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Old 05-05-10, 02:58 PM   #1
chimpanzee
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need replacement for Promax 85mm mini-V

I have a Schwinn Super Sport flat-bar road bike.

After 1600 miles, the brakes feel mushy. Probably housing/cables need to be replaced.

It comes with Promax 85mm mini-V (V brake). So, I had this idea to replace the brakes with Avid SD7 (100mm, $19 per). One problem..they don't fit!! Or, can I replace the stud that screws into the boss?

Or, can someone recommend a good replacement mini-V?

I did some research, & the Tektro RX5 have good reviews.

http://www.bikeforums.net/archive/in.../t-417670.html

Would the Tektro 926A be a candidate?

http://www.jensonusa.com/store/produ...ni+L-Pull.aspx

Another option is just to keep the Promax 85mm.

I ended up getting the Alligator Super Fortress cable kit (stainless mesh reinforced). I figure I should upgrade the brakes for this fancy cable (i.e., go with a Tektro rather than keep the Promax)
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Old 05-05-10, 03:00 PM   #2
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Originally Posted by SilverStar
How is it that the replacement brakes don't fit? All of those studs are the same, as far as I know...in other words, mini-Vs aren't designed to go on special studs.
The replacement brake (Avid SD7) is different:

1) less recess (to go over the stud's "mound")
1/8" vs 3/16"

2) the pin for the spring is "raised at the base"

as the result (due to 1), the arm won't seat flush to the boss.

vbrake..jpg

Last edited by chimpanzee; 05-05-10 at 04:00 PM.
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Old 05-06-10, 05:39 AM   #3
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Originally Posted by chimpanzee View Post
Would the Tektro 926A be a candidate?

http://www.jensonusa.com/store/produ...ni+L-Pull.aspx
The Tektros work well for me on a Miyata Triplecross.
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Old 05-09-10, 04:24 AM   #4
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Originally Posted by chimpanzee View Post
The replacement brake (Avid SD7) is different:

1) less recess (to go over the stud's "mound")
1/8" vs 3/16"

2) the pin for the spring is "raised at the base"

as the result (due to 1), the arm won't seat flush to the boss.

Attachment 149472
I went to 4 bike shops, & they told me the gap wouldn't affect operation. However, the pin for the spring would seem be a weak point (there would be leverage at the end of the tip, where it seats into the boss).

Suppose I ground down the brake boss stud from 3/16" to 1/8", so the Avid arms would fit flush to the boss. Would I weaken the stud? A bike shop claimed it would.
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Old 05-09-10, 06:45 AM   #5
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Originally Posted by chimpanzee View Post
I went to 4 bike shops, & they told me the gap wouldn't affect operation. However, the pin for the spring would seem be a weak point (there would be leverage at the end of the tip, where it seats into the boss).

Suppose I ground down the brake boss stud from 3/16" to 1/8", so the Avid arms would fit flush to the boss. Would I weaken the stud? A bike shop claimed it would.
when you remove metal it weakens it, especially in a critical place like a brake stud
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Old 05-09-10, 08:01 AM   #6
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Originally Posted by chimpanzee View Post
I went to 4 bike shops, & they told me the gap wouldn't affect operation. However, the pin for the spring would seem be a weak point (there would be leverage at the end of the tip, where it seats into the boss).

Suppose I ground down the brake boss stud from 3/16" to 1/8", so the Avid arms would fit flush to the boss. Would I weaken the stud? A bike shop claimed it would.
That gap is not unusual. Any Tektro Oryx brakes, ( sometimes branded as Cane Creek) will have that gap, even when supplied as original equipment on a new bike.
I would not grind anything, just mount the brake and be happy.
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Old 05-09-10, 09:14 AM   #7
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Originally Posted by Dan Burkhart View Post
That gap is not unusual. Any Tektro Oryx brakes, ( sometimes branded as Cane Creek) will have that gap, even when supplied as original equipment on a new bike.
I would not grind anything, just mount the brake and be happy.
+1. The brakes will work, it just might look a little different then what it was before.. All modern cantilever-style (centre-pull cantilever style, Vs and Mini Vs) all fit on the same standard studs and spring holes.
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