polymorphself 

This is on a uo18 mixte single speed with porteur bars and VO city levers. I noticed it takes some time to get the levers to pull enough to engage the pads fully. However, this does leave exactly 1” from lever to handlebar. And those levers seem to start far from the bars anyways, so maybe that’s thats throwing me off.

The gap from pad to rim is also large though. Would it be beneficial with this setup to try and get them closer?

degan

I would start by sliding the brake pad posts out a few MM. It seems as though they are as far in as possible and I don't believe they need to be. That should close the gap some.

blamester

The gap doesn't matter if the brakes work.
The gap is dependent on hand size, comfortably pulling the lever and how much power you need.
If they don't work the gap is wrong.

oneclick 

That rear straddle cable isn't properly seated in the hook-ended brake arm. Either the main cable is too short or the hook has become pinched so the round bit won't fit.

markk900

For Mafacs even though you can move the pads in and out I try to get the connection to the straddle cable as close as possible first because I find trying to keep the pads where I want them while tightening a challenge. Personally I like the pads much close to the rim (provided the rims are true) as there is a lot of flex in the system...

polymorphself 

Yanno, that shoulda been obvious. I looked this over late at night and those posts were the only thing I didn’t consider haha. I’ll start there, that should do it I imagine. Thank you.

ThermionicScott 

+1, having the pads close to the rim isn't a virtue or goal to be attained by itself. Flexy brake systems may require it so that you don't run out of lever travel before bottoming out on the handlebars.

One downside of having the pads close to the rim (apart from less tolerance of out-of-true wheels) is that it makes it harder to remove the wheel if the tire is much wider than the rim. The brakes need to open wider, so you need a quick-release at minimum, and potentially some way to release the rest of the cable tension. Deflating the tire is a workaround, but why sign yourself up for that if you don't have to?

polymorphself 

I noticed this too, but it doesn’t appear pinched. Is it
possible the round part used is just slightly too big? This is a friends bike ans she’s been riding it like that for awhile so I guess it works but clearly isn’t ideal.

mpetry912 

the round fitting on the cable is too big and won't seat. I'd call that a safety issue. could pop loose and nobody notice until - no brakes

/markp

davester

As ThermionicScott notes, closing the gap too much can cause problems getting the wheel in and out. In addition, for people with small hands (e.g. women), having a small gap also can increase the hand strength needed to brake effectively owing to the brake lever being further from the handlebar when contact with the rim is made. On one century ride I had to help a woman with small hands who was scared due to difficulty braking at the top of a long steep downhill because her mechanic had adjusted the brakes to have almost no clearance. She was unable to squeeze the brake levers hard enough to stop the bike on the steep part. The solution...adjusting the cable to increase the clearance substantially.

ThermionicScott 

The correct cable end for that brake is shaped like a little dumbbell. It looks like someone lost that part and just substituted a regular brake cable.

zandoval 

I have had to partially deflate my tires in order to remove the wheels for years now. It no longer bothers me as I don't change wheels out often. In my old racing days that would not have been tollerated. One of my most comfortable positions to ride has been on top of the hoods so I have always kept my pads very close to the rim so that I can feather the levers with the tip of my fingers...

By the way... NICE MIXTI!

Miele Man

It looks like someone has substituted an MTB brake cable for the proper straddle cable and holder.

To move the brake pads closer to the rim I'd do two things.

#1. I'd very carefully file that round end of the brake cable so that it fits flush inside the recess on the brake arm. The way it is now, if the brake caliper or brake lever were to stick a bit that round end could disengage from the brake thus leaving her with no rear brake.

#2. To maintain as much rigidity in the system as possible I'd loosen the brake cable anchor nut on the brake arm and then shorten the straddle cable by pulling more of it through that anchor bolt.

Check with your friend to be sure she can still reach the brake lever easily.

Cheers

79pmooney

I run into this a lot. I think the cables I use as straddle cables have larger discs than Mafac intended that are probably just perfect in their intended use. I file them down carefully for better fit. I feel more comfortable doing that then bending or removing metal from the brake.

Edit: Miele Man beat me to the punch. Another poster pointed out that the original straddle cable used a dumbbell shaped fitting. Yes. But time happens. Straddle cables are like cables, housings and housing clamps. All are regular replacement items or at least can be damaged or lost. Mafac stopped making all that stuff years ago. Bikes ride on. So do those brakes. We adopt. I've been using derailleur cable scraps (the trigger shifter ends I don't use) on Mafacs a long time. Second edit: To pull the wheel, I squeeze the caliper and pull out the straddle cable by the fitting just described. Always liked that Mafac provided that QR as part of the design! I don't need anything more until I am up to bigger than 35c tires on narrow (Open Pro and the like) rims.

And as for "a long time" - I've been using the Racers (and the very similar for everything we are discussing here Mafac cantilevers) for 54 years and 100,000 miles. I doubt there is one year I haven't had them on at least one bike.

Last point - if those rims are the original chrome steel Rigidas, do your friend a favor, replace them with aluminum equivalents. That will make a braking performance difference that makes this discussion like debating the merits of hiking boots as you walk off the cliff.

gugie 

As noted, you need MAFAC article 59, and use a derailleur cable for article 469 - see @ThermionicScott's pic, above.

The derailleur tip should seat inside the thimble counterbore (article 59, again). I've had to file them down to decrease the diameter just a bit in the past.

Back to the OP's original question, everyone's missing the obvious solution. Just use a wider rim to decrease the distance.

79pmooney

Have you heard stories of issues with straddles like the OP's when the disc is filed to fit? I split up Mafac pairs and use both as fronts and have been using filed discs for years. Do I need to worry?

gugie 

That works, the issue is that the "disc" you mention is a brake cable. Perhaps counter-intuitively a derailleur cable is better suited. Brake cables are much thicker, and gives a "mushy" feeling when you pull on the lever, as more force is required to "bend" a thicker straddle cable than a thinner one (brake vs. derailleur cable). The original intent and design on most MAFAC centerpulls uses a thinner cable. Before you ask "well, why are brake cables thicker than derailleur cables?" note that a brake cable won't stretch as much as a thinner deraileur cable, but a straddle cable takes up more force in bending than it does in stretching. Bicycle Quarterly had an article on his very subject, I took a quick look on the interwebs and couldn't find it, perhaps someone else will?

No need to worry, but try setting them up as MAFAC intended and see if you can feel an improvement. Of course, you'll need MAFAC article 59