ktm rear hubs

[drewMember]

with the 640 as a guide it suggests having it on the stand, and have about 30-40mm of chain touching the bottom of the swing arm, just back from the front/ pivot point, when you push it up with your fingers. and i also sit on the bike afterward and do the guitar string test as Axel suggests;)

[Bruce CurtisMember]

It does seem to happen on KTMs (PDS models- no it’s not a PDS fault) more often than others, and in their defence I reckon it’s as TB suggested, the KTMs have a very high swingarm pivot point, and slightly more overall rear wheel travel than claimed as well, which means the wheel centre travels a bigger arc than some others, there is several valid reasons for this(but i won’t go into that this time).

Now even though the owners manual may suggest 45-55mm (or similar from memory) of freeplay find out for yourself what is needed by getting a tiedown or something squatting the suspension down so the axle is at it’s furthest point from the countershaft (direct line or straight) and see how tight the chain is and make your own assessment of how much freeplay is needed.
A mate of mine bought a new KTM a few yrs back, he smashed the hub, ripped the swingarm and smashed botth cases and had a massive accident to boot, a $12k bike was reduced to a $800 wreck in seconds.

I suspect the chain was too tight in that case as well.

Check out DBW there was a wheelset for a kato on there a few days ago for sale.

BC

[GregMember]

Plenty of advice and help in this thread regarding KTM chain adjustment

TB

[alanMember]

the wheel sets are sold bruce thanks anyway .am getting that genuin hub and will give the rims a tune up today .another easy way to check your chain tension is pull your shock out with bike on a stand two bolts find tightest spot in suspension travel for chain and go from there ala ktm rat.think i may be getting TB s opinion of ktm s

[RoyMember]

I had heard about ktm’s cracking rims with tight chains as well and am a bit paranoid about it on my bike (not keen on the $800 wreck). When I check the chain on my bike i sit right on the back of the guard and this seems to give me enough leverage to get the swing arm basically level and then I reach down and make sure the chain is not tight. The chain slaps like a bastard when riding but thaqt’s the price I have to pay to save the hub apparently.

In saying that the ktm chain layout is a lot more touchy than my old yamaha for some reason. I minute adjustment in chain adjusters can see it go from chain slapping badly to pretty tight.

Can a too loose chain cause problems. I’m not talking loose enough that it comes off.

[Bruce CurtisMember]

Yep Roy but not as many as a too tight one, the loose chain causes what we used to call the “Dolphin” effect the chain arcs up and down like a dolphin surfacing and diving, this causes chain and sprocket wear and slider/guide wear, but usually that’s as bad as it gets.

[AlexMember]

Bundyroy wrote:
Can a too loose chain cause problems. I’m not talking loose enough that it comes off.[/quote]

G’day Roy, I can’t think of any but someone reading may have something to share. The chain should always have some tension when riding. Maybe if it was so loose and worn that under closed throttle the chain could ‘lift’ off the countershaft a little, giving your clutch slave a bit of a ‘hello’. In the past this issue happened because of rocks/sticks running with the chain not because the chain was loose.

[RoyMember]

Looking at my case saver, it must have been hit by the chain at some point back before the chain actually gets to the sprocket. My front sprocket has also worn down after 4000km and in the past (previous bikes) the first indication of sprocket wear has always been the clicking you get from the hooks on the teeth when you push the bike backwards. This bike doesn’t seem to get that. No hooks, but just deeper cuts between the teeth and the arc of the cut is a bit longer/deeper on the pulling side of the teeth.

Maybe I just haven’t let it get to the hooking stage yet. Maintenance was not a concern when I was a kid until it got to the point I couldn’t ride. Maybe it is better quality gear too. Never had o ring chains back then either.

[AlexMember]

It’s amazing what you can get away with with a little luck. Hooked teeth was always a big indicator. I’ve seen missing teeth on the rear of some people’s bikes. I’ve been know (when I had no money) to spin the countershaft the other way (bad). I try and pull the chain off the rear sprocket and that gives me an idea on wear. More than halfway off the teeth is not so good. I don’t subscribe to the idea of replacing sprockets without the chain (apart from the front sprocket, but rarely). If worn sprockets can wear out a new chain why wouldn’t that be the case the other way around? 4000 km is not a bad run in my opinion btw.

[RoyMember]

I’m certainly not complaining about the way they have lasted. I was happy to get 4000km. Never have on my old yamaha. More of a comment on the way it wore down than anything. Just surprised that there was no curling over of the front sprocket teeth.

Saw a bloke at a pony express missing 1 or 2 teeth on the front sprocket at the start of the race. By the end of the race it looked like he only had a few left and he’d lost a few off the rear as well. I would have loved to hear the noises coming out of it whilst he rode.

[alanMember]

fitted the new secondhand hub tonight was not as hard as i expected.pressed some of the dints out of the rim at work.the wheel is still a little buckled but 100% on what it was.so the money pit is going again

[AlexMember]

How much Al? You got the whole wheel complete then? I better go and check I still have a rear wheel on my 300….. :dry:

[alanMember]

na just a hub axle would have rathered your back wheel but.checked my chain tension again with the shock out definatly not a problem i run it a bit loose if anything

[Author]

Posts