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View Full Version : Changing a Dur Ace 7800 rear brake to a front brake....??

pablo pinchasso
11-15-2011, 09:16 AM
Are the mounting bolt parts between a 7700 Dura Ace brakeset and a 7800 brakeset interchangeable? I made a mistake and purchased a rear 7800 brakeset and would like to change the mounting bolt and mount it on the front. .....any parts avalible to do this. Shimano or QBP? I also have an extra 7700 Dura Ace brake ( front ) that I can take apart but ? if the parts are interchangeable?
oldpotatoe
11-15-2011, 09:24 AM
Are the mounting bolt parts between a 7700 Dura Ace brakeset and a 7800 brakeset interchangeable? I made a mistake and purchased a rear 7800 brakeset and would like to change the mounting bolt and mount it on the front. .....any parts avalible to do this. Shimano or QBP? I also have an extra 7700 Dura Ace brake ( front ) that I can take apart but ? if the parts are interchangeable?

No...different lengths(50.7-7700, 52.5-7800, from shimano tech docs).

Just use a real long brake 'nut' for the fork, using the rear brake . Have done it many times.
Chance
11-15-2011, 11:10 AM
When swapping calipers like this make sure shoes and pads go in right direction. It can be easy to forget.
oldpotatoe
11-15-2011, 11:28 AM
When swapping calipers like this make sure shoes and pads go in right direction. It can be easy to forget.

geee, I've never done that.......
rice rocket
11-15-2011, 11:45 AM
The Shimano pads have a set screw, so it should be fine.
guyintense
11-15-2011, 12:08 PM
The Shimano pads have a set screw, so it should be fine.

Famous last words!
Chance
11-15-2011, 02:24 PM
The Shimano pads have a set screw, so it should be fine.
Maybe, but why take a chance? It only takes a few seconds to swap from side to side; particularly since they will need to be loose for initial adjustment anyway.
pablo pinchasso
11-15-2011, 05:30 PM
Think I will just get another brake for the front.... the long nut only catches a few threads on the short bolt, not my idea of a good fix...
eddief
11-15-2011, 06:05 PM
i have a new 7800 front brake through bolt in Ti.
oldpotatoe
11-15-2011, 06:10 PM
Think I will just get another brake for the front.... the long nut only catches a few threads on the short bolt, not my idea of a good fix...

How long is the long nut? If not long enough, get a longer one.
guyintense
11-15-2011, 06:13 PM
It seems to me it would depend on the fork if a longer nut would work. I would just buy the correct bolt from Shimano and swap it, pretty easy operation. Contrary to popular belief you can buy replacement parts from Shimano.
jds108
11-15-2011, 06:20 PM
Think I will just get another brake for the front.... the long nut only catches a few threads on the short bolt, not my idea of a good fix...

Those nuts are available in all kinds of lengths. These guys: http://torontocycles.com/Selling/Titanium.html (almost at the bottom of the page) have them in ten different lengths. And they're Ti....

I bought some Superbe Pro calipers off of ebay and months later when I finally went to install them I noticed it was two rears. So longer nut for me was a great solution.