mddobbs

Regarding the Wound Up fork, is yours the V-brake version? I mounted but did not test a brake booster that I added to our V-brake fork until recently. Unlike my MTB singles, the V-brake on my Wound Up was pathetically weak. On the tandem, I was doing primary braking using the rear disc, and adding in the "un-boosted" V-brake to stop for the last few mph. With the booster, while not terribly strong, I can really feel the bite, even when braking from the hoods (I am using STI brake-shifters with a Problem Solvers travel agent). Hence, this stout carbon fork does flex from the V-brake actuation. FYI, the booster that I use is the Salsa Arc de Tri-Oomph. It is a bit ugly, and harder to find now, but worked better than some more slender boosters on my old MTB's. Da Vinci sells their version, but it is presently out of stock.

reburns

My experience with the Wound Up fork is very different. I did install a brake booster on a steel fork, to control brake squeal, but never felt the need on either of my Wound Up forks as the v-brake power is very strong. But the first fork I bought as part of a used bike showed some signs of galvanic corrosion on the legs near the aluminum crown. Wound Up recommended replacement and offered a very generous trade-in deal. I replaced the fork with the newer carbon crown design, which also provides a solid foundation for the v-brakes.

If a brake booster is making a noticeable difference on your fork, I would encourage you to carefully inspect the integrity of the crown/leg interface to make sure that you don’t have a potential safety issue.

mddobbs

Thanks for the heads up. I have a aluminum crown on my fork, and I don't see any corrosion. One thing I forgot to mention is that the rim in question, the Da Vinci V-22, has flat, but not machined side walls. In my experience with MTB rims, machined side-walls always worked better with V-brakes than flat, un-machined side walls. It may have been more costly/difficult to machine them with the extra lip, which was included to prevent brake pad induced sidewall blowouts:

The correct tandem bicycle wheels can be a big decision

Carbonfiberboy 

We also have the Wound-Up fork with the aluminum crown. We have Travel Agents both front and back and Shimano hoods and levers. I don't notice any movement in our fork under heavy braking. "Heavy" braking isn't all that heavy anyway. I can't skid either tire on dry roads. We do not have brake boosters. I can't imagine that they'd do anything. This is a tandem! They have stiff frames and those Wound-Up tubes are also really, really stiff. We have no bending at all at either end with max brake lever squeeze.

I doubt machining makes all that much difference once the pads bed in. I accidentally bought a disc rim with an unmachined and painted brake track. I sanded the paint off. No difference in braking.

mddobbs

I would not have believed it had I not tried it. It is not a night and day difference - just a noticeable difference. It was an experiment with an old part (booster) collecting dust, and I don't like to add unnecessary weight. The Salsa MTB sized booster on the front possibly has a slight aerodynamic benefit by shielding the brake arms and Travel Agent (reducing turbulence), but it may not be significant...hard for me to judge. I could not observe or feel any flexing of those stout carbon fork tubes without the booster - I could only feel the braking improvement with it.

It would be good to hear from any un-machined V-22 rim brake users on their experiences, but there may be none in current use. The newer V-23 version is machined and has no protective lip, but is available only with 40 holes for 700c.

Good that you are happy with your braking performance. If you don't mind me asking. what V-brakes and pads are you using?

reburns

[QUOTE=mddobbs;21936501.

Good that you are happy with your braking performance. If you don't mind me asking. what V-brakes and pads are you using?[/QUOTE]

On our Speedster with Wound Up fork, I am using Shimano XTR v-brakes (the old style with parallelogram structure) and SwissStop green pads (which are now no longer available, I am sorry to say, as they are quiet, rim friendly, and very powerful even when wet. They also last forever. I have spares in stock, but at some point I will have to get holders that take normal road caliper pads so I can use SwissStop’s latest compounds)

Carbonfiberboy 

We have Avid Single Digit 7 V-brakes. Funny that you should ask about the pads. I bought a pile of SwissStop GHP2 green pads back in 2015, still have a few pair. Sure enough, they don't make them anymore. I don't know what tandems are using for V-brake pads now. Those were the best ever, though riders with calipers liked the blue pads better, but they never made a blue V-brake pad. I don't remember the number for the blue pads.

With our brakes, I don't see how a booster would help. I can pull full strength on the levers and not bottom them out by about an inch. Can't do any better than that. I built a special touring rear with a drum brake, back when one could find them on ebay. Only used it on steep descents when loaded.