I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire.
My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together? I have checked to see that the quick release was fully closed when the brakes were adjusted for rim clearance.
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire.
My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together? I have checked to see that the quick release was fully closed when the brakes were adjusted for rim clearance.
Anyone come across this before?
Have you tried grasping the arms and spreading them out by hand to see if they'll extend further? Sometimes if the spring is gummed up or there's lots of drag in the cable the spring alone isn't strong enough to fully extend the arms.
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire. My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together? I have checked to see that the quick release was fully closed when the brakes were adjusted for rim clearance.
Anyone come across this before?
It's not unusual to have to "whack" the tire through -- especially if you run your brake pads close to the rim. (For example, I've had mountain bike tires that I actually had to DEFLATE to squeeze between the pads, although that /was/ highly unusual.)
If it's really tight you might open up some brake cable to install the wheel; then cinch it back down to the pad clearance you desire. (Also check symmetry as it's easy to knock the calipers a tad askew.)
"Rebecca Morris" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work
well,
Quoted message said:
but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It
doesn't
Quoted message said:
seem to depend on the brand of tire.
My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together?
I
Quoted message said:
have checked to see that the quick release was fully closed when the
brakes
Quoted message said:
were adjusted for rim clearance.
Anyone come across this before?
Thanks in advance
Bob Morris
What kind of tires and rims/wheels are ya using? I have 0 problems with Bontrager or Conti tires, on Bontrager rims on my bike with 105 brakes.
Your rim width can make a difference too. Narrower rims with wider tire accentuate the problem.
cel
"Rebecca Morris" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work
well,
Quoted message said:
but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It
doesn't
Quoted message said:
seem to depend on the brand of tire.
My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together?
I
Quoted message said:
have checked to see that the quick release was fully closed when the
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire.
Should not be a problem with 23mm tires. You may have brakes adjusted with the pads too close to the rim. You may be able to adjust the brake cable so the pads a little further from the rims (as long as the levers don't bottom out). Or you could use the cable adjuster so that the pads are close while riding, but not so close when removing the wheel (i.e., use both the adjuster AND the QR everytime you remove the wheel -- a PITA but it will work).
I use 105 brakes with 25mm tires and don't have this problem.
BTW, I have Mavic XP10 rims and have been using Vedestein Volante tires. For some reason, I don't remember having this problem years ago. The brakes are several years old.
I measured the rims and in their current condition (somewhat worn) they are just over 19mm wide and the inflated tire measures 24 mm.
"Rebecca Morris" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire.
My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together? I have checked to see that the quick release was fully closed when the brakes were adjusted for rim clearance.
I can identify with you on wanting to *know* why it's now a problem - perhaps a symptom of something else. It's like a splinter in your mind until you figure out the source of the problem.
Silly thought: is there a second brake-cable tension release mechanism somewhere along the cable run?
I had a touring bike some time ago, albeit not with 105 brakes, but it had an extra "cam action" cable tension release designed exactly so tires would slide past the brake pads.
You could add something like that or perhaps slide the tire past the pads at less than full inflation. Also: is there any chance the cable routing has changed - even slightly, such as putting the brake cable on the right guides versus left? Trying to think of small changes that could have altered the clearance by a millimeter or two.
Sorry I can't be more help. Since you mention this didn't seem to be a problem in the past.
"Rebecca Morris" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Quoted message said:
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire.
Quoted message said:
I measured the rims and in their current condition (somewhat worn)
they are
Quoted message said:
just over 19mm wide and the inflated tire measures 24 mm.
Bob:
I've fit 28 mm tyres through my 105 calipers. I'd say something is wrong with your brakes... a cable with a kink, dirty return spring not allowing full retraction, or something like that.
When you're not pulling the brake levers, try to pull on an exposed piece of cable. There should be no slack in the cable -- the calipers should move as soon as you start to pull the cable. If not, then the return spring is not taking out the slack for some reason. I suspect this is your problem. You might be able to narrow down the area of the problem by figuring out where the slack cable comes from.
I'll dare to bet that lubrication of all the pivot points in the brake, lubrication of the return spring (don't forget the ends -- the spring slides there!), and a new brake cable will rectify the problem. Maybe even new cable housing.
Your rim width can make a difference too. Narrower rims with wider tire accentuate the problem.
cel
"Rebecca Morris" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire.
My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together? I have checked to see that the quick release was fully closed when the brakes were adjusted for rim clearance.
I have a set of Shimano 105 brakes that work just fine, but do not have enough clearance to get a 23mm tire through with the quick release fully open. Everything seems to be assembled correctly and the brakes work well, but when fully open, the calipers are about a mm shy of allowing a tire through. A whack will get the tire through, but this seems odd. It doesn't seem to depend on the brand of tire. My brake pads are worn quite a bit - is there some quirk in the mechanism that limits the wide open position when the calipers are closer together? I have checked to see that the quick release was fully closed when the brakes were adjusted for rim clearance.
Anyone come across this before?
Thanks in advance
Bob Morris
When I take my wheels off, I flip open my 105 brake QR, then I click my Campy lever QR, and all is well! Long live Shimangnolo! 😉
The quick release mearly loosens the cable by a fixed amount. The pad must be set to a limited distance from the rim when the brakes are off to get adaquete braking. If differental between the tire width and rim width is too great then the quick release will not open the arms enough to clear the brakes. So if the same tire and brakes are used and one switches from a 22 mm rim to a 19 mm rim you will have 3 mm less when opening the cam.
cel
is greater than the "Phil, Squid-in-Training" <[email hidden]> wrote in message news:m5dZe.121232$Ep.98633@lakeread02...
Quoted message said:
Quoted message said:
Your rim width can make a difference too. Narrower rims with wider tire accentuate the problem.
The quick release mearly loosens the cable by a fixed amount. The pad must be set to a limited distance from the rim when the brakes are off to get adaquete braking. If differental between the tire width and rim width is too great then the quick release will not open the arms enough to clear the brakes. So if the same tire and brakes are used and one switches from a 22 mm rim to a 19 mm rim you will have 3 mm less when opening the cam.
