GS1000 1978 smaller rear caliper

[Highwaystar]

Wanting to change the huge rear caliper for something smaller like the brembo picture attached, appreciate I may require a different bracket and disc. Just wondered if anyone had done this .Also consider underslung caliper but unsure how this possible without torque arm. 

Edited October 20, 2021 by Highwaystar
Miss spelt word

[bluedog59]

Not a technically hard job, it just depends what kit you have access to. A hacksaw, drill and files could get 90% of it done nicely with a bit of care but you'd need a lathe for any spacers. Putting it "underslung" would just need a new torque arm mount fitting.

[Highwaystar]

OK thanks, firstly I'd better measure spindle size then go from there. I have friends that can assist reference lathe and spacers etc. So for example do you think I say I got a gsxr750 srad complete rear brake, it could be possible to fit with some work.

[TonyGee]

the later calliper brackets are shorter than the older GS/GSX brackets as far as i know so the calliper will sit too low unless you fit a smaller disc. 

interesting bike though, can we see the full thing ? 

[Highwaystar]

22 minutes ago, TonyGee said:

the later calliper brackets are shorter than the older GS/GSX brackets as far as i know so the calliper will sit too low unless you fit a smaller disc. 

interesting bike though, can we see the full thing ? 

I will post some pics soon, I hope to have new paintwork back next week, also front brake upgrade ready to fit. 

[wraith]

To fit a smaller lighter caliper is not going to be easy.

First, the later (say gsxr) calipers I believe have different bolt hole spacing and sit at a different distances (wheel bearing face to hanger).

You could make a new hanger to take all this into account and then fit any caliper you like, just check the distance from the Spock's to where the back of the caliper will sit to make sure you have the clearance.

The torque arm is the easy part. Ever weld a new mount on the swing arm or get a early gsxr torque arm that can be bolted to your frame and then to the caliper, then you can have it underslung.

[Highwaystar]

4 minutes ago, wraith said:

To fit a smaller lighter caliper is not going to be easy.

First, the later (say gsxr) calipers I believe have different bolt hole spacing and sit at a different distances (wheel bearing face to hanger).

You could make a new hanger to take all this into account and then fit any caliper you like, just check the distance from the Spock's to where the back of the caliper will sit to make sure you have the clearance.

The torque arm is the easy part. Ever weld a new mount on the swing arm or get a early gsxr torque arm that can be bolted to your frame and then to the caliper, then you can have it underslung.

Thanks,,I will look into it

[GSX1100dreamn]

Google shit

 

https://japan.webike.net/products/23123109.html

[Highwaystar]

2 minutes ago, GSX1100dreamn said:

Google shit

 

https://japan.webike.net/products/23123109.html

That looks smart, just a bit suspect of model fittment as it says gsx1000 !? I'll send them an email 

[TonyGee]

11 minutes ago, Highwaystar said:

That looks smart, just a bit suspect of model fittment as it says gsx1000 !? I'll send them an email 

GSX1000 katana

[Highwaystar]

17 minutes ago, TonyGee said:

GSX1000 katana

Ah yea !

[Ibbo]

Is the bolt spacing the same for the gsx750f rear caliper?

I have one on mine but used gsxr rear wheel and disc so used the gsx mounting bracket.

Mike

[Highwaystar]

Going to be checking bracket and disc pcd/bolt spacing later today. I've done a lot of research to see if there is a non underslung smaller caliper that looks compatible and has the lug to attach the torque arm, but only stuff I can find looks just as big as this lump.

[wraith]

The gsxr1000k2/3 use a nissin rear caliper that has a hole for the torque arm, but has a 220mm disc.

[Highwaystar]

Thanks, that's underslung which is route I may need to go. Still trawling the Web for a top/standard fitting caliper. Seen one off a Gs500e that may be smaller but hard to tell.

[TonyGee]

3 hours ago, Highwaystar said:

Thanks, that's underslung which is route I may need to go. Still trawling the Web for a top/standard fitting caliper. Seen one off a Gs500e that may be smaller but hard to tell.

yeah the gs500 caliper is a bit smaller than your caliper. 

[wraith]

Gs500 is the same for gsx600f and 750f I believe 

I think they are all 17mm wheel spindle, I know I've drilled one out to 20mm before.

 

Edited October 21, 2021 by wraith
Add a bit

[Highwaystar]

2 hours ago, wraith said:

Gs500 is the same for gsx600f and 750f I believe 

I think they are all 17mm wheel spindle, I know I've drilled one out to 20mm before.

 

Thanks, lots of info to go on here

[Rijko]

I have something like that on my GS1000. Check this pic, i do not have more detailed pics atm.

The disc is off a H**da MB5 and has 3 holes located correctly ; afaik (did not make this setup myself)

all that's needed is placing the old GS disc on top and drill the other 3 holes.

The bracket is a straight plate positioning the caliper over the disc by 2 spacers on either side on the axle.

 

Edited October 27, 2021 by Rijko

[Highwaystar]

On 10/27/2021 at 12:15 PM, Rijko said:

I have something like that on my GS1000. Check this pic, i do not have more detailed pics atm.

The disc is off a H**da MB5 and has 3 holes located correctly ; afaik (did not make this setup myself)

all that's needed is placing the old GS disc on top and drill the other 3 holes.

The bracket is a straight plate positioning the caliper over the disc by 2 spacers on either side on the axle.

 

That looks ace, like the bike too

[370steve]

GS 750 with MV F4 four pot Nissin caliper (GSX14 arm, CBR1000RR wheel) just goes to prove that anything will fit with a bit of thought and effort

 

Edited October 31, 2021 by 370steve

[Highwaystar]

On this subject I decided to stay with the original caliper but trim away all access metal to stream line it. Also did same with bracket

[rodneya]

Motogpwerks sells these billet brackets to fit a small Brembo under slung to a SRAD without a torque arm.

Shouldn't be to hard to get one made to fit.

 

[Highwaystar]

Quality stuff

[Mike711]

On 12/4/2021 at 5:04 PM, Highwaystar said:

On this subject I decided to stay with the original caliper but trim away all access metal to stream line it. Also did same with bracket

Very neat, are you using the OE master cylinder & does it work ok? I fitted a 16mm clutch cylinder on the left handlebar to operate the back brake & it's probably better than the front!