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-   -   Does it hurt the engine when you "lug" it? (https://www.horizonsunlimited.com/hubb/bmw-tech/does-hurt-engine-when-you-7777)

Tracy 15 Jul 2002 20:50

Does it hurt the engine when you "lug" it?
 
I ride my GS between 3.5k and 6.5k rpm area. Ari, my partner, rides her 1100R well below that. She gave me a ride home today and I noticed it. I'm not going to say anything if it is a personal preference thing (I know she thinks it's easier on the engine) but I read the thread about breaking in the bike and you should NEVER lug it and was wondering if the same applies to a bike that's got 60k km on it?

Timo 16 Jul 2002 07:39

Yes, you are correct. Lugging the engine is certainly not better for it, and could lead to premature wear. I think it was mentioned on the 'break in' post, but BMW initially had a problem with their bikes when they started importing to America. This was baffling at first (lots of low km bikes with problems) but was found to be a result of the american riders lugging the engines! A smooth engine is a happy engine. The shuddering caused at low rpms is not a happy state.

mmaarten 16 Jul 2002 17:30

Hi,

Traveling with "low rpm's" is not alway's bad. If your speed is constant and the bike has no problem keeping up to speed, 2500 or 3000 rpm is no problem as long as it run's smooth. It depends a bit on the design of the engine. Some like to run at high rev's and some like to run low.
It is, however, very bad to throtle up at low rpm's. The piston gets a big big push and has problems to go anywhere, so it's surching and therefore also putting a lot of presure to the cylinder-wall's even "chucking off" little bit's. This is especially bad with a new engine (it's rougher).

High is not alway's better.
You should look at it this way: The piston slide's along the cylinder-wall and with every cm it's sliding, it's wearing out.
If your rpm's are twice as hihg at a certain speed, the piston travels twice the distance, so the lifespan is reduce with 50%. http://www.horizonsunlimited.com/ubb/frown.gif

So you'll have to find a compromise between the bad low (chunking) and the bad high. This depends a lot on the "stroke" of the enging, the longer the stroke (harley-davidson) the lower the "good rpm's"

Theoretical a engine with a stroke longer then the bore would like to run low, while vice versa would like to run high.

In real life.... you just have to "feel" if the engine is http://www.horizonsunlimited.com/ubb/smile.gif happy.

By the way... also the transmission can get a real beating from low-hard rpm's. If you can feel the push, so can your gear and drive-chain.

Hope this helps.
Maarten

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- www.maartensworld.tmfweb.nl -

[This message has been edited by mmaarten (edited 16 July 2002).]

Tracy 16 Jul 2002 23:33

Thanks very much for the replies.

My GS 1100 seems to run real nice between 3 and 6,000 rpm.
My partner, Ari, her bike is an R1100R, basically same engine right? I thought it should like the same range. She doesn't have a tachometer which makes it hard to say exactly how low she runs it, but I rode it around a bit today and it seems to run exactly the same as my bike, first, second, third for city driving up to 85 km/h, fourth to about 120 km/h and then fifth for cruising.
Maarten, thanks for the enlightenment on the stroke > bore = low rpms and stoke < bore = higher rpms, will have to look it up in the Haynes manual. Also, re-reading what you said, as long as she doesn't throttle up at low rpms then the engine doesn't suffer from cruising say, in fifth, at 95 km/h which is a bit under 3,000 rpm? That is what she likes to do and as long as it doesn't punish the engine, I say to each her own way of riding.

BTW, we are in Amsterdam if you want to get together for a ride some weekend, although am sure you are a bit busy with pre-trip prep.

Cheers!


[This message has been edited by Tracy (edited 16 July 2002).]

JohnA 17 Jul 2002 02:25

Please note that riding at a low RPM is not the same as LUGGING. I normally ride with a low RPM, however, if I accelerate or begin moving uphill or some such, and the engine begins to labor (lug) then I downshift right away. Lugging is bad for your engine, period.

Regards,

John


mmaarten 17 Jul 2002 17:30

Hai Tracy,

I alway's find time to meet new (and old) friends. (actually I am not that buisy http://www.horizonsunlimited.com/ubb/wink.gif)
So, send me an email, you'll find the adress in the top of my posting (little face with qustionmark), and we can plan something.

CUlater
Maarten

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- www.maartensworld.tmfweb.nl -


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