Archival Review of Suntour Cantilever Brakes


It's probably not giving away a big secret to tell you that Dia-Compe's original Japanese parent company, Yoshigai Kikai Kinzoku (known in the industry as just "Yoshigai") of Osaka is the real maker, under contract, of these brakes. That Yoshigai makes these is why they have so many similarities to the Dia-Compe (and therefore Ritchey) cantilever brakes.

Mechanical explanation of the XC Pro brake. Although XC Pro brakes come boxed as a front or rear, their only difference is what direction the brake pad arrow points. Each brake pad has an arrow on the top that should point to the front of the bike. To make a "rear" XC Pro a "front" you merely switch from left to right the brake pads and see to it the arrow points forward. The XC Pro cantilever has forged aluminum arms Each arms internal tension spring is accessible and can be replaced. It is. One end of the spring fits into a small hole in the arm, the other end is fit into a carefully machined aluminum washer that the mounting bolt seats into.

Each arm's spring is adjusted from the front by turning this large aluminum washer, which can be gripped with a 13mm cone or box wrench. Once the spring is correctly tensioned, then tightening the mounting bolt holds the spring in place. (Notice this is like the Dia-Compe brakes, but the 13mm grip is on the top instead of the bottom.) The arm has a brass tube pressed into its base for the arm to swivel around. A chrome plated steel bushing slides into this brass tube. It is this bushing within the arm that slides over the brake mounting stud. To close and seal the spring, a black nylon washer is used beneath the spring and a molded Black nylon cup is positioned over the top. The aluminum adjusting washer sits inside this cup with the spring extending into it.

The mounting bolt is cadmium plated with 6mm by 1mm threads, a 13.5mm length and a 5 gram weight. The bolt has a 5mm hex fitting and fits recessed in a 10.3mm hole in the adjusting washer. The XC Pro brake pads mount in front of the arm. Fives pieces are used to hold the brake pad. The XC Pro uses an "eyebolt" type pad holder made of steel with a 5mm hex fitting for final adjustments on the front. We found that any of the SRP Titanium replacement pad holders will work in place of the 9 gram steel original. The short bulb shaped one would be our preferred choice (our part number 06-91-PH) because the bulb will hold the steel pad base washer in place even when there is no pad in the holder. The steel holder (or the Ti replacement) has 6mm by 1mm threads for the 10mm steel tightening nut. The XC Pro comes with a Black plastic cover which snap over the pad holder gripping the brake pad mounting post. This piece just adds a Black accent and will fit on the SRP replacements.

The XC Pro uses a traditional straddle cable and carrier. The lead anchor at one end of the 230mm long straddle wire fits into the top of the left arm. The other end of the cable fits into a pin anchor cinch system on the right arm. This pin anchor uses a keyed steel bolt and nut that draws up a steel plate, pressing the cable between the plate and the brake arm. The 11.5 gram cable carrier is stamped from aluminum plate then Black anodized. The brake inner wire is held by a bolt with a hole through it. The inner wire passes through the hole while a nut at the back tightens a washer against the plate gripping the wire.

Once the straddle wire has been nipped an included wire end cap is crimped in place. There is a steel mushroom head pin driven into the right arm below the pin anchor bolt. This is so the short length of cut, capped wire can be tucked behind and kept out of the way. The brake pads are a one piece molded design with steel re-enforcement and a non-threaded aluminum mounting post. The pads have a 49.7mm by 9.5mm rim contact area in an arch shape that mimics the rim curvature. As we mentioned, and Suntour tech support informed us, the position of the pad so that the arrow is on the upper side and points forward is all that makes an XC Pro a "front" or "rear". Reversing the pads effectively makes one brake the other. When ordering, if we are short on the one you desire, ask for the other and switch the pads. End of Mechanical.

The pair of brake pads weigh 34 grams. We found the XC Pro cantilever to have a Bike-Pro profile measurement of 52mm. The XC Pro brake weighs 175.5 grams, which includes mounting bolts. The straddle wire and carrier add another 18 grams for a total of 193.5 grams.

No longer made, the XC Pro canti sold for $37.99