Old Bald Dude
Hope's Answer To Rotor Install Question
The answer was as I suspected it would be. It's a shame they couldn't provide any technical response though.
From: HOPEUSAINC@aol.com [mailto:HOPEUSAINC@aol.com]
Sent: Monday, February 02, 2004 10:10
Subject: Re: FW: Custom Rotor Order
You can install the rotors any way you choose. Glad you like them. gwen
From: Christopher A. Dean
Subject: RE: Custom Rotor Order
I just wanted to let you know the rotors arrived today. They look great! Now, I have a technical question for you. The manual for the Mini brakes says to put the rotor on the bike with the vanes pointing in the direction of forward rotation. To read the text on the rotors from the brake side of the bike, I will have to install them with the vanes pointing in the opposite direction. Will this be a problem? I searched through the message boards on MTBR and found some pictures of other rider's custom Hope rotors and noticed they all mounted them with the vanes pointing against the rotation in order to read the text.
I know some manufacturers build their rotors with the vanes pointing forward and others with them pointing backwards. I know that the Shimano XT and Grimeca System 8 brakes are essentially the same, and these two systems have the rotor vanes pointing in the opposite direction. Again, searching through the MTBR message boards, I noticed about a 50/50 variation in mounting directions.
Let me know what you think. Thanks again for the cool looking rotors.
"A picture is worth a 1000 words", but I'll add a few anyway.
This is the direction most people point the "vanes", 'arms", "spokes", and the way I feel they should be. When the outer end of the vane reaches the position of the caliper, the force is being directed from the caliper staight down the vane, and to the hub, as it should. This is also why I believe the vanes are angled, or even spiraled a bit on some. Firm support of the braking forces along the vane should make the rotor feel stiffer and result in better performance. I'm not understanding why Hope told you what they did, or why they call them vanes for that matter (those crazy Brits).
BTW, what model of Hopes did you get, and let us know how you like them. I've heard a few early negative reviews of the Mono Mini, but it looks like it's got potential to me. I've been telling people they have narrower brake tracks on the new rotor, as this is what I've seen and heard, but in looking at them closer, it's only narrower at the first point the caliper touches between each vane. I have a photo for you and know I can upload it, but I've never drawn illustration marks on one before, so bear with me. I'l try to explain what I mean with further text, if successfull.
I've highlighted the area that I think is a cause for concern on this particular rotor (Mono Mini) in red, the yellow line is the edge I think would catch the brake pad too easily if mounted the other way, but as I said above, there are other reasons they're typically mounted this direction. Not bad for a first time illustration huh?
Last edited by Gnarlygig; 02-02-2004 at 02:28 AM.
Old Bald Dude
I've go the regular Mini brakes . . .
I read the reviews and put Speedgoat's power clamp on them from the beginning. I've had real good luck with them. The feel and power are more than what I expected, especially since I changed from Grimeca System 8s to the Minis. I moved the System 8s to my Super8 for downhill use vs. cross country. They work great themselves.
I've only put two rides on the new rotors. The only thing I've noticed is now the rear seems to pulsate. I haven't had a chance to take the rotor to my workplace and put it on a Super-micrometer to check the thickness yet. I'm pretty sure it's not grease or any other lubricant on the rotor/pads because I have already taken a torch to them just to make sure.
Thanks for the input on why the rotor should go the other way. I'll keep it the way it is so I can read the text from the caliper side of the bike. If I run into any problems, I'll switch the over just for the sake of trying it.
To see the rotors and the bike they are on, see my previous post, Hope Custom Rotor Question + Bike Porn.
Last edited by CruzinJapan; 02-02-2004 at 06:05 AM.
Reason: Forgot to put a title
That's bad news...
I'll bet you money the memo went out on Friday:
To: Custom Rotor cutters
From: Hope Management
Re: Custom Rotors
Flip the damn rotors over, dumbasses!
In the mean time, I've come up with my own solution:
Pulsating is usually caused be either rough edges on wavy rotors...
"The only thing I've noticed is now the rear seems to pulsate."
(which can be filed smooth), or improper pad/rotor breakin, where sometimes spots of material, be it pad, rotor, or dirt act like smudges on a rim and cause a grabbing sensation that pulses. Richard Cunningham calls this "invisible imprinting", and has gotten alot of sarcastic comments about it, but I think there is some learning to be had there. For now, I'd make sure the rotors are clean, tight, everything's aligned OK, and facing the right direction. If that fails you could sand the rotors and pads to see if there is some debri or spotty roughness that needs dealing with, just make sure you do it evenly.
This is not to imply that there aren't other factors that could be involved, disc setups are a bit complex, and need many components to be in proper order for them to work smoothly. You could also check, amount and equality of tension on the spokes, adjustment of hub bearings, trueness of rotor.
Old Bald Dude
I'll take your advise one step at a time . . . . . .
Thanks for the info. I'll give some of it a try, as I did a complete rebuild of the CK ISO Disc Hubs when I put the rotors on. The wheels themselves only have a half a dozen or so rides on them since built by my LBS, Nakazawa Gym (the best wheel builder in Tokyo). When I first installed the rotors, I did the alcohol thing on them, but when I went out in the parking lot see if the pads would bed quickly or not, I ended up with lots of black marks on the rotors. I assume this was from some contaminates that the alcohol didn't remove. So, I removed the rotors, took my dremel tool to them and carefully removed the black stuff, being careful to try and keep it even all the way around. Then, I did the same to the pads. Next, I took my torch to the rotors and pads to make sure there was no oil residue left. I'm hoping that a few more rides with some good DH sections will help bed the pads in and remove any possible rough edges on the rotors. Only time will tell.
Originally Posted by Gnarlygig
By Banshee Rider in forum Downhill - Freeride
Last Post: 02-01-2004, 12:34 PM