Bafang BBS02 included brake levers have too much travel?

[brickwall]

Hi,

I have installed a front disc brake (a TRP HY/RD) on my bike which worked really well with the no name brake lever that came with the bike, but the ones included in the BBS02 kit travel a much farther distance before the brake is applied. You can see the callipers moving from the first bit of movement, but it takes quite a lot to actually make them press against the disc. So much so that the lever almost reaches the handlebars, even though there's absolutely no cable slack.

The levers I have are the silver motorcycle-style levers and not the black ones I've seen elsewhere. I've read that there different kind of levers, with long and short cable pull. Do you guys know what these are and would it help to replace the levers with some other model?

TL;DR: I want my levers to travel less and grip the disc sooner, for a better brake feel.

 

[jtrops]

It sounds like you are trying to match a long pull lever made for V brakes with a road disc caliper made for a short pull road brake lever. So you have some options. First you could try to find a short pull lever with the brake cutoff. Second you could get a Problem Solvers "Travel Agent" that multiplies the cable pull from your current lever. And third, you could use a good quality lever like an Avid "Speed Dial 7" with a brake cutoff switch added.

Of course there's one more option which is to get a mountain bike disc caliper which is designed to work with long pull vbrake levers.

 

[LyonNightroad]

Sounds like you actually don't have enough travel. I had this problem. Eventually I bought the cable brake sensors and used the stock levers. However, I was able to get by for a quite a while by just adjusting the brakes so that there was the absolute. minimum clearance between the pads and rotor. A pain since it requires more frequent adjustment but you get a bit more stopping power because the longer brake handles give you more leverage.

 

[jtrops]

Sounds like you actually don't have enough travel. I had this problem. Eventually I bought the cable brake sensors and used the stock levers. However, I was able to get by for a quite a while by just adjusting the brakes so that there was the absolute. minimum clearance between the pads and rotor. A pain since it requires more frequent adjustment but you get a bit more stopping power because the longer brake handles give you more leverage.

Agreed. I had it backwards.

It's like you have a short pull lever matched to a long travel caliper. So, the "Travel Agent" will fix it, or installing a sensor in a suitable lever like your original lever, or an Speed Dial 7 (with adjustable pull)

 

[brickwall]

Sounds like you actually don't have enough travel. I had this problem. Eventually I bought the cable brake sensors and used the stock levers. However, I was able to get by for a quite a while by just adjusting the brakes so that there was the absolute. minimum clearance between the pads and rotor. A pain since it requires more frequent adjustment but you get a bit more stopping power because the longer brake handles give you more leverage.

Agreed. I had it backwards.

It's like you have a short pull lever matched to a long travel caliper. So, the "Travel Agent" will fix it, or installing a sensor in a suitable lever like your original lever, or an Speed Dial 7 (with adjustable pull)

Now I'm confused.

The travel I'm talking about is the actual handle, but if we're talking about cable travel then yes, not enough cable is pulled when the lever is squeezed. So I guess we mean the same thing? I need a brake lever that pulls more cable, i.e. a long pull one?

Are there any sensors that doesn't look like garbage on the bike? And are there any Bafang compatible long pull brake levers?

 

[jtrops]

Sounds like you actually don't have enough travel. I had this problem. Eventually I bought the cable brake sensors and used the stock levers. However, I was able to get by for a quite a while by just adjusting the brakes so that there was the absolute. minimum clearance between the pads and rotor. A pain since it requires more frequent adjustment but you get a bit more stopping power because the longer brake handles give you more leverage.

Agreed. I had it backwards.

It's like you have a short pull lever matched to a long travel caliper. So, the "Travel Agent" will fix it, or installing a sensor in a suitable lever like your original lever, or an Speed Dial 7 (with adjustable pull)

Now I'm confused.

The travel I'm talking about is the actual handle, but if we're talking about cable travel then yes, not enough cable is pulled when the lever is squeezed. So I guess we mean the same thing? I need a brake lever that pulls more cable, i.e. a long pull one?

Are there any sensors that doesn't look like garbage on the bike? And are there any Bafang compatible long pull brake levers?

This is the weird thing. My Bafang kit came with long pull levers that work fine with my Avid BB7 calipers. I wasn't aware that they made a short pull lever for the BBS0- kits. Still I think the Travel Agent will fix your problem without looking like a bodged up lever. you can get an inline TA that can mount near the caliper.

It is curious that you are having this problem though. With a road caliper a short pull lever should be just right, and a long pull lever would let you set the pads a little further from the rotor than normal (yet still have solid lever feel). This makes me think that double checking your cables for kinks, and line friction may be in order just to rule out these common factors that cause poor brake performance.

 

[brickwall]

I'm not sure what the issue is. The bike came with a mechanical front disk brake, which I upgraded to the TRP mechanical-hydraulic one for better performance. I wanted to avoid hydraulics in order to avoid unsightly external sensors. The brake feel with the original lever and the TRP brake was great. It's when I swapped out the original lever for the Bafang one that I noticed the brake feel got much worse.

It doesn't quite touch the handlebars now, but it's much closer than with the original lever. Then again the Bafang one is also much larger (almost like a motorcycle lever) so the distance the far end of the lever has to travel is greater, which may contribute to the feeling.

Just curious what my options are to improve the feeling. Then again, the long lever travel does give me a mechanical advantage and a larger dead zone before the brake is applied, which can be used as a "clutch" to cut off power to the motor. So it has its advantages too.

 

[jtrops]

Okay, I completely missed the fact that your brake is a hybrid Mech/Hydro. This changes things. In your system the cable pull activates a compression piston in a master cylinder that in turn activates a cylinder that pushes a piston towards the rim. As long as you have the cable tight, and the master cylinder isn't locked off from the cable you have done what you need to with the cable and lever. When hydro systems have too much travel, or feel spongy it usually means that fluid has left the system, and that air is in the line somewhere.

Did you notice fluid coming out of your caliper at any time when you installed the new cable? If so, it sounds like you will need ot bleed your caliper, and evacuate any air that entered the system.

I just looked at the tech bulletin for your brake, and it looks like the barrel adjuster on the cable at the caliper end only has 1.5 turns of adjustment before it locks the master cylinder. if you turned it more than that to remove slack in the cable it could possibly result in poor caliper actuation (or none at all).

Sorry for the run around. Hopefully this will get you on the right track.

Edit:
With that much travel this isn't likely, but it's possible that your pads retracted all of the way, and that pumping the lever a few times will push the pistons out to where they need to be for a solid lever feel.

 

[brickwall]

No need to be sorry. Thanks a lot for all your help.

No oil has come out and the brake is almost brand new, so I think the culprit is just the long Bafang brake lever. It seems to be a long pull lever too, so it should pull enough wire. It's just that the entire thing is so large. Pretty sure that's it, at least.

 

[brickwall]

Sounds like you actually don't have enough travel. I had this problem. Eventually I bought the cable brake sensors and used the stock levers. However, I was able to get by for a quite a while by just adjusting the brakes so that there was the absolute. minimum clearance between the pads and rotor. A pain since it requires more frequent adjustment but you get a bit more stopping power because the longer brake handles give you more leverage.

Agreed. I had it backwards.

It's like you have a short pull lever matched to a long travel caliper. So, the "Travel Agent" will fix it, or installing a sensor in a suitable lever like your original lever, or an Speed Dial 7 (with adjustable pull)

I just need to go through this again: The braking action feels like if I had a short pull lever matched with a long pull calliper, i.e. too much mechanical advantage and lever travel.

But the TRP HY/RD is made for road bikes which I understand have short pull levers, so it really should be made for short pull, while the BBS02 levers seem to be long pull levers. In other words, it should be the total opposite of what I'm experiencing.

I've ordered the HWBS e-brake sensor from em3ev.com so that I can use any lever of choice, but now I really don't know what to get.

Edit: actually, I'm starting to believe it's just me that prefers the feeling of a long pull lever matched to a short pull caliper. You get a much firmer feel but less mechanical advantage and thus less braking power. I think that's it. Both my original and the BBS02 levers are long pulls, but the latter is longer and of worse quality which gives a more spongy feeling.

I think what I'll do is I'll get a good quality Shimano Deore long pull lever and use that. It's a bit longer than your average lever which will get me some leverage even though I should actually be using short pull lever

Edit 2: I just finished reading a lot of reviews about the TRP HY/RD and some complain that the lever travel before it grips is a bit too long, and that's when using road bike-type levers. So maybe it's a short pull calliper that's just better off with long pull levers.