The Alta Factory LHRB

C5tor

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Well, I guess I will find out. I ordered both 9mm and 10mm. I guess I'll test them and see how they feel for my purposes.

My main problem with the stock foot brake is it is either on or off, and it has zero feel. It just locks up no matter how softly I press it. That was why I was going to try the hand brake (plus my son isn't experienced with foot brakes.)
So, I installed two LHRB setups over the weekend. (This is using the LHRB hose I got from Liquid Performance.) One was 9mm and one was a 10mm master cylinder. After using them both, I am definitely torn. Both have their pros and cons.

The 10mm feels super solid and firm. Very little lever movement before it bites. It feels firmer than my front brake. But it also doesn't have as much leverage. At full squeeze, it can lock up the rear (especially) at higher speeds, but it take a lot of effort. One or two fingers would probably not get it done, three fingers minimum.

The 9mm doesn't have the solid, firm feel of the 10mm. Lever travel is much longer for the 9mm. I can actually pull it almost all the way to the bar if I wanted to (and yes, I bled the system several times). But it has a lot more leverage, and pulling it in about half-way can lockup the rear. And effort is much less. One or two fingers is all you need. So, of the two, it is much easier to modulate on the 9mm.

At this point, I think I'm going to swap out the 10mm for a 9mm. I wish Brembo had a 9.5mm or a 9.3mm master cylinder. That would be pretty ideal. I think I saw Magura had a 9.5 clutch master cylinder, but not sure if it is compatible with Dot4 fluid or not. (I've heard bad things about using dot4 in a setup that is designed for mineral oil. But not sure if that applies in this case.)

My final conclusion is that both options seem to offer a lot more feel and modulation than the stock foot brake did. At least, that is my experience. I couldn't modulate the rear foot brake at all, it was either on or off as far as locking up the rear wheel. Your experience and expertise might be different than mine, though.
 

Oded

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I wonder how they feel compared to the Rekluse LHRB that I use.
Stopping power is not as great as the front Brembo, but the leverage does let you modulate the power delivered until full brake.
It has a knob that changes the feel of the brake (how much to press in order to get max power), however, we use it at the highest settings.

20200317_074702.jpg
 

OneLapper

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So, I installed two LHRB setups over the weekend. (This is using the LHRB hose I got from Liquid Performance.) One was 9mm and one was a 10mm master cylinder. After using them both, I am definitely torn. Both have their pros and cons.

The 10mm feels super solid and firm. Very little lever movement before it bites. It feels firmer than my front brake. But it also doesn't have as much leverage. At full squeeze, it can lock up the rear (especially) at higher speeds, but it take a lot of effort. One or two fingers would probably not get it done, three fingers minimum.

The 9mm doesn't have the solid, firm feel of the 10mm. Lever travel is much longer for the 9mm. I can actually pull it almost all the way to the bar if I wanted to (and yes, I bled the system several times). But it has a lot more leverage, and pulling it in about half-way can lockup the rear. And effort is much less. One or two fingers is all you need. So, of the two, it is much easier to modulate on the 9mm.

At this point, I think I'm going to swap out the 10mm for a 9mm. I wish Brembo had a 9.5mm or a 9.3mm master cylinder. That would be pretty ideal. I think I saw Magura had a 9.5 clutch master cylinder, but not sure if it is compatible with Dot4 fluid or not. (I've heard bad things about using dot4 in a setup that is designed for mineral oil. But not sure if that applies in this case.)

My final conclusion is that both options seem to offer a lot more feel and modulation than the stock foot brake did. At least, that is my experience. I couldn't modulate the rear foot brake at all, it was either on or off as far as locking up the rear wheel. Your experience and expertise might be different than mine, though.

This corresponds with what I found when I was messing around with the DIY rear brake. Hard to lock the wheel with the 10mm, easier to lock up the wheel with the 9mm. I find the 9mm works very well for the enduro racing, traction is usually low so it's easy to lock the rear and swing the bike around if needed.

The 9mm is more difficult to bleed, btw.
 

C5tor

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Yeah,
The 9mm is more difficult to bleed, btw.
Yeah, @Rashid510 and I were just discussing that this weekend. It shouldn't be any different, but it seems to be more finicky with the bleed process, maybe just because it has more leverage, and is moving less fluid per squeeze. We both had some success with the classic "zip-tie" method. That's where you squeeze the lever and zip-tie it to the bar overnight. Or even better, in the back of your truck when you are driving, so that the vibration helps work loose any bubbles. I think the theory is that the pressure in the line helps work the bubbles loose, so that they can more easily work their way to the top. Always helps if you can get the reservoir at the highest point, too.
 

Rashid510

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The 9mm is more difficult to bleed, btw.
Bleeding the brakes this past weekend was a fun task. Tried the traditional method of bleeding, was able to get fluid into the line and out of the bleed valve. Could not get decent amount of pressure. After a break and watching some Youtube on reverse bleeding (thanks @C5tor ), sucessfully got pressure and bled a crap ton of air from the MC after using the reverse method. Get the right plastic tubing and syringes (Lowes only has turkey ones....wtf) and its a cake walk.
 

OneLapper

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I have had some luck by removing the white plastic disc inside the reservoir, tipping the bike on the right side, and pumping the lever.

Also, I've left the bike on it's side overnight. I don't know why that would help, but it has.

Push bleeding from the caliper up to the MC is helpful, too. But temporarily removing that disc helps alot.
 

Honcho

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I wonder if that was a supply constraint issue. The 9mm is definitely more difficult to get.
Bumping this old thread to corroborate (as said CEO) that I requested the change to 10mm from 9mm. Not a supply issue, much more of a feel issue. I wanted to make sure that the front and rear brakes had a similar level of firmness and pressure to lock up. (Given more weight and traction on the front under braking) with the 9mm the rear was softer and locked up with less pressure than the front; at 10mm they’re similarly firm and lock up on equal ground at about the same pressure.
That’s not to say the 9mm is wrong or you can’t run it, but I had a very strong preference for the 10mm so requested the change.
 
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