Hope Tech 2010 V2 Bite Point Issue
I have got a set on Hope V2 2010 (Tech Lever). First ride today. Power is amazing, however, when setting them up, I was suspicious that something wasn't quite right. The lever pulls almost all of the way to the bar. First pad contact is two thirds of the way through the stroke, then there is some flex in the system that allows me to pull the lever such that there is not room for my other fingers behind the lever.
I rang Hope before my first ride, dude told me it was likely a bleed problem. So I bled them as per the hope video. No bubbles of air came out. All good, but the bit point problem remains.
So, first ride today at Cwm Carn. Again, amazing power, but when compared to another dudes brakes, identical setup to me, his first ride also, his bite point is only about 1cm into the lever stroke. At a guess, I would say less than a third of the stroke.
This isn't a bite point adjuster issue before anyway says. With no adjustments to reach or BPC, his lever was totally different to mine, early bit and a lot firmer feeling.
I will try another bleed, but I cannot believe this will affect the bite point.
Does anyone have any pointers?
Have you confirmed that both pistons are moving fully/equally? The combination of excessive lever travel and the lack of firmness in the end of the stroke would make me think either a bleed (air) issue or a stuck/slow piston. Maybe even both...
When I was setting up, following the hope video, I had to centralise the pistons. During this exercise, I tested to see if I had rotor flex when the brake was applied, which I didn't. This would seem to preclude a stuck piston but I will check. This problem also affects both front and rear, both purchased at the same time, as a special order through my lbs. They had to order from hope, so they may be part of the same manufacturing run.
If you're happy with the piston movement, then attentions can turn to the bleed. Hope aren't known for bad factory bleeds, and getting two bad bleeds together (front & rear) seems improbable, although that doesn't mean it isn't the case. When you bled, how much fluid did you bleed out? Have you shortened the hoses?
Just curious - how far inboard in your lever mounted?
thanks for the replies.
So, in chronological order.
fit them as per hope video - straight out the box - no shortening or messing at all. Ps they are braided / floating
don't feel right
purchase my little bleeder kit
watch hope bleed video.
Ignore bleed kit, and for front brake only, follow the video instruction for a tech lever. I did not push the pistons back before doing this, since this was not detailed.
Bleed complete, no air. Probably pushed out almost a full lever to caliper in volume. Hard to judge as I don't know what the id of the braided is versus my waste pipe.
Anyway feeling of brake doesn't change.
Call hope. Guy says I have a bleed problem.
Fix up my little bleeder kit, push pistons back. Do a full bleed using perhaps a half bottle of fluid. More than enough to flush the whole system. During the bleed I squeeze the lever every few seconds as instructed. I finish off in the same manor as director on the hope video. Drop the lever to get last morsel of air from mc.
Still no change in feeling.
Repeat my little bleeding technique for rear. No change there either.
A mystery indeed.
Levers are mounted to allow one finger braking. So the lever overlaps my grips by about an inch. And I ride with my hands quite wide on the bars.
make sure the brake bosses on your frame are faced. i had a similar problem years ago and i had the brakes bleed several times, they even upgraded my brakes to a more powerful model still no dice, tech guy came from the factory and the problem was the lbs did not face my frame. that little bit of paint on the frames brake boss was causing the problem all along. once they faced it the problem was gone, and the brakes were fantastic....
thanks for posting.
Originally Posted by david8613
it isn't a power issue though. The brakes are massively powerful. I cannot think how facing affects the issue. To test this, I will unbolt the caliper and hold it on the rotor, let my hand be guided by the application of the brake / pad movement. In effect, letting the caliper align itself how it likes. I am better, after pumping the lever, there will be little impact. I will try as soon as I am home.
It's hard to picture how it could be a mechanical problem, so, and without having the brake in front of me, I'd want to concentrate on the bleed. The best way to confirm a perfect bleed is to get something solid in between the pistons (no pads). As long as you can fill the width of the rotor slot you'll be able to extend the pistons without emptying all of the fluid from the MC. You could even just stack washers up in between the pistons, as long as they fit neatly inside the center recess. You're basically looking to test the lever feel at the point you know the pistons are clamping onto something. If you have a good bleed, the end of the lever stroke will be a dead-stop - something you won't ordinarily get with Hopes when the brake is in its usual set-up.
Agreed. I am planning on getting some washers this week to test. I will leave the setup as it is, just in effect replacing the rotor, pads and air gap with washers. Ie I won't push the pistons back.
What I still don't understand is how air in the line or caliper affects bite point, surely you'd still get an early bite, but with a spongy feel?
Because the air in the line needs to be compressed before the pistons will move.
Originally Posted by trickbooter
Oh yes. Of course. Air will be easier to compress than pistons are to move, and this would explain the soft feeling of the levers compared to the other dude.
When bleeding, pushing the pistons back reduces the chance of air in the pots. But surely the orientation of the caliper plays a role. If I take the caliper off. Push the pistons back. Load it with washers then do the bleed, whilst moving the caliper around to help free bubbles in the caliper body, do you think that would help. Obviously keeping the bleed nipple upright to let the bubbles float up will be important.
Oh yes. Of course. Air will be easier to compress than pistons are to move...
If it is indeed that which is causing the problem!
...and this would explain the soft feeling of the levers compared to the other dude.
It does, but the main reason is to ensure that there's the proper amount of fluid in the system. Do a bleed with the pistons extended and the system will be over-filled. I usually start with the pistons free to move, then, after a couple of lever's worth of fluid pumped through, I push the pistons back into the caliper and wedge them in with a black of wood before carrying on.
When bleeding, pushing the pistons back reduces the chance of air in the pots.
It makes sense to have the bleed nipple at the highest point, yes. That said, I have a bench set-up for bleeding where the caliper is at a similar angle to that which it would be when fitted to the rear (frame) mount. The nipple is still uppermost, just not as acutely as it is on, for example, the fork mount.
But surely the orientation of the caliper plays a role.
As I've said, I use a wooded block when bleeding, simply because it's easier than washers; although you could tape them together. Just make sure that they fit into the piston's recessed center. If they overlap the recess they could chip the easily damaged phenolic piston material or result in the piston twisting in the caliper.
I have a little Wera ratchet drive which has a rubberised handle/grip - I use this to gently tap the rear of the caliper to dislodge air bubble when I bleed.
You raise another interesting point. So I finish bleeding. The pistons are pushed back and the mc if full. Since I run a floating rotor, the pistons need to pump out a long way to meet the rotor. During this time the mc oil level is depleting. Do I then top up the mc? The hope video shows our man doing a final top up.
Yes, the pistons should be in the sat right back in the caliper, so that the face is flush with the caliper interior, and the MC topped off before replacing the diaphragm and top cap.
Originally Posted by trickbooter
The pistons will indeed come out quite a bit further with the floating rotor (rather than with the vented) and therefore reduce the amount of fluid left in the MC, but you don't need to top it off when the pads have moved out into their working position. If you were to top-off the MC at this point the system would have too much fluid in it. The V2s are not a brake to be troubled too much by fluid expansion, but you'll reduce their overall resiliance to heat if you remove the air space in the MC.
I would just like to thank you Steve, and the others who have posted these super quick and helpful replies.
I am away for the next couple of days with work, but as soon as I am back I will be making my piston spacer non-damaging devicy thinger-orama, I will test the lever for feel / air. If the bleed seems bad, I will do a bleed (and a caliper tap), and remember not to overfill the MC!
Thanks again guys, I'll let you know how I go.
No problem; just hope - no pun intended - that you get to the bottom of it.
Are you running the v 2 rotors? I believe the v 2 rotors are thicker than the x and m series rotors which would have you using all of your lever travel closing the gap to the rotor instead of grabbing the rotor.
Presuming that you have got the right rotors for your brake, do check this bleeding process out, as apparently there maybe some bubbles stuck in a cavity within the reservoir.
You can use floating or vented rotors with the hop tech v2. When I started this post, I was using floating. I have just acquired a pair of vented, so I have both now.
After a disaster bleed, I have finally got things sorted, a thorough bleed, tapping the caliper, no bubbles etc. I have set everything up again, this time with the vented (I know, multi variable change). The feel of the lever is a bit firmer, not significantly, but the bite point is significantly improved.
I have yet to put a solid object in between the pistons to test lever feel. I need to find an appropriate object.
Yes, the video is the guide I was using, with the exception that he doesn't detail whether he pushes the pads bad. Also, when finishing off, he drops the lever vertically and pumps it. If I were doing this, using floating rotors, this would jack out the pads, and hence when I did my final top-off, i'd have overfilled my system.
Based on Steve's comments, I finished off as per the video, but only gently pulled the lever so as not to extend the pistons too far, then topped off and sealed the mc.
I still think the lever should feel firmer, but without have another setup to hand right now, it is hard to tell.
I have only done the front. I still have the back to do. I might do this on the floating, so I get a like-like comparison before mounting the evnted.
Hi there !
I think I can give you a hand with this problem couse when I bought my Hope's I experienced the same. :)
Do this following:
1. Zero-position BPC knob. Bleed your brakes propertly.
2. When bled - take the calipper off the disc and check the clearence between pads. If it's bigger than a disc's thickness ( surely is ;) ) then keeping a caliper in one hand rapidly but gently pump the lever up so the pads get closer. The best pads' position is when the calipper goes tightly back onto a disc.
3. Gently mount the calipper back onto a disc.
4. Press the lever few times; you'll get some free stroke and the wheel will start spinning freely. BPC knob still turned to "-" max.
5.Open the maser-cyllinder's resservuar and top the fluid up. Roll down the diaphragma and close up the resservuar.
6. Now when the system is tight closed you can align the pads center.
7 Adjust lever reach and BPC. Enjoy the best brakes ever ;-)
The calippers are equiped with very strong seals which not only hold the pistons but pull them back when lever released. Beacause of huge hydro leverage ratio (that's why the brake is so powerfull ) master cylinder's piston has to travel long way for making the padds contact the disc ( the thinner disc the the bigger nominal free stroke ). In this case you have to expose a little bit the cal. pistons reducing the primer gap between the disc and the padds.
Following this procedure you will achieve desired free stroke of the lever. Don't give up couse you bought the best brakes on the market; it's only needed to tweak them lill' bit.
All you've done is overfilled the system. Your method does nothing that a few pulls of the lever and proper piston centralising will do, except that your brake is more likely to pump-up during prolonged descents/braking.
Do this following...
Trust me - since I got my brakes and treated them this way the brakes never pumped up, I've never felt rising level. Mind that I use them hard and the bike is extra loaded - Scott Gambler + 110 kg of myself.
Originally Posted by SteveUK
Originally Posted by mayacorps
I said that you'd increased the chances of problems from fluid expansion, not that you were guaranteed to get them. My point is that you could have achieved the exact same results without topping the MC up; hence, all you've done is overfilled the system.