DIB
Retro Newbie
I have a storry to tell. Maybe you could learn something from it, or maybe not. In short: I am looking for information on seals in the old Formula Evoluzione brakes. I would like to replace them, but the old ones might have swollen to the point they cannot be used as a trustworthy guide. If anybody can help, please do so!
And the long storry...
I have been looking for a set of brakes to put on my 1998 Rocky Mountain 2XS for quite a while now. it is almost stock condition, so a set of Formula Evoluzione seemed the best fit. Took me around an year and a half or two till I found a pair. And it was cheap! Less than 35 euro in somewhat questionable condition sold by a clueless seller. I was ready to spend even more than a hundred euro, but finding a pair of Evoluzione in good condition seems impossible, so I just bought the set with little to no expectation regarding the condition.
When they arrive I didn't bother to even take a closer look at them for a few months, because I was pretty sure they would be trashed. Well... It turned out that except the hoses and the pads everything else is in superb condition considering the age. Barely any serious visual damage and even internally they seemed to be kind of working. Took them apart and would you believe: after a bit of washing and cleaning they shined with barely any technical damage anywhere. Everything needed were pads and hoses. Even the fittings were in good condition and reusable.
The pads were easy - 30 USD for 2 pairs, sold at DiscoBrakes with free shipping. There were more expensive ones sold for around 25 USD per pair, but the cheap ones fit me just fine. Ordered and at the day of publishing this post I am still waiting for them to arrive.
Hoses on the other hand... not exactly so easy. You see, there are a few widely popular standards nowadays. Usually very similarly build and only different in the internal (the PTFE tube) and external (the rubber protector) diameter. In most cases this is not a big issue because every single popular brand uses hoses compatible with both Mineral Oil and DOT (all of the fluids) and as long as you have the proper fittings everything is fine. Even if something is not fine you could order a replacement. But the 3 decades old Formula Evoluzione are a very interesting piece of tech. They use something that i will call "quick connection" fittings that have internal mechanisms (spring, ball bearing and gasket) that lock the flow of oil when you take out the hose. With other words the lever cannot pump oil out when the hose is not inserted nor the calliper will drip. And this whole thing are basically the reusable fittings.
Olives are split and reusable, needle is easy to take out and move to another hose, but in order to make this work is by using hoses that are ø 2,5 mm internally and ø 5,5 mm externally. And NO, the original formula hoses (or the ones I had) do not work. They seemed to be around 2,1/5,0 mm, so I couldn't put the needle in nor believe the olive would manage to squize the hose properly.
Luckily I found a substitute: Tektro / Hayes / Promax brakes appear to be using 2,5/5,5 mm hoses at least for some of their brakes and I think TRP as well. Besides that JagWire do have some sets available that cover the specs.
Unfortunately I couldn't find those options either so I went with a substitute of the substitute - some generic brand sold for 7 euro a meter that was 2,5 int. Ø and 5,4 ext. Ø and by all means it seems to be perfect!
And just when everything seemed to be going smoothly and I was about to assemble the brakes and drink a glass of rakia before I go to bed... It happened... The too good to be through became not good enough... Two cheap little o-rings ruined everything. Seems like due to the long exposure to DOT the rubber has swollen enought to cause issues. The o-ring that seals the lever chamber cannot even fit inside the brakes unless an immense amound of power is used and then gets stuck, making it extremely difficult to take out the piston assembly. The main seals that create pressure appears to be somewhat fine, though i would happily replace those as well.
Eventually a friend told me he could try to help if I send him the brake. He would bring it to someone who knows his seals (ha-ha-ha...) and try to find the proper fit. And this is pretty much what I am planning to do. And I was thinking that if I am to send the brake I could change all of the seals anyway.
AND HERE I NEED YOUR HELP!!!
I have no idea what size are those seals. Measuring the old ones does not appear to be a good idea, because they have most likely swollen. Besides that i couldn't find any reference to what they could be. I managed to find files with the original service manuals or those brakes but there are no specs there. So, if you by any chance could fill in the void or tell me accirate way of calculating those sizes I would appreciate it highly!
I decided that if i manage to find everything needed I would even write it down and share it with everybody including the service manuals and some other tips and tricks in case others want to rebuild a pair of those brakes and need more information. I tried looking on the internet with no success. Next step is writing to Formula in case they could help me out, but I have doubts that would yield any results. In the past I have tried contacting companies regarding old products and so far never managed to succeed.
And here is a file with the original service manual if someone needs it. I am sharing it from my adobe reader, but it could be found online as well:
https://acrobat.adobe.com/id/urn:aaid:sc:EU:38bf6237-7ff2-4e75-8dcb-7e95ad206f3f
Thank you for the attention. Have a beautiful day and keep the community alive!
PS The brakes should be Formula Evoluzione, but I am not sure what is the exact model and I know there are a few. It has 9,5 mm Ø of the lever assembly. If someone can tell from the photos, please do so. Thank you again!
And the long storry...
I have been looking for a set of brakes to put on my 1998 Rocky Mountain 2XS for quite a while now. it is almost stock condition, so a set of Formula Evoluzione seemed the best fit. Took me around an year and a half or two till I found a pair. And it was cheap! Less than 35 euro in somewhat questionable condition sold by a clueless seller. I was ready to spend even more than a hundred euro, but finding a pair of Evoluzione in good condition seems impossible, so I just bought the set with little to no expectation regarding the condition.
When they arrive I didn't bother to even take a closer look at them for a few months, because I was pretty sure they would be trashed. Well... It turned out that except the hoses and the pads everything else is in superb condition considering the age. Barely any serious visual damage and even internally they seemed to be kind of working. Took them apart and would you believe: after a bit of washing and cleaning they shined with barely any technical damage anywhere. Everything needed were pads and hoses. Even the fittings were in good condition and reusable.
The pads were easy - 30 USD for 2 pairs, sold at DiscoBrakes with free shipping. There were more expensive ones sold for around 25 USD per pair, but the cheap ones fit me just fine. Ordered and at the day of publishing this post I am still waiting for them to arrive.
Hoses on the other hand... not exactly so easy. You see, there are a few widely popular standards nowadays. Usually very similarly build and only different in the internal (the PTFE tube) and external (the rubber protector) diameter. In most cases this is not a big issue because every single popular brand uses hoses compatible with both Mineral Oil and DOT (all of the fluids) and as long as you have the proper fittings everything is fine. Even if something is not fine you could order a replacement. But the 3 decades old Formula Evoluzione are a very interesting piece of tech. They use something that i will call "quick connection" fittings that have internal mechanisms (spring, ball bearing and gasket) that lock the flow of oil when you take out the hose. With other words the lever cannot pump oil out when the hose is not inserted nor the calliper will drip. And this whole thing are basically the reusable fittings.
Olives are split and reusable, needle is easy to take out and move to another hose, but in order to make this work is by using hoses that are ø 2,5 mm internally and ø 5,5 mm externally. And NO, the original formula hoses (or the ones I had) do not work. They seemed to be around 2,1/5,0 mm, so I couldn't put the needle in nor believe the olive would manage to squize the hose properly.
Luckily I found a substitute: Tektro / Hayes / Promax brakes appear to be using 2,5/5,5 mm hoses at least for some of their brakes and I think TRP as well. Besides that JagWire do have some sets available that cover the specs.
Unfortunately I couldn't find those options either so I went with a substitute of the substitute - some generic brand sold for 7 euro a meter that was 2,5 int. Ø and 5,4 ext. Ø and by all means it seems to be perfect!
And just when everything seemed to be going smoothly and I was about to assemble the brakes and drink a glass of rakia before I go to bed... It happened... The too good to be through became not good enough... Two cheap little o-rings ruined everything. Seems like due to the long exposure to DOT the rubber has swollen enought to cause issues. The o-ring that seals the lever chamber cannot even fit inside the brakes unless an immense amound of power is used and then gets stuck, making it extremely difficult to take out the piston assembly. The main seals that create pressure appears to be somewhat fine, though i would happily replace those as well.
Eventually a friend told me he could try to help if I send him the brake. He would bring it to someone who knows his seals (ha-ha-ha...) and try to find the proper fit. And this is pretty much what I am planning to do. And I was thinking that if I am to send the brake I could change all of the seals anyway.
AND HERE I NEED YOUR HELP!!!
I have no idea what size are those seals. Measuring the old ones does not appear to be a good idea, because they have most likely swollen. Besides that i couldn't find any reference to what they could be. I managed to find files with the original service manuals or those brakes but there are no specs there. So, if you by any chance could fill in the void or tell me accirate way of calculating those sizes I would appreciate it highly!
I decided that if i manage to find everything needed I would even write it down and share it with everybody including the service manuals and some other tips and tricks in case others want to rebuild a pair of those brakes and need more information. I tried looking on the internet with no success. Next step is writing to Formula in case they could help me out, but I have doubts that would yield any results. In the past I have tried contacting companies regarding old products and so far never managed to succeed.
And here is a file with the original service manual if someone needs it. I am sharing it from my adobe reader, but it could be found online as well:
https://acrobat.adobe.com/id/urn:aaid:sc:EU:38bf6237-7ff2-4e75-8dcb-7e95ad206f3f
Thank you for the attention. Have a beautiful day and keep the community alive!
PS The brakes should be Formula Evoluzione, but I am not sure what is the exact model and I know there are a few. It has 9,5 mm Ø of the lever assembly. If someone can tell from the photos, please do so. Thank you again!
