Grand Bois

Actually, "dude", I think it may work. I'll give it a try on my daughter's bike this weekend. It can't look any worse than the way I've got it set up.

moxfyre

Wait a sec... are you actually saying you think my idea is good?

Or did I completely misinterpret your post

Grand Bois

It wasn't easy for me. Not so much to admit you're right, but to admit I'm wrong.

moxfyre

Hahaha. Well I appreciate it

FWIW, I did the same thing as what you did on your daughter's brake with my hybrid. Didn't work so well on mine, mostly because the "frame noodle" (or whatever it's called) was at a very awkward angle for conncting to a V-brake noodle, and created a surprising amount of cable drag.

Anyway, hope you can improve on it!

Grand Bois

That Nashbar hanger is a nice piece for the price, but the hole for the seatpost bolt is roadbike size (8MM). I made a shim with brass tubing to get it to fit the bolt on my Trek 930 mtb.

moxfyre

Clever! I'd be interested to see a photo of it set up for V-brakes, if you get a chance.

Grand Bois

I will post a picture when I get to that project. I'm preoccupied with another bike problem today.

My Fuji mixte frame arrived today and I've got another brake cable routing problem. I think the bike had one of those upside down girls' bike rear brakes. There's another cable guide a few inches back from the seat tube on the center stay. I want to make Shimano 600 centerpulls work on it. This is the best I've been able to come up with:
[IMG][/IMG]
It will look better with some nicer clamps, but it's still pretty lame. Got any better ideas?

Retro Grouch 

I don't have any better ideas off of the top of my head. I checked my QBP book for a brake caliper that looked like you might be able to reverse the cable pull hardware. Other than a Tektro caliper that looks like a Weinmann/DiaCompe clone, I didn't see anything. I also looked for top tube cable clamps, but I couldn't find them anymore either. If it was my bike, I'd probably do the same thing that you did.

Grand Bois

I don't really want to change the brake. Those 600's are nice. Loose screws has stainless top tube clamps and I think I have a bag of them somewhere. I guess I'll leave the cable like that and hope those bends don't create too much friction. It's going to have upright bars, so maybe I'll be able to find levers with springs.

I like the rear brake setup on the Raleigh mixte much better, even though I'm not a big fan of centerpulls.
[IMG][/IMG]

moxfyre

That does look nice! I dunno why all mixte frames don't put the brake bridge on the mixte stays...

Glen_Wisconsin

I was talking to my bike shop guru yesterday evening about this very topic for 2 of my bikes (before i logged into this forum). He told me that I should be very careful if I do the conversion. Because of the increased braking pressure exerted by V-brakes the seat stays can twist (or the mounting posts for the brakes) on frames not designed for V-brakes leading to metal fatigue and catastrophic failure (the mounting posts will bend and eventually snap off). If you make this conversion while doing most of your riding in flat areas don't try to ride in a city like San Francisco where you'll be using your brakes constantly. I trust this mechanics advice based on his own experiments (and just plain hardcore riding) that have resulted in numerous trips to the emergency room and multiple shoulder surgeries. It's not just the brakes you're changing, you're changing stress on the frame too.

TallRider

First, I don't think the Nashbar rear cable hanger will work as a cable stop from the other direction, because it would be under compression toward the seatpost instead of tension from the seatpost, which would cause it to rotate around a lot to find the shortest distance for the cable when the brake lever is pulled. I've used these on multiple old road bike builds with centerpull brakes, and I like them. It could work but it's pretty iffy in my mind.
And especially for the rear brake (where you don't need nearly as much braking power) I'd say just stick with the current cantilever brakes, but soup them up into better working order. Front will benefit more from a stronger brake.

I don't know if anyone has linked Sheldon Brown's article on cantilever adjustment, but here it is (sorry if it's a redundant repost):
https://www.sheldonbrown.com/canti-trad.html

moxfyre

Well... I had thought about this when I proposed that hanger as a solution. I'm not sure how much of a problem it will be in practice though. If it's tightened down enough, the friction of the seatpost bolt should hold it pretty well. The other issue is the stiffness of the hanger... presumably it's not so weak that it will buckle from the compression.

TallRider

Nah, the hanger itself is plenty stiff. But usually it's just hanging on the seatpost bolt, not clamped between the frame or seat collar unless they come really close together. But the hanger itself is pretty thin and designed to be able to rotate freely on the bolt.

If I were to propose a solution, I would just get a clamp-on cable stop, that clamps onto the tubing. Like what was used on old Schwinns before they started brazing cable stops into the frame. I assume stuff like that is still available.

After looking at Sheldon's website, this is the only thing I can come up with. It's a shifter stop but should work for brake cables. Most mountain bikes with the sort of cable routing in question probably have 28.6mm diameter top tubes.


But I'd guess that an LBS will have a clamp-on cable stop, too.

well biked

The solution to excessive flex in the seatstays due to braking is a brake booster, which is an arch that attaches at each brake boss, along with the brakes. It will stiffen everything up and eliminate any "fade" in the brakes due to flexy stays.........Shimano's "servo wave" v-brake levers are notorious for transferring enough force to the brakes to flex the seatstays. These levers come with removable "leverage blocks", and if you remove the blocks, you increase the levers' leverage quite a bit. I noticed excessive flex in the seatstays on an aluminum framed bike after I installed some XT v-brakes and XT servo wave levers (with the leverage blocks removed), installed Salsa brake boosters, and now the brakes are absolutely solid, I really can't imagine stronger rim brakes. And there's no detectible flex in the seatstays now. When Shimano first introduced the high-leverage servo-wave levers, they recommended brake boosters be used with them, I found out later-

Retro Grouch 

I wouldn't bet the rent money on that.

moxfyre

Yeah, I've seen those too. But the modern ones sold by Harris are so... damn... ugly. And expensive too. I have some old ones that I pulled off my Fuji before converting it to fixed gear that are much prettier.

TallRider

Yeah, I've got some of the old Shimano cable stops, chromed-steel, from old Schwinns and the Miyata. They can mark up the paint job in a way that the one from Harris won't, but I agree that they look pretty, and should be much cheaper.

Here's the Shimano ones I'm talking about:


But surprisingly, I didn't find anything else on Loose Screws website.

urbanknight

There is still a very noticeable difference. I used to be a bike mechanic, and when we first started selling V brakes, the head mechanic was tripping out. When I walked into the shop, he told me to take this new bike for a test ride, then laughed his @$$ off when I almost went over the bars.

Retro Grouch 

Check post #16. The only real drawbacks are that the regular retail price will be around $25.00 and it's going to be a special order part so you have to plan ahead.

moxfyre

Yeah, I got ones like those except without the long tab on the bottom... they're just little sheet-metal bands with two cable stops on them, made by SunTour. Looks like they should cost about $1 Too bad they don't make 'em anymore.

Retro Grouch 

You've got to match the tubeing sizes too. The ones in the picture look like they fit a standard diameter steel frame downtube.

moxfyre

Yep, all the old SunTour/Shimano ones are for standard steel downtubes.... don't think they'd fit an aluminum frame.