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Everyone,
I'm considering to upgrade the front brake of our 2018 SX250 KTM by replacing the original caliper by a Factory/SXS version. I've read some (moderate) positive feedback about them.
It looks however that there are 2 versions:
- KTM part SXS09125512 (pistons 24 mm in diameter, like the standard caliper)
- Brembo part XQ21361 (pistons 28 mm in diameter (36% more area))
See pictures below.
Does anyone have experience with either of them? Any pro/con of either?
I don't have experience with the SXS parts specifically, but I can make a recommendation on choosing between the two.
The later bikes (somewhere around 2013? and up) use a 24mm caliper and a smaller master cylinder.
Earlier bikes use a 28mm caliper and 11mm master cylinder.
Mixing those could result in a pretty bad braking setup...
Small master with the larger caliper would have a TON of power, but the lever motion would be excessive with a vague bite point.
Small caliper with the larger master would give you a very firm and short lever motion, with a significant loss in braking power.
The 28mm calipers pair VERY nicely with a Honda / Nissin 11mm diameter master cylinder. So far, that is the best brake setup I've ridden.
That makes sense. I went through the KTM parts lists and found:
Diam. master piston Diam. caliper pistons
up to MY2008 11mm 28mm
2008 10mm 28mm
2009 and later 9mm 24mm
Having a MY2018 bike, it's maybe better not to mess things up and stay with 24mm caliper pistons. For more braking power, without affecting the "feel"of the lever I could consider to use use a larger brake disk (standard 260mm)
270mm: 4% more brake power compared to standard
280mm: 8% more brake power compared to standard
Why use a Honda/Nissin 11diam master cylinder over the older pre-2008 KTM master cylinder? They're both 11mm.
There are a lot of differences between each M/C and caliper from each brake manufacturer and bike manufacturer.
The main differences you feel are:
1) Different mechanical leverage ratio and lever shape.
2) Different port size and position within the M/C bore.
Most people seem to prefer the modern 9mm / 24mm brembo feel.
There's a reasonably detectable bite point and you have a lot of lever movement to increase braking power.
I feel that the brembo becomes grabby under hard braking. For me, it's a problem on wet conditions or on slick hard pack.
I prefer the lever feel of the Honda / Nissin unit as well as the lever shape and I run them on all of my bikes.
The Honda/Nissin has a very well defined bite point and after that, there isn't much lever travel to increase braking force.
As you apply lever force, you get more braking power, but it never feels grabby.
The caliper doesn't do as much for the braking system as the master, the hose, and the rotor diameter.
The 270mm kit on the brembo will make a bigger difference than the caliper with the same size pistons.
Thanks cwtoyota. I'm a bit sceptical towards all of the claims made by KTM about the Factory caliper. Unless the shape of the caliper is different I can't imagine why going from casting to milling would give a big improvement. The material is still aluminum; the elasticity of aluminum barely varies between the different alloys. They look nice though. BTW, what is the part number of the Honda/Nissin MC?
About the brake line: I agree that this can make a difference. But I believe that the standard KTM ones are allready steel braided? (or are there still better ones?).
And then of course the brake pads will also have an effect...
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I don't know the part number, but if you look up the master cylinder from around 2009 through 2018 CRF450R, they're all interchangeable 11mm Nissin. I don't know if they are the same from 2019 or 2021 or whenever they updated the CRF450R caliper. The newer Hondas have two different piston diameters in the front caliper... I've stayed with the older stuff that has two 27mm pistons... The M/Cs are probably still the same 11mm unit.
Combined with a BrakeTec or brembo 28mm caliper and the standard KTM hose, the Honda M/C works really well.
I have that setup on a 2023 GasGas 350 with the stock 260mm rotor and prefer it to my 2024 KX450 which has a 270mm rotor and brembo 9mm / 24mm components.
I've bought the KTM factory caliper (SXS09125512) with 24mm pistons, had no opportunity yet to try it with the stock (9 mm) master cylinder. I noticed by the way that apparently on the KTX SXF450 factory edition bike a "24mm" caliper is paired with a 10mm master Brembo PS 10/16 master cylinder:
https://www.brembo.com/en/solutions/for-original-equipement-bike/references/ktm-450-sx-f-factory-edition
Read Cadpro's comment towards the bottom.
https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/18-KTM-Front-Brak…
Post a reply to: KTM Factory/SXS Front Caliper. Two versions?