"Right to Repair" required for bikes

Joined
Jul 7, 2014
Messages
5,133
Location
Winnipeg MB CA
The rear Shimano hydraulic brake caliper on Jr's winter bike (single-speed, 29" studded tires) was leaking. I removed it and took it apart. It's a very simple design, single-piston, with mineral oil serving as the hydraulic fluid. The cylinder and piston looked fine, leaving the O-ring as the culprit. It's different from any O-ring I've ever seen before, though; rather than being round in cross-section, it's square. Nothing like that in my collection. :unsure:

I did a fair bit of research online, and it looks like replacement O-rings are not available anywhere at any price. So, I bought a new caliper from my closest local bike shop. But they don't sell just the caliper; I had to buy the entire assembly - caliper, brake hose, master cylinder, and brake lever. I chose to transplant the caliper only, saving the rest as spare parts. I don't have the bleeding tool for the new-style master cylinder. I get why they sell the whole thing complete, as it comes as a sealed unit, which means no bleeding is required. But the bleeding was easy, no problem at all.

I would like to have the choice to buy only the caliper, or, better yet, just the O-ring. Perhaps I was lucky to get the parts I needed - I suppose bike manufacturers and bike stores would prefer that I buy an entire new bike.

OK, rant over. :D
 
Probably a quad seal or a custom seal. Quad seals are available. Not a fan of "right to repair" laws. Chances are the manufacturer will find a way around these laws. After all, do right to repair laws stipulate what the cost will be for said seal?
 
Probably a quad seal or a custom seal. Quad seals are available. Not a fan of "right to repair" laws. Chances are the manufacturer will find a way around these laws. After all, do right to repair laws stipulate what the cost will be for said seal?
Agreed on the crazy price of replacement parts. I replaced the heating element on our dryer about three years ago. With tax, it was close to $300. If I'd had to pay for the diagnosis and replacement labour, that would have been good justification to replace the dryer. Perhaps that's what they want.
Mcmaster-Carr has square profile o-rings by the boat load.
Good to know - thanks!
 
I replaced the o-ring on the distributer shaft on out 1965 Olds 4-4-2. The original o-ring looked flat, sorta square.
I had never seen anything like that...
It was the 50 years of use, hrat cycles, etc. Rock hard.
 
I buy just calipers all the time, usually on Ebay. On all of my bikes, I like to run 4 piston calipers on the front wheel and the cheapest way to accomplish that is buy the brakeset and swap the front caliper to 4 piston.
 
Late to this party- go to McMaster as all have said.

Worst case scenario- any machine shop can adapt the groove ( L-W-D) to fit any standard size with no alteration of function ( do that all the time too) [ ETA: as long as the material and heat range along with crush tolerances remain the same for the new ring]
 
If I remember correctly, Shimano doesn't supply parts for its shifters either. Campagnolo used to, but I'm not sure if that's still the case.
I agree, parts should be available across the board. 5 dollar repair vs 100 dollar parts are ridiculous.
 
You have a right to repair but nobody said they have to stock parts.
I suspect there's a bit of a liability issue at play as well. I can see someone replacing the seal and messing it up somehow then suing Shimano when they hurt themselves.

A couple of other points:
- Square seals are what is generally used in disc brake calipers. The flex in the seal is what causes the pad to return after the brakes are let off. See here.
- If you are buying a replacement make sure it's compatible with the mineral oil Shimano uses in their brakes.
 
Mcmaster-Carr has square profile o-rings by the boat load.
Late to this party- go to McMaster as all have said.

Worst case scenario- any machine shop can adapt the groove ( L-W-D) to fit any standard size with no alteration of function ( do that all the time too) [ ETA: as long as the material and heat range along with crush tolerances remain the same for the new ring]
Thanks, I'll check them out!

You have a right to repair but nobody said they have to stock parts.
I suspect there's a bit of a liability issue at play as well. I can see someone replacing the seal and messing it up somehow then suing Shimano when they hurt themselves.

A couple of other points:
- Square seals are what is generally used in disc brake calipers. The flex in the seal is what causes the pad to return after the brakes are let off. See here.
- If you are buying a replacement make sure it's compatible with the mineral oil Shimano uses in their brakes.
Fascinating, great information! Basically, it sounds as though the square (in cross-section) O-rings act as a bit of a spring to retract the extended piston, correct?

I buy just calipers all the time, usually on Ebay. On all of my bikes, I like to run 4 piston calipers on the front wheel and the cheapest way to accomplish that is buy the brakeset and swap the front caliper to 4 piston.
Four-piston caliper? For a bike? o_O Wow! I'm impressed by dual-piston calipers on a car!

Must be a really nice bike I’ve never seen a bike with hydraulic brakes.
It's a neat bike for sure - older son built it for his younger brother around 2014. It's seen a lot of use. The single-speed drivetrain is very durable for the punishing winter riding it's used for. The hydraulic brakes work great.

I have a touring bike (2010 Kona Dew Deluxe), also equipped with hydraulic brakes.

Both bikes use plain mineral oil as the hydraulic fluid. The brakes work very well, but the potential for leaks in the system is their Achilles's Heel of course.

Or if you have a hydraulic shop near you
Another good suggestion! Thanks.
 
Fascinating, great information! Basically, it sounds as though the square (in cross-section) O-rings act as a bit of a spring to retract the extended piston, correct?

No, the square ring gives a greater seal contact area ( than its round cousin) and as such can withstand marginally higher pressure than the round ring.( all things equal of course) In the case of moving shafts, they tend to last longer simply because of the greater area.

The square ring also has an added benefit of being a better "wiper" at keeping debris out.
 
Shimano is pretty famous for not having repair parts available for their brakes, A few people have found replacements from other companies throughout the years but often they don't work 100%. If you want rebuildable brakes best to go with another company such as magura or hope.

It's sad because Shimano has made some pretty good brakes through the years that eventually get tossed because of the leaking.


number_35
4 piston brakes are getting more common in the bike world, there are even some 6 piston models for the DH racers and ebikes, crazy

unnamed (1).jpg
 
No, the square ring gives a greater seal contact area ( than its round cousin) and as such can withstand marginally higher pressure than the round ring.( all things equal of course) In the case of moving shafts, they tend to last longer simply because of the greater area.

The square ring also has an added benefit of being a better "wiper" at keeping debris out.
Yes, greater contact area makes more sense!
 
Back
Top