5 or 7?auraslip said:
Let's talk about brakes
- Thread starter patrickza
- Start date
heathyoung
100 kW
185mm avid juicy 3's on the front, and some cheap V brakes on the rear (mainly to get some feel in the lever) with regen is enough for safety at 65-70Kph on the commuter bike.
The offroad bike however has hayes nines with 8" rotors and stops like it has hit a brick wall. The forks need to be solid for 8" rotors (I'm using a rochshox boxxer world cup), triple T is recommended - as you may find you will bend the stanchions (ahem!) on a lesser shock.
The offroad bike however has hayes nines with 8" rotors and stops like it has hit a brick wall. The forks need to be solid for 8" rotors (I'm using a rochshox boxxer world cup), triple T is recommended - as you may find you will bend the stanchions (ahem!) on a lesser shock.
I wonder what part of my setup is just not working right, because I can't really get the stopping power I expect I probably should get out of *any* of the rim brakes I have ever used, and these Avid SD5 arms I have on there are the best ones I've had. I don't have the Avid levers, though, and am using a Shimano lever meant (AFAIK) for this style of brakes.
I've done all the possible adjustments, AFAIK, and tried a few different brake shoes, with some difference in each one, but none quite good enough.
One possible issue is the cable itself; ATM it is a long cable from (I think) SickBikeParts, something AussieJester sent me, like the ones he has used successfully. The housing is a two-part housing, as I didn't have a single one long enough. I've planned (but never had the chance to try) running a cable thru very short housings to cable stops on the frame, with bare cable between the stops, which would probably significantly help the housing compression losses I get.
Another possible issue is the crappy front fork, as the bosses could be moving or pivoting around the suspension post. I tested these brakes first on the much better (but still not great) RST fork, just before and at the DeathRace, but due to the geometry problem causing the death wobble for various maneuvers, speeds, and braking, I coudln't ever really hit them hard on that fork--it might make them much better.
Given that me and the bike is about 300lbs, I'm not surprised I have trouble with the brakes, as I only have the front brakes. I tried some rear caliper style for a while, but they were just about useless, and I had to take them off for some other experiment and never bothered putting them back on.
If I could find a large enough disc brake rotor to modify into a hubmotor-cover-bolt-ring-attached rotor on the front, I'd try the large-diameter disc brakes on there and probably get plenty of stopping power.
So far, no luck in that yet (except a used motorcycle rotor that was way way too thick for my calipers, and far too big to stick on the lathe to shave it down).
I've done all the possible adjustments, AFAIK, and tried a few different brake shoes, with some difference in each one, but none quite good enough.
One possible issue is the cable itself; ATM it is a long cable from (I think) SickBikeParts, something AussieJester sent me, like the ones he has used successfully. The housing is a two-part housing, as I didn't have a single one long enough. I've planned (but never had the chance to try) running a cable thru very short housings to cable stops on the frame, with bare cable between the stops, which would probably significantly help the housing compression losses I get.
Another possible issue is the crappy front fork, as the bosses could be moving or pivoting around the suspension post. I tested these brakes first on the much better (but still not great) RST fork, just before and at the DeathRace, but due to the geometry problem causing the death wobble for various maneuvers, speeds, and braking, I coudln't ever really hit them hard on that fork--it might make them much better.
Given that me and the bike is about 300lbs, I'm not surprised I have trouble with the brakes, as I only have the front brakes. I tried some rear caliper style for a while, but they were just about useless, and I had to take them off for some other experiment and never bothered putting them back on.
If I could find a large enough disc brake rotor to modify into a hubmotor-cover-bolt-ring-attached rotor on the front, I'd try the large-diameter disc brakes on there and probably get plenty of stopping power.
So far, no luck in that yet (except a used motorcycle rotor that was way way too thick for my calipers, and far too big to stick on the lathe to shave it down).
auraslip
10 MW
- Joined
- Mar 5, 2010
- Messages
- 3,535
I would definitely try better levers... the avid ones are $10 each and the difference between them and the wuxing ones are night and day.
No doubt, brakes can be fickle. Something as silly as the cable housing can really sap power. Best bet might be to take it to a serious bike shop (I know you hate those... I do to!) and ask them what they think....
No doubt, brakes can be fickle. Something as silly as the cable housing can really sap power. Best bet might be to take it to a serious bike shop (I know you hate those... I do to!) and ask them what they think....
The "serious" bike shops won't look at it, because it is a cobbled-together bike built by me. 
There is one I probably could take it to, Build-A-Bike, but I would have to ask them first how much it'd cost before I did, and save up for that. Most likely, I could buy all the parts for a good disc brake system (the one using the hubmotor cover bolts and a large rotor) and build and install it for whatever they'd charge just for looking at my existing one and fixing it.
If I could find out what the difference is between the Avid levers and the Shimano ones, I could probably modify the Shimanos to take care of that--they are both for the same kind of brakes. I know that certain brakes use different amounts of leverage, different pivot points in the handle, etc., and I could compensate for that in at least one way--with a pulley system that changed the leverage ratio from lever to arm, if I knew what the lever put out and what the arm required.
There is one I probably could take it to, Build-A-Bike, but I would have to ask them first how much it'd cost before I did, and save up for that. Most likely, I could buy all the parts for a good disc brake system (the one using the hubmotor cover bolts and a large rotor) and build and install it for whatever they'd charge just for looking at my existing one and fixing it. If I could find out what the difference is between the Avid levers and the Shimano ones, I could probably modify the Shimanos to take care of that--they are both for the same kind of brakes. I know that certain brakes use different amounts of leverage, different pivot points in the handle, etc., and I could compensate for that in at least one way--with a pulley system that changed the leverage ratio from lever to arm, if I knew what the lever put out and what the arm required.
Farfle
100 kW
700-800 to fix brakes on a bicycle? why not buy three new bicycles? holy ehf. Take a look at pricepoint, they have a good stock of brakes and brake parts. http://www.pricepoint.com/thumb/3-Parts-911-Brakes/Rims-True.htm
@Farfle: that was a spammer, copypasting something from nov2010 on a blog somewhere. I already nuked him.
Farfle
100 kW
amberwolf said:@Farfle: that was a spammer, copypasting something from nov2010 on a blog somewhere. I already nuked him.
/facepalm
Pure
10 kW
My bike only has one break and no regen on the rear hub. I'm going to have to do some frame modification to fit a v break on the rear. My hub was bought just before the release of the X5s that would allow he disk break cover. Anyhow when building my bike the first thing I did was upgrade the front disk break as I knew it would have to stop me. I put an avid jucy 7 on it as at the time that was the biggest and the best you could reasonably find. I'm pushing 250 and my bike is 90 odd pounds and that one front break can stop me dead and even toss me over the handle bars if I'm not paying attention.
To the OP. The reason people recomend disk breaks over pull breaks is for a couple of reasons. At the speeds most ebikes cruise at using a pull break can heat up your rim and can in most cases cause the rim itself to become soft from the heat. Also with as much use that is required of the break v breaks can eventually start to actually wear the metal of the rim down. Converting to a disk break is as simple as buying the break kit and installing it. Provided you have a fork that is fited with the proper instilation mounts/holes. It took me all of 15 minutes to install my new front break setup. And the new one is hydrolic.
To the OP. The reason people recomend disk breaks over pull breaks is for a couple of reasons. At the speeds most ebikes cruise at using a pull break can heat up your rim and can in most cases cause the rim itself to become soft from the heat. Also with as much use that is required of the break v breaks can eventually start to actually wear the metal of the rim down. Converting to a disk break is as simple as buying the break kit and installing it. Provided you have a fork that is fited with the proper instilation mounts/holes. It took me all of 15 minutes to install my new front break setup. And the new one is hydrolic.
Kingfish
100 MW
- Rim brakes get dirty and squeal.
- I use Regen to slow down and engage mechanicals at the last to complete the stop.
- New version of P1 has 203mm Disc front and rear. I use the Avid 7 over the Shimano XTR; lighter and easier to adjust. Been running on the rear for some time and I am quite happy, though recently swapped out the front which has been problematic though strictly with the mating to the hub.
- Trailer: Slightly OT, I have not yet figured out how to mechanically-brake the trailer; I’m going to rely on heavy ebrake instead. Perhaps it would be very cool to work up an electromechanical braking system though like with auto-trailers and 5th-Wheels. 8)
Moving silently, KF
geetarboy
100 W
I have started doin the same now that I have 'regen' again. The Avid BB7 185mm up front brings me to a stop. You might as well recoup some of that juice so you can ride a little longer... 8)Kingfish said:
darkshirikens
10 W
Has anyone here use the Jagwire brand cable and housing for their brakes ? I found it to improve the overall performance of my braking power and when i go to high end bike shop they seem to recommend using it . i like the jagwire i can tell the difference when i stop my bike over the standard or cheaper stuff you can find anywhere ! But also i found that when some people install their brakes they have too much slack or not enough or their brakes aren't aligned properly especially v brakes .
mobybike
10 mW
- Joined
- Jun 13, 2011
- Messages
- 30
One thing you can do to greatly enhance your rim brakes especially on a lower end suspension fork is to use a simple "brake booster" for about $12-$40.
http://shop.ebay.com/i.html?_nkw=bike+brake+booster&_frs=1&_trksid=p3286.c0.m359
It helps prevent the brake bosses from spreading when you apply force. A good rim brake/lever combo mounted to strong bosses, and using a matching machined rim can provide exceptional stopping power. (disc brakes have other advantages/disadvantages but sheer stopping power need not be sacrificed by a rim brake even a properly set up cantilever brake!)
Many Avid (and other brands) of higher end brake levers allow you to dial in the amount of leverage you desire, so you can adjust the "feel" at the lever. It's easy to over do it on "V" brakes sometimes, and so you adjust the modulation and feel at the lever... light pressure or hard pressure to achieve the stop.
Brake cable and house...
I really like Jagwire L3 housing. It is permanently lubed by a special liner, not a regular liner nor grease, but a special lube liner, that never needs lubed again. L3 specifically.
On the cable housing ends, it is important to "finish" your cut. After you cut, make sure to file the end parallel and flush. I use a Dremel tool to grind a slight bevel as well around the outer edge to perfectly match the barrel adjuster and the "V" brake noodle. Then when you use a thin brass case cap (or not), it won't get malformed and cause friction on the cable inner wire. If you can find and afford thicker aluminum caps they will last a lot longer and are very difficult mess up.
Use thick stainless steel Shimano inner wire, or QualityBikes "slick" cables. There is a noticeable difference using stronger thicker SS wire over cheaper zinc wire. Special coating on the wire isn't necessary or beneficial really over Jagwire L3 house. You can get weather sealing with special cable kits, but you won't get better stopping power.
Lever set up is also often over looked. You want to grab that lever at the end, with your index finger or middle finger. That means your levers are going to be set farther away from the grip, and towards the stem than what you might be used to seeing, but this simple tip solves a lot of power issues.
http://shop.ebay.com/i.html?_nkw=bike+brake+booster&_frs=1&_trksid=p3286.c0.m359
It helps prevent the brake bosses from spreading when you apply force. A good rim brake/lever combo mounted to strong bosses, and using a matching machined rim can provide exceptional stopping power. (disc brakes have other advantages/disadvantages but sheer stopping power need not be sacrificed by a rim brake even a properly set up cantilever brake!)
Many Avid (and other brands) of higher end brake levers allow you to dial in the amount of leverage you desire, so you can adjust the "feel" at the lever. It's easy to over do it on "V" brakes sometimes, and so you adjust the modulation and feel at the lever... light pressure or hard pressure to achieve the stop.
Brake cable and house...
I really like Jagwire L3 housing. It is permanently lubed by a special liner, not a regular liner nor grease, but a special lube liner, that never needs lubed again. L3 specifically.
On the cable housing ends, it is important to "finish" your cut. After you cut, make sure to file the end parallel and flush. I use a Dremel tool to grind a slight bevel as well around the outer edge to perfectly match the barrel adjuster and the "V" brake noodle. Then when you use a thin brass case cap (or not), it won't get malformed and cause friction on the cable inner wire. If you can find and afford thicker aluminum caps they will last a lot longer and are very difficult mess up.
Use thick stainless steel Shimano inner wire, or QualityBikes "slick" cables. There is a noticeable difference using stronger thicker SS wire over cheaper zinc wire. Special coating on the wire isn't necessary or beneficial really over Jagwire L3 house. You can get weather sealing with special cable kits, but you won't get better stopping power.
Lever set up is also often over looked. You want to grab that lever at the end, with your index finger or middle finger. That means your levers are going to be set farther away from the grip, and towards the stem than what you might be used to seeing, but this simple tip solves a lot of power issues.
cancerkazoo
100 mW
Mark C. said:
This may be of some help, a steel front caliper mount
do you have a 32 or 36 hole hub up front?
If you retrofit a disc front brake, be careful to notice the maximum diameter disc the front forks can handle. Several aftermarket suspension forks mention they can handle a maximum of 185 mm. Many fork specs are silent an maximum size. I understand that any fork with an IS fitting can handle 160 mm and that few can handle 204mm.
I guessed that my 2004 Manitou South forks could handle 185 mm discs and then ordered BB7's of that size. The 185's had about 4mm of interference fit on the outside that slowed, but didn't stop the front wheel revolution. Fortunately, I was able to grind away the interference from the stanchion, but there is no way a 204 mm would have fit. The interference fit was slight enough that I don't think I've significantly weakened the stanchion.
I guessed that my 2004 Manitou South forks could handle 185 mm discs and then ordered BB7's of that size. The 185's had about 4mm of interference fit on the outside that slowed, but didn't stop the front wheel revolution. Fortunately, I was able to grind away the interference from the stanchion, but there is no way a 204 mm would have fit. The interference fit was slight enough that I don't think I've significantly weakened the stanchion.
dannyboyohyeah
100 W
- Joined
- Dec 28, 2009
- Messages
- 157
Hi All~
I think it's generally important to buy a bike that has mount for rear discs on the frame, if possible. But...of the bikes I have, my favorite is one that had NO discs. Solved half of that by getting a nice Manitou "Black" off've ebay with the disc mount.....and...lo and behold, ran across the fact that you can buy HYDRAULIC rim, V-brakes. You sort've have to watch the wear on yer rim....but stop, she will.
I think it's generally important to buy a bike that has mount for rear discs on the frame, if possible. But...of the bikes I have, my favorite is one that had NO discs. Solved half of that by getting a nice Manitou "Black" off've ebay with the disc mount.....and...lo and behold, ran across the fact that you can buy HYDRAULIC rim, V-brakes. You sort've have to watch the wear on yer rim....but stop, she will.
dannyboyohyeah
100 W
- Joined
- Dec 28, 2009
- Messages
- 157
Here's the source.....Magura HS33 EVO Hyraulic Rim Brake ($109.99) from Dan's Comp ..product # 482865
o00scorpion00o
100 kW
Hi Everyone,
I was thinking about upgrading from 160mm -203mm disks front and rear. I was reading on the net where some people said it was a bad Idea because the extra braking force was too much for front forks, the ones you tighten up the wheels with skewers.
Can anyone confirm this might be too much of a risk ?
Mark
I was thinking about upgrading from 160mm -203mm disks front and rear. I was reading on the net where some people said it was a bad Idea because the extra braking force was too much for front forks, the ones you tighten up the wheels with skewers.
Can anyone confirm this might be too much of a risk ?
Mark
Drunkskunk
100 GW
You don't get more braking force from bigger brakes. You get better cooling and better modulation of the brakes.
The maximum braking force any brake can ever give is to lock up the wheel. Any brake you put on a bike should be able to do that.
Bigger brakes will be fine.
The maximum braking force any brake can ever give is to lock up the wheel. Any brake you put on a bike should be able to do that.
Bigger brakes will be fine.
DAND214
10 MW
I am running a 203 frt and 160 rear hydro. I did see an improvement with the 203 over the 160 in the frt. better control with less pressure. I was thinking of going to a 203 rear for better feel but after changing pads it feels just right.
I had mechanical frt & rear which were not as good as v-brakes IMO. Went to hyros frt and rear and there was a big improvement.
Good brakes are a really needed if you are going anything over 20mph. Even at 35+ they stop without lockup in a short didtance.
Good brakes Are A Must!
Dan
I had mechanical frt & rear which were not as good as v-brakes IMO. Went to hyros frt and rear and there was a big improvement.
Good brakes are a really needed if you are going anything over 20mph. Even at 35+ they stop without lockup in a short didtance.
Good brakes Are A Must!
Dan
o00scorpion00o
100 kW
Thanks for the replies,
I have the tektro auriga comp, they aren't the best, but hopefully with new disks and pads it will stop in shorter distance!
The price of bicycle components is really ridiculous!
I have the tektro auriga comp, they aren't the best, but hopefully with new disks and pads it will stop in shorter distance!
The price of bicycle components is really ridiculous!
DAND214
10 MW
Your telling me!
It seems that a lot of things (prices) today are ridiculous!
Dan
I wish...so far on my heavy cargo bikes, especially with a big load, I've been unable to ever setup any of my rim brakes to be able to lockup the front wheel, especially from 15-20MPH, even squeezing so hard that either cables snap a wire in them, or the lever actually hits the bars. None of these are great brakes, cables, or levers, but they're all typical bike stuff (mostly Shimano, including some of the Shimano Deore LX stuff salvaged from midrange 80s/90s bikes).Drunkskunk said:
Rear wheel I can sometimes lock up, depending on where the weight/load is.
On the regular bikes, the same brakes will usually lockup the wheel at the 13MPH or so I can typically pedal at, if squeezed the same way, so I must be pushing the amount of energy they can absorb past their limits, with the weight and speed of the cargo bikes.
Though, thinking about it, all of the regular bikes are solid front forks, not suspension, but the cargo bikes are all cheap suspension forks. So perhaps it is something less stiff aobut the suspension forks allowing the pads to twist and not fully engage that causes my problem?
I'm hoping the larger diameter disc brake (on the hub motor cover) I'm working on will fix that problem (at least in combination with the existing rim brakes). I guess we'll see.
o00scorpion00o
100 kW
I ordered a set of pads and 203 mm disks and adapters on E-bay from the U.K so hopefully I will get better performing brakes. Stopping from 40 mph is a whole different ball game!
When I save up more money, I may upgrade the hydraulics as I don't really like the Tektro auriga comps, it's scary the price of a decent set of brakes!
I would like to see dual disk brakes!
But I don't know if what I was reading was right, maybe the skewers were not tightened enough, but the larger diameter disk was blamed for putting more force on the hub part of the wheel, forcing the wheel out of the forks! A very scary thought at 40 mph!
When I save up more money, I may upgrade the hydraulics as I don't really like the Tektro auriga comps, it's scary the price of a decent set of brakes!
I would like to see dual disk brakes!
But I don't know if what I was reading was right, maybe the skewers were not tightened enough, but the larger diameter disk was blamed for putting more force on the hub part of the wheel, forcing the wheel out of the forks! A very scary thought at 40 mph!
