Awful brakes on my ebike

flik9999

Pedelecer
Dec 11, 2016
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london
Hey so my kit (Cyclotricity 250W front) is working on myebike and its runs fine. However I wasn't able to install my new dual callipur brakes to the bike as the reach on them is way to long. What I have found is that these brakes which did fine before and I dont seam to be going that much faster now are not slowing the wheel down fast enough.

This bike has gone through many incarnations steel rims to alloy rims was the first upgrade now its gone to Ebike. My brakes now feel like im using an old steel rim. What I do notice is that the brakes dont seam to rub on the rim that well, my back brake is much stronger and I seam to be hitting both of these brakes.

So what would people suggest I do? My fork only supports calipers and uses an old nut style.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
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Tabs

Esteemed Pedelecer
Jul 1, 2016
279
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Scotland
Not sure what brakes you've got but something I learned from here is the brake levers can make a difference, I fitted an EBC conversion kit to an old GT mountain bike, everything worked fine but I wasn't 100% happy with the brakes and was looking to fit a disk on the front but someone pointed out that the brake levers I had were for v-brakes and not for the cantilever brakes I had??? After a wee bit of research I ordered a set of v brakes and the difference is night and day.
 
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Fordulike

Esteemed Pedelecer
Feb 26, 2010
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Heres pictures of my bike. It is a carbolite 103 I assume the fork is the same its just got a puegeot logo on the front.
Woah, was expecting something entirely different. Might have a 1" steerer tube and not the later 1 1/8", so I would imagine disc brake forks are even rarer.

Have you tried changing the brake blocks for maybe a softer grippier compound?
 

niggle

Pedelecer
Feb 2, 2017
60
14
61
Cornwall, near England
You have a classic road bike with single pivot side pull caliper brakes, attached with traditional hex nuts rather than the modern design with recessed allen nuts.

I do not think that a disc brake conversion would be a good idea in this case, even if you could find the right fork, as the fork would necessarily be significantly stiffer than the current one and give a harsh ride. This change in fork stiffness and ride quality does not happen with an MTB or hybrid with either already quite stiff rigid forks built for off road use, plus fat tyres, or with suspension forks and fat tyres, hence people with that type of bike find going to disc brakes an improvement without any drawbacks.

Suggestions to change the pads could bring an improvement, and the suggestion of Swissstop pads is good, but the ones linked to are for v-brakes, you would want the 'Flash Pro' variant for caliper brakes, and I would pick the green GHP compound for use in all weathers on and off road, however they are not cheap and I find they do wear the rims at an average rate, whereas BBB Roadstop BBS-02 are better value, very nearly as good in the wet as the Swissstop GHP and very low rim wear:

http://www.tredz.co.uk/.BBB-BBS-02C-RoadStop-Campag-Cartridge-Brake-Pads_60340.htm?sku=174725&utm_source=google&utm_medium=cpc&utm_campaign=google_shopping&gclid=CIbgi5iM9tECFZMy0wody5gKOQ

Note this is a full bike set, i.e. two pairs of two pads and they have replaceable pad inserts which are cheaper to buy and easier to change once the first lot wear out: http://www.tweekscycles.com/Product.do?method=view&n=3418&p=438209&d=124&c=4&l=2&utm_source=Google&utm_medium=Base&utm_campaign=Rim Brake Pads&gclid=CMuCuouN9tECFRS6Gwodd5EJ9A

Another upgrade would be some 'linear' or 'compressionless' brake cable outer housing. The road stuff is quite expensive but Chain Reaction have lots of examples of BMX sets that are way better value, even allowing for the fact that the inner cables included are no use with drop bar levers as they have the wrong ends:

http://www.chainreactioncycles.com/stolen-whip-linear-brake-cable/rp-prod38268

http://www.chainreactioncycles.com/wethepeople-vector-linear-brake-cable/rp-prod135567

Unfortunately no black sets left now, but I would think red would work on your bike.

Changing your current brakes for modern dual pivot brakes would certainly improve things even more, and there are some out there with hex nut fittings, but you say the ones you tried were too long- what exact model did you try and what is the stated brake drop for that model? Looking at the pics I would have thought a brake with a 47-57mm-ish drop would work, e.g these: https://www.sjscycles.co.uk/brakes/tektro-r359-caliper-brake-set-4757-mm-drop-nut-fitting-silver/
 
D

Deleted member 4366

Guest
http://www.ebay.co.uk/itm/700c-HYBRID-FORK-V-DISC-MOUNT-1-STEERER-25-4mm-260mm-90mm-THREADED-STEERER-/391677720153?hash=item5b31cfb659:g:p6kAAOSwa~BYU~HJ

I have disc forks on one of my road bikes and I have two others, one with carbon fibre forks, the other is a classic type similar to yours. I can't detect any difference in ride. Forks are rigid, otherwise your bike wouldn't handle properly. This is the same argument as whether an origininal 1959 Gibson Les Paul sounds better than a modern one made with 57 years of experience, computer analysis and design with modern electronics. It would be one hell of a coincidence if they got it right first time with no previous experience, and then could never do it again after 57 years of trying.
 

niggle

Pedelecer
Feb 2, 2017
60
14
61
Cornwall, near England
http://www.ebay.co.uk/itm/700c-HYBRID-FORK-V-DISC-MOUNT-1-STEERER-25-4mm-260mm-90mm-THREADED-STEERER-/391677720153?hash=item5b31cfb659:g:p6kAAOSwa~BYU~HJ

I have disc forks on one of my road bikes and I have two others, one with carbon fibre forks, the other is a classic type similar to yours. I can't detect any difference in ride. Forks are rigid, otherwise your bike wouldn't handle properly. This is the same argument as whether an origininal 1959 Gibson Les Paul sounds better than a modern one made with 57 years of experience, computer analysis and design with modern electronics. It would be one hell of a coincidence if they got it right first time with no previous experience, and then could never do it again after 57 years of trying.
Well I would like to point out that this is just your own experience, how a rim brake fork can flex depends on how it is designed and using what materials, whereas a disc brake fork absolutely has to be made stiff and strong enough to resist the very significant forces that the disc brake caliper imparts on the one lower fork end. My experience with many forks of various vintages from 1970s onwards, and materials, including carbon fibre, is that at least some rim brake forks, e.g. built with Reynolds 531c blades, can flex much more than any disc brake fork can or should.

My own clearest example is previously riding a Planet X Kaffenback 2 road bike disc frameset and now having an On One Pompino with rim brake frame & forks (same company, same geometry, visually identical forks apart from the Kaff having the ISO disc mounts and the Pomp having v-brake bosses) and seeing and feeling more flex and comfort with the Pomp on identical tyres.

The steering issue is not really true either- the flex we are talking about is vertically, obviously steel road bike forks are stiff enough laterally, with the wheel axle installed which adds to lateral stiffness without affecting vertical, to keep the wheel in line and steer a road bike as accurately as desired (but if raced on an off road downhill course with a big fat tyre attached they might well struggle).

Also the Gibson Les Paul analogy is a total red herring, the design development of the steel bicycle fork was already well into its maturity by the time the OP's Peugeot was built- a development that had been ongoing for about a century already by that time. Granted new materials such as carbon fibre do bring in some new possibilities, but even then the basic physics of having to build a disc fork to resist strong forces that a rim brake fork does not have to are going to be rather hard to get around.

Of course just my opinion and no offence intended....
 

niggle

Pedelecer
Feb 2, 2017
60
14
61
Cornwall, near England
I missed the bit about changing brake levers earlier- I think this would depend on where you grip the bars most of the time: modern aero levers are more comfortable and give better braking from the hoods, but no real advantage when in the drops.
 
D

Deleted member 4366

Guest
Well I would like to point out that this is just your own experience, how a rim brake fork can flex depends on how it is designed and using what materials, whereas a disc brake fork absolutely has to be made stiff and strong enough to resist the very significant forces that the disc brake caliper imparts on the one lower fork end. My experience with many forks of various vintages from 1970s onwards, and materials, including carbon fibre, is that at least some rim brake forks, e.g. built with Reynolds 531c blades, can flex much more than any disc brake fork can or should.

My own clearest example is previously riding a Planet X Kaffenback 2 road bike disc frameset and now having an On One Pompino with rim brake frame & forks (same company, same geometry, visually identical forks apart from the Kaff having the ISO disc mounts and the Pomp having v-brake bosses) and seeing and feeling more flex and comfort with the Pomp on identical tyres.

The steering issue is not really true either- the flex we are talking about is vertically, obviously steel road bike forks are stiff enough laterally, with the wheel axle installed which adds to lateral stiffness without affecting vertical, to keep the wheel in line and steer a road bike as accurately as desired (but if raced on an off road downhill course with a big fat tyre attached they might well struggle).

Also the Gibson Les Paul analogy is a total red herring, the design development of the steel bicycle fork was already well into its maturity by the time the OP's Peugeot was built- a development that had been ongoing for about a century already by that time. Granted new materials such as carbon fibre do bring in some new possibilities, but even then the basic physics of having to build a disc fork to resist strong forces that a rim brake fork does not have to are going to be rather hard to get around.

Of course just my opinion and no offence intended....
The forks are in more or less a straight line from the axle to the steering head. How far forward would they have to bend to give 1 cm of vertical spring? The compliance is totally insignificant compared with the difference you'd get from the size of the tyre. If you want more comfort, you get a bigger tyre.