strom chain loose enough to be able to almost touch the bottom of the swing arm when fully loaded on the side stand. Your photo seems to show that yours is quite a bit tighter than that. I don't think the tension is causing the wear but I'd loosen it before checking the bearings etc. I believe chain tension usually takes out the seal and or bearing on the output shaft rather than the rear wheel bearing and your seal is obviously not leaking but maybe you got lucky?

Roger

Sorry to not yet have responded to all the people who have replied: I need to go out for food. Mongolia is 7 or 8 hours ahead of Europe. I will tomorrow.

Possibly I put the rear spacers on the axle on the wrong way round on the last tyre change. Hence the sprockets are out of allignment.

Can somebody with a rear disk model pd06 Transalp (or even Africa Twin) nip out to their bike and tell me which side which spacer is? On my bike it's currently the bigger one on the left (sprocket) side and the smaller one on the right (brake disk) side.

I will do all the checks suggested tomorrow in the daylight. There's a dutch Toyota Landcruiser man here too who has a full workshop with him. I'll be raiding his stuff

Many thanks!

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CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective

Hi Chris. sorry I cant see all the photos, but should the front sprocket be the other way round ? it looks like the chain is catching the engine cases . I seem to remember the front sprocket as a flat side, which faces outwards and the side with the raised face, faces the engine cases. hope this helps.

Dazzer

Hi Darren
Hope you and Leigh are having a fun time.

The front sprocket on my bike is bolted on as shown in the sketch in this thread at xrv.org.uk: T/A Front sprocket question, similar question, but different to others?

It doesn't have any nylon cushioning on it, like previous sprockets I've had from David Silver.

It's past 10pm here in UB. At least the here tastes great.

I need to do a full set of checks tomorrow.

cheers!

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CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective

Sorry for taking so long to get back to you all. Been busy working on the bike and dodging sand storms. Now it's raining!



Hope you don't mind me admitting that I posted my original help request on 4 different forums. The level of help and really useful advice has been outstanding. It's great to know that so many people care about your wellbeing. Please take this reply as aiming at all of you. Sorry, with is super slow internet connection, I'm unable to reply to you individually.


The posts are at


http://www.horizonsunlimited.com/hub...929#post390382

Advice needed in Mongolia: Transalp output shaft/ sprocket/ retainer problem, Urgent

Show us your TransAlp modifications! - Page 905 - ADVrider

http://www.transalp.de/forum/beitrae...em_urgent/#pid


So I did the following today.


Removed bashplate and checked chassis for damage: None found.


Checked engine mounts: All tight


Checked swingarm for damage: None found.


Rechecked swingarm bearings: Fine


Checked rear wheel bearings: Seemed fine.


Checked sprocket carrierbearing: Some play


Checked chain tension again: Still too tight, so loosened after doing all the work on the bike


Removed front sprocket and checked output shaft: no movement l/r, up/down, nor in/out.


The front sprocket is definitely on the correct way round. It may or may not be an OEM part, the discussion from May this year about it is at T/A Front sprocket question, similar question, but different to others? There is no writing on it.


The sprockets inside and out are pictured below. There is clear wear on the outside front and inside rear. Hence chain out of alignment, as suggested by most people. So if the front sprocket is cool, the problem is with the rear?!...



Rear outside


Rear Inside


Front outside


Front inside



As was also suggested, I put the bike vertically on a stand with the back off the ground, removed retainer, put front sprocket in correct position, started motor and engaged 1st gear: The front sprocket immediately skipped outwards to the end of the shaft, then continued to move left/right way beyond where it should sit.


So removed back wheel. The cushdrive rubbers looked a bit dubious (They will also be replaced next summer before setting off for Siberia)




Replaced carrier bearing and also the other 2 rear wheel bearings (I knew there was a good reason to carry all these heavy spares...). I say replaced, It was Roy the nice Dutch chap in the Landcruiser who did all the work. He's a heavy plant mechanic, so a fat Honda was quite familiar to him:



After cleaning everything, smoothing out the burrs in the central bearing spacer tube and greasing stuff we put everything back together. The 2 outer spacers were in the same position as previously. Longer one on the left/sprocket side, shorter one on the right/brake disk side. Everything seemed to fit much better.


Finally, ran the bike in 1st again, with a looser chain too and the front sprocket stayed where it should! While I was twisting the throttle somebody else standing 3 meter back behind the bike thought the chain was running true too.


I put on my final new retainer (number 4) and will take the bike for a spin out the the giant Chinggis statue tomorrow. Wish me luck! I'm very hopeful things will go well.

If all does work out well then the problem was caused by a slightly loose carrier bearing, a tight chain and possbly sh!te cushdrive rubbers. On the last tyre change in the stoney/dusty/dirty carpark in front of the Russian tyre-wallah's shop I may have been less than subtle too. If not...?

Next summer I'll also bring a complete new C and S set, plus new spare retainers and also a couple of modified retainers as described by East Coast in post number 6 at Advice needed in Mongolia: Transalp output shaft/ sprocket/ retainer problem, Urgent Conveniently I have a 1987 TA at home too, so have a demo model to test it on. Or EC will sell me one of his :-)


I'll advise how I get on following the test ride.


Cheers!

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CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective

The test is done and the evidence is below. Only 100km/60miles virtually all on pavement, but I did regularly try to simulate riding offroad/sand by riding like a tosser, er I mean, a Mongolia car-jockey/trucker.



thickness



Inside



Outside


There's v little wear on the retainer that started the morning as a new part. One of the 6 splines on the retainer is even spotless! I believe all Transalp retainers will inevitably have some surface damage just because of the (stupid?) design of the shaft. As my current front sprocket wobbles (do they all do this from new? As mentioned in a previous mail the ones on a BMWf650 don't/shouldn't), probably because of the tight chain/shagged carrierbearing/cushdrive pulling it the wrong way.


I'm going to do the trip to Siberia as planned next summer and take the parts with me as mentioned.


So, 2 things I've learnt when riding Honda v-twin dualsport bikes when doing a lot of offroad/sand/mud: Run your chain real loose. Also (all the time) when checking rear wheel bearings, don't just wiggle the back wheel in the swing arm, but also wiggle the sprocket carrier separately too.


All the best to all and hope to see you near a bar somewhere :-)


C

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Brighty's website: TheBrightStuffDotCom

CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective

Can´t say I´d not worry about this retainer. This is IHMO far from normal after such a short distance. You should not have any such marks on the retainer even after 10.000 miles. I´d suggest you post the pics at xrv.org.uk to get more feedback.
Cheers
Chris

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Need to fix your Africa Twin? Check out my step-by-step frame strip pictures at
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Have you tried using washers/shims to take up the axial play on the output shaft?
How is your sprocket alignment?
All the best with it.
Dave.

Once again I'll offer something for what it's worth.


Yep, I agree.

I've never had retainer wear anything like you show in your latest photos.
Consequently I've never paid any attention to the play that existed, if any, between sprocket and shaft.

But what I do remember clearly, when fitting a new sprocket (usually pattern parts) for the first time, is the difficulty in actually getting the sprocket to start to slide onto the shaft. It has to be offered up and lined up absolutely perfectly. So I'm pretty sure once the sprocket was on, there'd be hardly any freeplay at all.

Does your sprocket pop onto the shaft dead easy without having to jiggle the alignment so that it's perfect? If it does, could be a bad sign.

I looked again at your shaft photos. It looks to me like there are wear marks where the inner side of the sprocket would line up on the shaft.






Or might just be dirt marks?

So, how about seeing if you can find someone with a good measuring gauge (Mercedes dealer or similar if there are such things?) and accurately measure the diameter of the shaft over the splines at a point where the sprocket sits. And the width of the splines where worn. And the shaft diameter between the splines, although in effect you'll be measuring the unworn part between the retainer groove and the end of the shaft (unless you can find a gauge that will measure over shoulders).
Then when you're back home, find an AT workshop manual. In my experience those Honda manuals (maybe even a Haynes?) have all those sorts of measurements of parts subject to wear, with the wear limits.
That'll answer the question about the state of the shaft.
(Or back home, find someone with an AT running fine and test the sprocket play on it and how it compares with yours).

But, whatever you find, I'd get some of those large-size two-piece retainers made up that were suggested on one of the other forums. They look pretty substantial, specially if you get them heat-treated/hardened as well (heat to cherry red, quench in oil).
Maybe 3 pairs of those would see you through (purely a guess!) Use good bolts with loctite on the threads, as effectively there's only one bolt per piece.
It might be handy to measure the width of the groove in the shaft to tell you what thickness of steel to use. Maybe just find a coin that fits snugly and take that home with you.
(Are there coins in Mongolia?)

__________________
TTR250 - London to Cape Town

Whilst the wear marks on the inner "bars" of the shaft don´t seem to be excessive, the outer "bars" seem to be significantly worn by constant hammering impact of the retainer, for which the marks on the newly used retainer are proof. There´s too much play in the longitudinal movement of the sprocket on the shaft; usually the retainer fits nicely in the groove between inner and outer bars and has constant, full contact with the inner vertical faces of the outer bars.

Your earlier advice with solidly wrapped wires in between the retainer and the outer bars should do the trick for several thousand miles I would think; it´s easy enough to check occasionally whether the wires have come off or not. Maybe there´s even a way to sort of soft-weld those wires around the shaft, like using a gas torch and a removable material. I´m not a welding expert but I know that it is firstly a difficult job to weld anything on the shaft and that the shaft bearings won´t like any layman´s job on welding. Lastly, any weld-the-sprocket-itself-in-place will be a permanent, non-removable solution and be the last sprocket on that shaft. I can´t think of anything else how to fix this, short of replacing the shaft, which can be done within three days or so, but which requires a lot of spares and a clean work bench. Taking the engine back home for repair is not an option, I guess?

Some folks with TA and AT have started glueing the front sprockets to the shaft lately, but this is to reduce/eliminate the wear on the inner bars and not to prevent longitudinal movement of the sprocket, which it will not do. In theory one could grind the outer bars to a sharp angled inner face again, and then using a thicker retainer, but I guess that´s theory with the shaft installed and without a proper workshop at hand; the shaft is hardened after all.

Sorry for being not more helpful. xrv.org.uk should be a great resort for more opinions, though.
Cheers
Chris

__________________
Need to fix your Africa Twin? Check out my step-by-step frame strip pictures at
Google+ album: http://tinyurl.com/6u93yv2
Dropbox with zip-File: http://tinyurl.com/czj8qgw

Thanks for these comments guys.


I mentioned in post number 8 above that I asked over on xrv for advice too. A lot of useful stuff came back from there.


On ADVrider on page 906 at Show us your TransAlp modifications! - Page 906 - ADVrider a TA guru (mas335: they only have 1989 model TAs in the USA, mine's an 88 engine, which is the same) says a “wiggle” of the sprocket on the shaft is normal. I believe the (possibly excessive/possibly not) sprocket wiggle/wobble on my bike is caused by a shagged out front sprocket cause by a too tight chain combined with deceasing sprocket carrier bearing pulling the front sprocket in all sorts of directions and enlarging the hole.


I also have a 1995 rd07 Africa Twin at home and the teeth on the shaft (it has 8 teeth, rather than the Transalp's 6) are about a third worn away!! (from using non-oem sprockets by previous owners: the holes on non-oem sprockets are harder than the shaft, so the shaft wears; on oem sprockets, the hole is softer, so the hole wears, not the shaft, I believe). By comparison, the shaft on my Transalp looks virtually mint!


I think only a new sprocket (and an a couple of spares) held on with a modified retainer (thanks for the advice ref heat treatment/hardening) is the way to go. I have a 87 Transalp (also same shaft as on 88 and 89 models) at home, so can use this as a demo-model.



With regard to possible welding, what I can also do is bolt and weld a second sprocket (with teeth ground off) onto the outside of the “main” sprocket. This will increase the length of the surface that connects to the shaft, and then the outer bit can be spot welded onto the end of the shaft and also (hopefully) removed again with a (small) angle-grinder.



Cheers guys. I'm off to fix my Scottoiler and spotlights. They got a bit wet...







Sorry, the alightment from the bike is a bit unspectacular. Must try harder... Turn up the volume!

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CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective

The grove the retainer sits in is 3.15mm wide (the oem retainer is 2.3mm thick).

They don't have coins in Mongolia. I had to borrow various washers from the Toyota man's tool kit to try out. The inflation rate is so wild it's already 1 buck = 1350 Thingies (The smallest note is the 10 Thingie note that probably cost more to print than it's worth. Sorry, I should take the currency seriously, but can't be bothered enough to remember what it's called).

Being the banana republic it is, the paved roads are so bad in downtown UB that speed cameras aren't necessary and shock repairers/tyre wallahs make an excellent business. At the same time, last year, apparently, all state employees received a 100% payrise...

Good news: managed to get special dispensation from Mongolia Customs today to leave my bike here for a year. They believed my bike is genuinely only worth 600 bucks... Hence only v low deposit needed.

Siberia 2013 is on!


cheers guys

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CURRENT RR WITH REGULAR UPDATES: The Wife Takes on Chlamydia: A South American Retrospective