banging into gear

[The smudger]

Hi all, I just bought an F650GS DAKAR (March 05 model). It is an ex BMW school bike and has been, well, run in, shall we say, but I got it for the right price. I have a query that you guys may be able to answer although I think i've found the answer already but need it confirned. When I put the bike in gear it really, (and I mean really!), 'bang's. I think I have located the problem to the cush drive. There is about 1-1 1/2 inches freeplay at the outside of the rear sprocket, which suggests to me worn out cush drive rubbers. Now the bike has only done 2,000 miles and someone else told me that this is quite normal for one of these?

I suspect these will be done under the warranty by my local dealer, but just wanted to know if anyone else has sufered with this fault?

Smudger.

 

[Max_Kool]

Replace the cush rubbers, you are absolutely right. On my bike there's hardly any play at all. And while you're at it, check the bearing of the sprocket carrier.

 

[Pondboy]

The gears (especially first) can be crunchy.

Try adjusting nearly all the play out the clutch. There should be just 1-2mm of movement in the lever before it starts engaging. Mine still startles horses if I engage first as they pass.

PB

 

[billy56]

ahh , i thought mine was the only one that did that. so pondboy yours is similar billy

 

[nick]

My bike always clunks badly engaging 1st gear.

Been like this since new.

 

[Dave Hall]

My bike always clunks badly engaging 1st gear.

Been like this since new.

I love the way it occasionally jumps out of 1st, usually as the lights go green, leaving you looking a plank.

A bike with character as they say

 

[The smudger]

cush drive result

Just had the cush drive rubbers renewed today. What a difference, tightened the bike up no end, feels like a new one!!!

Anyone got any excesive freeplay in theirs I suggest you have a set fitted, fantastic difference.

 

[Micky]

I love the way it occasionally jumps out of 1st, usually as the lights go green, leaving you looking a plank.

A bike with character as they say

D'ya know Dave, mine never dun dat! Have I got a baddun?

 

[LandRover]

When I put the bike in gear it really, (and I mean really!), 'bang's. I think I have located the problem to the cush drive. There is about 1-1 1/2 inches freeplay at the outside of the rear sprocket, which suggests to me worn out cush drive rubbers.
Smudger.

They all do that Sir ....





Someone had to say it ...........

 

[The smudger]

Oh it still bangs into gear, just doesnt 'lurch foward' so much now, like someone said, pondboy I think, its a feature!

 

[michnus]

Dumb question, but what is the cush rubbers? I see the front sprocket has a rubber on it, is it that or the rubbers in the backwheel that is in the hub/sprocket assembly?

 

[Micky]

Dumb question, but what is the cush rubbers? I see the front sprocket has a rubber on it, is it that or the rubbers in the backwheel that is in the hub/sprocket assembly?

Hi Michnus... not a dumb question at all mate.. The cush rubbers, three of them, live in the rear chain sprocket hub.. With the rear wheel out you just pull the rear sprocket away and there they are...

The lurching or jumping when first gear engaged, that people are speaking about is nowt to do with the cush rubbers, it's down to friction in the clutch plates, type of oil, and clutch cable adjustment!

Hope this helps

 

[Max_Kool]

Yes you're right, no you're not.

That banging when engaging first surely has something to do with the clutch, kind of oil, etc.

But it will get worse when the cush rubbers get worn, and they will!

 

[Micky]

Yes you're right, no you're not.
But it will get worse when the cush rubbers get worn, and they will!

you're right of course. It's down to clutch cable adjustment or oil, but it will get errr mmm BETTER as the rear cush drive wears. Won't it? Given more backlash in the worn rear cush drives there will be less directness from the gearbox sprocket to the rear wheel contact with the ground! Might sound noiser but the bike wont lurch/jump as much!

But you're right... I'm being pedantic. Allowed at my age maybe

 

[michnus]

What is the lifetime of the cush rubbers? Or how will I know if they had their time? I see the front sprocket have a rubber inset on is it necessary as other aftermarket sprockets has not.

 

[The smudger]

What is the lifetime of the cush rubbers?

Thats a million dollar question. My dealer and I agreed to disagree over this one. My bike has done 2000 miles and the rubbers were quite badly worn. When I asked them to do them under warranty they were a bit concerned that the bi8ke had been used off road all its life, (March 05 registered, previous owner BMW off road training school, Nr Swansea, South Wales, so it has had numerous riders of differing abilities).

Now my point was that the bike is built for serious off road use, hence the name 'dakar', and so any parts fitted to the bike should be 'up to the job'. If you peruse the terms and conditions of the warranty it does not exclude these rubbers, and there is no 'service life' on them, by that I mean that it is not suggested in a maintenance schedule that these should be replaced at any given mileage. My dealer, (Bath Road Motorcycles, Bristol ), were very decent about it and did the job.

I dont want to bore everyone about warranty etc but the definition is usually 'A MANUFACTURING DEFECT'. These bushes are, in my humble opinion, defective. Not because they are broken etc, but because they have worn out prematurely. A bit of a 'grey area' I know, worn parts are not usually covered by any sort of Warranty but I for one would not consider it reasonable to have to renew these every 2000 miles wether or not I was using the bike permanently off road or not?

Anyone still awake?

 

[JohnnyBoxer]

The Dakar is not really built as a serious off-road bike without serious mods like the TT Rallye bikes.

However it is a dualsport bike and will stand some off-roading, how much is open to debate..........but it stands up very well.

With normal road use, the cush drive rubbers will last a set of C&S, which could be 5000 - 30,000 depending on use and oiling etc.

However serious off-road bikes don't have cush drives fitted, they are direct drive

 

[michnus]

Why would the rubbers take more beating off-road than just normal riding? Normal commuting stopping/pulling away will more likely damage them more than off-road. It does not seem's like the rubbers really give trouble, even on f650.com there is no mention of them as a problem part

 

[The smudger]

I think my bike was an exception because of the history. Generally they dont really wear out, although as someone suggested, you should replace them when you fit a chain & sprocket set. They all have a bit of freeplay at the rear sprocet, although mine was pretty severe!