Help me brake my bike
welkman
Posts: 396
I love my bike. It didn’t cost much from ebay and has served me well so far, however the brakes just don’t work. I want to do some touring and the idea of taking a hill at any speed is scaring the hell out of me. The bike is a Kona Jake circa 2007 and is equipped with avid shorty cantis, did I mention that they are crap? I can’t reach the brifters in order to brake so rely on the top bar mounted levers which works fine. What are my options for replacement? Can I just remove the whole break setup and fit some cheap V brakes? Can I fit standard road type breaks to the frame and fork? Will I need to replace the brifters?
Please help me stop myself :P
W
Please help me stop myself :P
W
0
Comments
-
If you have canti's you can fit V-brakes, but they do need the right lever's with the right pull ratio or they will be worse than canti's!
Canti's can be made to work fairly well (they have served cyclocross well enough for a fair few years) so maybe its time for a check over, decent pads, well lubed cables (due to the short cable travel its more of an issue than with V-s) and pivots and making sure they are correctly adjusted all help (bridge form over the tyre is crucial).
My daughter can do a stoppy on her basic Shimano Canti's (alivio arms and STX levers) on her commuter (OK she is sub 8.5 stone which helps).
SimonCurrently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
Thanks, I will give stripping them down a go. When setting them up I find it hard to stop them rubbing, they do not seem to recoil as they should which means I need to allow loads of room between the pad and the rim. Any reccomendations on pads?
W0 -
koolstop pads should sort you out.FCN 2 to 80
-
I have the same bike and the same problem.
I'm using Avid pads, but they're not great. I think the Koolstops for MTBs are compatible, but not tried them yet.
One thing I haven't tried yet is to drop the front brake cable hanger to just above the fork (it's presently just below the stem). They need constant adjustment. I've tried closing my eyes and praying, too, but that doesn't seem to slow the bike either.
Keep them clean and lubed around the area of the bosses.FCN 2-4.
"What happens when the hammer goes down, kids?"
"It stays down, Daddy."
"Exactly."0 -
If they aren't returning properly that could be a sticky cable or arm.
Koolstops are meant to be very good (never tried them myself).
SimonCurrently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
-
The Beginner wrote:Koolstops are meant to be very good (never tried them myself).
Simon
Koolstop Salmon, not Koolstop Simon
I'll get my coat0 -
welkman wrote:The bike is a Kona Jake circa 2007 and is equipped with avid shorty cantis, did I mention that they are crap? I can’t reach the brifters in order to brake so rely on the top bar mounted levers which works fine. What are my options for replacement? Can I just remove the whole break setup and fit some cheap V brakes? Can I fit standard road type breaks to the frame and fork? Will I need to replace the brifters?
1.Mini V's
2. A different Canti brake.
I can't really comment on the Mini-V's but I got better results when I switched from the Avid provided pads to Kool stop dual compound. However I didn't get truly good results until I changed the front brake to a Kore Race cantilever brake. It is a a completely different design to the Avid brake with a lot more flexibility in the way it is set up. This brake change also got rid of the serious juddering issues I got with the Avid's. Since this change I've now got enough confidence to go quite fast downhill and be confident in the performance of the brakes. You can get the Kore Race brakes from chainreaction for about £30.
This was all on a 2008 Jake the Snake. I'm now planning on doing the same substitution on the rear brake as the return spring mechanism in the Avid has gotten seriously sticky on the rear brake causing one of the pads to rub occasionally. If you have the Jake with a steel fork it might have disk tabs. If you were willing to replace the front wheel you could switch to a cable pulled disc brake. Just make sure you get one designed for road levers not MTB ones.
Mike0 -
Canti leverage (mechanical advantage) is most sensitive to the angle of the straddle cable to the horizontal (assuming the brakes are vertical).
Mechanical advantage is (to a good approximation) inversely proportional to the angle to the horizontal of the straddle cable at the biting point. Halve the angle, double the leverage.
So to increase mechanical advantage, make the straddle cable as short (near horizontal) as possible.
Canti leverage is much less sensitive to the angle between the pivot, the point the straddle cable joins the canti arm, and the straddle cable. Call that angle "C". Adjusting pad spacing to make angle "C" close to a right angle will slightly increase leverage. The dependency is on sine(C), and sine(C) ~=1 for C even vaguely close to a right angle, for example sine(60 degrees) ~= 0.866.
Some instructions suggest that this second point is more important than the first, trying to tell you to make angle "C" a right angle, and then stop. This is wrong.
We have two bikes with CR520s with Koolstop MTB pads. They're set up with the front straddle as low as possible, and the rear straddle quite high, so the rear brake has less leverage, is a bit harder to lock, and needs less adjustment.0 -
Right, first of all thanks for the help.
I think I am going to take the plunge and buy a front kore race brake and some kool stop pads for front and back. Lets see if that stops me from mounting the car in front of me on the way to work.
Cheers
W0 -
jejv wrote:Canti leverage (mechanical advantage) is most sensitive to the angle of the straddle cable to the horizontal (assuming the brakes are vertical).
We have two bikes with CR520s with Koolstop MTB pads. They're set up with the front straddle as low as possible, and the rear straddle quite high, so the rear brake has less leverage, is a bit harder to lock, and needs less adjustment.
Mike0 -
mudcovered wrote:jejv wrote:Canti leverage (mechanical advantage) is most sensitive to the angle of the straddle cable to the horizontal (assuming the brakes are vertical).
We have two bikes with CR520s with Koolstop MTB pads. They're set up with the front straddle as low as possible, and the rear straddle quite high, so the rear brake has less leverage, is a bit harder to lock, and needs less adjustment.
Mike
Yep. Fine-tuning just isn't possible. I thought about cutting the straddle cable length down, but not convinced that will work. May plump for those Kona Races you mentioned. Nice one.FCN 2-4.
"What happens when the hammer goes down, kids?"
"It stays down, Daddy."
"Exactly."0 -
take them off and fit some hs33/hs11's modifying the lever to work as an interrupter.
Simples0 -
ride_whenever wrote:take them off and fit some hs33/hs11's modifying the lever to work as an interrupter.
http://cgi.ebay.co.uk/tektro-cr-520-fro ... 0447233635
That is a set of Front & Rear CR520s.
Get's a bit more expensive when you add in the Koolstop Simons...0 -
any thoughts on the ebay bargin, seems too good to be true?
W0 -
cjcp wrote:mudcovered wrote:jejv wrote:Canti leverage (mechanical advantage) is most sensitive to the angle of the straddle cable to the horizontal (assuming the brakes are vertical).
We have two bikes with CR520s with Koolstop MTB pads. They're set up with the front straddle as low as possible, and the rear straddle quite high, so the rear brake has less leverage, is a bit harder to lock, and needs less adjustment.
Mike
Yep. Fine-tuning just isn't possible. I thought about cutting the straddle cable length down, but not convinced that will work. May plump for those Kona Races you mentioned. Nice one.
You might have noticed that letting your brake blocks wear away and shortening the brake cable to maintain correct clearance is the opposite of the above, and results in decreased mechanical advantage i.e weaker braking.0 -
snailracer wrote:cjcp wrote:mudcovered wrote:jejv wrote:Canti leverage (mechanical advantage) is most sensitive to the angle of the straddle cable to the horizontal (assuming the brakes are vertical).
We have two bikes with CR520s with Koolstop MTB pads. They're set up with the front straddle as low as possible, and the rear straddle quite high, so the rear brake has less leverage, is a bit harder to lock, and needs less adjustment.
Mike
Yep. Fine-tuning just isn't possible. I thought about cutting the straddle cable length down, but not convinced that will work. May plump for those Kona Races you mentioned. Nice one.
You might have noticed that letting your brake blocks wear away and shortening the brake cable to maintain correct clearance is the opposite of the above, and results in decreased mechanical advantage i.e weaker braking.
Do you need to swap the washers over to the wheel side of the brakes?FCN 2-4.
"What happens when the hammer goes down, kids?"
"It stays down, Daddy."
"Exactly."0 -
welkman wrote:....I can’t reach the brifters in order to brake so rely on the top bar mounted levers which works fine.....
You sound happy with the responses but when I read your original post, I read it that you physically can't reach the brake levers. If that is the case, then I'm not sure how changing from canti's to v's can help.0 -
japsy wrote:welkman wrote:....I can’t reach the brifters in order to brake so rely on the top bar mounted levers which works fine.....
You sound happy with the responses but when I read your original post, I read it that you physically can't reach the brake levers. If that is the case, then I'm not sure how changing from canti's to v's can help.
These spacers should have come with the brifters, but I believe they can be got afternarket. ?sjs?
Otherwise, moving the levers down round the bends a bit might help, and tilting the bars up to match.
Why don't drop-bar levers just have reach adjustment screws like flat-bar levers ???0 -
welkman wrote:any thoughts on the ebay bargin, seems too good to be true?
Not spotting the different branding, I was a bit suprised when they turned up.
But after close examination, it seems that they are CR520s, but with "Colorado" printed on the arms instead of "Tektro". The pads say Tektro - but I don't plan on using them.0 -
cjcp wrote:snailracer wrote:You CAN increase mechanical advantage, thereby increasing stopping power, even if your straddle cable length is fixed, by remounting the brake blocks further inboard (i.e. don't push the blocks up against their arms when mounting). You will need to let out some brake cable first, to maintain the normal 2mm or so clearance between brake block and rim. Your straddle cable will end up hanging lower.
You might have noticed that letting your brake blocks wear away and shortening the brake cable to maintain correct clearance is the opposite of the above, and results in decreased mechanical advantage i.e weaker braking.
Do you need to swap the washers over to the wheel side of the brakes?
Canti brake blocks usually come with a long and very solid post so you can mount them anywhere along that post. This is not really to allow riders to tune the braking force (although it does), it's more to accommodate different wheel rim widths so it is safe to do, you are not doing anything beyond their design. Some block posts even have gradations stencilled into them, so you can more easily mount both posts with the same amount of spacing from the brake arms.0 -
snailracer wrote:cjcp wrote:snailracer wrote:You CAN increase mechanical advantage, thereby increasing stopping power, even if your straddle cable length is fixed, by remounting the brake blocks further inboard (i.e. don't push the blocks up against their arms when mounting). You will need to let out some brake cable first, to maintain the normal 2mm or so clearance between brake block and rim. Your straddle cable will end up hanging lower.
You might have noticed that letting your brake blocks wear away and shortening the brake cable to maintain correct clearance is the opposite of the above, and results in decreased mechanical advantage i.e weaker braking.
Do you need to swap the washers over to the wheel side of the brakes?
Canti brake blocks usually come with a long and very solid post so you can mount them anywhere along that post. This is not really to allow riders to tune the braking force (although it does), it's more to accommodate different wheel rim widths so it is safe to do.
I was looking at the spherical nature of the washer on the outside of the block and couldn't see how that would fit on the wheel side. Haven't checked the post, though, so will do that at lunchtime. Cheers.
Failing that, I'll buy some new brakes. Do the Kona Races or the Tektros squeal as much as the Avids? It's enough to startle wildlife.FCN 2-4.
"What happens when the hammer goes down, kids?"
"It stays down, Daddy."
"Exactly."0