Author Topic: What have you done with your bike today? (Read 239114 times)

kwackboy · « **Reply #1801 on:** November 03, 2020, 21:39:27 »

@ mr nick ..

Knowing what KTM spindle nuts are like, I am also surprised and would have thought the nut thread would have stripped first .. 🤔.

Rixington43 · « **Reply #1802 on:** November 03, 2020, 21:44:08 »

Is the block and dropout assembly the same on the other side?
Looks like there's a concave channel behind that nut block which could mean tightening the axle has pulled that block in at the centre and stressed it over it's height. Of course, if both sides are identical that's a herring of the rouge variety.
Likewise, very surprised the threads didn't go first, strange failure but at least you caught it before it ended in tears.

Rusty Nuts · « **Reply #1803 on:** November 03, 2020, 22:00:59 »

I was thinking that if a spacer had been omitted at some point maybe the shoulder at the end of the spindle's thread had been forced into the block, forcing it to split.

Mr Nick · « **Reply #1804 on:** November 03, 2020, 22:04:52 »

I'm curious about the channel myself but have no pics of the other side to hand to be sure. The other end of the axle is the same but the adjuster block is obviously loose. The fiche has the fixed end on the sprocket side and a few video clips of wheel changes etc I've looked at seem to concur. Just remembered I have the workshop manual in pdf and it shows the axle oriented that way, but doesn't warn against fitting it the other way round. It looks like there is the same groove both sides too.

I'd wondered about whether the 90Nm torque figure is a dry or greased value, but the manual does confirm greasing the threads.

It may be that some spanner jockey has hammered it through somewhat enthusiastically in a previous life when it's been hung up on the edge of the channel, just enough to weaken it: maybe the same one who put it in the wrong way round.

Sim: did a KTM rider bully you at school or something? There are people who you can talk to you know.

mr_diver · « **Reply #1805 on:** November 03, 2020, 22:16:21 »

Josh had a KTM.
We spent an hour in his garage pointing out design and production issues common with modern KTM bikes.
He sold it before it was worthless and got the far more reliable DL650 L7

mr_diver · « **Reply #1806 on:** November 03, 2020, 22:18:08 »

If anyone wants to go into design for design sake I can go into some depth on Honda's fecking Dual Combined Braking System # # #

Mr Nick · « **Reply #1807 on:** November 03, 2020, 22:27:37 »

They tried to sell me a 790 at the bike show back in March but I didn't fancy it either: didn't look or feel like a KTM to me.

mr_diver · « **Reply #1808 on:** November 04, 2020, 09:13:11 »

Not enough orange?

Rixington43 · « **Reply #1809 on:** November 04, 2020, 09:30:15 »

Looks like someone else has encountered this problem:
https://www.cjdesignsllc.com/products/axle-blocks/

Only other suspicion would be someone in the past wailing on the axle nut with the rear wheel not aligned properly so the load isn't pulling square on that axle block. I'm no KTM basher but that does seem like engineering a solution to a problem that doesn't exist and creating a worse problem in the process. What exactly was wrong with clearance blocks on both sides with a flange on the axle, dare I say it, like an old V-Strom (Hush my mouth)

SimStrom · « **Reply #1810 on:** November 04, 2020, 09:31:34 »

@MrNick: no bullying, the only KTM owner I know has emotional issues, he keeps breaking down.

Mr Nick · « **Reply #1811 on:** November 04, 2020, 15:02:54 »

Rix: just like everything in the additions market, people will try to sell you products that are just all show & no real purpose. Whole brands are built on that premise - look outside your local fancy coffee place for examples.

The potential to apply excessive torque while it is not aligned from side to side is really low if you take a second to look at everything: the adjustment blocks drop into their tracks and are a broad guide that is larger & more positive than the plain Suzuki axle. The possible damage I'm suspecting is from it being rotated as it was hammered through, catching a corner of it on the outside of the guide. Unlike the internal bolt & blocks used on other bikes, it's pretty obvious when the block isn't against the adjuster bolt before you crank it down.

I'm going to put that minor detail out there that the multiple world championship winning off road bikes still use the same system it seems from the fiches, so it can't be all that bad as it comes out of the factory, but something untoward has happened here. Maybe someone used 90 ft lb instead of Nm? I keep saying someone as I don't think it was me - I'm fairly careful with what I do as it's my own arse that's on the tarmac if it's wrong.

At the end of the day, it's been picked up and it's a lot less hassle and expense than repairing knackered final drives or the like, so I'm not fussed about it.

Rixington43 · « **Reply #1812 on:** November 04, 2020, 15:13:59 »

Oh absolutely, I was only observing that it's happened to someone else before, not that's it's probably or inevitable. I don't think the design is fundamentaly flawed and I'm sure they go on forever if treated exactly as the OEM intended, just maybe there is less allowance for heavy handedness than there is with an old fashioned clearance axle block where you'd only ever risk someone hammering on a steel axle end.

* Most world championship winning bikes will be almost completely replaced before a normal person runs out of fuel. Longevity and performance can be poor bedfellows.

kwackboy · « **Reply #1813 on:** November 04, 2020, 15:37:36 »

This one bucks the trend @125000 miles on the clock, bevel oil never been changed.

The clutch however, rattles a little ..

SimStrom · « **Reply #1814 on:** November 04, 2020, 16:06:53 »

It's a faulty one

Mr Nick · « **Reply #1815 on:** November 04, 2020, 17:15:11 »

Quote from: kwackboy on November 04, 2020, 15:37:36

The clutch however, rattles a little ..

Inspired by Ducati?

How often should it have been changed, or did they just not develop an oil change frequency as they expected it to be rebuilt often enough that it didn't need one by itself? Guzzi still say change it every 30,000 km (every 10k on my SP3).

Rix: if it was fundamentally flawed, you wouldn't run it at all, regardless of how frequently you change it. But they've only won 18 straight Dakars with it on the bike, so there must be something wrong... There's a few tales on this forum about galled nuts & rusted axles to say the Suzuki version isn't perfect either.

Rixington43 · « **Reply #1816 on:** November 04, 2020, 18:47:41 »

I really wasn't trying to rag on the design, or on your chosen brand of bike and I certainly wasn't saying the Suzuki way is perfect. All designs have their pros and cons, was just interested in the differences and what might have caused this particular failure.
You caught it, you're happy it won't happen again 👍.

Mr Nick · « **Reply #1817 on:** November 06, 2020, 12:38:28 »

I stripped the cracked adjuster block from the axle last night and I think I have a better idea about what's happened to it.

On the tip if the block that sits against the adjuster bolt, there are a couple of indentations where the head of the bolt has been pressed into the underside of the block.

The crack actually crosses the centre hole. pretty much putting thoughts of a simple faulty material failure to rest in my mind, and I'm even more convinced this is human error. Not paying attention and having the block on top of the bolt when you try tightening the nut would result in a failure, and the thinnest wall section is where it has cracked initially. The crack then weakened that axis and even applying normal torque then propagated the failure along it.

The block is 11.5mm thick, so it's been a pretty decent effort to break it. There are two dents, so it wasn't just one go they had at it: well done whoever you were.

Brockett · « **Reply #1818 on:** November 06, 2020, 19:01:29 »

Brockett · « **Reply #1819 on:** November 10, 2020, 18:29:31 »

VX800:-. Used a colortune to view the combustion colour and tweaked it to electric blue. Fitted new plugs and used the Carbtune to balance the carbs. Fitted the tank and seat. Filled and bled the front brake (new disc, pads pistons and seals). I hope to get the rear wheel off and change the rear disc tomorrow and then it may be good to go. I just need to arrange and MOT and take it off it's two year SORN holiday.