brownbike

I just posted this in "Road Cycling" but I decided it might be more appropriate here... I hope that's okay..

So I got this great '74 Gitane Tour de France and I was surprised to see it came with 27" wheels. (i guess I didn't do my research) Anyways, I'd love to get my 700s on there, for a wider range of tire options, and just to update it a little, but even with the 27" wheels, the rear brake is maxed out. It's a Shimano600 Arabesque caliper (matches all the other components) so I dont want to replace it, plus, it appears to be at 57mm, which is standard long reach (right?)

Unless I can get a longer reach Shimano600 caliper that matches - is there any way of extending the reach? Is there such a thing as an offset brake pad, or a jogged mounting bolt of some kind that I can get the extra 1/8" that I need?

Thanks!!
Shane

unworthy1

Shane, yes that's called a "drop-bolt" and there are some homemade options you can make yourself if you're a little handy. Do a search of these archives and see.

wrk101

Factory made drop bolts are expensive. You sure you can't get 4mm more reach out of the existing calipers?

brownbike

Yes wrk101, I have adjusted everything down. The front caliper works maxed out, but the rear is all the way down, I even loosened the mounting bolt and rotated it a little (there was a little bit of wiggle room) I'd prefer not to drill out the holes, or modify the calipers. I found this - im not sure it will work for these single pivot calipers, but, maybe? and really 30 bucks isnt so bad right?
https://cgi.ebay.com/Rare-Vintage-Cam...#ht_500wt_1166
its an open auction though and could go way up i guess. There are others like this for 150 dollars... crazy

WNG

Drop bolts aren't manufactured anymore, and it'll be next to impossible to find one. The easiest option is to replace the caliper with a long-reach model, like the Tektro or Shimano Sora dual pivot long reaches.
But if you're handy with a drill, you can fabricate your own "drop" from steel bar stock, and a bolt and nut.

wrk101

It will go up. The auction has more than five days left. the price with five days left rarely has anything to do with the final auction price. They appear to be going for $50 to $75. I would expect this one to sell in that range.

Myself, I might pick up a replacement caliper and do some work with a round file. But I cannot recommend that to others.

JML

Rivendell sells a couple of long reach dual pivot brakes that will fit.

I remember, going back a long time ago, trying 700c wheels on a bike made for 27" wheels, and it felt different (not good, to me anyway). The lower BB and COG, and a different amount of trail, I guess.

Ragooch

For an 1/8" I would just file the slots to drop the pads.

Grand Bois

If it's really a '74 it would have originally had Mafac Competitions and 700c tubular wheels. The cheapest and best solution may be to put Mafacs back on it. You can sometimes get Mafacs cheap. I've even gotten them for free.

NormanF

The cheapest solution is to get a long reach brakeset. I had to do that to convert my Peugeot PX 10 from 700C to 650B. Tektro is reasonably priced.

Grand Bois

A Mafac brakeset is a long reach brakeset.

Chris W.

Mafacs get my vote too! First thing I thought of when I started reading this post "needs Mafacs".

Cheers,
Chris

tatfiend 

So far as I know Shimano never made longe reach high quality brakes than the Ultegra that you have. As others have noted Tektro does do modern very long reach dual pivot sidepulls. They have 55 to 73mm reach ones available. Harris Cyclery carries most of the Tektro longer reach brakes.

https://sheldonbrown.com/harris/brake-calipers.html

They even have a number of them in nutted versions for older bikes that are not drilled for recessed nut mounting brakes.

Rabid Koala

On my TdF, the old style with foil decals, I tried to put some 27" clincher wheels on and they would not fit. I put 700's on with the Mafac brakes and they work just fine. Originally, it had tubular rims/tires.

Road Fan

Yes, this is the reverse of the OP's problem.

big chainring 

I think Mafac brakes are a requirement on a Gitane TDF of that vintage. It just wouldnt be right without them.

Bianchigirll 

so no one else besides Campi made these odd little dropbolts?

I don't mean to hijack the thread but.. I made an offer on a bike today for the group, then surfed over to Soma only to discover their Mixtie has 57mm brake reach!! so much for the worlds first mixtie with an Athena group

brownbike

you all might think I'm nuts, but this is what I did to get the reach I wanted and keep my Shimano 600 Arabesque brake set... Pulled a little Sheldon Brown action, but I worked to try and make it look nice.
Campy drop bolt = $75 and up
My solution = $6...and a little elbow grease/grinder action
(1) New 1/4" bolt and nut
(2) steel brackets ground into a rounded shape with 2 holes each
(1) brass plumbing connector with 1/4" inner diameter, cut to length.
Turned out nice and stiff, actually. There is no play in its position, I'm happy with it.
As you can see from these shots, it hasn't even been cleaned yet... That will be next.



It's okay, tell me I'm crazy, but I'm kinda proud of it!

By the way, not sure why I stopped receiving notifications of other peoples responses, but I thought I'd follow up on a few comments. This bike was originally ordered through a bike shop in Chicago, for their race team. They ordered about 20 frames, had them painted this metallic black and built them up with their own selection of parts. In this case, it was Shimano 600 Arabesque derailleurs, brakes, levers and crankset. Zeus (sp?) headset, and I have not inspected the BB yet. Being that the paint isnt exactly original, I'm considering having it powdercoated, that's what's holding me up on rebuilding it...
Okay, thanks everyone for all of your thoughts!!

ironwood

MAFACs should work as will Weinmann and Dia-comp 610 centerpulls. Universal centerpulls also work. Weinmann and Dia-Comp 750s might be another possibility if they are not too long.

phillyrider

Actually, there are a number of generic options to campy - but they're all somewhat expensive.
I have 4 on my bikes (3 back, 1 front). With some patience, you can find them. The better deals are when a brakeset is sold and the drop bolts are still on. If a seller knows what they are - then $50 to $70 range is the usual going rate. It's a crazy amount for a bolt - but the're not made anymore.

jtgotsjets

Great work! I was honestly surprised when everyone started lamenting the high price of drop bolts and telling you to get new brakes. This is such an easy part to make yourself--pretty sure there's even a Sheldon Brown page on it, as you've implied as well.

Zaphod Beeblebrox 

Nice work. Incidentally, how do you like those 600 Brakes? I've got a set just sitting around waiting to be used but perhaps they should be in use while something else sits.

unworthy1

I have owned a couple pair of SunTuor Superbe brakes that came with drop-bolts, so I assumed these were SunTour brand (which means made by DiaCompe for them). The Campy items have their brand stamped on them.

tatfiend 

Of course one disadvantage of using drop bolts is that short reach brakes limit tire sizes that can be fitted compared to using longer reach brakes. The use of short reach brakes also makes it a lot harder to fit fenders with adequate tire clearance.

One reason so many European bikes were designed for longer reach brakes was that fenders were commonly fitted to most bikes in Europe.

Jeff Wills

Why, yes there is: https://www.sheldonbrown.com/home-drop.html
Doesn't anybody Google anymore?