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 Post subject: Brake reach problem
PostPosted: Thu Mar 28, 2013 2:22 pm 
Old School Hero
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Joined: Sat Nov 24, 2012 5:06 pm
Posts: 231
Location: Diepenbeek
Hello everyone,

I'm upgrading this bike to a more or less complete campy gran sport group: http://www.retrobike.co.uk/forum/viewtopic.php?f=23&t=238076&hilit=flandria. Everything is fitting well, I just have a problem with the rear brake reach. The gran sport caliper doesn't reaches the rim, it's short of +/- 1cm. I need a minimum reach of 59mm... So I have some options to solve the problem:

Constraint: it's not a topquality bike and I'm a student so extremely low on funds. So looking for an affordable but decent solution :)

-keep the universal super 68 caliper on the rear: this one has a reach of 64mm. Not the preferred option of course, since I want it to be campagnolo :).

-buy a drop bolt like these: http://velobase.com/ViewComponent.aspx?id=bbcbb211-1445-4dfd-bba2-9d3709410cd0. Also not a prefered option since they ask ridiculous prices for these bolts ($70 what :facepalm: )

-fix a DIY-dropbolt (any ideas?). This is what I was thinking about: a bended piece of aluminium that is fixed on the brake bridge and 'lowers' the hole....

Image

-find/buy a campagnolo record rear brake caliper, since they have a bigger reach. I've found there are two versions:
- the standard reach calipers with a range of 50-65mm: they'll fit for sure. Link: http://velobase.com/ViewComponent.aspx?ID=9667bfaa-8c76-4b63-82d7-2087a9b4ebca
- the short reach calipers with a range of 45-60mm: http://velobase.com/ViewComponent.aspx?ID=2e83607d-e755-4d41-8fc9-8532c7c25b90. I have these on another bike, and measured them myself. I measured the max reach as 58~59 mm, so they'll be more or less ok. If it's not enough, is it possible to drill the holes for the brake pads a bit so there's a little bit more space?

I prefer the last option... Maybe it's possible to find just the brake arms and fit these on my gran sport axle? Anyone has an old wrecked record caliper with intact arms? Don't need NOS or spic and span quality at all :)

So what do you think? Any advice?


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 Post subject: Re: Brake reach problem
PostPosted: Thu Mar 28, 2013 4:20 pm 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8222
Location: New Forest, UK
I think you have a good idea there - I would make one slightly differently from a 50mm section of 25mm diameter 2mm wall aluminium tube, but the principle is the same.


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 Post subject: Re: Brake reach problem
PostPosted: Thu Mar 28, 2013 10:31 pm 
Devout Dirtbag

Joined: Mon May 31, 2010 9:10 pm
Posts: 116
Re diy drop bolt type solution - I once used pedal cleat inserts, thick alloy type. A bolt through the bridge with the spacers either side. The brake then bolted on to the part of the spacer at the bottom. Sorry haven't got any pics but it was spot on for 700c wheels in 27" wheel frame using standard drop calipers. Not sure I'd want to do it on a bike used for anything more arduous than shopping or short local rides.


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 Post subject: Re: Brake reach problem
PostPosted: Thu Mar 28, 2013 10:44 pm 
rBoTM Winner
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Joined: Wed Dec 12, 2012 10:18 pm
Posts: 2373
Location: California
The only problem with the DIY solution is that you will add some flex to the action on the rear brake which will reduce braking performance. Given the choice I personally would stick with the Universal on the back. Alternately, I recently saw someone re-manufacturing the drop bolt but I can't remember where I saw this. (It wasn't a whole lot cheaper) Also from an aesthetics perspective I think the Super 68 has it over the homemade solution.


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 Post subject: Re: Brake reach problem
PostPosted: Thu Mar 28, 2013 10:52 pm 
rBoTM Winner
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Location: California
here is someone who seems to have the same idea:


Attachments:
dropbolt2.jpg
dropbolt2.jpg [ 66.25 KiB | Viewed 1728 times ]
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 Post subject: Re: Brake reach problem
PostPosted: Fri Mar 29, 2013 11:17 am 
Old School Hero
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Joined: Sat Nov 24, 2012 5:06 pm
Posts: 231
Location: Diepenbeek
lewisfoto wrote:
The only problem with the DIY solution is that you will add some flex to the action on the rear brake which will reduce braking performance. Given the choice I personally would stick with the Universal on the back. Alternately, I recently saw someone re-manufacturing the drop bolt but I can't remember where I saw this. (It wasn't a whole lot cheaper) Also from an aesthetics perspective I think the Super 68 has it over the homemade solution.


Good point on the added flex, but I think this will be more or less ok since I just need a small drop and I can keep both the axles close to each other?

For the aesthetics: If I pick the DIY option, I'll try to make it look a bit better than the example given! Thinking of painting the bended aluminium in red and look for a 'chrome' cilinder to guide the brake axle or something like that.

What do you think about the record brake arms-option? No one out there who can supply me with some old record brake arms for some quids to fit on the gran sport axle :)?


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 Post subject: Re: Brake reach problem
PostPosted: Fri Mar 29, 2013 2:25 pm 
Retro Guru
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Joined: Mon Sep 24, 2012 9:10 pm
Posts: 669
I think your diy drop-bolt idea is sound, but I would use steel, at least 1mm thick, instead of aluminium. I would also make it a bit wider than in your diagram- maybe 2cm? with plenty of metal left around the holes you drill for the bolts.

Another alternative- You may not wish to consider this, but rebrazing the brake-bridge is probably a five-minute job for a framebuilder, especially if you can meet them halfway by removing some paint and having ready a slightly longer bridge with ends mitred to fit the seat-stays? I dont know what it would cost.


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 Post subject: Re: Brake reach problem
PostPosted: Fri Mar 29, 2013 4:42 pm 
rBoTM Winner
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Joined: Wed Dec 12, 2012 10:18 pm
Posts: 2373
Location: California
Campagnolo did have a longer reach record brake, though I can not remember the exact specs, I was able to solve a reach problem some years back this way. You would be looking for the early Nuovo Record brakeset, easily recognized by the flat quick release. Bad news is they are becoming rare and command a high price. Spare parts are also expensive. If it were me I would stick with the Super 68 until the proper Campagnolo set comes your way.

Steven


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 Post subject: Re: Brake reach problem
PostPosted: Fri Apr 12, 2013 7:01 pm 
Old School Hero
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Joined: Sat Nov 24, 2012 5:06 pm
Posts: 231
Location: Diepenbeek
I've been looking for some longer record brake arms but couldn't find them, at least not for reasonable prices. I'm still convinced that installing a record caliper is the best solution from an aesthetic perspective, so I'll keep looking for them!

But in the meanwhile, I went for the DIY-path today and this is the result:

Image

Image

Don't have the bike here at the moment so I had to do it with some rough measurements I made some weeks ago. I'll try to fit this proto-type next week, crossing fingers it will fit :)!


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 Post subject: Re: Brake reach problem
PostPosted: Fri Apr 12, 2013 8:43 pm 
rBoTM Winner
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Joined: Wed Dec 12, 2012 10:18 pm
Posts: 2373
Location: California
You may want to put some cloth bar tape on the brake bridge so that bracket doesn't mar the paint, otherwise looks good.


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