BB7s to Hope V-Twin?

[Red Light]

Thinking of swapping my Avid BB7s on my Genesis Day One to Hope V-Twins - the Avids just don't have that rock solid reliable braking feel that I get from the Hopes on my other bikes plus I can't get them so they reliably don't rub without giving so much gap that the brake lever goes to the bar. Hydraulics have that nice feel of once they start to bite, the lever doesn't move further, you just squeeze it harder to brake more. Can't go full Hope because the Day One has drop bars with the Alfine drop bar shifter so I need a cable to hydraulic conversion

So the question is do I need new rotors as well or can I use the Hopes on the Avid rotors? Any other things I should look out for?

 

[Howard]

I've heard good things about the hope unit. I would have thought rotors came with it? The rotors are shown in the product description photo.

I've also set up BB7s & BB5s to work perfectly with drop bars from both Shimano and SRAM - no rub & progressive hydraulic-like power. Requires time, patience and pricey full length cable housing though.

Your other, cheaper option is to try a pair of Travel Agents which will trade you more cable pull for a decrease in mechanical advantage.

 

[Andrew Br]

................plus I can't get them so they reliably don't rub without giving so much gap that the brake lever goes to the bar.

I've got BB7s on all 3 of my bikes (one straight bars, the other two are drops) and I don't have this problem.
I set the inner pad as close as possible to the rotor then dial in the outer pad as close as possible without rubbing.
As the pads wear, I move them in until they rub and then back them off a few "clicks".

So the question is do I need new rotors as well or can I use the Hopes on the Avid rotors? Any other things I should look out for?

I can't see why you'd need the Hope rotors but they do look really, really good. IMO. I've got them on two of the bikes.

If you do go down the V-twin route, please report back.
Despite my satisfaction with BB7s, I've looked at going down the hydraulic route.
I'm particularly interested in the weight comparison between each system.


.

 

[Andy_R]

I've actually swapped from hydraulic (shimano m775) to cable (bb7) for the simplicity of the system and now they've bedded in, I can honsetly say the bb7s are almost as good as my old m775s. Simply put, when properly adjusted they can stop a fat lad going downhill on a bike. Take some time to set them up and never have to worry about bleeding or over boiling.

 

[Howard]

I think the OP may struggle with Cable Pull discs because the Alfine (Joytech?) drop bar shifters are a bit cheap and cheerful. The may pull less cable than others. Who knows.

 

[Red Light]

I think the OP may struggle with Cable Pull discs because the Alfine (Joytech?) drop bar shifters are a bit cheap and cheerful. The may pull less cable than others. Who knows.

I suspect actually its more to do with the difficulty getting the pads perfectly parallel to the rotor. I've tried the instructions of loosening the bolts, clamping the pads on the disc and then tightening the bolts up but when you squint down there is always a wedge gap rather than a parallel gap. Which means a bigger mean gap is needed to clear the rotor. There is also a slight wobble in the rotor which doesn't help either. Because of cable stretch when you pull the brake levers this matters on the Avids whereas on my Hopes as soon as the brakes bite the lever goes more or less solid and you just increase pressure on it without it moving closer to the bars.

 

[Andy_R]

Are you using full length compressionless housing? Have a look here for setup tips BB7 setup

 

[Howard]

I found the loosen clamp tighten method doesn't really work either. Instead I clamped the disc using the dials rather than the leaver - that approach worked for me.

 

[GrumpyGregry]

These are the rules I follow for BB7 road and drop bars.

 

[Howard]

Apart from the bits specific to speed-dial, obviously

I followed this to begin with - it's good. There's also a page by Avid that spells it out that you shouldn't use anything but full-length compressionless cabling, yet plenty of bikes ship without it and the rumors persist that BB5/7s are difficult to set up and don't work. Go figure.

 

[Red Light]

I have just tried the instructions posted by Greg and Andy and both result in a lever that pulls to the bar very easily. And that is with it set up just one click out from rubbing.

Howard, you may well be right in that the bike uses no-name cables that came with it although they are both full length. However the movement of the brake lever is reflected in the movement of the caliper arm all the way to the brake lever being up against the bar so it can't all be cable stretch/housing compression with a big chunk of it coming from within the caliper itself. So the question is do I mess around with trying other cables or just switch to compressionless hydraulics?

 

[GrumpyGregry]

Red Light, I'd buy some full metal jacket cables and use them in combination with full metal jackets before going down the hydraulic route. They made a huge difference over the entry level jagwire outers on the bike originally.

and ideally you want inline adjusters fitted to.

 

[MacB]

I have just tried the instructions posted by Greg and Andy and both result in a lever that pulls to the bar very easily. And that is with it set up just one click out from rubbing.

That seems extremely slack using the same setup I actually back the pads off a bit further than I need to allowing for more lever movement. Two thoughts spring to mind and apologies if you've tested this already:-

1. when I touch a brake lever my calipers actuate immediately, there is no loss in the system. To achieve this on the rear brake I had to tinker for longer and be a bit more robust in the setup process.

2. you mention earlier about the caliper not aligning to the rotor correctly, this gave me terrible trouble on one bike as I was new to discs etc. Following an online tip I tried mounting the wheel and then the adaptor only, no caliper. What became instantly apparent was that the disc brake tabs weren't aligned correctly. We're talking 3-4mm here and using the caliper mounting bolts to correct for this meant the pads had to be a long way out to avoid rubbing. I sorted this with a spacer washer on one of the adaptor mounting bolts. This brought the adaptor almost square to the rotor and the caliper adjustment was easy after that.

 

[Red Light]

That seems extremely slack using the same setup I actually back the pads off a bit further than I need to allowing for more lever movement. Two thoughts spring to mind and apologies if you've tested this already:-

1. when I touch a brake lever my calipers actuate immediately, there is no loss in the system. To achieve this on the rear brake I had to tinker for longer and be a bit more robust in the setup process.

2. you mention earlier about the caliper not aligning to the rotor correctly, this gave me terrible trouble on one bike as I was new to discs etc. Following an online tip I tried mounting the wheel and then the adaptor only, no caliper. What became instantly apparent was that the disc brake tabs weren't aligned correctly. We're talking 3-4mm here and using the caliper mounting bolts to correct for this meant the pads had to be a long way out to avoid rubbing. I sorted this with a spacer washer on one of the adaptor mounting bolts. This brought the adaptor almost square to the rotor and the caliper adjustment was easy after that.

I've been playing about a bit and think I understand it a bit better now. The pads are parallel to the rotor although its a bit fiddly to get them so. And the caliper arm moves with the brake lever so its not cable stretch/housing compression that's the problem. The rear brake is better than the front but then comparing the two its because the free travel of the rear brake lever is much further than the front. Basically the big downshift paddle on the front brake lever hits the bar well before the brake lever on its own would. And that restricted travel makes the difference. I guess I could go US style front brake on the right but that's not a good idea in an emergency when you've been brought up on the opposite all your life.

 

[MacB]

Hmmm, theoretically the front should be easier to set up and I have one lot in combination with Shimano 105 10 speed STIs so the same sort of shift paddle thing. Just checked on mine and due to the splay of my bars and lever alignment the shift paddle can't contact the bars anyway. But actuating the lever in the garage it comes to a stop with the paddle approx 20mm from the bars. So it would be closer under heavy braking on the road, but not that much.

Another quick test is to dial both pads in fully so that the wheel can't move. Then try, fairly gently, to move the brake lever, it shouldn't move at all.

Another thought could be your bars and the positioning of the levers, maybe a small tweak would allow the shift paddle to pass on the outside of the bars.

Finally, and apologies again if this is too obvious/stupid, but you have paired the correct calipers with the correct levers re pull ratio haven't you? The BB7s come in a road and a MTB version, or silver/red compared to black/red, mxismatching caliper and lever could create what you're experiencing.