Old MTB Canti brake question---where's the spring end?
09-24-09, 09:53 AM
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Old MTB Canti brake question---where's the spring end?
Sorry if this is a question with a really obvious answer. I'm pretty new to working on bikes (this year) but think I can usually see what's going on, with a little help from Lennard Zinn. This has me stumped though.
We have a beat up '96 Specialized Hardrock which my 13 y o son and I are using as a demo/project. We're going to SS it, give it a rattle can paint job, etc. We cannibalized the brakes to get a working set of brakes (Shimano Altus with the funky plastic part) for another Hardrock which we sold. So I was looking for some inexpensive canti brakes for this bike, and grabbed a set of NOS Suntour XS from eBay. I figured at $6 + shipping I couldn't go far wrong.
But now I don't get it: how is this (the left) supposed to work? The instructions note the 'spring tension balancing sleeve nut' but the spring doesn't come through it, so how does it secure to the boss? The other side is normal, with the spring end poking out with plenty of room to insert into the boss hole. I checked and this is not because the springs got switched, they're both the same.
I did try installing the brakes in case there was some magic I just didn't understand but it went as I expected: completely loose, then completely tight, with no spring tension because the spring isn't engaged.
Am I missing something here? And if so, is it an actual part or something in my head?
Thanks for any advice.
(dang it...I put a pic in but forgot to upload it...sorry--here it is!)
We have a beat up '96 Specialized Hardrock which my 13 y o son and I are using as a demo/project. We're going to SS it, give it a rattle can paint job, etc. We cannibalized the brakes to get a working set of brakes (Shimano Altus with the funky plastic part) for another Hardrock which we sold. So I was looking for some inexpensive canti brakes for this bike, and grabbed a set of NOS Suntour XS from eBay. I figured at $6 + shipping I couldn't go far wrong.
But now I don't get it: how is this (the left) supposed to work? The instructions note the 'spring tension balancing sleeve nut' but the spring doesn't come through it, so how does it secure to the boss? The other side is normal, with the spring end poking out with plenty of room to insert into the boss hole. I checked and this is not because the springs got switched, they're both the same.
I did try installing the brakes in case there was some magic I just didn't understand but it went as I expected: completely loose, then completely tight, with no spring tension because the spring isn't engaged.
Am I missing something here? And if so, is it an actual part or something in my head?
Thanks for any advice.(dang it...I put a pic in but forgot to upload it...sorry--here it is!)
Last edited by Chicago Al; 09-24-09 at 11:08 AM.
09-24-09, 12:34 PM
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I think yours are similar to the set of DiaCompe canti's on my Bridgestone. The spring only engages the 'spring tension balancing sleeve nut' that you mentioned. The spring doesn't actually engage the frame boss. They mount up and then you set the tension by turning the 'spring tension balancing sleeve nut' and locking it down with the thru-bolt.
09-24-09, 12:49 PM
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I just read that these brakes were made by DiaCompe so that would make sense. So it's just supposed to be friction between the boss and the 'sleeve nut' that holds the brake in position? Wow. Do they work okay for you?
09-24-09, 12:53 PM
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I think yours are similar to the set of DiaCompe canti's on my Bridgestone. The spring only engages the 'spring tension balancing sleeve nut' that you mentioned. The spring doesn't actually engage the frame boss. They mount up and then you set the tension by turning the 'spring tension balancing sleeve nut' and locking it down with the thru-bolt.
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09-24-09, 09:18 PM
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Mine work great. YMMV.
09-25-09, 12:17 AM
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Mine (Dia-Compe 986's and 987's) have always worked fine. I find them easier to adjust than the Shimano/Tektro style with the tiny adjustment screw on the side.
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09-25-09, 04:11 AM
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the brake pivots on the sleeve. Not directly on the brake stud on the frame.
so its less likely to seize onto the stud. Would still grease the stud, so its easier to remove it.
BMX U brakes use sleeves. Took me a bit of figuring to work out how it operated.
I thought one of the reasons that they made cantis that had sleeves was to get the arm and pad nearer to the frame. so to avoid the leverage that they give on the stud. It looks like those brakes are even further away from the frame. Or am I seeing it wrongly
so its less likely to seize onto the stud. Would still grease the stud, so its easier to remove it.
BMX U brakes use sleeves. Took me a bit of figuring to work out how it operated.
I thought one of the reasons that they made cantis that had sleeves was to get the arm and pad nearer to the frame. so to avoid the leverage that they give on the stud. It looks like those brakes are even further away from the frame. Or am I seeing it wrongly
