# Tried front 160mm rotor on my Synapse HiMod



## jmess (Aug 24, 2006)

I tried out a 160mm front rotor with the 140mm rear and ended up going back to the 140F. Bike, me, water, and gear probably weigh 195lbs so I was thinking a 160 in front would be good. Braking felt good/better until a wet ride with a couple of steep technical descents on wet/slick paved roads. While braking for sharp corners on 10+ % down slopes I got rear tire lockup. The lock ups were hard to predict/feel and I almost went down the first time it happened. At no time was I pushing the limits with speed or by late braking which made the lockups even more surprising. 

My theory is the 160 front is causing faster forward weight transfer unloading the rear tire faster/more and causing the lock up. Over time you may be able to re-calibrate your brain to manage the front/rear brake lever balance but who needs the drama on slick roads? I have ridden similar wet descents with the 140F/140R setup and not experienced the same imbalance. So I am back to the 140/140 now. I would think a 160F/160R would be easier to manage but I haven't tried it yet.


----------



## harryman (Nov 14, 2014)

I normally run 180F/160r on my mtbs and have for years, a decade probably. I honestly didn't notice a huge difference switching from 160 up front to 180, less cooking of the rotors though.

On my road bike, it's supposed to have a 140 in the rear, but I can stuff a 160 in just fine, so I'm 160/160. Maybe see if that will work? I'm @ what you weigh, live in Colorado and I talked to a disc brake engineer who told me to run 160's. Road bikes are harder on discs than mtbs IME.


----------



## jmess (Aug 24, 2006)

At our weight and doing lots of down hills I think 160/160 would be the better config.

Another interesting thing I discovered during my 160F rotor test was my 2014 Synapse HiMod shipped from Cannondale with Metailc pads. I had removed the pads and clean them several times and never noticed the label. Swapping them out for resin pads solved the squealing problems that had bugged me on cool damp days. My 160F/140R test was done using resin pads.


----------



## wrshultz (Feb 10, 2005)

jmess said:


> I tried out a 160mm front rotor with the 140mm rear and ended up going back to the 140F. Bike, me, water, and gear probably weigh 195lbs so I was thinking a 160 in front would be good. Braking felt good/better until a wet ride with a couple of steep technical descents on wet/slick paved roads. While braking for sharp corners on 10+ % down slopes I got rear tire lockup. The lock ups were hard to predict/feel and I almost went down the first time it happened. At no time was I pushing the limits with speed or by late braking which made the lockups even more surprising.
> 
> My theory is the 160 front is causing faster forward weight transfer unloading the rear tire faster/more and causing the lock up. Over time you may be able to re-calibrate your brain to manage the front/rear brake lever balance but who needs the drama on slick roads? I have ridden similar wet descents with the 140F/140R setup and not experienced the same imbalance. So I am back to the 140/140 now. I would think a 160F/160R would be easier to manage but I haven't tried it yet.


jmess, When you tried the 160mm rotor on the front of your Synapse,did you use the Shimano SM-MA-F180P/P2 post-to-post adapter on your fork? Thanks, Bill


----------



## jmess (Aug 24, 2006)

No, I used an adapter kit made by Avid that has longer bolts, spacers, and conical washers that raise the caliper up. Didn't find any info about the Shimano adapters when I was looking, definitely a better solution.

BTW I have done a lot of hard braking with my Synapse and have never felt the 140s weren't doing the job. I am probably 180lbs with my full winter kit on.


----------

