V-brake problems on Sherpa build

[hutzelbein]

Hi,

I recently bought a Sherpa frame and built it up myself. I'm still learning (it was my first complete build), and was wondering if somebody could help me find out what I did wrong with the v-brake installation. Since they were highly recommended by Thorn, I bought XTR v-brakes, but I used Deore v-brakes for a couple of days and had the same problem: the brake arm alignment looks like this: \ / instead of this: I I

I simply can't get the arms parallel; instead of the recommended 4 cm inner cable showing above the arms, there are about 8 cm showing. I already exchanged the washers on the brake shoes (KoolStop Supra 2 salmon), so that the thinner washer is between brake arm and rim - but this didn't fix the angle.

Pictures can be seen here: http://picasaweb.google.com/hutzelbein/VBrakes#

What could be the problem? The Sherpa fork and frame should accept v-brakes. How much can you do wrong when installing v-brakes?

Thanks!

[geocycle]

They do look odd, but I use Avid not Shimano so I cannot say for certain.  Have you checked that the locator pin on the arm is inserted into the correct frame hole (usually the central one).  If not then you would not be able to pull the arms together with the cable?

[hutzelbein]

Yes; it doesn't matter which of the 3 frame holes I use. This only changes the tension, not the angle. The problem is, that the brake pads hit the rim a long time before the arms would be parallel. Somebody suggested that the fork might not be built for v-brakes, but since Thorn sell the built up bike with v-brakes, I assume that this is not the problem.

[mikerr]

Hi,
Have just compared my Sherpa brakes with yours, mine 5cm wire showing with LX brakes.
The only thing I can see that looks odd are the Koolstop Supras, they seem very chunky.
When I Googled Koolstop Supra 2, they were for BMX bikes.
Have you tried setting up the brakes with the original supplied Shimano brake shoes and blocks?
Mike

[rualexander]

Are you using unusually wide rims?
Try giving SJSC a call, they are pretty helpful with advice on building up their frames into complete bikes.

[hutzelbein]

I hadn't thought of that. I love the KoolStops; they're light years better than any other pads I ever tried (including Shimano). Have been running the Supras with my Club Tour cantis with no problems. I'll check if the problem is solved with thinner brake pads; but I don't think that I'll ditch the Supras.

Also checked on the KoolStop website: they say "The Supra 2 has been redesigned and now has new internal hardware and comes with V-brake washers or can be fitted with the original "pad-lock" gripper washer system to fit all types of brake systems."

If it's really the pads, I might try finding thinner washers, or live with the brake set up as is. They do stop alright. The braking power is about the same as with my cantis.

[hutzelbein]

The rims are normal size; I bought the wheels (Rigida Grizzly 26") from SJS as well. But might call them up if I can't work it out on my own. Thanks!

[mikerr]

Hi,
I have Koolstop salmon/black on my bike, but they are cartridges that slide into the original Shimano shoes and then you pin them secure.
Mike

[sbseven]

I have XTR's on a Nomad, with XTR cartridge holders, Swissstop pads and Rigida Andra rims. I have 6.5cm wire between the noodle and fixing point. My calipers are 11cm apart (measuring caliper centre to centre at the top). My bike was set up by Thorn and the braking is excellent.

If the pad / washer arrangement you're using is thicker than the Shimano cartridge pads, that probably accounts for the difference. In fact, both our rims are 19mm and the frame and forks are very similar, so that should be the only difference.

My calipers aren't ||, they make a very shallow \/ shape. This shape is a product of the rim width, fork width at the V-brake bosses and the pads used. It could vary a little between bikes.

Shaun

[PhilD]

There are some pics of my Raven Tour here for comparison purposes.

http://picasaweb.google.com/Philip.Daniels1971/ThornRavenTour#

[john28july]

Hello
Are the rear the same?
John

[hutzelbein]

Thanks for the pictures; my brakes don't look too much different - so I guess it's alright.

Yes, the rear brake looks pretty much the same. I checked the pads that came with the v-brakes, and they are 1-2 mm thinner. I won't exchange the Supras for the moment; the braking is fine (as far as I can say), but might go for the Thinlines the next time.

Thanks for all the help!

[john28july]

Thanks for the pictures; my brakes don't look too much different - so I guess it's alright.

Yes, the rear brake looks pretty much the same. I checked the pads that came with the v-brakes, and they are 1-2 mm thinner. I won't exchange the Supras for the moment; the braking is fine (as far as I can say), but might go for the Thinlines the next time.

Thanks for all the help!

Hello
I just yesterday fitted a pair front and rear to my Sherpa. XT V brakes but with the thin Shimano pads. They are in close as might be expected. The only thing I can tell from your pictures, is that you have rather fat pads which appear to be the 'problem'/
If they work OK its not really an issue but of course its what they look like as well!
John.