Small Clunk - Big Clunk (Rear wheel)

[Soliton]

Howdy howdy,

I seek the collective wisdom. The rear end of the bike (R1150r) is making a little clunk- big clunk sound they:
1 - Only happen after the bike is warmed up, and
2 - Are separated by approximately ninety degrees of wheel rotation (picture below, skinny strip = little clunk, fat strip = big clunk
3 - Only happen once (little clunk and big clunk as a set) per rotation.
4 - Can be felt through the rear brake when the bike is warm and coasting in neutral down a steep hill. (Underground car park drive way)

As you can see I have a non standard rear wheel. It is an R1150 GS hub mated to a 17" spoked hub. To ensure the correct offset it uses the large 4 hole spacing washer (R1150 GS part # 36317653286) between the wheel and the final drive. This is the same part as used in the Rockster (5.5" rear wheel) to achieve the right offset.

I did not notice the clunking until recently and the wheel has been in place for about six weeks.

Theory one - Could be the rear universal joint on the final drive shaft. This part was replaced about 60,000km ago but I could only afford a good used part not a new one. My feeble brain is trying to work out though how many times the shaft rotates for each wheel rotation when the bike is in neutral. A ratio of 1=1 doesn't make sense. if it was this part it seems it should not clunk once for each wheel rotation.

Theory two - Could it be something to do with the re-attachment of the rear disk rotor. The rotor bolts that match the GS hub are 5mm shorter that the standard R1150r rotor bolts. I only realised this out when the wheel was off and at the shop. I couldn't get the correct part so my bush mechanic solution was to shorten the existing rotor bolts on a bench grinder. As the disk gets warmer might some misalignment cause the sound? Not sure, I would have thought it would just have rubbed or touched against the pad. The sound is an audible soft/loud clunk sound. I suppose the simplest test for this theory is the removal of the wheel and the replacement of the rotor bolts with five factory bolts.

I haven't removed the wheel again yet... Before I do so I would like to have at least some theories about what may be causing it.

I don't want something to lock up at speed and hurl me to my doom or mess up something expensive in the final drive area.

Any suggestions are much appreciated.

Sol

[kirby]

Rear ratio is 2.82 to 1. That would be aprox I drive shaft revolution per 127 degrees. If you remove the caliper that should tell you if it has anything to do with noise.
Hard to believe you would be using the rear brake enough to put much heat in it unless its dragging on the brake pads.
My first guess is its the u joint. Do you feel any resistance when your turning the wheel? The joints will make some noise (possible) when hot. If the bearing cup has a bad needle or two depending on how bad you can sometimes feel a little resistance while turning the wheel. When on the center stand the angle is not the same as when your riding. If the swing arm is leveled out and the noise goes away it could be an indication its the u joint is the source and maybe not a problem.

The other thing is the main bearing(s) supporting the crown gear or the pinion bearing.
Look for metal in the drive oil for that.
Noises are hard to imagine as your clunk might be my squeak!!

Hope its nothing.

BTW, good idea with the tape!

:-)

[Soliton]

Okay....

Good news/bad news.

I tried Kirby's eminently sensible suggestion and removed the caliper. The clunking is still there, oddly enough if I roll backwards it occurs in a different position but still separated by ninety degrees. This indicates that it isn't anything to do with the brakes.

It does not appear to make the sound when the wheel is rotated whilst the bike is on the centre stand.

However...when I removed the callipers I noticed they were screwed on super tight. Re-installing them I tightened them up and the rear bolt has stripped the thread straight out. I am exceedingly cross! I think it is fair to say that this is quite a bother and my level of annoyance is high.

Anyhow, thanks Kirby for the suggestion, at least one cause is off the list.

Sol

[CycleRob]

Soliton,
You have loose spokes. Check them for tightness by hitting them midway with a 14mm wrench. They should all sound the same, but yours definitely will not. Some loose spokes can make a clacking sound as the wheel turns with the weight of the bike on it but not make a sound when spinning on the center stand. They need to be re-trued ASAP!

[Soliton]

Cycle Rob,

These wheels are virtually brand new. The rear one has only been on the bike for about six weeks. I have tested them as you suggested and they are definitely not ringing at the same frequency.

I am not sure how much tolerance their should be in the "ring"

Will email Woody's and see what they have to say.

Rs,

Sol

[CycleRob]

Soliton,
The tones I was referring to are dramatically different between tight and loose. I have hit loose spokes and have them make a "dunt" sound, while tight ones nearly sound like a small bell ring.

"These wheels are virtually brand new. The rear one has only been on the bike for about six weeks".
When you have wheels trued or re-spoked at an established business, it is VERY RARE that it will be done incorrectly. The clunking you are hearing could also be grain slippage, like the tinking sounds you hear when your exhaust cools down on shutdown. The fact you say it happens in a different wheel location when going backwards correlates with grain slippage. Maybe they are TOO tight?

So . . . what do the spokes sound like, compared to other new bikes with spoke wheels?

[peels]

can you put in the center stand and turn by hand and find the spot where it clunks? press your ear up to the final drive and listen. could be a bad tooth or something, like main bearing going?

Or does it only do it if weight is on it?

if that's the case... moneys on cyclerob's theory, which I never would have thought of. Very interesting-Iv'e never had a motorcycle with spokes.

[Soliton]

Woody's gets pretty good reviews. The wheels are superlaced and the spokes are full stainless, supersized with matching SS nipples. By their description they are the strongest wheels they could build using the BMW hubs. The were definately not cheap, but I note that when the tyre was fitted the tech said he had never seen a rim as true, his comment "There is not a cigarette paper's worth of movement when that wheel is spun up."

I have emailed them to get their opinion. At this point it woould seem the best technique for diffeential diagnosis would be to re-tyre and replace the cast wheel and see if the issue continues. Of course I am not keen to do this as it means yet more $$$

This aspect of the job has been the most expensive and the scariest. Everything was test fitted before I sent the hubs away for building but I still have to fiddle with stuff to get everything mounted square. On the front, the front speedo drive will need modifications and on the rear it required a spacer and shortened rotor bolts.

When the Treasury Secreatary found out the cost I had to sleep with one eye open for a month. I they don't fit or work, I fear my continued safety would be in jeopardy.

Rs,

Sol

[peels]

Woody's gets pretty good reviews. The wheels are superlaced and the spokes are full stainless, supersized with matching SS nipples. By their description they are the strongest wheels they could build using the BMW hubs. The were definately not cheap, but I note that when the tyre was fitted the tech said he had never seen a rim as true, his comment "There is not a cigarette paper's worth of movement when that wheel is spun up."

I have emailed them to get their opinion. At this point it woould seem the best technique for diffeential diagnosis would be to re-tyre and replace the cast wheel and see if the issue continues. Of course I am not keen to do this as it means yet more $$$

This aspect of the job has been the most expensive and the scariest. Everything was test fitted before I sent the hubs away for building but I still have to fiddle with stuff to get everything mounted square. On the front, the front speedo drive will need modifications and on the rear it required a spacer and shortened rotor bolts.

When the Treasury Secreatary found out the cost I had to sleep with one eye open for a month. I they don't fit or work, I fear my continued safety would be in jeopardy.

Rs,

Sol

do you have any friends or acquaintances that have an oilhead beemer that you could snag their wheel for a few minutes? Or a shop? I mean, I wouldnt re-tire it unless you know.

[Soliton]

Well guys I found out what the noise was....

When my rear tyre was fitted I don't think they tightened the wheel nuts properly. The entire rear wheel came off as I dropped into a roundabout and the bike dragged it's butt and mine across a couple of lanes of traffic.

I'm ok but I feel like weeping. I just spend $3k on wheels and the best part of five years of work and it has all come apart because someone didn't fit a wheel properly.

Sol

[peels]

Well guys I found out what the noise was....

When my rear tyre was fitted I don't think they tightened the wheel nuts properly. The entire rear wheel came off as I dropped into a roundabout and the bike dragged it's butt and mine across a couple of lanes of traffic.

I'm ok but I feel like weeping. I just spend $3k on wheels and the best part of five years of work and it has all come apart because someone didn't fit a wheel properly.

Sol

umm whoa.

that's remarkably bad. and embarrassing that we didnt even think of that! sometimes, It's the simple things.... But, honestly. glad you're here to "weep" about it. that could have come off at highway speed, about to brake for a tight right hand corner with an 18 wheeler coming your way in the opposite lane.


I remember when my front valve stem just went "pssssshshhhh" sitting at a restaurant, 10 hrs from home, right after a LOOOONG 90mph+ stretch in high speed traffic. Had that happened 10 minutes earlier...I might not be here to complain about it

good luck with the repairs and ride safe.

[riceburner]

Well guys I found out what the noise was....

When my rear tyre was fitted I don't think they tightened the wheel nuts properly. The entire rear wheel came off as I dropped into a roundabout and the bike dragged it's butt and mine across a couple of lanes of traffic.

I'm ok but I feel like weeping. I just spend $3k on wheels and the best part of five years of work and it has all come apart because someone didn't fit a wheel properly.

Sol

Ah poo. :(:(

I hope the bike is repairable and you're not too bruised.

[Soliton]

Thanks guys,

I am trying to get some good pictures but the thread in bolt wells in the hub is almost completely stripped out. I think the two bolts that were loosest have been allowing the others to rock and this has caused them all to eventually fail when they stripped out and pulled free.

My beloved is suggesting I should buy a lottery ticket. Had this happened only a few km up the road I would have been doing 80km/h or 100km/h and been surrounded by vehicles at the same speed. I walked away with a bruise and a small graze (although I feel like I have been in a tumble drier).


Rs,

Paris

[CycleRob]

Wow! We all missed this one (especially me ). The problem is we all assumed too much. The lugbolts are right there, easy to see, easy to access, literally Job-1 on the check list for any rear wheel problem. The rotor bolts, the spokes, the ring gear teeth? The rear wheel lug nuts were assumed to not be a factor because a dealer did the work. It does appear that they have not tightened the wheel lugbolts properly (2 were very loose) and there should be restitution. They have very expensive insurance just for this type of error (We had $2 Million coverage on my "retired-from" shop).

Why I also blame myself: "These wheels are virtually brand new. The rear one has only been on the bike for about six weeks".
It is SOP (StdOperatingProcedure) to re-check the torque on new wheels after about 100 miles (160km) of riding because new and heavy stresses are being placed on a brand new casting. The dealer that put the brand new wheel rims on should have told you something like that, and arranged for the re-torquing to be performed without an appointment.

20:20 hindsight: It would be a good practice to re-check the lugbolt's torque when anyone else puts the rear wheel on for you -and- any time you change the rear tire on a single sided rear wheeled bike (like mine).

[kirby]

And oil, trans, and rear drive plugs when serviced by someone else.

[sykospain]

Amazing - loose lug bolts, eh ? The only time I ever heard such a clunk-clunk noise at the back of one of my earlier Boxers was when I had failed to re-torque the lug bolts after fitting a new rear wheel. The wheel was literally shifting laterally on the bolts with every revolution 'cos they had worked loose. Could have killed me.

[sykospain]

Incidentally Soliton, which brand of rear-wheel hugger is that in your foto ? The Powerbronze one is supplied in glossy black only - ugh....

[Soliton]

To answer the question about the hugger - Puig and it was painted with truck bed paint.

They are going to write off my bike. Repairs are quoted at AUD$11,000. I will seek first right of refusal on the bike but re-registering a repairable writer off is troublesome here. My intention is to buy another R1150r....in black and use the parts between them. There are at least two currently available with less than 60,000km on them (35,000 miles)

This bike was a single spark with no ABS. This was deliberate, a mechanic friend said if the ABS fails it costs a bomb to fix and the dual spark bikes have issues with the stick coils.

My questions are, if folks were going to buy an R1150 R.
1 - Generally what year and model would you suggest e.g.
- Single or dual spark
- ABS or no ABS
2 - Does anyone have the number/ date etc of the tech advisory that deals with cutting the cable ties holding the wiring under the head light.
3 - What year did the new style cam chain tensioners become standard.
4 - Beyond the following mods what do you consider de-rigeur
- AF-Xied
- Lennies Rocket Sprockets
- Replace dash light tell tales with LEDs
5 - What stuff would you be keeping a real look out for as technical problems that could cause grief.

Sorry to ask so many questions but with the money I get back I really need to get the very best bike i can get. I can't afford a whole new range of expensive things to fix. BMW parts here can cost from 150% to 400% of the cost you guys get them for. I really don't want to buy someone else's problems.

Regards,

Sol

[sykospain]

What a sad tale, Soliton - poor you.
The issue with twin-spark coil-sticks is mainly the problem of water-ingress rusting the metal parts of the 'tube' and swelling it. If you don't ride in rain a lot, and never jet-wash a BMW bike, don't worry.
In general, 2-spark fuelling / ignition is much more positive than single-spark, smoother and better so don't cross-out a 2-spark bike.
As with any 2nd-hand purchase of any Beemer that's more than 10 years old, when Berlin made the bikes entirely in-house with no outsourced parts from China - unlike today - the quality and reliability of such a vehicle should be absolutely kushtie.
In weighing-up a purchase, it's condition, condition, condition.
Aided by chatting extensively to the current owner for assessing their attitude to caring for the bike, looking at the service history documentation, peering in great detail at every nook & cranny of the vehicle, and if possible, having a half-hour test ride of course, when you get back and the bike's on its centre-stand, listening at the back for the slightest hint of graunching final-drive bearings, even a slight rumble as you turn the back wheel by hand with the motor off should scare you off, and if the owner is very co-operative, spending half-an-hour taking off the starter motor and poking at the edge of the clutch friction plate - see loads of posts about possible premature spline-wear assessment all over the forums.
On startup, check the briskness of the engine turning over, listen for any difference in noise between pulling in the clutch lever compared to not doing so and check whether the upgraded Cam Chain Tensioner kit has been fitted to the left-hand pot. The nut on the old one which causes the initial death-rattle is 17mm, and the new one - lovely - is 15mm.
I would ALWAYS invest in an older Boxer, rather than in the 80% Chinese-made new ones at a totally ridiculous price for what they are - 125bhp notwithstanding.
Happy hunting - there's loads of 'em about. And I'm shocked to see your quote for Oz spares prices. Deal instead on Skype with people like Motorworks, Motobins and James Sherlock and pay the shipping...
AL in s.e. Spain

[sykospain]

Oh sorry - forgot - don't buy an ABS bike ! they can be REAL trouble....