Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Recreational Cyclocross and Gravelbiking This has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like :The Dirty Kanza". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-23-14, 08:58 PM   #1
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Shimano Mech. Discs Overheating!

Hello,
I've got a 2013 Spec. Roubaix disc with the Shimano Br-R517 (mechanical, replacement to the recall) and they overheat way too easily. Coming down a big hill in the Rockies I nearly could not slow and the discs are now blued like a motorcycle exhaust. That's hot. I'm about 200 lbs. They came with resin pads and I cannot find any metal pads to fit and not even sure if that would be enough. Not anywhere near as strong as the Avid roads I had before. Also got an odd, strong vibration from the front rotor at one point. Very scary.

Anyone have a similar experience? Any resolution? I'm going to take it back to the shop where I bought it but thought I'd gather some info first, if possible. Thanks!

JD
SVO is offline   Reply With Quote
Old 07-23-14, 10:19 PM   #2
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 19,697
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 457 Post(s)
Quote:
...Coming down a big hill in the Rockies...
You have a death grip on the brakes the whole descent? no feathering, surge and release or alternating wheels?

Saw a Video test demo of TRP's Hy Rd, showing them repeatedly heating the disc till it glowed ..

maybe combine that in a 210, oversize disc with a finned heat sink like Shimano sells, and it may work better in your situation
'

Last edited by fietsbob; 07-23-14 at 10:25 PM.
fietsbob is offline   Reply With Quote
Old 07-24-14, 09:44 AM   #3
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
No, I know how to brake properly. Happened WAY too easily. The Hy/Rd is pricey bought outside of a bike build. Bought the bike as a last-year's model just a few months ago. Hoping/expecting the shop/manufacturer to step-up. A big reason I bought the bike was for better braking- rather ironic. I have 2 mountain bikes with 160mm XC brakes (older Hope and Formula) and both come down that same hill no problem. In fact they can do a descent twice as long and just start to fade a bit at the bottom.
SVO is offline   Reply With Quote
Old 07-24-14, 01:29 PM   #4
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 19,697
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 457 Post(s)
report back when you finish with the shop conversation ..

Read a Magura Letter in a bike industry Trade Magazine
stating why they will not really jump on the disc _ road bike band wagon
but then they seem to sell a cable to hydraulic disc, under stem converter like Hope and TRP .
so who knows ..

sure can't tell from here..

you tore it down and looked at the pads ? they may have been out of adjustment ..

Mech disc brakes are DIY in the adjustment dept. Hydros self adjust for pad wear.
fietsbob is offline   Reply With Quote
Old 07-24-14, 06:00 PM   #5
chriskmurray
Senior Member
 
chriskmurray's Avatar
 
Join Date: Aug 2012
Location: Colorado Springs
Bikes: Borealis Echo, Ground Up Designs Ti Cross bike, Xtracycle, GT mod trials bike, pixie race machine
Posts: 1,121
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Even though it is not listed as such I am pretty sure your pads are the same ones as these kool-stop D-620's which offer a metallic option. You can tell pretty easily by just pulling out your pad and seeing if the shape matches.

Kool Stop International - High Performance Bicycle Brake Pads Since 1977

If you are willing to spend the money, I really dislike most Shimano mechanical discs and feel Avid BB-7's are a MUCH better brake so that is worth checking into as well.
chriskmurray is offline   Reply With Quote
Old 07-24-14, 06:13 PM   #6
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
, Most certainly not the same. Thanks for trying!
Attached Images
File Type: jpg KS-D620_B.jpg (82.3 KB, 3 views)
File Type: gif spacer.gif (43 Bytes, 156 views)
File Type: jpg pad2.jpg (48.4 KB, 3 views)
SVO is offline   Reply With Quote
Old 07-24-14, 06:26 PM   #7
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Just got back from the bike shop. They MIGHT be able to give me a small discount on upgraded brakes. That is pretty sad. I live in Boulder CO and I have tons of bike shop options. That they feel the need to make more money off me after selling me a bike with poorly-performing brakes is infuriating. This is University Bikes for anyone local. I know a bunch of people in the business and know that Uni is HIGHLY profitable. They sure don't need to add insult to injury with me. They said that Shimano et al released product that was not ready for prime time but accept no responsibility for promoting and selling it.

Didn't expect them to give me a new bike. Shimano aluminum core rotors at their cost would seem to me to be the least they should do. It would cost them zero (I'd be happy to install them myself). Fortunately there is Yelp, MTBR forums and word of mouth where I can express my frustration. There need to be consequences.

FYI: Ive been riding seriously for 35 years. My family has 14 bikes of about $20,000 total value. I have been a mechanic, racer, tourist, patroller, etc., on and off road.

JD
SVO is offline   Reply With Quote
Old 07-24-14, 08:38 PM   #8
chriskmurray
Senior Member
 
chriskmurray's Avatar
 
Join Date: Aug 2012
Location: Colorado Springs
Bikes: Borealis Echo, Ground Up Designs Ti Cross bike, Xtracycle, GT mod trials bike, pixie race machine
Posts: 1,121
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by SVO View Post
Just got back from the bike shop. They MIGHT be able to give me a small discount on upgraded brakes. That is pretty sad. I live in Boulder CO and I have tons of bike shop options. That they feel the need to make more money off me after selling me a bike with poorly-performing brakes is infuriating. This is University Bikes for anyone local. I know a bunch of people in the business and know that Uni is HIGHLY profitable. They sure don't need to add insult to injury with me. They said that Shimano et al released product that was not ready for prime time but accept no responsibility for promoting and selling it.

Didn't expect them to give me a new bike. Shimano aluminum core rotors at their cost would seem to me to be the least they should do. It would cost them zero (I'd be happy to install them myself). Fortunately there is Yelp, MTBR forums and word of mouth where I can express my frustration. There need to be consequences.

FYI: Ive been riding seriously for 35 years. My family has 14 bikes of about $20,000 total value. I have been a mechanic, racer, tourist, patroller, etc., on and off road.

JD
If you are frustrated, voice those frustrations with Shimano. Bike shops do not make much money on new bike sales as the margins are simply not good and the best they can usually do is pass along the offer from Shimano. Any time there is a recall, bike shops are already loosing money as they are rarely compensated enough to cover their time/costs dealing with it.

I will say though, if I was in a retail shop and this happened I would be willing to give my customer a great deal on a different brand of new brakes but there is no way it could be below my cost and chances are I would not be able to do much in the way of giving them credit for the mechanical brakes Shimano sent because very few people want to buy Shimano mechanicals and the market will be flooded with them so they would likely sit on a shelf for a few years before being sold for next to nothing.

Recalls are tough on all parties involved but in the end Shimano should be the one held accountable since it was their product they released too early, not the bike shops.
chriskmurray is offline   Reply With Quote
Old 07-24-14, 10:48 PM   #9
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by chriskmurray View Post
If you are frustrated, voice those frustrations with Shimano. Bike shops do not make much money on new bike sales as the margins are simply not good and the best they can usually do is pass along the offer from Shimano. Any time there is a recall, bike shops are already loosing money as they are rarely compensated enough to cover their time/costs dealing with it.

I will say though, if I was in a retail shop and this happened I would be willing to give my customer a great deal on a different brand of new brakes but there is no way it could be below my cost and chances are I would not be able to do much in the way of giving them credit for the mechanical brakes Shimano sent because very few people want to buy Shimano mechanicals and the market will be flooded with them so they would likely sit on a shelf for a few years before being sold for next to nothing.

Recalls are tough on all parties involved but in the end Shimano should be the one held accountable since it was their product they released too early, not the bike shops.
Kinda seems like you didn't really read my post. I said I thought a fair offer would be replacements at cost, not below. And I provide the labor. I am well aware of the economics of operating a bike shop. But that shop has annual revenue well into 8 figures from, I'll guess, 5,000 s.f. Trust me, they do quite well. The shop employees actually discouraged me from approaching Shimano because they would just refer me back to the retailer, which is exactly the experience I've had in the past with the Big S if the component is not physically broken or missing parts. I have about zero leverage with Shimano. A shop that moves a ton of their product has a good deal more. They simply chose not to take the issue up for me, on a $2k+ bike still under the 1-year warranty.

Both University Bicycles and Shimano did not stand behind their products/merchandise. It's not necessarily an either/or proposition. But I will give Shimano a call and see what they say. Seems that most steel needs to get to well over 500 degrees for the blueing to occur. For a 200-lb load on a 1,000 foot descent, that is far short of "standard" performance.
SVO is offline   Reply With Quote
Old 07-24-14, 10:53 PM   #10
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by fietsbob View Post
report back when you finish with the shop conversation ..

Read a Magura Letter in a bike industry Trade Magazine
stating why they will not really jump on the disc _ road bike band wagon
but then they seem to sell a cable to hydraulic disc, under stem converter like Hope and TRP .
so who knows ..

sure can't tell from here..

you tore it down and looked at the pads ? they may have been out of adjustment ..

Mech disc brakes are DIY in the adjustment dept. Hydros self adjust for pad wear.
This is the first complete bike I have purchased in about 15 years. I do my own builds most often, including wheels, so re-checked everything even before the first ride. The brakes are operating as designed.
SVO is offline   Reply With Quote
Old 07-25-14, 08:58 AM   #11
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 19,697
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 457 Post(s)
Shimano is infamous for its lack of small parts.. Repairs tend to be whole assemblies

looked at the shop's QPB catalog (old print one) Avid/SRAM shipped spares for every part of the BB7 to them @ QBP,
so can be ordered through your LBS

FWIW, Looking at the exploded parts digram, I learned the pieces that are different between the MTB & Road versions .

Though if the per hour cost was charged by the bike shop, like what it cost to fix your car at the dealer, whole new caliper is way cheaper .
fietsbob is offline   Reply With Quote
Old 07-25-14, 12:53 PM   #12
Null66
Senior Member
 
Null66's Avatar
 
Join Date: Jun 2013
Location: Garner, NC 27529
Bikes: Built up DT, 2007 Fuji tourer (donor bike, RIP), 1995 1220 Trek
Posts: 2,103
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You know they make larger rotors and ones with more metal to them.
Null66 is offline   Reply With Quote
Old 07-25-14, 04:06 PM   #13
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Null66 View Post
You know they make larger rotors and ones with more metal to them.
Yup. On a carbon frame not a great idea to size-up rotors.
SVO is offline   Reply With Quote
Old 07-25-14, 04:19 PM   #14
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
So I called Shimano.
"Tektro rotor- not our problem."
Called Specialized,
"Never heard of that, but we might be able to get you better brakes. The shop has to initiate a warranty process."
Called the shop back,
"Just bring it in and we can do that."
Umm, I already did that and not one but two of your service techs sent me away saying there was nothing you could do.
Supervisor: "I don't know about that, I wasn't there. Just don't bring it in this weekend, we'll be too busy."
Whom should I talk to when I do bring it in?
"Anyone"
Nice. Can't even manage a half-hearted sorry for wasting your time (very limited, metered, street parking only near the shop). I specifically questioned the service techs on taking it up with Specialized, too, and was rebuffed. No shocker: I won't be using University Bikes again.
SVO is offline   Reply With Quote
Old 07-25-14, 04:23 PM   #15
Null66
Senior Member
 
Null66's Avatar
 
Join Date: Jun 2013
Location: Garner, NC 27529
Bikes: Built up DT, 2007 Fuji tourer (donor bike, RIP), 1995 1220 Trek
Posts: 2,103
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by SVO View Post
Yup. On a carbon frame not a great idea to size-up rotors.
Really? Wow!


well, that still leaves rotor w/ more metal... Though I've come down long 7-9% hills loaded, as I'm way heavier...
Null66 is offline   Reply With Quote
Old 07-25-14, 04:28 PM   #16
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
BB7s with standard rotors would be fine, I'm sure, but I'm not paying for them if I can help it.
SVO is offline   Reply With Quote
Old 07-25-14, 04:39 PM   #17
Null66
Senior Member
 
Null66's Avatar
 
Join Date: Jun 2013
Location: Garner, NC 27529
Bikes: Built up DT, 2007 Fuji tourer (donor bike, RIP), 1995 1220 Trek
Posts: 2,103
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by SVO View Post
BB7s with standard rotors would be fine, I'm sure, but I'm not paying for them if I can help it.
That's exactly what I'm running, road bb7's. Well over 350 vehicle weight and greater than 40 and it hauls it down just fine!
Null66 is offline   Reply With Quote
Old 07-25-14, 05:00 PM   #18
jsigone
got the climbing bug
 
jsigone's Avatar
 
Join Date: Jan 2005
Location: San Diego
Bikes: one for everything
Posts: 8,465
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Not sure that IF the shop helps you, that I'd trust them brakes again even if new. I'd spend the $130ish to upgrade to road BB7s. I love mine, decent down Palomar Mt on knobby tires like a sport car cuz the braking was so good and never faded at the bottom of a 4000ft decent (25mins or so) and about the same weight
jsigone is offline   Reply With Quote
Old 07-26-14, 09:42 AM   #19
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 19,697
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 457 Post(s)
NB, I have seen the outer plastic adjustment Knobs, on BB7 , melted , by customers seeking repairs .. nothing is perfect..
fietsbob is offline   Reply With Quote
Old 07-27-14, 06:33 PM   #20
grolby
Senior Member
 
grolby's Avatar
 
Join Date: Jan 2005
Location: BOSTON BABY
Bikes:
Posts: 9,268
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
New pads. Clean rotor. Perform a proper bedding in procedure. See if that helps before proceeding.
grolby is offline   Reply With Quote
Old 07-28-14, 05:05 AM   #21
jimc101
Senior Member
 
Join Date: Oct 2007
Location: West Yorkshire, United Kingdom
Bikes:
Posts: 4,772
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Change the pads to Sintered (metal), and it will make a huge difference, currently using CX77, also replacement from the recall, and these came with stock resin pads, which offered poor braking, and needed constant adjustment. Swapped to sintered (Ashima pads, they need a bit of filing to fit) and the brakes now stop really well.

For metal pad availability, not sure why you are having issues sourcing them, the pads are the same for the R517, CX77, M615, M675, R785 & M785 brakes (non-finned versions) Shimano's parts codes are G03S or G03Ti, and there are plenty of aftermarket ones also available.

If you are looking to upgrade the rotor size, would check the spec of the fork, this is often the limiting factor for installing larger rotors
jimc101 is offline   Reply With Quote
Old 07-29-14, 11:19 AM   #22
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by grolby View Post
New pads. Clean rotor. Perform a proper bedding in procedure. See if that helps before proceeding.
That's what I did the first time. Not repeating it with my time/money.
SVO is offline   Reply With Quote
Old 07-29-14, 11:45 AM   #23
SVO
Junior Member
Thread Starter
 
Join Date: Dec 2012
Bikes:
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by jimc101 View Post
For metal pad availability, not sure why you are having issues sourcing them, the pads are the same for the R517, CX77, M615, M675, R785 & M785 brakes (non-finned versions) Shimano's parts codes are G03S or G03Ti, and there are plenty of aftermarket ones also available.
This is a really good point. Several U.K. sellers note that the above pad spec works with the R517, but NONE of the U.S. sites do and the QBP (huge distributor) catalog is the same. Interesting. Perhaps U.S. Shimano distribution screwed the pooch on this and don't list them as compatible? Shop tech checked this on their computer also and agreed with me that it appeared there are no sintered options.

I'll pull the pads and compare in person. Yes, my experience with all sorts of disc brakes tells me that sintered pads and rotors with more material (not even a larger size) would likely be good enough.

And road carbon disc frames AFAIK do not have a listed maximum rotor size the way MTBs do. It is assumed that the rotors are maintained at stock size. To keep them super light the frames are only modestly over-engineered, again in contrast to carbon MTB frames from good makes. I'd go back to rim brakes before up-sizing rotors. I come down some mountain passes at over 50 MPH.
SVO is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 02:19 AM.