Suitable 4 piston or 2 piston slider caliper for a 125 project?

[Dvsrd]

I have a 90% finished Suzuki 125 project, originally for my youngest son. A GN125, now with a shortened fork, 18" spoked front and rear wheels,  143 cc Wiseco big bore, etc, etc.
One of the really poor aspects of this bike is the original  front brake. A tiny disc and a single piston caliper setup just is not enough, even for its 70 mph or so top speed.
So I am looking for a better caliper, ideally 4 piston, alternatively 2 piston sliding type. Most sport bike calipers are just too large (Yamaha blue spot, Bremobo, etc)
Any recommendations for LH side mount, behind fork slider caliper? Disc size should be in the 240-260 mm region, but I want to source a suitable used caliper first.

[oxford]

Some Ducati monsters had a 2 piston sliding Brembo caliper.  They were dual disc so you can get a right or left.

I don't really think they are that much better than a 2 piston that would come on a jap bike like the 250 ninja but it does give you a little more bling.  I had a set of these at one time and the brackets made up to out on a Kawasaki H1.

[m in sc]

cbr300 or honda grom. twin piston. or, ktm 390. (its a brembo by a different name)
usually with small wheels, the issue is clearance from the disc to the spokes. small 4 pot just may not fit.

[Dvsrd]

 I will space out the disc as much as possible/ neccessary for an opposed piston caliper if doable. I am really no fan of sliding calipers, but if opposed piston is impossible then I have to.

The caliper on my RD 350 is way superior to the sliding caliper on  my 77 XS650. Those are shit in my opinion. Maybe the Daytona have the same?

[oxford]

I have seen in the past calipers that had the backside milled to the spoke angle enough to clear them.  Probably not doable on every caliper and may take a spare to see how much material is back there. 

Bigger the rotor the less of a problem there is with clearance. 

[m in sc]

yeah, tried doing that with my g3 disc conversion, just no room. good luck with it.
slide calipers work really well, especially twin pot ones if serviced correctly.  its a 125, coming down from 70. i mean... 

[oxford]

its a 125, coming down from 70. i mean... 

I have to agree, a 4 pot seems like a little overkill.  It seems like a larger diameter rotor would serve you better than more caliper. 

If I was wanting to do something trick on a small bike and wanted the fixed caliper look I would be considering a single modern sport bike rotor and a 2 piston opposed caliper made for a rear brake and make up the adapter.  I can't imagine that it wouldn't be enough brake

[Dvsrd]

Just checked the dimensions on a couple of ISR calipers. 31 and 32 mm from disc centerline ti back side.

[elliottles1]

dvsrd,

just putting a dt400 engine in a tdr125, I have the caliper  in my hand. it has a twin sliding front caliper, on the left. measuring from the surface of the rear (pulled) brake pad to the rear of the caliper is approx. 25mm.

might help
cheers
les

[elliottles1]

forgot

https://www.ebay.co.uk/itm/Yamaha-TDR-125-1997-Front-Brake-Caliper/233423831736?hash=item36592502b8:g:7ZQAAOSwE7FZ1jEy,

cheers

[Dvsrd]

dvsrd,

just putting a dt400 engine in a tdr125, I have the caliper  in my hand. it has a twin sliding front caliper, on the left. measuring from the surface of the rear (pulled) brake pad to the rear of the caliper is approx. 25mm.

might help
cheers
les

Is that with a new pad ?

[elliottles1]

dvsrd,

its not a new pad, it came to me with used pads and I have no idea what the measurement of a new one would be, however its got about 3/4mm on it, so its not far off.

cheers
les

[elliottles1]

if you look on the last pic of the ebay ad that I attached, they are about the same.

les

[Dvsrd]

Thanks!
I will have to take some measurements one of these days!  That TDR had a decent size disc as well, 280 mm.

[NoRiders]

Have a look at a Honda NSR125 Grimeca leftside front twin pot slider....the NSR has a big dics (not measured but it big!!)
Simple aligned mounting points.