Disc brake size

Joined
Jan 5, 2023
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I'm currently building the delta runner and I'm looking at disc brake groups on Amazon. It looks like the disc's are around 6 1/4 diameter will these fit without hitting the frame or do I need smaller disc's if they can be found.
Thanks for any help on this.
Terry
 
Joined
Oct 19, 2012
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Wakefield, UK
160mm would be considered the standard size. You can get 140mm and even 120mm and 100mm though the latter are mainly escooters. Going the other way 180mm and 203mm are common. I can't say what max size will fit but discs below 160mm tend to be low performance due to the size. I'd expect 160mm will fit looking at the pictures.
 
Joined
Jan 16, 2011
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Vilvoorde / Flanders / Belgium
140 and 160 are very common. 180 is for serious applications, and 203 is a very rare beast. Anything below 120 is expensive toy size. But the real brake power comes from the calipers and brakepads.

You need the right balance between pad size and caliper power. To much power per surface, and you wear down the pads in a hurry, or overheat both brakes and rotors.
 
Joined
Feb 7, 2008
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Nottinghamshire England
Not sure I understand the question ?
All Brads plans start with the premise everyone uses what every parts they can find locally , they are not tied to any particular dimensions/make etc ?


So if the back looks like this then space the rear cross member far enough away the bearings to get the disk you have available to fit in the space ?
You also really need two disks , especially if you are some what beefy or fancy carrying a heavy load ?
Paul
 
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How much variation is there in bike pads/calipers? I know autos and motorcycles have a huge range available (not to mention multi piston calipers).
That variation is HUGE. From el cheapo Chinese "mini calipers" to hidiously expensive branded 4 piston downhill monsters. From mild steel 100mm disks to 203mm composite "floating and ventilated" everything including a bathroom composite disks. A few posts on this forum mention dirt cheap "Chinesium" single side calipers that do the job wonderfully.
 
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Good to know. Nice thing is that the standardization of rotor sizes should make a caliper upgrade much more likely than on motorized vehicles.
Emiel did try a few different "cheaper" Chinese options, and in the end, it seems they all are usable.
Even those dirt cheap (€13 for a left and right pair, delivered at home) small ones.
I fitted those on a Riksha, combined with Shimano 180mm center lock disks, and the stopping power is impressive. The driver will have to dose very carefully.

 
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