kevrider

my wife an I have gravel bikes, Diamondback Haanjo and Haanjenn, they were bottom of the line, purchased last year. the plan was to use these as commuters and errand runners, but they turned out to be quite fun for all sorts of rides. so far this year, it's the only bike I have ridden, this mixed surface thing is great, so there have been upgrades. the first change was to move from TRP Lyra to HyRd on my bike. I was underwhelmed at first, but facebook advised my to change the pads to SwissStop and that made a huge difference. based on that, I bought the same brakes for my wife. unfortunately, while my bike can accommodate 160mm rotors on both ends, her frame will not clear the HyRd caliper with a 160mm adapter. that was disappointing, I prefer that she has the same equipment that I have, or slightly better, I think it helps her confidence, esp on dirt. right now, she has the better wheels and tires, same upgraded drivetrain with a lower granny gear. but that scheme will not work with the brakes. I have reverted her bike to 140mm rear with the HyRd in place, but another option would be TRP Spyre with a 160mm rotor.

HyRd 160 front + HyRd 140 rear
-- or --
HyRd 160 front + Spyre 160 rear

which combo would you prefer? do you think a Spyre 160 will stop as well, or better than an HyRd 140? would there be a dramatic difference in feel at the lever if there is a hyrd on one end and spyre on the other end? I think it's fine if she has a little less braking power at the rear, maybe preferable, my rear locks a little too easily. but I think she would rather have the 160 on the rear. I just don't want it to feel weird at the lever and cause any problems in a tricky spot on a trail.

fietsbob

I already had 160 discs front and rear

my rear hub R'off, 4 bolt 160 disc made by avid (wet weather transportation bike)

I changed from a BB7 caliper , to Hy Rd... (406 wheel Bike Friday )

140 is a common offering on road and cross bikes , as a weight savings, and the physics..

rear brake is not effective, as you unweight the rear wheel decelerating rapidly..
and mass is shifted forward.. [Newton, Isaac]

I like the auto pad wear compensation function of the Hy Rd..





....

Slightspeed

I've got regular TRP Spyres on my Culprit road bike, and I'm pretty happy with the performance of the Spyres. A friend with an identical frame put the HY/RD on his front wheel. The rear frame design is too tight to allow the HD/RD to fit, so he has been fine with the HD/RD on the front only. We have stock 160/140mm rotors front and rear. I'm not sure, but hope it helps to answer your questions, at least for road use. I have not ridden his bike with this set-up, but it makes sense since the front wheel does most of the stopping. Here's my stock set up.

CliffordK

Some might advocate for slightly stronger brakes on front than on the rear.

So, I would try the 160/140 brakes, and see how you like them.

GamblerGORD53

My heavyweight tour bike has had SA drum front brake since new. For the first 12,000 miles the rear brake was a crummy caliper that couldn't stop a fly, so that tells you how good the drum was working.
Then I finally got a DIY mount welded on for a 203 disc on the Rohloff, with a cable Spyre brake. It can now EASILY stop the wheel 100%.
So now I use the drum to slow down and the disc to stop.. NOW. Rear brakes supposedly don't do much??
My bike has a limo WB 4 or 5" longer than usual and is 80 or 120 lbs.

Last week I blundered in front of a car turning right. Got a slow speed bump broadside against my wrap around KS/ bumper. Didn't even fall over. LOL I just needed to unbend the KS.

shelbyfv

I can't imagine she could tell the difference between 160 and 140 on the rear. Tell her she can save the extra weight of the 160s because she is petite.

Rick

The CPSC sent a bulletin to bicycle shops years ago stating that the bicycle shops should not adjust brake shoes to close to the rims. This was supposed to keep people from going over the bars. This statement instead of teaching riders how to stop and be in balance so they don't pitch over the bars.
The industry pushed disk brakes and now they are limiting the size of the rotor by frame design to save money. My touring bike came with the spyre. I also tried the spyke and the HY/RD. I settled on the Paul Klamper calipers. I have a 203mm rotor on the rear and a 180mm rotor on the front. If you have a bicycle with cantilever or V brakes the Magura hs33 hydraulic rim brakes are superior to all other rim or disk brake made.

Troul 

It shouldn't matter any.

I often wonder why the rear cable for some bicycles route from the bottom then up? It is just harboring moisture, dirt, & puts the cable under unnecessary conditions. Any solutions around that while not getting expensive?

Phil_gretz

I'm late to comment for the OP, but I'd never worry about using 160mm rotor on the front and 140mm on the rear. It's the front brake that matters most. In practice, and once familiar with disc brake use, she'll have plenty of stopping power either way, even with 140's on both.

jimincalif

I run 160 front / 140 rear on my gravel bike. It’s perfect, better than the original 140/140. I see no need for 160 rear, I can easily lock the rear with the 140, so the limiting factor is the tire/surface contact, not the brake. I suppose for really long sustained braking a 160 might deal with heat better, but I ride some pretty hilly routes both on and off road and it’s just never been an issue. I weigh 204# BTW. You’re wife’s bike should be just fine.

Wilfred Laurier

In the vast majority of riding, your rear brake doesn't need to be used at all. In any other situation, like trying to scrub off speed when cornering on a loose surfaces, even a 140mm rotor should easily make the rear wheel skid..

kevrider

thanks guys! as a motorcyclist, I am quite familiar with the physics of front vs rear braking. my mountain bikes were both 180/160 for a while, but a long descent cooked the fluid on a fully, so it's 180/180 now. my gravel bike became 160/160 because I already had the rotors and that was the cheapest way to set up two wheelsets per gravel bike. I figured I would handle a skidding rear better that she would. anyway, I was concerned about her feeling outgunned relative to my ride, then her new calipers arrived with two 160mm rotors. but I had a moment of clarity and asked her for a preference: she told me to KISS. so it'll be a HyRd 140 rear. figures.