Commuting - Disc brake mounts

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Has anyone ever heard of sucessfully attaching a set of disc brake mounts to a frame that did not orginally come with them? I am looking to change my bike over to disc, but would like to keep the steel framed beast that I regularly commute on. Any suggestions. I saw a set of disc brake mounts from a framebuilding supply and I was wondering if anyone knew if I could just send my existing fram out and have them put on.
DCCommuter
12-06-06, 01:06 PM
I bought the A2Z converter off of Ebay. I think it was about $25. It clamps onto the chainstay and has a hole the skewer goes through. I'm essentially happy, although I never use my rear brake, it's only there as a back-up in case the front brake fails.
The downsides: I had to grind away some metal to get it fit on my aluminum frame cannondale. Also, to remove the rear tire I now have to remove the skewer.
I've heard people bash these adapters, saying they put strain on the frame in an unintended place. I say nonsense, the mounting is essentially identical to a coaster brake, and on a rear brake the disc isn't going to generate any more force than a coaster brake, both can skid the tire.
The rear brake is not really useful for braking, and cannot generate significant braking force, so the value of the disc brake on the rear is minimal. I only did it so I could change wheels without having to adjust the brakes.
For the important brake, the front one, you need a new fork. They are increasingly available with disc mounts, Nashbar has a few at reasonable prices, both road and mtb.
When I did my conversion, by the time I was done I had spent a pile of money -- new fork, brakes, wheels, adapter, cables. In retrospect I would have been better off buying a moderately priced new or used bike.
dynaryder
12-06-06, 02:05 PM
Someone posted a site that had disc brake adapters,but I've never heard from anyone that used them. You really only need a disc on the front;just swap your fork.
just the front? I dont traditionally use my front for braking. Mostly because of the 257 lbs. that I am moving around while on the bike. I already have the fork and other various parts. The wheels and brakes are take offs from my mtn bike since i upgraded to better components for it. So I would rather just convert my Commuter to disc
I replaced my fork with a fork that had disc mounts, and added an avid 7 road disc.
I never use my rear brake, if your not using your front brake, your doing it wrong :)
DCCommuter
12-06-06, 07:01 PM
Here's a link to the adapter I use, $23 on ebay:
http://cgi.ebay.com/New-a2z-DM-UNI-Adapter-Non-Disc-Brake-Frame-Mount_W0QQitemZ330058526363QQihZ014QQcategoryZ58082QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Here's a link to the article that explains why you should only use the front brake:
http://www.sheldonbrown.com/brakturn.html
greenstork
12-06-06, 07:13 PM
A word of caution, your current fork most likely can't handle the force that would be applied by a disc brake and could snap/fold under heavy braking. You're better off just buying a fork designed for disc brakes. Vicious makes a nice one...
dynaryder
12-07-06, 01:43 PM
just the front? I dont traditionally use my front for braking.
70% of your stopping ability is in the front brake.
I'm not sure I fully agree with Sheldon's article. I've ridden motorcycles for 21yrs and you definitely stop quickest when using both brakes. Weight transfer is a little different on a bicycle(ex:175lbs rider on 25lbs bicycle vs 175lbs rider on 650lbs motorcycle),but if all the weight is on the front tire you don't want to hit anything with it. On say,a track,you could get away with front only,but on most roads(DC anyway) at some point you're going to hit some sort of irregularity and will want the stabilty of weight on both wheels. JMHO.
cwodave
12-07-06, 04:11 PM
I was just considering adding a similiar thread myself. I hadn't considered the new front forks idea, thanks for the tip. I need new forks anyways, something to do with kids, growing old, and almost making a jump, but I digress...
My problem with the front brake only is one turn I have to make. It involves going down a hill, in traffic, and having to signal and turn all at the same time. I have to use the back brakes, and I need good brakes to stop my fat a@#, panniers, and steel bike.
Has anybody considered having a lug welded on to the frame? Shouldn't be a big problem, would it?
Dave
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