Most frames are made with the disc brake tabs on the seatstay. I've noticed a growing number of frames with the tabs mounted on the chain stay and trying to figure out which is really the ideal place for mounting. Seatstay or chainstay? What are the considerations when choosing?
Disc brake tabs: Seatstay vs Chainstay mounting
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bee
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Most frames are made with the disc brake tabs on the seatstay. I've noticed a growing number of frames with the tabs mounted on the chain stay and trying to figure out which is really the ideal place for mounting. Seatstay or chainstay? What are the considerations when choosing?
I put my mount on the chainstay and love how clean it looks. However Mr. Gerhardt is quite right. My old Deore 555 fits just fine, but my Xtr 975s from my 29er will not fit. The 975 caliper is thin vertically but very fat. The 555 has most of its mass to the outside of the rotor, vertically.
Drew
Drew
ducking to get slammed......but I believe there is also consideration to the physics and forces on the stays as mounting on the chainstay is more rigid than on the seatstay: you find the additional support/brace (not always) with seatstay mounts but the idea is the under braking, the force is driving the seatstay towards the chainstay (if mounted on the seatstay). If mounted on the chainstay, since the force is coming from 'inside the triangle', it already has the extra 'support/brace' built in.
....I probably should never be a technical writer......but if you understand the above, you get it.
....I probably should never be a technical writer......but if you understand the above, you get it.
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There's also the hassle factor of aligning the caliper when installing the brake. People I've talked to with chain stay mounts are split about it being more difficult than seat stay mounts.
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I am actually a technical writer, but we all have our bad communications days. :thumbsup:
I understand what you're saying (I'm used to rewriting documents written in Jenglish
). However, I disagree. Forces applied inward to a triangle have the save effect as forces applied outward.I believe the reason a brace is not needed on chainstay mount is because chainstays usually have thicker walled tubing than seat stays and therefore stronger.
On a semi-unrelated note, I can't figure out why I always want to use "chainstays" as one word and "seat stays" as two words.
many times in my world i am also taking into account fenders and or rear racks. a pita when mounted on seatstays (one word. lol ) i am a firm believer in having all your design thoughts figured out before any metal cutting. good luck with your final desision
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Unless you need to mount racks and bags, seatstays are the way to go. Chainstay mounting forces spacial problems with the rider and are hard to work on. They also force some pretty lame dropout designs. For any type of performance riding seatstay is the only way to go.
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Spoken from a person who truly knows lame dropout designs.
So exactly how does the location of the caliper affect "performance riding"?
You don't always have to route from the DT to the CS. :thumbsup:
This bike was built to carry a rear rack as well as a baby seat, and the seatstay mounted caliper would have been in the way, forcing too many compromises.
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I guess that I probably know a lot less about dropout design than some others. I should put some work into that.
Besides having issues with rider heal clearance and being closer to mud, I don't see the CS mount sharing much of the bending load with the seatstay. I would want a brace in there, but then it starts getting really crouded. It's all opinion, but I've done one bike with them and swore to never do another without good reason. It also looks crappy to me.
That build looks great. Haven't seen top tube routing with a chainstay mount. Clever solution to avoid the issues with rear rack and baby seat. Does routing along the top tube and mounting on the chainstay only work for a certain type of brake (i.e., hydraulics)? What about mechanical disc brakes? Could you use those brakes on a chainstay mounted disc frame with routing along the down tube instead?
After thinking about this for awhile, I don't think that is very accurate. Rider heal clearance should not be an issue at all with chainstay mounted disc brakes. Why would they be? Look at the pics above. No way that a person's foot would even come close to even touching the disc brake when pedaling.
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847 Posts
That's not entirely true either in all cases; my frame uses CS mounting for the caliper and the CS starts inward right at the dropouts because my IS mount is parallel to this disc, not the CS. The IS mounting tab sits on the CS at an angle to account for the bend in the stay.
Also, like the previous poster said, heel clearance is a non issue. Nothing on my caliper sticks out past the CS itself. There's absolutely no way you'd snag your foot on the caliper, unless you were trying to stuff your foot in the spokes..
My only beef with CS mounting is the fact that not all brands and models of caliper will fit in the CS position.
Drew
Am I just high, or does it look like moving the angle of the cable pull 90 degrees clockwise would diminish the ability to adjust the BB7? It just looks like maximum force would be generated very early in the lever pull and that there would be a lot less rebound travel (which might not be a huge issue if your rotors were very true).![Image]()
I'm not bashing anyone's work, I'm just curious if this set-up has any drawbacks stemming from the removal of the brake's built-in housing stop and the alteration of the angle from which the cable is pulled.
-Matt
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