BB7 Rotor recommendations

[Lurkin]

I've recently purchased some BB7 calipers for a Flux Beta bike which will be used for commute style purposes. It will travel large distances frequently and maintenance and the cost of that maintenance is important. They are to be paired with fresh, uninterrupted cables and new BB5 levers.

I'm trying to choose rotors to match with them. I was thinking 200mm front and 180mm rear. The obvious answer is Sram G2 Cleansweep rotors as I understand they have a larger brake track and are designed to be used with these brakes. However, it appears SRAM has cut online retailers from selling SRAM to Australia (particularly CRC and Wiggle). This is an unfortunate trend which I think will continue. I have noticed Rockshox shock mount hardware recently disappear from CRC, which I assume, is for the same reason.

The original plan was to have genuine consumables (pads, rotors etc) to be purchased from sites like this to maintain quality components but keep the costs down. However, that no longer appears to be an option. I could arrange a redirection service, but it's more work and I'd rather not if I can avoid it. At this time, I'm trying to identify alternatives which would work as well as the SRAM genuine item, for preferably the same, or lessor cost.

There are many on ebay, but from searching other forums, it appears they are not usually genuine SRAM and are usually considered inferior. The discussion there usually is about determining whether the items were bulk purchased and therefore genuine and/or disputing that by various ways of identifying the genuine version.

It's left me wondering a few things:
- is it worth trying to buy genuine SRAM rotors? I've always replaced genuine with genuine previously, but I'm curious to find out how bad the non genuine really are? Or is it that there is no standard and its luck of the draw as to their quality? Are rotors difficult to manufacture well?

- is there a Shimano equivalent 6 bolt rotor? I note there is differences in Shimano/Sram disc sizing (200mm vs 203mm) yet others on the internet allege they have used Shimano rotors just fine? This could offer an alternative supply of quality rotors which can be bought from CRC/Wiggle etc. Ideally these need to have the same larger style track which the G2 has. Is there anything else I should be trying to check first?

- what pads are recommended? I imagine there are many different types out, but the trade off between price and quality is difficult given I need to be careful the costs don't blow out in the long run.

- any other advice in relation to these brakes. Its the first time I've used mechanical discs and they seem pretty simple. Others have recommended >200mm discs to increase the braking power, but I doubt the alloy fork mounts would be tested that kind of force and this isn't something I'm considering at this stage. I would be more incline to go for a better or more effective pad at this stage, but thats just a musing/opinion without experience or support.

- Is 200mm front and 180mm rear ideal or should I go 200mm front and rear?

 

[d8veh]

I wish you'd asked first before buying those calipers. Rather than worry about rotors, I'd chuck the calipers and get hydraulic brakes. Hydraulics are set and forget. They always give consistent reliable braking.

 

[Raged]

I wish you'd asked first before buying those calipers. Rather than worry about rotors, I'd chuck the calipers and get hydraulic brakes. Hydraulics are set and forget. They always give consistent reliable braking.

I run standard shimano rotors for my BB7 Road calipers. They work fine for normal duties (like every other mechanical disc brake) but as mentioned, it doesnt have the modulation and control of hydraulics and I do need to adjust them every few months for pad wear. I had to go BB7 due to drop bar/gravel grinder brake pull. If you have a flat bar ( which you should ), then a set of shimano SLX (about US$82 per kit) will stop you as fast as your tires can maintain grip. Every time I change pads, I go with Nukeproof Enduro which is a sintered pad. Lasts longer but sometimes squeals if its cold.

 

[Lurkin]

I didn't buy these brakes out of ignorance of other options, I bought them because I'm interested to try them for myself rather than rely solely on others testiment. Others on the form have had good results with mechanical brakes and I thought I would give them a go. I already have another commute bike with hydraulic brakes, another with v-brakes, another with regular caliper brakes. This is just another to add to the collection.

besides, I have a set of Saint Hydraulic brakes in a box ready to go if these fail... I just want to set them up correctly the first time round to give them a fair go, rather than set them up with incorrectly and blame the brakes rather than the setup.

 

[flangefrog]

I've seen some recommendations for Alligator rotors. Note that some models are very light and may not be good for long descents. I'm not sure how their brake track compares to the G2. Some are probably smaller. You can find them on eBay.

Velogear have rotors from several brands including Avid and Alligator. I wouldn't necessarily assume their Avid rotors are genuine.

For pads, check out http://www.discobrakes.com I haven't tried them myself yet but they're pretty cheap and have some good reviews.

Jagwire Ripcord (now Mountain Pro) are good compressionless brake cables with teflon covered stainless wires and include a tube to cover exposed brake cables on the top or down tube. You can find them on eBay by searching "jagwire ripcord brake" and they're mostly sold by gobike88.

Here's a good link with some more info: http://howtosetuptheavidbb7.weebly.com/how-to-set-up-the-avid-bb7.html

 

[Chalo]

I wish you'd asked first before buying those calipers. Rather than worry about rotors, I'd chuck the calipers and get hydraulic brakes. Hydraulics are set and forget. They always give consistent reliable braking.

Hogwash. I see effed-up hydraulics all the time. The difference is that I can set a cable brake in order in a few minutes and send the customer on his way for a few dollars. A malfunctioning hydraulic brake needs scheduled maintenance at the least (cleaning and bleeding), but often needs hoses, fittings, or caliper replacement. That means waiting for special order parts and paying a lot more to get rolling again.

Most of the properly functioning hydraulic discs I see simply don't work as well as BB7. The ones that do, aren't better enough to be worth the trouble and expense.

P.S. to the OP:

Rotor diameter doesn't make as much difference to braking performance as folks would have you believe. The main difference is in feel, with significant differences in how easy the rotors are to damage. In the pedicab fleet I work with, we started with BB7s and 203mm rotors, but pretty quickly migrated over to 160mm rotors because they provide plenty of stopping power without warping nearly as much.

And for what it's worth, many of our trikes use a Magura Big Twin hydraulic lever and gokart/moped caliper acting on a center differential disc rotor. Those are the most maintenance-intensive, poorly working brakes in the whole shop. Almost all of them require two squeezes-- one to pump up the brake and another to actually apply it. They are industry standard, but they suck because they're hydraulic.

 

[drew12345]

I have bb7. Like them a lot. Very adjustable and cheap. Sometimes I prefer over hydraulic because more adjustable. Go with big rotors if you can. Definitely 200 in front. And same in rear to cover rear hub if you have one. I have avid rotor. Not sure if genuine but have several them and never had a problem.

 

[WoodlandHills]

I wish you'd asked first before buying those calipers. Rather than worry about rotors, I'd chuck the calipers and get hydraulic brakes. Hydraulics are set and forget. They always give consistent reliable braking.

Hogwash. I see effed-up hydraulics all the time. The difference is that I can set a cable brake in order in a few minutes and send the customer on his way for a few dollars. A malfunctioning hydraulic brake needs scheduled maintenance at the least (cleaning and bleeding), but often needs hoses, fittings, or caliper replacement. That means waiting for special order parts and paying a lot more to get rolling again.

Most of the properly functioning hydraulic discs I see simply don't work as well as BB7. The ones that do, aren't better enough to be worth the trouble and expense.

P.S. to the OP:

Rotor diameter doesn't make as much difference to braking performance as folks would have you believe. The main difference is in feel, with significant differences in how easy the rotors are to damage. In the pedicab fleet I work with, we started with BB7s and 203mm rotors, but pretty quickly migrated over to 160mm rotors because they provide plenty of stopping power without warping nearly as much.

And for what it's worth, many of our trikes use a Magura Big Twin hydraulic lever and gokart/moped caliper acting on a center differential disc rotor. Those are the most maintenance-intensive, poorly working brakes in the whole shop. Almost all of them require two squeezes-- one to pump up the brake and another to actually apply it. They are industry standard, but they suck because they're hydraulic.

Ditto, I spent hours this summer fixing the sticking lever pistons in my Avid Guide hydraulic discs and bleeding, they are fine now, but my BB7s haven't needed a seconds attention. As far as braking power after switching to Jagwires, I really cannot see any difference between the two. That said, I do prefer the feel and modulation of the hydraulics, but only very slightly..... 200mm and 180mm genuine SRM pads and rotors on both bikes.

 

[d8veh]

I wish you'd asked first before buying those calipers. Rather than worry about rotors, I'd chuck the calipers and get hydraulic brakes. Hydraulics are set and forget. They always give consistent reliable braking.

Hogwash. I see effed-up hydraulics all the time. The difference is that I can set a cable brake in order in a few minutes and send the customer on his way for a few dollars. A malfunctioning hydraulic brake needs scheduled maintenance at the least (cleaning and bleeding), but often needs hoses, fittings, or caliper replacement. That means waiting for special order parts and paying a lot more to get rolling again.

Most of the properly functioning hydraulic discs I see simply don't work as well as BB7. The ones that do, aren't better enough to be worth the trouble and expense.

P.S. to the OP:

Rotor diameter doesn't make as much difference to braking performance as folks would have you believe. The main difference is in feel, with significant differences in how easy the rotors are to damage. In the pedicab fleet I work with, we started with BB7s and 203mm rotors, but pretty quickly migrated over to 160mm rotors because they provide plenty of stopping power without warping nearly as much.

And for what it's worth, many of our trikes use a Magura Big Twin hydraulic lever and gokart/moped caliper acting on a center differential disc rotor. Those are the most maintenance-intensive, poorly working brakes in the whole shop. Almost all of them require two squeezes-- one to pump up the brake and another to actually apply it. They are industry standard, but they suck because they're hydraulic.

BB&s are better than most cable disc brakes. Yes, they can be adjusted to work well, but I say that they're like a polished turd - better than a normal turd, but still a turd. There's absolutely no comparison with any branded hydraulic brakes, which a normal user will never need to adjust. Sure, if you're doing downhill racing, you can fall off and break your hose, or if you crash into the back of a car because you weren't looking where you were going, you can bend a lever or rip the reservoir off, so I'm not surprised that a bike shop gets a few to repair.

 

[Lurkin]

This is devolving into another mechanical brake vs other brake. I'm not changing my mind until I've given these a fair go. If they are inconvenient or rubbish at that point I can very easily switch. I had all but given up on cable operated brakes, some of the road stuff I've owned has been very expensive, branded, impressive.... feats of marketing yaya and general wastes of money. However, having recently rediscovered v-brakes and their surprising ability and economics, I'm pretty willing to give these a decent shot.

Chalo, interesting that you mention disc size can be less important than disc design choice. I've been trawling forums etc for the last couple of days and it seems that whilst BB7 can be used with Shimano discs, the pad is supposedly larger than the brake track typically available on them, meaning the brake track width of Shimano rotors is less than the SRAM G2 rotor which these are designed to be used with. Having said that, more than one person has used Shimano RT66 rotors with relative success. I can't decide whether its likely the (if any) mismatch in rotor brake track to pad width is worth debating/worrying about. Courtesy of an ebay vendor who cannot get their sizing right, I do have some knock off 160mm HS1s which I could give a go, although they have the same issue as the RT66 rotors earlier discussed.

In addition, on another forum, a member has suggested that smaller discs can be more optimal for heavier users combined with fork flex as it may encourage a larger rotor to touch the pad to the rotor whilst flexing. I haven't experienced this, but its food for thought.

It seems Hayes may make rotors with a larger track, however their website has no useful information. Clark also may make larger track rotors, but their larger sized rotors seemed to have a bad reputation for warping and excessive heat. Discobrakes have also come up in ebay searches, but again, no information on track. I might start asking manufacturers/ ebay vendors and see what I can get back.

Chalo is there any rotors you would specifically recommend suitable for a heavy user?

 

[Cephalotus]

I like my BB7 brakes quite well. Stopping power is very good, maintenance is quick and simple and they are not easy to damage.

I use them on the front wheel of my cross / trekking bike (rear is mechanical v-brake), because they are easy to fix if something brakes when on tour. It's no fun to fix a hydraulic disc brake somewhere in a country where those are not common.

I also use them front and rear on the Dahon Flo MTB, Thats a MTB frame that you can devide in two halves. So hydraulic brakes are simply not an option.

I use them on the Dahon Flo with original 180mm rotors and with cheap Shimano SLX 180mm rotors on the cross bike. I use those Shimano SLX 180mm rotors also on all other bikes with disc brakes, because they are cheap. Main problem for me with Shimano SLX rotor + BB7 is very load noise when wet (they are silent when dry). But it got better with organic brake pads.

Good hydraulic brakes are better for adjusting the exact amount of brake power while using them, but for normal use the BB7 are just fine.

In only use 180mm rotors on all of my bikes, never ever felt the need for a larger diameter, but I do not do any downhill racing...

 

[d8veh]

I'm not saying that there's anything wrong with BB7s. OP will get an improvement on what he had before. It's just that the price to upgrade from whatever you have to BB7s is the same as upgrading to hydraulic brakes, which are much better, so there's no sense in upgrading to BB7s.

 

[Cephalotus]

I have electric bikes with mechanical and hydraulic rim brakes and electric bikes with mechanical and hydraulic disc brakes. They all have advantages and disadvantages and all have their place. I do not see a "winner"...

 

[WoodlandHills]

I'm not saying that there's anything wrong with BB7s. OP will get an improvement on what he had before. It's just that the price to upgrade from whatever you have to BB7s is the same as upgrading to hydraulic brakes, which are much better, so there's no sense in upgrading to BB7s.

A cable brake can be serviced with the tools you are using on the rest of your bike, but hydraulics require you to shell out for a bleeding kit and sometimes even special tools such as snap ring pliers. It all adds up......

 

[nutnspecial]

I totally agree with d8veh. Mech needs the most adjustment per mile, and imo is more of a pita to adjust than V or C. Hydro needs none- just pop new pads in when needed. I think simpler is generally better tho, some fancy designs seem to be troublesome.

Another build consideration is full cable housings for any mechanical brake. There will be so much more housing compression to deal with. Actually that might be why my mech's felt ridiculously inadequate. I skipped right to a 100$ pair of pre-bled formula c1 with 200/180. Night and freakn day in install, tuning, performance.

_____
That said, 203 or 200 isn't more than a washer or two away if needed. I'd go 20x/180 and sintered pads, that others are buying in AU for reasonable money. I usually just go to amazon/ebay and am more price/review conscious than name brand.

 

[d8veh]

I'm not saying that there's anything wrong with BB7s. OP will get an improvement on what he had before. It's just that the price to upgrade from whatever you have to BB7s is the same as upgrading to hydraulic brakes, which are much better, so there's no sense in upgrading to BB7s.

A cable brake can be serviced with the tools you are using on the rest of your bike, but hydraulics require you to shell out for a bleeding kit and sometimes even special tools such as snap ring pliers. It all adds up......

I've been using hydraulic brakes for about 6 years now, and most of my friends have them too. None of us have ever had to bleed them or do any other adjustment or repair since fitting, except sometimes, if you turn the bike upside-down to fix a puncture, you can get air in the pipe. You don't need to bleed the brakes - just remove the lever/reservoir and hold it vertical for a bit, and the air comes back out of the pipe to restore normal operation.

I'm guessing from your comments that you've not used hydraulic brakes. Try some, then see if you think the same.

 

[WoodlandHills]

I have a set of Avid Guides, the ones with the sticky lever pistons......... And even if you don't have issues with manufacturing errors, DOT 5.1 brake fluid is hygroscopic and will absorb moisture, thus it should be changed on a yearly basis. To do that you will need to bleed the brakes afterwards. Check your manual for service intervals: hydraulic discs still need regular servicing and to do that they need special tools.

Are you saying you haven't changed the fluid in your brakes in six years!?

edited to correct boneheaded error identifying brake fluid type:

 

[Chalo]

DOT 5.1 is hygroscopic glycol fluid; DOT 5 is non-absorbent, seal compatible silicone.

Why any bicycle hydraulic brakes use DOT 3, 4, or 5.1 is entirely beyond me. It's using a system that has no concrete benefits in return for its many drawbacks, then adding more drawbacks with the choice of hydraulic fluid.

But, what's best for my car must necessarily be best for my bike. Derp.

 

[WoodlandHills]

I just went out and checked the bottle of brake fluid that came with my SRAM brake bleeding kit and its DOT 5.1. :x

So there will be no issue with flushing the system next time I open it up and replacing with a high quality DOT 5?

 

[Chalo]

DOT 5 is considered to be compatible with both glycol-filled and oil-filled systems.

 

[WoodlandHills]

Thanks. Would a system filled with DOT 5 be maintenance free from then on or at least not need annual fluid changes?

 

[Chalo]

Thanks. Would a system filled with DOT 5 be maintenance free from then on or at least not need annual fluid changes?

Silicone fluid doesn't need frequent changing, but could still require periodic bleeding and topping up to remove air from the system.

 

[nutnspecial]

There is plenty of evidence on the web from plenty of bikers that do not change fluid or bleed within 5 years of normal use, and some have never. Mineral oil is also popular although any moisture that gets into system stays separate and actually pools @ bottom where it's most unwanted. Oil may need more frequent care/upkeep but the catch22 is it's usually easier to do so than dot. I use dot and don't plan on changing it soon, maybe ever. Dot slowly loses it's usefulness as it picks up moisture. Cars can go >30yrs on the same fluid, even in their loosely sealed systems.

Let us know what you settle on Lurkin. I doubt the rotor braking area will be a very noticable difference among the various offerings, or brand, save for the most demanding of users. Btw my offbrand (truckerco iirc) sintered pads are quite loud when wet too. It's fun tho- they sound more like a dual tone airhorn than a rim brake squeal, and stopping power seems barely affected if at all.

I think flangefrog brought up the good point about with jagwire housings that are supposed to resist compression. Besides the pad adjustment necessary on mech brakes, the housing run length/integrity is the other major characteristic consideration.

 

[d8veh]

Some brake fluids are hygroscopic, but how can the moisture get in, when the system is completely sealed? Surely, if water could get in, the oil would get out, or does the water use osmosis to get through the brake pipes? I've never changed the brake fluid in my bicycle in six years. What's more, my motorbike (Honda NTV650) is 23 years old and never had its original brake fluid changed, and the brakes work perfectly.

 

[Punx0r]

If you want an answer get the boiling point checked. Also, fluid gets dirty with time and dirty fluid damages seals. I don't know how exactly water gets into a sealed system, but most materials are very slightly porous. I've only experienced fluid boil once and that was piling into an-intended 30mph corner at around 80mph in a car and the brake pedal just went to the floor - brown trousers time. There was no warning or change in feel on the previous corner.

OP: you probably are worrying too much about rotor selection - I think most will work just fine. My greatest priority for a rotor is it be true from the factory and stay true in use. I'm distrustful of rotors formed of funky patterns that are more open space than metal. That could be me being biased, but it feels like little more than marketing (or a way to rapidly wear your pads).