Cantilever brakes ..... HELP !!!

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landsurfer
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Re: Cantilever brakes ..... HELP !!!

Postby landsurfer » 13 Sep 2019, 10:05pm

Brucey wrote:lever?
brake blocks?
setup?


OEM.
OEM.
OEM.
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RickH
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Re: Cantilever brakes ..... HELP !!!

Postby RickH » 13 Sep 2019, 10:25pm

landsurfer wrote:
Brucey wrote:lever?
brake blocks?
setup?


OEM.
OEM.
OEM.

If you aren't going to provide more helpful information then I might suggest what I did once, many years ago - I went to the local bike shop to buy some new brake blocks....




... & returned home with them attached to a shiny new bike! :twisted:

Brucey
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Re: Cantilever brakes ..... HELP !!!

Postby Brucey » 13 Sep 2019, 10:39pm

believe it or not there has been more than one version of the Jamis aurora, with different levers, slightly different boss spacings and different bike mechanics can set the brakes up differently too. There's also more than one version of the Tektro 992 and one of the differences is the brake block type. So there is no such thing as 'OEM'.

If you are keener to understand and fix the problem than just to mither about it, some more actual information would be useful.

I can tell you one thing for free though; the cables almost certainly won't have been greased when the bike was put together and furthermore any passage of time/wear on the brake blocks won't have improved them either....

If you have done no maintenance or adjustment of your brakes and are now moaning that they don't work, this is (IMHO) a bit like complaining that your tyres have gone flat when you have not pumped them up.

cheers
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horizon
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Re: Cantilever brakes ..... HELP !!!

Postby horizon » 13 Sep 2019, 10:49pm

Brucey wrote:If you are keener to understand and fix the problem than just to mither about it, some more actual information would be useful.



It's a useful thread though (for those of us who have plenty of cantis). It presents a fairly extreme (though not uncommon) scenario, an actual result and some details. It would be good to explore it further. I am hoping the OP will come back with more info.
I have two doctors, my left leg and my right leg. (G. M. Trevelyan)
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9494arnold
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Re: Cantilever brakes ..... HELP !!!

Postby 9494arnold » 13 Sep 2019, 11:25pm

Really need a picture of your brake set up as has previously been mentioned.

Don't think Tektro brakes can be that bad , no actual experience but they make brakes for Campagnolo I believe.

Something that can make Cantilevers not work well is the relationship between the primary cable and the Cantilever yoke /cable (known as the MA factor I think) .(Mechanical Advantage?)

You see a lot of Cantilevers with the yoke too low down.

I run Weinman and Mafac Cantilevers on Trikes and they work well.

Google Sheldon Brown and the MA factor of Cantilever brakes.

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Chris Jeggo
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Re: Cantilever brakes ..... HELP !!!

Postby Chris Jeggo » 14 Sep 2019, 1:04am

Sheldon Brown's analysis is not correct - see Chris Juden's:
https://forum.cyclinguk.org/viewtopic.php?f=5&t=57410#p481693

landsurfer
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Re: Cantilever brakes ..... HELP !!!

Postby landsurfer » 14 Sep 2019, 10:31am

RickH wrote:
landsurfer wrote:
Brucey wrote:lever?
brake blocks?
setup?


OEM.
OEM.
OEM.

If you aren't going to provide more helpful information then I might suggest what I did once, many years ago - I went to the local bike shop to buy some new brake blocks....


Sorry about that ... GOM moment. Just returned from the WIMPS Sea to Sea ride and still a little drained .... I'll sort a pic out .... but the squealing of mine and Flash's canti's as we came down Whinlatter must have deafened other road users ... :)
For now this link gets you a good look at the bike ... https://www.evanscycles.com/jamis-auror ... e-EV339179
The big difference is that i am using Shimano SORA STI levers.
The Road Goes On Forever ...

pwa
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Re: Cantilever brakes ..... HELP !!!

Postby pwa » 14 Sep 2019, 10:42am

My Tektro cantis (black things, 520s possibly, nicer made than Oryx) will stop me on a 25% hill so long as the tyres will grip. That is usually the limiting factor rather than the brakes. In the wet there can be a delay as the pads rub water off, but I suppose I have factored that in and brake earlier ; harder in the wet. I wonder if the straddle wire isn't at the right angle. Or if some waxy residue has got onto the rims.

Brucey
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Re: Cantilever brakes ..... HELP !!!

Postby Brucey » 14 Sep 2019, 10:53am

I think Sora 3500 and Sora R3000 have 'New Super SLR' cable pull, which is a lower lever MA than older brake levers meant for DP brakes.

These brake levers should not be paired with most cantilever brakes.

If you do decide to use them with cantis, you need to choose the cantis with care, be 100% on setup, and good brakes may still elude you if (say) the bosses on the frame are not set high enough, or the cables are not good enough. Bad cables can feel 'not too bad' but still result in brakes that are less than half as good as they could be.

cheers
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landsurfer
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Re: Cantilever brakes ..... HELP !!!

Postby landsurfer » 14 Sep 2019, 10:56am

I've been using the SORA levers for over 12 months and 2000 miles + so far ..Whinlatter Pass decent on Tuesday was the first time my brakes failed to stop me .... they slowed me considerably but would not stop me.
The Road Goes On Forever ...

fatboy
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Re: Cantilever brakes ..... HELP !!!

Postby fatboy » 14 Sep 2019, 11:08am

landsurfer wrote:I've been using the SORA levers for over 12 months and 2000 miles + so far ..Whinlatter Pass decent on Tuesday was the first time my brakes failed to stop me .... they slowed me considerably but would not stop me.


Sounds like some routine maintenance is in order. When you say that you couldn't stop did the levers bottom out? Could be as simple as adjust the cables?
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly

nigelnightmare
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Re: Cantilever brakes ..... HELP !!!

Postby nigelnightmare » 14 Sep 2019, 11:42am

landsurfer wrote:I've been using the SORA levers for over 12 months and 2000 miles + so far ..Whinlatter Pass decent on Tuesday was the first time my brakes failed to stop me .... they slowed me considerably but would not stop me.


Sounds like "BRAKE FADE" to me, Where they have got overheated on the hill.
Also if they are squealing a lot then they need adjusting (toe-in).

P.S.
I use 70mm "V" brake pads on my old canti's and they really improved the braking compared to the OE spec ones at around 50-55mm.

HTH

landsurfer
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Re: Cantilever brakes ..... HELP !!!

Postby landsurfer » 14 Sep 2019, 12:25pm

I've been cycling for over 40 years and maintain and build all my bikes ...
Toe-in, toe-out, various manufactures brake blocks, cable alignment et al have all been addressed a long time ago ....
One recommendation i had from a fellow traveller was to use Kool Stop brake shoes ... thats the next possible step but at £24 a set i'd like some opinion before i buy please.
The Road Goes On Forever ...

reohn2
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Re: Cantilever brakes ..... HELP !!!

Postby reohn2 » 14 Sep 2019, 2:02pm

landsurfer wrote:I've been cycling for over 40 years and maintain and build all my bikes ...
Toe-in, toe-out, various manufactures brake blocks, cable alignment et al have all been addressed a long time ago ....
One recommendation i had from a fellow traveller was to use Kool Stop brake shoes ... thats the next possible step but at £24 a set i'd like some opinion before i buy please.

Koolstop Salmon are very good,BBB Tristops are better though,but they don't last quite as long a Koolstops.
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LollyKat
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Re: Cantilever brakes ..... HELP !!!

Postby LollyKat » 14 Sep 2019, 3:24pm

+1 for Tristops - they are cheaper than Koolstop, too.