larger disc brake

[chisixer6]

On the bike that I am currently building, I plan on having disc brakes on the front. The fork has the tabs to mount a disc brake, I am going to use hydralic brakes instead of mechanical this time, hopefully for better stopping power. I was wondering, since I am used to 160 mm disc, was maybe considering buying either 185 or 203 mm disc brake kit. Would the standard fork tab mount be ok? I mean with the larger disc, the calipher would need to be further out, wouldn't it? thanks in advance.... Jerry

 

[biohazardman]

They make adapters, just a big machined spacer, for larger rotors. Probly specific to your brand of brake and maybe a twist for some not so standard forks. Pretty much the same on the front forks.

 

[chisixer6]

biohazardman;

Just looked at my Avid kit and notice the adapters, with 160F and 145r stamped on them.The the 185 kits should have 185 stamp on them.

thanks... Jerry

 

[MadRhino]

Use 203mm, that is the standard today. When you buy the brake set, buy the specific disc and caliper adapter altogether. Most disc brake calipers work much better with their own specific disc, with some you have choice of 2 disc quality and you can upgrade for a small extra at purchase.

 

[chisixer6]

okay..sounds good...will get the 203mm kit...thanks

 

[neptronix]

One thing to mention is that most cheapo forks are OK with 180mm, but not 203mm.
If you have a cheap suspension fork, you might get a lot of flex on 203mm, leading to stress failures.

The question is.. does your fork already flex a lot on 160mm?
If so, ya may want to hold back.. go 180mm.. and let 'er be.

 

[chisixer6]

It's an all steel non suspension fork, it didn't flex on my other bike with 160mm mechanical disc. Will be used main on flat Chicago pot hole roads, hopefully filled by spring. It's spring like this past week(40's and 50's), the next 2 days, then instant drop to the 20's. propulsion is 48v gear hub on a 24" rear from ebikekit, with a Lyen controller so far.

 

[neptronix]

oh, then go for the 203mm

 

[Kingfish]

I run 203mm on both F & R hubs. Stopping is not an issue :wink:

I'd follow that with some good meaty tires. There have been times where I am at the rear-right corner of a car doing 25 mph and then suddenly without warning they turn right, and I you would not believe how fast I can lock that bike up and stop on a dime, even with studded tires!

The only issue with large discs is they sing a little bit when they're warm; they warp easily. But then they cool down quickly and return to their normal state.

Good luck on your purchase, KF

 

[chisixer6]

Kingfish;

I get singing on my 160mm disc now, I got some disc quiet(haven't use it yet), and see if that will stop the singing, it is very annoying. Thanks for the info... Jerry