Everything I'm about to write is true.
If anything, it's me who'd rather believe it was a lie or a joke...
A customer left me a Specialized SHIV to work on.
They'd bought it at Silvest Cycle about 11 months ago.
A friend of the bike's owner had mentioned to me about a month prior
that they'd be bringing it to my shop eventually
(the friend is one of my customers)
so I had some advance warning.
There's a problem with the Magura hydraulic caliper brake, they said.
In reality, it was far worse than just a "problem."
This SHIV is a frameset-based complete bike,
and the frameset breakdown includes frame, fork, headset,
aero bar set, seatpost, crankset, and Magura hydraulic brake.
Triathlon bikes have rulebooks for frame geometry that differ from UCI rules
and are somewhat more lenient.
So things like this tiny storage box, which appears designed solely
to block off the front triangle, aren't prohibited.
It's called a Fuel Cell.
You bolt a Fuel Cell mounting bracket into the bottle cage hole on the seat tube,
then insert the plastic lower section into it.
When it clicks in place, you can't remove it without lifting the tabs.
Then you attach the rubber upper section.
If you store items like repair tools—things you won't need while riding—in the lower part,
and food supplements in the upper part, it's quite convenient.
It's not waterproof, but both parts have drain holes at the bottom,
so water won't accumulate even in rain.
The brake is a Magura RT8.
It comes in two models—this one and the lower-spec RT6—
but the retail version of the RT8 has caliper arms colored red/black on left and right,
while the RT6 is black/black.
This RT8 being black/black is a special version specific to this frameset.
↑It works like this.
When a pod with an arrow-shaped part on its tip gets pushed out from the brake caliper...
...the arms move and the pads grip the rim.
Though the pivot points differ, it's basically like hydraulically spreading a clothespin.
Though not shown in the diagram, a return spring equivalent to the spring in a clothespin
is mounted on the back of the caliper.
The problem was that after braking, the caliper return was abnormally sluggish,
with the pod not returning fully. That's why I took it in.
This is hard to believe, but Silvest Cycle's response to this was
Wrap a rubber band around the caliper so it returns properly
That's what they said.
When the customer went to pick up the bike after the second service visit,
they were told this was the best they could do and were handed a rubber band.
This wasn't a temporary fix (though even that would be bad)—it was their final answer.
Hey everybody! If you let Silvest Cycle
service Magura brakes,
this is what you get!
I watched as the customer carefully pulled the rubber band from the Fuel Cell
and insisted, "It's essential equipment for racing, if not for training!"
I held back—thinking "this is not the time to laugh."
If a rubber band is truly essential to Magura brakes, so be it,
but with proper service, it shouldn't be necessary.
I squeezed the brake lever hard.
The brake isn't completely non-functional, but there's sloppy play
before the caliper engages—clearly air bubbles in the brake fluid.
The electronic drivetrain's satellite switch interferes with the lever squeeze being too weak. That's dangerous.
The extension bars mounted on the base bar have lateral play for some reason.
Especially the right bar—it makes a creaking sound each time you shake it.
Because it moves in a fan-like motion
↑I tightened the left and right alignment.
↑And spread them apart again.
The extension bar had
the right bar suddenly come off while riding.
The customer hasn't mentioned this to Silvest Cycle.
I would've stormed in and yelled at them.
Afterward, the customer tightened the fastening screw on the right bar very hard,
but that actually didn't solve the problem.
As long as the bar has play, tightening the screw only
delays loosening/coming off—it doesn't actually fix it.
The fact that the tightened right bar still makes noise when moved left and right
told me what the problem was right away.
To be clear: after receiving the bike, the customer never once
adjusted or touched the bars until they came off.
The bar heights differed significantly left to right, so I asked the customer
if this was a deliberate position preference.
If it was, I'd need to remember it.
But they said, "No, not at all. Please make them equal."
This discrepancy didn't come from the original build—
it resulted from reinstalling the bar after it came off.
The extension bar mounting bracket section
↑right
↑left
It's like a single-bolt seatpost clamp where the saddle gets loose and wobbly.
The rear brake was also spongy like the front, so the customer—
losing faith in Silvest Cycle—brought it to Rabbit Street
(the Esaka Specialized Concept Store) for rear brake adjustment.
They thought "Specialized's own shop must be trustworthy."
But somehow it got swapped out for a retail-version RT8.
The customer was told beforehand that "we'll replace the brake,"
but replacing something means there's a defect worthy of replacement.
If a part is good but just needs service, swapping it out is fraud.
If they're going to replace it anyway, they should explain to the customer
what's wrong and why replacement is necessary—
but they didn't provide any such explanation.
I wanted to try servicing the original brake (the black/black RT8) first,
so I asked the customer to bring it in. But they said
the original brake was never returned by Rabbit Street.
They weren't even asked "what do you want to do with the old brake?"
Of course, the customer already paid for the red/black brake caliper and labor.
They never said they didn't want the original brake.
The only reason I can think of to replace a hydraulic caliper is
seal degradation causing brake fluid leaks.
It's been less than a year since buying the bike with the brake,
and Magura offers a 5-year oil-leak warranty, so
if there really was a defect requiring replacement, Specialized
(the framemaker) should have been consulted first—
that's what should've been said.
With online purchases, you're stuck, but this was from an authorized dealer.
Without seeing it myself, I can't say for certain, but
I suspect the original brake could've been fixed with proper service.
But even if the brake got "fixed" this way...
Squeezing the brake lever caused so much air to bubble into the bar tape.
There was no point replacing the brake caliper.
From the previous image: the pod still doesn't return, and
the brake is mounted off-center,
so the right pad is dragging on the rim continuously.
Magura's hydraulic calipers can be mounted on any road bike with a bullhorn bar.
That's probably why the rear brake is oriented
as if it'll be mounted on the seatstay brake post. Probably.
↑The pads are reversed left and right.
Probably they just took the seatstay-oriented brake orientation
and installed it as-is.
This isn't even a Magura issue anymore.
If the foolproof pad-retention screw hadn't been there,
this could've been life-threatening.
The customer hasn't touched any of this.
In fact, besides retightening the external right bar, they've adjusted nothing.
I asked about this repeatedly to establish responsibility.
After taking it in, I rode it a bit in front of the shop
and was terrified at how little braking I had.
I couldn't descend a slope—it's impossible.
Mechanical brakes would definitely work better,
and the rear brake alone, even while fully squeezed, I could still pedal forward.
To be clear: so far, I've only ridden it a bit,
shaken the bars side to side, and squeezed the brake levers—
I haven't begun any service work yet.
It's still in the condition it arrived in.
Hard to believe, but that's the truth.
I pray that divine punishment falls on scumbag shops
who work solely to extract money from customers.
I might get burned too, but if the customer's interests are restored, so be it.
One more small detail.
When you straighten the handlebar, you notice
↑this part is installed at an angle.
And it's tightened so firmly I can't bend it back by hand.
It's not a functional handlebar component, so there's no injury risk,
but the details matter.
The bottle cage bracket mounted to the saddle
...the lower fastening screw was loose and rattling.
That's the extent of the damage assessment! Now for repairs.
I removed the pad bracket on the extension bar.
The tool I'm pointing at with my four-prong picker (resembles an ice pick)
is the problematic screw.
Out it came.
The bar had been rattling constantly; there are wear marks on the bracket.
The screw's flank scraped the bracket, leaving thread marks.
That's what happened from riding.
I could've machined the original screw, but I just replaced it with a new one happily.
It's not that expensive, and
I'm keeping records in case the customer asks for the original screw back.
That way I can explain why it needed replacing.
↑Yes, that's absolutely a dig at the rear brake situation
The split washer I added below is insurance.
I've calculated the screw length including this.
A tangent: stem bolts are steel—either black or zinc-plated—not stainless.
This is because stainless has lower breaking strength than steel,
so breaking strength takes priority over rust resistance.
That said, titanium bolts are a weaker class...
It's now solidly fixed.
Even if I shake the extension bar with all my strength left and right,
there's only the slightest flex in the carbon bar itself—completely immobile.
The fan-like wiggle that was happening before was pure abnormality.
I also straightened that angled part.
The small details matter.
I also gave it a wash.
This frame has mysterious grime that won't wipe off with a finger.
Here we go.
Technical archive
If anything, it's me who'd rather believe it was a lie or a joke...
A customer left me a Specialized SHIV to work on.
They'd bought it at Silvest Cycle about 11 months ago.
A friend of the bike's owner had mentioned to me about a month prior
that they'd be bringing it to my shop eventually
(the friend is one of my customers)
so I had some advance warning.
There's a problem with the Magura hydraulic caliper brake, they said.
In reality, it was far worse than just a "problem."
This SHIV is a frameset-based complete bike,
and the frameset breakdown includes frame, fork, headset,
aero bar set, seatpost, crankset, and Magura hydraulic brake.
Triathlon bikes have rulebooks for frame geometry that differ from UCI rules
and are somewhat more lenient.
So things like this tiny storage box, which appears designed solely
to block off the front triangle, aren't prohibited.
It's called a Fuel Cell.
You bolt a Fuel Cell mounting bracket into the bottle cage hole on the seat tube,
then insert the plastic lower section into it.
When it clicks in place, you can't remove it without lifting the tabs.
Then you attach the rubber upper section.
If you store items like repair tools—things you won't need while riding—in the lower part,
and food supplements in the upper part, it's quite convenient.
It's not waterproof, but both parts have drain holes at the bottom,
so water won't accumulate even in rain.
The brake is a Magura RT8.
It comes in two models—this one and the lower-spec RT6—
but the retail version of the RT8 has caliper arms colored red/black on left and right,
while the RT6 is black/black.
This RT8 being black/black is a special version specific to this frameset.
↑It works like this.
When a pod with an arrow-shaped part on its tip gets pushed out from the brake caliper...
...the arms move and the pads grip the rim.
Though the pivot points differ, it's basically like hydraulically spreading a clothespin.
Though not shown in the diagram, a return spring equivalent to the spring in a clothespin
is mounted on the back of the caliper.
The problem was that after braking, the caliper return was abnormally sluggish,
with the pod not returning fully. That's why I took it in.
This is hard to believe, but Silvest Cycle's response to this was
Wrap a rubber band around the caliper so it returns properly
That's what they said.
When the customer went to pick up the bike after the second service visit,
they were told this was the best they could do and were handed a rubber band.
This wasn't a temporary fix (though even that would be bad)—it was their final answer.
Hey everybody! If you let Silvest Cycle
service Magura brakes,
this is what you get!
I watched as the customer carefully pulled the rubber band from the Fuel Cell
and insisted, "It's essential equipment for racing, if not for training!"
I held back—thinking "this is not the time to laugh."
If a rubber band is truly essential to Magura brakes, so be it,
but with proper service, it shouldn't be necessary.
I squeezed the brake lever hard.
The brake isn't completely non-functional, but there's sloppy play
before the caliper engages—clearly air bubbles in the brake fluid.
The electronic drivetrain's satellite switch interferes with the lever squeeze being too weak. That's dangerous.
The extension bars mounted on the base bar have lateral play for some reason.
Especially the right bar—it makes a creaking sound each time you shake it.
Because it moves in a fan-like motion
↑I tightened the left and right alignment.
↑And spread them apart again.
The extension bar had
the right bar suddenly come off while riding.
The customer hasn't mentioned this to Silvest Cycle.
Afterward, the customer tightened the fastening screw on the right bar very hard,
but that actually didn't solve the problem.
As long as the bar has play, tightening the screw only
delays loosening/coming off—it doesn't actually fix it.
The fact that the tightened right bar still makes noise when moved left and right
told me what the problem was right away.
To be clear: after receiving the bike, the customer never once
adjusted or touched the bars until they came off.
The bar heights differed significantly left to right, so I asked the customer
if this was a deliberate position preference.
If it was, I'd need to remember it.
But they said, "No, not at all. Please make them equal."
This discrepancy didn't come from the original build—
it resulted from reinstalling the bar after it came off.
The extension bar mounting bracket section
↑right
↑left
It's like a single-bolt seatpost clamp where the saddle gets loose and wobbly.
The rear brake was also spongy like the front, so the customer—
losing faith in Silvest Cycle—brought it to Rabbit Street
(the Esaka Specialized Concept Store) for rear brake adjustment.
They thought "Specialized's own shop must be trustworthy."
But somehow it got swapped out for a retail-version RT8.
The customer was told beforehand that "we'll replace the brake,"
but replacing something means there's a defect worthy of replacement.
If a part is good but just needs service, swapping it out is fraud.
If they're going to replace it anyway, they should explain to the customer
what's wrong and why replacement is necessary—
but they didn't provide any such explanation.
I wanted to try servicing the original brake (the black/black RT8) first,
so I asked the customer to bring it in. But they said
the original brake was never returned by Rabbit Street.
They weren't even asked "what do you want to do with the old brake?"
Of course, the customer already paid for the red/black brake caliper and labor.
They never said they didn't want the original brake.
The only reason I can think of to replace a hydraulic caliper is
seal degradation causing brake fluid leaks.
It's been less than a year since buying the bike with the brake,
and Magura offers a 5-year oil-leak warranty, so
if there really was a defect requiring replacement, Specialized
(the framemaker) should have been consulted first—
that's what should've been said.
With online purchases, you're stuck, but this was from an authorized dealer.
Without seeing it myself, I can't say for certain, but
I suspect the original brake could've been fixed with proper service.
But even if the brake got "fixed" this way...
Squeezing the brake lever caused so much air to bubble into the bar tape.
There was no point replacing the brake caliper.
From the previous image: the pod still doesn't return, and
the brake is mounted off-center,
so the right pad is dragging on the rim continuously.
Magura's hydraulic calipers can be mounted on any road bike with a bullhorn bar.
That's probably why the rear brake is oriented
as if it'll be mounted on the seatstay brake post. Probably.
↑The pads are reversed left and right.
Probably they just took the seatstay-oriented brake orientation
and installed it as-is.
This isn't even a Magura issue anymore.
If the foolproof pad-retention screw hadn't been there,
this could've been life-threatening.
The customer hasn't touched any of this.
In fact, besides retightening the external right bar, they've adjusted nothing.
I asked about this repeatedly to establish responsibility.
After taking it in, I rode it a bit in front of the shop
and was terrified at how little braking I had.
I couldn't descend a slope—it's impossible.
Mechanical brakes would definitely work better,
and the rear brake alone, even while fully squeezed, I could still pedal forward.
To be clear: so far, I've only ridden it a bit,
shaken the bars side to side, and squeezed the brake levers—
I haven't begun any service work yet.
It's still in the condition it arrived in.
Hard to believe, but that's the truth.
I pray that divine punishment falls on scumbag shops
who work solely to extract money from customers.
I might get burned too, but if the customer's interests are restored, so be it.
One more small detail.
When you straighten the handlebar, you notice
↑this part is installed at an angle.
And it's tightened so firmly I can't bend it back by hand.
It's not a functional handlebar component, so there's no injury risk,
but the details matter.
The bottle cage bracket mounted to the saddle
...the lower fastening screw was loose and rattling.
That's the extent of the damage assessment! Now for repairs.
I removed the pad bracket on the extension bar.
The tool I'm pointing at with my four-prong picker (resembles an ice pick)
is the problematic screw.
Out it came.
The bar had been rattling constantly; there are wear marks on the bracket.
The screw's flank scraped the bracket, leaving thread marks.
That's what happened from riding.
I could've machined the original screw, but I just replaced it with a new one happily.
It's not that expensive, and
I'm keeping records in case the customer asks for the original screw back.
That way I can explain why it needed replacing.
↑Yes, that's absolutely a dig at the rear brake situation
The split washer I added below is insurance.
I've calculated the screw length including this.
A tangent: stem bolts are steel—either black or zinc-plated—not stainless.
This is because stainless has lower breaking strength than steel,
so breaking strength takes priority over rust resistance.
That said, titanium bolts are a weaker class...
It's now solidly fixed.
Even if I shake the extension bar with all my strength left and right,
there's only the slightest flex in the carbon bar itself—completely immobile.
The fan-like wiggle that was happening before was pure abnormality.
I also straightened that angled part.
The small details matter.
I also gave it a wash.
This frame has mysterious grime that won't wipe off with a finger.
Here we go.
Technical archive
Products Mentioned in This Article
- 🛒 Magura RT8 hydraulic disc brake caliper
- 🛒 Specialized Fuel Cell storage box triathlon bike
- 🛒 Magura RT6 hydraulic disc brake caliper
* Amazon affiliate links — prices may vary
Original Japanese post: のむラボ日記 #1584