Disc brake conversion

Getting your chassis to handle your blazingly fast Suzuki powerplant.

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pull the wire
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Disc brake conversion

Post by pull the wire »

I'm trying to figure out the best route to take to convert the rear drum to disc set up on my GT750. I think my biggest problem is that I don't want to give up my spoke wheels. Call me traditional but I believe motorcycles are supposed to have spoke wheels. Does anyone know if the early GS series bikes have a spoke rear and disc set up? Is it possible to use the entire swing arm/wheel and disc set up from another Suzuki model?

Thanks for your help
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Alan H
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Re: Disc brake conversion

Post by Alan H »

LOOK HERE
This answers your question.
I do know the GS550 swing arm fits the GT550 without modification as I have one for my next resto.
You have to use the swing arm too as the caliper torque arm is completely different.
You'll have to make up a bracket for the master cylinder and pedal.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
pull the wire
On the main road
Posts: 105
Joined: Mon Oct 21, 2013 10:04 pm
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Suzuki 2-Strokes: 73GT750 75GT750 84RZ350 89 FXRS-CONV
Location: Phoenix, AZ

Re: Disc brake conversion

Post by pull the wire »

Easy enough. Now I just have to find a GS spoke disc type hub to lace my aluminum wheel to.

Thanks
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Suzukidave
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Re: Disc brake conversion

Post by Suzukidave »

The first yr GS750 had a spoke disk rear wheel .
the older i get the faster i was
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Re: Disc brake conversion

Post by pull the wire »

Thanks Dave. That's the one I'm looking for
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Suzukidave
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Re: Disc brake conversion

Post by Suzukidave »

77 GS750 http://www.google.com/imgres?imgurl=htt ... CCwQ9QEwAA" onclick="window.open(this.href);return false;
the older i get the faster i was
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Alan H
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Re: Disc brake conversion

Post by Alan H »

Suzukidave wrote:The first yr GS750 had a spoke disk rear wheel .
And second year.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
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Suzukidave
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Re: Disc brake conversion

Post by Suzukidave »

My bad i thought it was 77 that the GS750 came out .. looks like 76 was . https://www.google.com/search?q=76+suzu ... 20&bih=992" onclick="window.open(this.href);return false;
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Alan H
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Re: Disc brake conversion

Post by Alan H »

Click the LOOK HERE in my earlier post above. Lots of info about ALL Suzukis.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
pull the wire
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Joined: Mon Oct 21, 2013 10:04 pm
Country: united states
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Location: Phoenix, AZ

Re: Disc brake conversion

Post by pull the wire »

I finally found a rear spoke wheel from a 78 GS750. It definitely took hours of searching but the effort paid off. I'm gonna go with the same year swing arm, caliper set up. The swingarm pivot shaft is the same part number so it's got to slide right in. I will have to purchase shocks that use clevis style lower shock mounting. I need rear shocks anyway. Just for kicks I mocked up my RZ 350 rear master cylinder to the frame and I'm sure I can use a similar set up to bolt on with the addition of a bracket. I will have to modify the brake pedal and right peg mount to get clearance for the master cylinder pushrod. Does anyone know if the GS 750 swingarm will accommodate a larger rear tire??


Thanks
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tz375
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Re: Disc brake conversion

Post by tz375 »

Larger than what?

I have 130 rear tires on two bikes with stock swingarms. I may have ground a little extra clearance out of the web around the front, but that's all it took. I should mention that one of those wheels is 3.00" rim and the other is a 2.50" x 17. 120 is about the limit on stock rims and that will clear the swingarm on a GT at least and probably on a GS
pull the wire
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Country: united states
Suzuki 2-Strokes: 73GT750 75GT750 84RZ350 89 FXRS-CONV
Location: Phoenix, AZ

Re: Disc brake conversion

Post by pull the wire »

I ended up buying a swingarm, caliper, aluminum spoke rim and rotor off a 1978 GS1000. It simply slid right in. The GT pivot shaft is 14mm and the GS1000 is 16mm. I'm just going to enlarge the frame mounts to get the strength of that larger pivot shaft. The GS1000 swingarm is also about 2 inches longer. I hope it rides nice. I'm not much of a knee dragger so longer wheelbase won't bother me. LOL

I used the right passenger peg mounting point to install a reaction lever to operate the master cylinder, I have it set up to maintain the stock brake lever. I'll have pics soon
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Alan H
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Re: Disc brake conversion

Post by Alan H »

Good progress. I'll be interested to see the finished article.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
pull the wire
On the main road
Posts: 105
Joined: Mon Oct 21, 2013 10:04 pm
Country: united states
Suzuki 2-Strokes: 73GT750 75GT750 84RZ350 89 FXRS-CONV
Location: Phoenix, AZ

Re: Disc brake conversion

Post by pull the wire »

Here's a couple pics of my brake lever to master cylinder set up. The side cover and oil tank have plenty of room. It should work well.
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Suzukidave
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Re: Disc brake conversion

Post by Suzukidave »

Any progress after Dec ?
the older i get the faster i was
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