Sudden stop!

[Scribner]

Out for a ride on Sunday morning moving along at 45+/- in third when the engine stopped. The rear wheel locked and the back tired slid to the left. I just let it slide to a stop because I didn't want to release the back tire with the clutch when both wheels were not in line. This has never happened to me and this is my second RT. The bike started fine and over the next 110 miles never exhibited any problems. I did not accidently tap the stop switch or anything else I know of to cause the engine to stop. Due to the great weather lately the bike has sat for 2.5 weeks with about three gallons of fuel on board. Any ideas why this happened or is there anyone else out there with similar experiences.

[DaveTheAffable]

...The rear wheel locked...

 

That's unnerving. I don't have the answer, but the engine dying won't cause the rear wheel to lock.

 

I recently was doing some restart testing and hit my kill switch at traffic speeds, and the bike simply started slowing down with the engine turning. I pulled in the clutch, restarted, and went on my way.

[Scribner]

Having pushed off bikes to start them back in the day that's what I thought. This really puzzles me.

[DaveTheAffable]

Maybe some electrical/computer malfunction that killed ignition and affected braking/ABS?

 

If you remember, once you were stopped, did you turn key off and back on? That would allow the computer to reset.

 

Or, did you leave key on, and once stopped, just push the start button?

 

(I KNOW there are people on the board that know FAR more than me about RT's...lol)

[dirtrider]

Afternoon Scribner

 

There is something really wrong there! As mentioned, in 3rd gear, the engine shouldn’t be able to slide the rear wheel (really no different that just closing the throttle).

 

You need to bring that to the attention of your BMW dealer & get THE EXACT thing it did on the record.

 

It really sounds like something locked up in the drive train, like the trans going into two gears at once, or the rear brake locking up, or something wrong in the final drive, or even a piston tightening up.

 

By chance did you smell anything when, or just after, the lock up? Like brake smell or gear oil?

 

After you get it on record with your BMW dealer I would call BMW customer support & talk to them about what to do next. Maybe they have seen it before & have an idea what happened.

 

At the very least file a complaint with NHTSA as a SUDDEN locking rear wheel could be devastating at speed.

 

BTW-- BMW had a similar problem back in the 1150 oilhead days-- From a BMW Service Bulletin on rear wheel lock up see below--

 

 

"If a gearbox is affected in this way there is a possibility that when the rider attempts to

shift from 5th to 6th gear, that both gears can be engaged simultaneously. This may

cause the gearbox to seize, locking the rear wheel"

[eddd]

 

I concur that there had to be a significant driveline issue, and it needs to addressed ASAP. I guessing that pulling in the clutch would not have changed anything since that would only disengage the engine from the transmission. It would seem unlikely that there would be anything in the engine that could seize so completely and then fire up immediately. The drive shaft and final drive would seem to be an unlikely source of the problem since you were able to get underway immediately.

 

The one thing you did alter to get going again was the transmission. You shifted into neutral to start the engine, or down shifted to first to take off, or maybe both. In any case you were back to normal and the only thing changed was the transmission.

[Scribner]

That's interesting; I did smell an odd odor that I thought may have been the rear tire but it did have more of an electrical smell to it. I have called the local dealer but no info yet.

[Danny caddyshack Noonan]

K100RS gearbox did that once after an incorrect shim.

[Guest Kakugo]

If my experience is anything to go by, you should get the gearbox inspected at once. And it should be on the house.

 

I had exactly the same issue on my 1995 Speed Triple. As I was turning back to get home (something was obviously very wrong), the gearbox literally froze solid with a very loud metallic sound.

 

Given the rear wheel was completely stuck, the bike had to be dragged on the breakdown truck with a winch. While I got a completely new gearbox from Triumph, the explanation I was given almost defies belief: according to the dealer a circlip had jumped out of place and initiated a catastrophic cascade of events which resulted in the gearbox committing suicide.

It was obviously an assembly error of some kind and, given the bike was almost new, more or less believable.

 

Hope your case turns out to be something less complicated.

[Scribner]

Just an update. 630 miles later and no problems at all. I didn't take it to the shop but looked over everything I could and cautiously rode. I'm still not sure why this occurred but she has performed perfect since.

[AnotherLee]

If that was my bike, I'd drain the transmission into a clean container and look for metal shavings and send a sample for oil analysis. Maybe put in a magnetic drain plug.

[marcopolo]

If that were my bike, I'd have it inspected by a BMW dealer. Even if they were to find nothing now, at least you'd have it on record. My first priority in all this would be my personal safety.

[Skywagon]

Nothing to add relative to the advice given and safety issue...however if I understand that your engine had sudden stop and was not turning over, e.g. rpm's to 0 from say 3000, I would be very concerned of internal damage. I would want to have BMW examine my crank, valve train, crank bearings, etc. I've seen more my share of similar issues in airplanes resulting in catastrophic engine failure at a later date. I realize this isn't an airplane engine, but depending on your speed and the conditions, I would press BMW hard for an examination. I don't know if these engines have counterweights but if they do that would definitely be a problem.

[racer7]

I don't find the problem description consistent.

 

So my first question is did the rear wheel truly lock up?

If that is the case, the evidence is on the pavement as a solid skid mark. The RT can have rather ferocious engine braking in lower gears (the compression ratio is high) if power dies instantly from other causes (my fpc crapping out got my attention from engine braking).

 

If the wheel truly locked up that means a driveline serious problem. And only a darned fool would fail to determine its cause ASAP- it could kill you next time. Such problems always repeat, usually sooner rather than later. Which is why that 690 problem free miles has me questioning the pro0blem description.

 

If its just engine braking being mistaken for a locked driveline and was managed once by the rider, its likely the rider can manage the second. Some things that cause motor cutouts leave diagnostic codes that can be seen with a dealer computer or GS-911 but not all.

 

In any case, this bike needs competent examination. Even something a simple as having power quit with an 18 wheeler on your butt can be bad for your health if rider response is inadequate. Get it figured out lest you find out the hard way.

[Deek]

Just an update. 630 miles later and no problems at all. I didn't take it to the shop but looked over everything I could and cautiously rode. I'm still not sure why this occurred but she has performed perfect since.

 

I think you really ought to take it to the dealer ASAP. Warranty or not, you experienced something that could be a lot more dangerous the second time, friend.

[Blind Squirrel]

 

By chance did you smell anything when, or just after, the lock up?

 

I did smell an odd odor...