Africa Twin - Clutch feeling slippy on bumpy roads
 

Hi everyone,

I have a feeling my clutch is slipping sligjhtly on bumpy roads.
Now I wonder what that could be.

* It has some milage on it (90.000) but I've read before the clutch should easily last longer. What are your clutch lifetime experiences
* It has freeplay so the clutch is definitly closed
* Strange thing is, I have a feeling it started with changing the tires from "road enduro" to Heidenau K-60 Scout with a bit more profile.
* I ran a bit too much Oil for about 500-700km since I checked the level with oil not set properly yet (no stupid comments on this :) ) but I equaled the level afterwards - still its more at the top rather than the bottom level at the moment
* front sprocket/chain looks like brand new as well - and it should, it only has 6000km on it or so

I have a bad feeling it could be the clutch or the clutch springs but since I do not have too much experience with that I would like to ask for some additional comments...especially since I just started my trip from Germany to Australia (in Turkey at the moment).
If it is a first sign of clutch failure, how long do you think it will last from now. Im crossing to Iran next week, then I'll take a ship from Dubai to NZ. I prefer fixing it in NZ which would be additional 4-5k more km because the season in Iran slips away and it would probably take me 1-2 weeks getting parts and changing them.

Best Regards
Manuel

Hi, Manuel,
Did you change the oil recently?
Some oils make the clutch slip.
On the bumpy roads, can you see the rpm's suddenly jump?
If not, check if the rubbers of the cushdrive are placed correct.

Good luck,

Peter


www.amsterdamtoanywhere.nl

Hi Peter,

thanks for the quick reply.
I did change the oil about 5-6k km ago but havent noticed that behaviour within the first 3k.
I didnt looked at the RPMs but I guess you could hear it and it doesnt sounded that way - just felt like missing torque for a split of a second while bumpy sometimes.
Cushdrive? Wasnt able to translate that unfortunately :)

Best Regards
Manuel

Hi Manuel,
Cush drive is just a wild gues, it is the rubber block you find when you pull off the rear sprocket from the rim.
Since it started when you changed your tires, I would look at everything you took off. How is the chain tension and are the sprockets not worn?
Otherwise 90000 miles is not uncommon for a clutch to wear out.


www.amsterdamtoanywhere.nl

You changed the oil. Motorbike oil? Some car oils have additives that play havoc with wet/slip clutches.

are you sure you're not just loosing traction on the bumps?

Have you disabled your side stand switch?

Check the connectors to the CDI unit. Or possibly the CDI unit itself is starting to expire, that the bike is intermittently running on 1 cylinder.

CDIs are a know weak spot on Africa Twins and Transalps.

I'd definitely check this first, before looking at the the CDIs that I mentioned above.

I had it once where the spring on the side was weak and when I was stood up on the pegs ,with having size 12 feet my heel was catching the side stand enough to let the kill switch kick in for a brief moment .

I disabled the kill switch and problem solved. BUT Don't forget to lift your side stand before you set off !!!!!

Our at's with 189.000 and 165.000 km's on them have the original clutches, and did a lot of off road riding during our RTW.
One of 'em (the one with 189.000 on it) ran on one cylinder at extreme altitudes in Bolivia and I burned the clutch a lot to get through the mud. 3 oil changes later you can still smell it when you take the oil out!

Having said that, you can burn up a clutch in a day if you really want to, so it is not possible to tell you a 'decent mileage' for a clutch as it differs per rider and the use.

Usage of non-motorcycle oil MAY result in slipping clutch as mentioned above. This would be solved by a good engine flush and new friction plates.

I don't see how the sidestand sensor would give you a feel for a slipping clutch. Sidestand will cut the power and lower the revs, slipping clutch would send the revs up.

The rubber blocks in the rear wheel won't give you power loss or anything, only there for chain life and comfort.

Carb breathers can mess up power of the engine when you drive bumpy roads fast - they tend to flood the carbs and then drown the engine.
If you did the 1997 and later mod on a pre-1997 bike, make sure the hose can drain completely so no saggy point in which you can have fuel sitting. Else, just pull off this shit and see if it works.
I actually had this problem and the bike would actually stall sometimes after a few bumps.

@Petrus: I can see you didn't drive your AT lately ;-) The rubber blocks fit only one way! :-D

Hey, sorry for the late reply and thanks for your replies! I should remember subscribing my own threats :/

Yes I'm pretty sure I'm not loosing traction. However, it started somewhat around (+1000km) when I changed tires from Dunlop TR91 to Heidenau K60 Scout.

Also I'm pretty sure that it's not the kill switch - I tried to watch the RPMs but couldn't really notice something, but its hard since its only a split second. However, might be immagination, but I think they gone up minimal (maybe 100rpm).

@Chris: Cant imagine the CDI to be the issue - I've done about 8.000km now - It would have probably failed by now. However, looking at the connectors I will consider.

@dstehouwer:
Thanks for your "statistics" - good point for orientation - I drive mostly road and quite relaxed I would say, touring pace. However, I did only 30 out of 100k now on the bike so no idea about the previous owners.
The fact that it not got worse at all over the last 8000km might indicate another reason.

I changed oil but 6000km before it started and only used proper brand motorcycle oil.

The carbs I don't believe to be the reason as well - because it's so instantly at the bumps and also not constantly and I would imagine if something is flooded I would recognize it over a slightly longer timeframe and not just that split of a second I hit a bump or pothole.

I need to do an oil change anyway, I might just have a look at the clutch while I do that and measure it. I'm in UAE now and will stay here for a while to work for a few months so time for troubleshooting, but on the other hand, after that will probably be Pak>Ind>Thai>etc. so better get a new one now because I think 100k is a lot for a clutch.

Just put the bike in 5th gear, put some tension on the chain.
press hard on rear brake
rev to 2000rpm
dump the clutch
engine should cut out 'easily', say within a full second max. (

If it keeps running, your clutch is gone or not engaging
If it cuts out it but takes 10 seconds, clutch is gone
If it cuts out quickly, clutch is good.


100kkm is nothing for a clutch if it is used properly. Again, it can be worn out within one day if you want to.
I just have the feeling it is not your clutch at all if I read you posts.


Clutch slippage results in revs going up without the rpm's of the rear wheel going up, that's all.
If the engine cuts out while riding (like if side stand switch activates) reduces rpm
If carb has issues, reduces rpm
If clutch slips, rpms go up mostly when you have max power, so at full throttle, when you hit your powerband (say >5000rpms) you'll hear a sudden increase in rpms from the engine.

If you are really worried about it, contact me directly via email or my website - and we'll arrange a Skype meeting shortly so we can discuss and help you out.

Hey, thanks for the tips, did the test with the 5th gear - seems fine.

I've heard that the clutchs springs can also get worn, could this result in the behavior?

I'll be in UAE for probably half a year now since I got a good job offer to raise the travel budget so plenty of time to troubleshoot and not wasting money for a new clutch not needed - and on the good roads here the AT runs perfectly fine.

If your springs would be worn - then it would slip with the '5th gear test' too. (and they don't really wear, but loose maybe a bit of strength)
No worries - again, our springs are original in both our AT's.