Excellent video, thank you! I learned so much about hydraulic brakes. I’ve always wondered what the bladder is for and how it works. Any chance of a video on scram code rsc brakes? They have a contact point dial adjuster but isn’t effected by the lever position adjustment. Any idea how that works?
Hello Bertie, what a nice question! Thank you - I never touched one of these SRAM CODE RSC brakes, but there is enough stuff in the net to understand what is going on there - here is my explanation: Let us first summarise what we learned in my video... Stroke adjustment: This is to simply define the start position of the piston - means the distance between inlet port and front sealing. The sooner this sealing is closing the inlet port the sooner you will build up pressure by moving the lever. Reach adjustment: This is to simply bring the lever in a starting position that is ideal for your hand. If you are e.g. having small hands, you want the lever in a closer position to the handlebar. SHIMANO Ultegra lever: Stroke adjustment is realised with the little screw in a way that basically the lever is pushed a little bit forward if you screw inwards and vice versa. Means that your target stroke adjustment is influencing reach adjustment. Reach adjustment is realised with the little screw in a way that you independently can rotate the lever around the pivot. BUT in the very end position the lever is reaching the mechanical end position and if you keep on going you then will influence the pusher and push the sealing forward. In other words, you are influencing stroke adjustment. This works different with this nice technical solution at the SRAM lever: Reach adjustment: The initial position of the lever can be adjusted completely independent. Means you can just rotate the lever around a pivot without reaching mechanical borders. The screw just offers that much travel that only the lever can be rotated, no force will be given back to the piston. There is no influence on stroke adjustment at all. Stroke adjustment: Very nice solution - here you can use the external dialer to rotate the red element inside (maybe you find a picture of a replacement kit so you know what I am talking about). This red element is defining the end position of the piston. And this then is defining the gap between sealing and inlet port - our stroke adjustment! BUT how can they manage it that if you can modify the starting point of the piston that this has no influence on the lever position? Because everything inside is moving to the lever side and should then normally push the lever outside... The trick is the little silver rod that is the connection between the lever an the piston actuator - once you use the dialer and the red part is moved and then the piston is moving at THE SAME TIME this little silver rod with a tread is rotated as well - and will be screwed in or out the lever pusher. In other words: If the piston is moving at the same time this tread will compensate this amount of travel - so only the piston will move without interfering the lever! That is the secret! By the way: If you want to reassemble the lever it is necessary to use a special tool to define the exact position of the silver rod - because the initial position of this rod has to be in sync with the initial position of the red element and in consequence with the starting point of the piston in relation to this initial position of the rod! They are offering a special plastc tool for this in a repair kit. Hope that I answered your question with this step by step explanation even though I did not produce a new video! Thanks again for the question - I learned a lot about SRAM technic!
Thank you so much for your detailed reply! It’s really helpful to understand how it works. So the key, if I understand correctly, is the small silver rod which rotates as well when you turn the contact dial. I’m assuming it moves in the opposite sense of the piston, ie the piston moves one way the rod moves the other way to compensate such that lever stays in the same position. I started looking into this as the contact adjuster dial on one of my levers is jammed solid, I will dismantle it soon to see if it can be fixed. This has been super helpful in understanding how it works before I start dismantling the lever. Thank you again for taking the time to investigate this and reply 👍
You almost got it! If the piston moves, the rod normally would move exactly the same amount, but because the rod is srewd in or out the lever pusher this is compensating that amount of piston travel. So the lever is not moving! You can see all details on ZoubTube channel "SRAM Brakes Contact Point Adjustment". He is not really explaining this magic, but you can see all parts and the understand the mechanism! Thanks for question, nice brain gymnastic! 😂
Fantastic explanation , I must commend you on the time and effort you have put into this tutorial. However more important was the fact that it was genuinely interesting , so much so that I’m just about to watch #2. Well done , you should be working for Shimano as head of their technical department 👍👍
@@Pastapit A big topic and a growth industry for bike shops. I’ve been riding and racing bikes from the late 1960’s. From trying to emulate the great Roger De Vlaeminck to watching the results of wind tunnel positioning enable gifted riders to go unbelievably fast , technology is extremely specific for desired outcomes. However with your skill level at presentation I am extremely interested. 👍👍
Congratulations for your great work and video. I'm having a problem with oil leaking from the piston and I can't identify the part numbers of the seals or the piston seal kit to purchase them. You know these numbers or where to buy them. I will appreciate your help
Hi, thanks! Unfortunately there are no spare parts available as far as I know! The best way would be to just buy a used lever - you can find them... sometimes described as: Electronic is working but hydraulic does not work - I am quite shure that these guys are exactly facing the described filling topic! All the best!
Thank you for the fantastic video! Do you know if the internal parts like the piston seals and bladder are available for purchase? I have a bad right R8070 shifter which I would like to repair if these parts are available.
Hi - thanks for compliments! I think that there is no possibility to buy these spare parts - maybe you can find a defect used lever with electrical malfunction! Most likely the hydraulic parts then are in good condition so you can reuse them! All the best!
Excellent video, thank you! I learned so much about hydraulic brakes. I’ve always wondered what the bladder is for and how it works. Any chance of a video on scram code rsc brakes? They have a contact point dial adjuster but isn’t effected by the lever position adjustment. Any idea how that works?
Hello Bertie, what a nice question! Thank you - I never touched one of these SRAM CODE RSC brakes, but there is enough stuff in the net to understand what is going on there - here is my explanation:
Let us first summarise what we learned in my video...
Stroke adjustment: This is to simply define the start position of the piston - means the distance between inlet port and front sealing. The sooner this sealing is closing the inlet port the sooner you will build up pressure by moving the lever.
Reach adjustment: This is to simply bring the lever in a starting position that is ideal for your hand. If you are e.g. having small hands, you want the lever in a closer position to the handlebar.
SHIMANO Ultegra lever:
Stroke adjustment is realised with the little screw in a way that basically the lever is pushed a little bit forward if you screw inwards and vice versa. Means that your target stroke adjustment is influencing reach adjustment.
Reach adjustment is realised with the little screw in a way that you independently can rotate the lever around the pivot. BUT in the very end position the lever is reaching the mechanical end position and if you keep on going you then will influence the pusher and push the sealing forward. In other words, you are influencing stroke adjustment.
This works different with this nice technical solution at the SRAM lever:
Reach adjustment: The initial position of the lever can be adjusted completely independent. Means you can just rotate the lever around a pivot without reaching mechanical borders. The screw just offers that much travel that only the lever can be rotated, no force will be given back to the piston. There is no influence on stroke adjustment at all.
Stroke adjustment: Very nice solution - here you can use the external dialer to rotate the red element inside (maybe you find a picture of a replacement kit so you know what I am talking about). This red element is defining the end position of the piston. And this then is defining the gap between sealing and inlet port - our stroke adjustment! BUT how can they manage it that if you can modify the starting point of the piston that this has no influence on the lever position? Because everything inside is moving to the lever side and should then normally push the lever outside...
The trick is the little silver rod that is the connection between the lever an the piston actuator - once you use the dialer and the red part is moved and then the piston is moving at THE SAME TIME this little silver rod with a tread is rotated as well - and will be screwed in or out the lever pusher. In other words: If the piston is moving at the same time this tread will compensate this amount of travel - so only the piston will move without interfering the lever! That is the secret!
By the way: If you want to reassemble the lever it is necessary to use a special tool to define the exact position of the silver rod - because the initial position of this rod has to be in sync with the initial position of the red element and in consequence with the starting point of the piston in relation to this initial position of the rod! They are offering a special plastc tool for this in a repair kit.
Hope that I answered your question with this step by step explanation even though I did not produce a new video!
Thanks again for the question - I learned a lot about SRAM technic!
Thank you so much for your detailed reply! It’s really helpful to understand how it works. So the key, if I understand correctly, is the small silver rod which rotates as well when you turn the contact dial. I’m assuming it moves in the opposite sense of the piston, ie the piston moves one way the rod moves the other way to compensate such that lever stays in the same position. I started looking into this as the contact adjuster dial on one of my levers is jammed solid, I will dismantle it soon to see if it can be fixed. This has been super helpful in understanding how it works before I start dismantling the lever. Thank you again for taking the time to investigate this and reply 👍
You almost got it! If the piston moves, the rod normally would move exactly the same amount, but because the rod is srewd in or out the lever pusher this is compensating that amount of piston travel. So the lever is not moving! You can see all details on ZoubTube channel "SRAM Brakes Contact Point Adjustment". He is not really explaining this magic, but you can see all parts and the understand the mechanism!
Thanks for question, nice brain gymnastic! 😂
Fantastic explanation , I must commend you on the time and effort you have put into this tutorial. However more important was the fact that it was genuinely interesting , so much so that I’m just about to watch #2. Well done , you should be working for Shimano as head of their technical department 👍👍
Thank you very much! I really had to invest that work in order to find out how the system works in detail...
...maybe the next video about bike fitting is interesting for you as well...
@@Pastapit A big topic and a growth industry for bike shops. I’ve been riding and racing bikes from the late 1960’s. From trying to emulate the great Roger De Vlaeminck to watching the results of wind tunnel positioning enable gifted riders to go unbelievably fast , technology is extremely specific for desired outcomes. However with your skill level at presentation I am extremely interested. 👍👍
Congratulations for your great work and video. I'm having a problem with oil leaking from the piston and I can't identify the part numbers of the seals or the piston seal kit to purchase them. You know these numbers or where to buy them. I will appreciate your help
Hi, thanks! Unfortunately there are no spare parts available as far as I know! The best way would be to just buy a used lever - you can find them... sometimes described as: Electronic is working but hydraulic does not work - I am quite shure that these guys are exactly facing the described filling topic! All the best!
Thank you for the fantastic video! Do you know if the internal parts like the piston seals and bladder are available for purchase? I have a bad right R8070 shifter which I would like to repair if these parts are available.
Hi - thanks for compliments! I think that there is no possibility to buy these spare parts - maybe you can find a defect used lever with electrical malfunction! Most likely the hydraulic parts then are in good condition so you can reuse them! All the best!