If I smell my clutch

[marked23]

If I smell my clutch in stop-and-go traffic, am I doing something wrong? I do tend to ride the clutch a bit longer than I should, when starting from a stop, but I figure that will improve as I gain experience. Every once in a while, I smell it getting hot.

 

Am I ruining my clutch? ..or is an occasional sniff pretty normal?

 

My 97 RT had a new clutch put in it a few months before I bought it.

[Dave Parry]

Bmw's use a dry clutch, they don't take kindly to excessive 'riding',

Dave.

[upflying]

You shouldn't smell the clutch unless you are using it wrong.

There was a thread that covered proper technique recently. Ill see if I can find it.

Here it is, good advice here.

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=642414&page=1

FWIW, I engage mine as quickly as possible at idle from a full stop. No throttle until the clutch is fully engaged. Engagement should be just above the speed where the engine stalls. Very minimal slipping to move.

[Tony_K]

Think of your clutch as a on off switch because that is what it is. Lingering in the middle is not a happy place.

[marked23]

Yeah, I'm a new rider.. Got my training on a wet clutch 250 and the instructor dared us to try and burn them up.

 

We learned a lot of very low speed maneuvering and his teaching curriculum required us to slip the clutch for extended periods of time.

 

I never slip the clutch ^that^ much on my RT, but I'm left with the false impression that it's ok to spend some time in the friction zone. I'll read that other thread and see what I can learn.

 

[NonComp]

We learned a lot of very low speed maneuvering and his teaching curriculum required us to slip the clutch for extended periods of time. I never slip the clutch ^that^ much on my RT, but I'm left with the false impression that it's ok to spend some time in the friction zone.

I would not say that your impression is false. It is perfectly normal to slip the clutch for slow speed manoevering. Motorcycle police officers are trained to slip the clutch riding RTPs. Their clutches may not last as long, but I wouldn't consider it abuse or bad technique.

[dirtrider]

Yeah, I'm a new rider.. Got my training on a wet clutch 250 and the instructor dared us to try and burn them up.

 

We learned a lot of very low speed maneuvering and his teaching curriculum required us to slip the clutch for extended periods of time.

 

I never slip the clutch ^that^ much on my RT, but I'm left with the false impression that it's ok to spend some time in the friction zone. I'll read that other thread and see what I can learn.

 

Afternoon marked23

 

Yes, your BMW has a dry single plate clutch that can’t take the abuse of the wet clutch bikes but you can slip it without any problems as after all it is clutch.

 

The secret to slipping the clutch on a BMW boxer without doing lasting damage or smelling the thing is only slip it for a short times and only at low engine RPM’s .

It isn’t the actual casual slipping that kills or overheats the BMW clutch it is slipping it at elevated engine RPM’s. The more RPM and torque the engine produces the more heat that is generated in the clutch assembly when it slips.

 

You didn’t say what you are doing, but if slipping that clutch at fairly high engine RPM’s is it then try to change your usage.

One way is to sort of modulate the clutch in and out while in the friction zone, just a little clutch to get it rolling then pull it in to just outside the friction zone then back into the friction zone again to gain more speed or pull. Kind on in/out/in out/in/out in the gray zone with quick succession until you get out of the low speed area you are trying to control with the clutch. Also try to keep the engine RPM as low as possible as that protects the clutch as much as anything.

 

There are just some riding situations that you can’t keep the clutch engaged continuously as the engine will lug too much or the road speed will be too high for the situation.

 

I have slipped a BMW GS dry clutch all the way up a very long slippery sandy washes and haven’t killed a clutch yet but the engine is at idle or just above idle, never at elevated RPM’s. “Remember speed kills and that applies to elevated engine speed and dry clutches”.

 

 

 

 

 

[DavidEBSmith]

I would not say that your impression is false. It is perfectly normal to slip the clutch for slow speed manoevering. Motorcycle police officers are trained to slip the clutch riding RTPs. Their clutches may not last as long, but I wouldn't consider it abuse or bad technique.

 

They are trained that way, largely because they're being trained by guys who learned on Harleys and Kawasakis with wet clutches. Departments that figure out how much money they're spending or how much downtime they're losing on frequent clutch replacements train their officers not to slip the clutch.

 

It's not unusual for Oilhead clutches to last 100K or more with proper technique. When CHP got their first Oilheads, riding them like Harleys, they were lucky to get to 50K on a clutch.

 

When the Oilheads first came out, the clutch freeplay spec was only 2 mm. A little pressure on the brake lever, a little wear on the clutch, and you got slippage. Clutches burned out very fast. BMW increased the freeplay spec to 5 mm. Clutches started lasting longer. BMW increased the freeplay spec to 7 mm. Clutches started going 100K miles.

 

Slipping the clutch so you can smell it on a regular basis will seriously shorten the life of your clutch.

[marked23]

Tell me more about this "freeplay spec". Are you talking about the gap at the clutch lever?

 

If mine is set for 5mm, then 7mm would help me behave?

[Selden]

In my opinion, a gap that "feels" right to your hand is the "correct" freeplay gap, although as a rule of thumb, looser is better than tighter, as long as the clutch completely disengages when pulled in (less of a problem with a dry clutch than wet).

 

I just measured the gap at 11.5 mm, which feels right for my not so large left hand. At this gap, the engagement point is where I want it, and I get smooth launches and clean shifts. As little as a quarter turn of the adjustment wheel makes a noticeable difference in clutch "feel". The transmission makes no noise whatsoever when put into first at a stop, so I know the clutch isn't dragging. At smaller gaps, I have a hard time modulating the engagement point, because the clutch lever is too far away from the grip for my hand size.

 

83,000 miles on the original clutch, and I have never smelled it -- even in difficult conditions such as stop and go traffic on a steep grade while riding 2-up.

[Quinn]

You can try my system: At idle or slightly above, let out the clutch into the "friction zone". Once the bike starts moving, increase the throttle and finish letting out the clutch. Main idea is minimal engine speed until bike gets moving; but has to be enough to not stall in that high first gear.

 

 

In the interest of truth: I just replaced my clutch at 73k.

 

---

 

 

[Jim Moore]

I would not have less than 7 mm of freeplay. I think more thatn 7 mm is probably OK.

[topdal46]

Are you sure it's the clutch you smell, is it a rubbery smell? If so it might be the alternator belt.

[dan cata]

My alternator belt never had any smell, even when half of it broke and had only 2 ribs left to do the job :|

 

 

[marked23]

The history on my bike is that the previous owner bought it not-running It had a broken alternator belt that took out the hall sensor. He fixed it, used it for a single trip, then sold it to me. So it's got something less than 3k on the alternator belt.

[NonComp]

Slipping the clutch so you can smell it on a regular basis will seriously shorten the life of your clutch.

I agree. If you are slipping the clutch and reving the engine to the point where you are smelling the clutch, then you are doing it wrong. You should be working the engagement zone for slow speed manoevering only, as dirtrider suggested, with RPMs just about idle speed. You should not be smelling the clutch at all during normal riding.

 

I learned these techiques by taking an advanced civilian version of the riding course taught to and by police riders. They teach the same techiques to Harley, BMW and ST1300 riders. Lots of beemers in the course. No smoking clutches.

 

The orignal "free travel at clutch lever" adjustment in my '96 1100 Rider's Manual is 3 to 5mm. It was later revised to 7mm. See page 30.

 

As for clutch life, if you are going to split the bike occasionally to look at/lube the splines, it's not that much more effort to do the clutch while you are there. I bought my '96 with a blown clutch and 60k miles on it.