Dry clutch

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madforitkev
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Dry clutch

Post by madforitkev »

Probably a dumb question.

Aside from different plate/pad material what stops a GT clutch being a dry clutch.

Obviously the rest of the bits in the housing need lubrication sorting but is there anything else?

There are some very expensive TR dryclutch conversions but I was looking for an cheaper/fun engineering solution.
Honest baby....this is probably the cheapest bike I have ever bought!!
teazer
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Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Dry clutch

Post by teazer »

In simple terms the clutch has to be on the outside of a primary cover and the gears on the inside, so start with a clutch and clutch gear combo. Side covers can be cast or machined and welded and remember to allow space for a seal.

The next wrinkle is that the new clutch and drive will be rather wider than stock, so you need a longer clutch input shaft. Fortunately a GS750/1000/1100 transmission comes with longer input shaft.

It might be possible to use say a Ducati primary drive but the chances of shaft spacing being correct is small, so that it is probably that you would need to modify a stock driven gear, and since you would want to go with straight cut gears, maybe it's a good idea to get a TR style gear instead of a GT style. Clutch hub from a GT or GS might be able to be adapted and that just leaves the drum which would have to be modified.

As an exercise, why not. It's possible that you could make something work.
madforitkev
Posts: 292
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Dry clutch

Post by madforitkev »

So to be clear. The drive gear on the back of the clutch basket has to come off/somehow be re positioned inside the 'oil compartment'/primary cover?
I know the GS shaft is a little longer but would it be long enough? I guess when I understand the previous question I can work that out.

I think the TR primary is the best option.

Clutch release mechanism looks easy enough to fabricate.

I am doing the GS conversion as well.

Thanks again
Honest baby....this is probably the cheapest bike I have ever bought!!
madforitkev
Posts: 292
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Location: Poole

Re: Dry clutch

Post by madforitkev »

The GS 750 also had straight cut primary drive on the crank.

I wonder if anyone has looked at grafting that onto a GT and fitting a modified GS clutch?
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Alan H
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Re: Dry clutch

Post by Alan H »

Don't forget the lekky start clutch behind the real clutch. No oil and it'll either wear or seize.
There's several bearings that rely on the clutch casing oil as well as the gearbox of course and as mentioned, the GT has offcut gears so are side loaded and need oil.
Proof that four strokes are over complicated
madforitkev
Posts: 292
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Location: Poole

Re: Dry clutch

Post by madforitkev »

Looking at the BDK clutch kit for the TR, I've worked out how the drive is transferred through to the clutch basket which probably means a fairly heavy mod to the clutch basket.

I'm going to get a GS basket and see how it compares to the GT and the TR one.

BDK sell the crank and basket primary drive gears so that might be a useful investment as they will fit the existing crank then the basket just needs sorting.

Will post pics as it progresses.
Honest baby....this is probably the cheapest bike I have ever bought!!
teazer
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Location: Chicago

Re: Dry clutch

Post by teazer »

GS basket is a little different but may work with what you are playing with. And GS gears are different diameter than a GT. I have not looked at a GS crank or crankcases to see what would be possible, but a set of NOVA or BDK or Oily Tom (MPE) straight cut gears are a good place to start.

Clutch lifter won't be too difficult to work out.
teazer
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Re: Dry clutch

Post by teazer »

Alan H wrote:Don't forget the lekky start clutch behind the real clutch. No oil and it'll either wear or seize.
....
Eh? Starter clutch is off the left end of the crank on a GT750. Someone may be thinking about a 550.

Oiling is a worry, but the TR doesn't seem to have that oil feed through the end of the clutch lifter side so maybe it's not necessary.
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Alan H
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Re: Dry clutch

Post by Alan H »

teazer wrote:
Alan H wrote:Don't forget the lekky start clutch behind the real clutch. No oil and it'll either wear or seize.
....
Eh? Starter clutch is off the left end of the crank on a GT750. Someone may be thinking about a 550.
Ah yes, must have been a brain fart. :oops: :lol:
In my defence, I have done very little with the GT750 engine, and assumed (bad thing to do, I know) that it was the same as the 550.
Why change something that works? It uses the same parts as the early 550 clutch after all.
Proof that four strokes are over complicated
teazer
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Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Dry clutch

Post by teazer »

..
Why change something that works? ..
Because you can. :? :tw :lol:
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