Adding a front disc to a road bike !! And Now Hydro!

Workshop tales, trials and disasters.
Maintenance tips, techniques and myths.
Technical discussion, description and outright lies

Re: Adding a front disc to a road bike !!

Postby MichaelB » Fri Aug 27, 2010 10:05 am

Nobody wrote: .... It would leave too much of an opening for Shimano to step into the gap with a good road-cable or hydro-STI setup. I think the market is expanding for road style discs.


Lets hope so. A hydro STI version would be nice indeed :D
User avatar
MichaelB
 
Posts: 6829
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

by BNA » Fri Aug 27, 2010 10:09 am

BNA
 

Re: Adding a front disc to a road bike !!

Postby rustychisel » Fri Aug 27, 2010 10:09 am

3 pages, the bikes not built and half the components haven't even turned up :twisted:

does this flaming thread go all the way to 20?
rustychisel
 
Posts: 3361
Joined: Thu Jan 10, 2008 12:39 pm

Re: Adding a front disc to a road bike !!

Postby janus77 » Fri Aug 27, 2010 10:16 am

be cool if the disk was in the middle of the hub, and there was a hydro actuated brake, not sure what the caliper part would connect to though.
User avatar
janus77
 
Posts: 799
Joined: Mon Aug 27, 2007 3:09 pm

Re: Adding a front disc to a road bike !!

Postby Nobody » Fri Aug 27, 2010 10:44 am

rustychisel wrote:3 pages, the bikes not built and half the components haven't even turned up :twisted:

does this flaming thread go all the way to 20?
Sorry, you need to get onto a CT or Missy thread if you want to see 20 pages on nothing. Just look at the "I spent $10K on clothes this year" thread, or "My wheels went out of true" thread, or whatever they're called.... :wink:
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Adding a front disc to a road bike !!

Postby MichaelB » Fri Aug 27, 2010 11:00 am

rustychisel wrote:3 pages, the bikes not built and half the components haven't even turned up :twisted:

does this flaming thread go all the way to 20?


Yeah, but at least something will happen. And meaningful content.

The front hub, 2 x Velocity A23 rims, and 1 x DA7700 rear hub, and a fork are all here. :P

Bloody Wiggle threw a spanner in the works :evil:
User avatar
MichaelB
 
Posts: 6829
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Adding a front disc to a road bike !!

Postby baabaa » Fri Aug 27, 2010 11:09 am

But is the underlying Q - is Avid going to keep making it, or is it just the distributors not stocking it due to poor aftermarket sales ?
A model freshen up is overdue. Look at http://www.parktool.com/repair/readhowto.asp?id=124 and you will see the first pic of the original model. I also expect a "lighter" BB9 is on the books.
Last time I picked up a pair, (bikeman.com, about this time last year) it was quite easy to find a pair of mtn or road at 100 Aud delivered so I think you are at the tail end of the stock run out?
User avatar
baabaa
 
Posts: 307
Joined: Sun Apr 19, 2009 8:47 am

Re: Adding a front disc to a road bike !!

Postby cooperplace » Sat Aug 28, 2010 3:53 pm

Hi Michael,

one thing you should be prepared for is noise: my BB7 makes a lot of it. I resisted the temptation to squirt some WD40 on it.

Peter
Please be nice to me, I'm not very bright.
cooperplace
 
Posts: 288
Joined: Sat Sep 12, 2009 11:42 pm
Location: Adelaide

Re: Adding a front disc to a road bike !!

Postby Nobody » Sat Aug 28, 2010 6:01 pm

cooperplace wrote:Hi Michael,

one thing you should be prepared for is noise: my BB7 makes a lot of it. I resisted the temptation to squirt some WD40 on it.

Peter

What rotor?
Wet, dry or both?
Any particular speed?
What pads?

I've got 185 roundagons on the road bike and 160 Shimano SLX disc on the MTB, both with BB7 and sintered pads. I find the SLX disc more noisy and a bit more again when wet. The noise is not too loud like rim brake pad squeal is. At its worst it sounds like a metallic scraping sound that a pad back-plate makes rubbing on a car disc when the brakes have worn out. I mainly get the noise at lower speeds.

I've heard that the organic pads are quieter but don't last as long.
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Adding a front disc to a road bike !!

Postby MountGower » Sat Aug 28, 2010 8:40 pm

I'm using BB7s with Alligator Windcutters and the standard pads, which are excellent. No noise at all, wet or dry. The Roundagons were hideous.
MountGower
 

Re: Adding a front disc to a road bike !!

Postby cooperplace » Sun Aug 29, 2010 1:29 am

Nobody wrote:
cooperplace wrote:Hi Michael,

one thing you should be prepared for is noise: my BB7 makes a lot of it. I resisted the temptation to squirt some WD40 on it.

Peter

What rotor?
Wet, dry or both?
Any particular speed?
What pads?

I've got 185 roundagons on the road bike and 160 Shimano SLX disc on the MTB, both with BB7 and sintered pads. I find the SLX disc more noisy and a bit more again when wet. The noise is not too loud like rim brake pad squeal is. At its worst it sounds like a metallic scraping sound that a pad back-plate makes rubbing on a car disc when the brakes have worn out. I mainly get the noise at lower speeds.

I've heard that the organic pads are quieter but don't last as long.



It's a BB7 out of the box, standard pads and rotor. Very noisy in the dry and wet.
Please be nice to me, I'm not very bright.
cooperplace
 
Posts: 288
Joined: Sat Sep 12, 2009 11:42 pm
Location: Adelaide

Re: Adding a front disc to a road bike !!

Postby Nobody » Sun Aug 29, 2010 8:32 am

cooperplace wrote:It's a BB7 out of the box, standard pads and rotor. Very noisy in the dry and wet.
Maybe have a look at the possible solutions in this MTBR article. I will add that maybe your pads could be glazed and it may be worth trying to bed them in again. My standard setup is almost silent now at speed and only gets a bit noisy when going slowly. It used to always squeal (to the point of being embarrassing) before I went to a big hill and bedded it in properly.

Since you are using a XACD Ti fork with the shims/washers, it may worth swapping the fork to see if the fork is the problem. Ti having a bit more flex may be introducing the movement to allow the squealing. That is the same reason I believe my steel forks (on both bikes) are a bit noisier at low speed.
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Adding a front disc to a road bike !!

Postby Nobody » Sun Aug 29, 2010 8:56 am

MountGower wrote:I'm using BB7s with Alligator Windcutters and the standard pads, which are excellent. No noise at all, wet or dry. The Roundagons were hideous.
This just goes to show how much different setups change the results. As said above I found the more cutout SLX disc noisier. Although the Avid is 6 bolt and the SLX is centrelock.
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Adding a front disc to a road bike !!

Postby cooperplace » Sun Aug 29, 2010 12:32 pm

Nobody wrote:
cooperplace wrote:It's a BB7 out of the box, standard pads and rotor. Very noisy in the dry and wet.
Maybe have a look at the possible solutions in this MTBR article. I will add that maybe your pads could be glazed and it may be worth trying to bed them in again. My standard setup is almost silent now at speed and only gets a bit noisy when going slowly. It used to always squeal (to the point of being embarrassing) before I went to a big hill and bedded it in properly.

Since you are using a XACD Ti fork with the shims/washers, it may worth swapping the fork to see if the fork is the problem. Ti having a bit more flex may be introducing the movement to allow the squealing. That is the same reason I believe my steel forks (on both bikes) are a bit noisier at low speed.



Bed them in again????????? What do you mean by that? I followed the instructions from Avid to bed them in. As for swapping the fork, I don't think so.
Please be nice to me, I'm not very bright.
cooperplace
 
Posts: 288
Joined: Sat Sep 12, 2009 11:42 pm
Location: Adelaide

Re: Adding a front disc to a road bike !!

Postby Nobody » Sun Aug 29, 2010 4:56 pm

cooperplace wrote:Bed them in again????????? What do you mean by that? I followed the instructions from Avid to bed them in. As for swapping the fork, I don't think so.
Well, without changing anything or doing anything, it looks like you're stuck with the noise then...
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Adding a front disc to a road bike !!

Postby MichaelB » Mon Aug 30, 2010 8:54 am

Cheers for the tips re noise guys and link to MTBR.

The BB7 comes with the G2 rotor, and have a couple of roundagons, so some experimenting can be done re noise & bedding in.

Just need the damn parts to arrive :?
User avatar
MichaelB
 
Posts: 6829
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Adding a front disc to a road bike !!

Postby Crawf » Thu Sep 02, 2010 5:36 pm

I've got all my bits for the front end conversion :D
Well almost, I forgot to order a crown race and brake cables, I assumed a cable would come with the BB7's - but no.
Calliper and rotor alignment doesn't look to be an issue either.
Should be altogether this weekend ready for next Mondays commute!

I have some pics of the fork camparo if you want? There's an obvious change in trail and other geometry, so i'm wondering how sloppy the handling will get...
Crawf
 
Posts: 1685
Joined: Wed Jan 09, 2008 8:20 pm

Re: Adding a front disc to a road bike !!

Postby MichaelB » Thu Sep 02, 2010 8:47 pm

Jacobite wrote:I've got all my bits for the front end conversion :D
Well almost, I forgot to order a crown race and brake cables, I assumed a cable would come with the BB7's - but no.
Calliper and rotor alignment doesn't look to be an issue either.
Should be altogether this weekend ready for next Mondays commute!

I have some pics of the fork camparo if you want? There's an obvious change in trail and other geometry, so i'm wondering how sloppy the handling will get...


Pics would be great :D

The BB7 and G2 rotor arrived today :D :D

Just waiting on the spokes from Starbike (they left 2 days ago) and the headset from Wiggle.

I too found that the cable didn't come, so that will come from the LBS :roll:
User avatar
MichaelB
 
Posts: 6829
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Adding a front disc to a road bike !!

Postby Crawf » Thu Sep 02, 2010 9:16 pm

Image
Image

The factory rear wheel has 6 bolt so i'm looking into also getting a rear mount welded on, depends on whether the rear stays are up to the stresses of a disc?
Crawf
 
Posts: 1685
Joined: Wed Jan 09, 2008 8:20 pm

Re: Adding a front disc to a road bike !!

Postby MichaelB » Fri Sep 03, 2010 8:38 am

Looking good there. Paint matches well :D Thanks for the pics.

Welding on rear mount - not sure about that one. Def can't do it on mine :?

The main issue is that the rear stay was never (big assumption here) designed for rear disc, but if you can make it one that uses both seat and rear stay, then that would be better, and go with a 140mm disc ?

Similar style to this from Fixie Inc 2011

Image

I'd be interested to see what your thoughts are on the handling side.

Are you chnaging your stem to get the same end height to counteract the extra fork length ?

BTW, installing the headset bearing on the fork, do you need a press to do that ? Or does it just need a bit of 'gentle persuasion' and care ....

Cheers

Michael B
User avatar
MichaelB
 
Posts: 6829
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Adding a front disc to a road bike !!

Postby rowdyflat » Sat Sep 04, 2010 3:03 pm

Provided the fork doesnt flex too much a front disc brake makes sense though I have found mtbike brake levers + pads increase the braking power of road brakes considerably+ have them on my straight bar commuter.
One of my mtbikes has a BB7- the pads squeal a bit when new.
Ewen Gellie has a front + rear disc brake road bike on his web site. He braced the left fork to stiffen it.
rowdyflat
 
Posts: 147
Joined: Tue May 17, 2011 6:33 pm

Re: Adding a front disc to a road bike !!

Postby MichaelB » Sat Sep 04, 2010 11:00 pm

Actually managed to achieve something today :D

Tokk the fork to tyhe LBS to get the lower race fitted & purchased the brake cable housing and cable.

Took the opportunity to put the disc on the hub, and align the caliper to this disc. Looks pretty sweet I must say.

Can't wait to get the forks on the bike and the spokes in the mail.
User avatar
MichaelB
 
Posts: 6829
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Adding a front disc to a road bike !!

Postby Crawf » Sun Sep 05, 2010 3:18 am

My front conversion is done, having issues with road lever cable slackness, they don't grab so well and don't pull you up incredibly well if you want to stop on a dime.
Alignment is great, no issues there. I can get the pads spot on.
But when you try to reduce the cable slack to improve lever reaction, the pads will move and start rubbing? Catch 22.
Crawf
 
Posts: 1685
Joined: Wed Jan 09, 2008 8:20 pm

Re: Adding a front disc to a road bike !!

Postby Nobody » Sun Sep 05, 2010 8:01 am

Jacobite wrote:...they don't grab so well and don't pull you up incredibly well if you want to stop on a dime.
Like car disc brakes when new, they need to be bedded in. Until you see a darker continuous strip around the disk on both sides, you're not there yet. You will know it when you are as IMO they will have more retardation leverage or braking power than road calipers eventually.

Jacobite wrote:But when you try to reduce the cable slack to improve lever reaction, the pads will move and start rubbing? Catch 22.
I didn't have this problem as I have the linear pull version. However you are probably better off having them a bit loose as you probably have more hand strength closer to the bar. I also prefer the cable to be looser than the disc to rub. Things will take time to settle, stretch and bed-in. Even then you'll probably find they need adjusting fairly regularly as your skewer loosens or something moves slightly. The tolerances are a lot tighter than a road caliper. I find I'm adjusting my MTB every few rides. Not everything is wonderful about the BB7, but the most important thing is definitely there. When you need to stop fast, it won't let you down in any weather (once bedded in).

If you want to fast track the bedding-in process, find a big hill and do some emergency stops on the way down (but don't come to a complete stop, same as car brake bedding-in). The pads may become a bit too sticky and noisy after this, but it should soon settle down.
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Adding a front disc to a road bike !!

Postby Rek » Sun Sep 05, 2010 11:12 am

You shouldn't be adjusting the pad position using the cable tension because the torque arm has limited movement and you don't want to use it up. Take up the cable slack with the barrel adjuster then use the adjustment dials to get the pads into position.

I've run into much the same problem with my BB7s - they either rub or the levers don't feel right because of the extra travel. I suggest checking your rotors are true and still allowing for a small amount of rotor rub.
Rek
 
Posts: 111
Joined: Fri Dec 05, 2008 1:14 pm

Re: Adding a front disc to a road bike !!

Postby Nobody » Sun Sep 05, 2010 3:22 pm

Rek wrote:Take up the cable slack with the barrel adjuster...
Does Shimano STI have a barrel adjuster? My Cane Creek V brake drop bar levers don't.
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

PreviousNext

Return to The Shed

Who is online

Users browsing this forum: garibaldi



Popular Bike Shops
Torpedo 7 Torpedo7 AU
Ground Effect Ground Effect NZ
Chain Reaction Cycles CRC UK
Wiggle Wiggle UK
Ebay Ebay AU

“Bicycles BNA Twitter
“Bicycles BNA Facebook
“Google+ BNA Google+
“Bicycles BNA Newsletter

> FREE BNA Stickers
> BNA Cycling Kit