Help! Front/rear brake confusion

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
I've had a 2021/2022 Scott Strike 920 for 1/2 year now and I'm having mental trouble with the brakes. I'm a lifelong motorcyclist and have always swapped the brakes on all my bikes so the right brake was my front brake, so it matched the way my motorcycles braked. No problems.

When I brought my Strike 920 home i was a little dismayed because it looked like the brakes are not designed to be able to flip them over so I can switch sides. I thought, "no worries, I will just learn to brake with reversed controls, no sweat!" However, after six months I still can't keep the front and rear brakes sorted in my head when I need to use them. It's driving me crazy actually and is dangerous. I might just stick with it until I get it down except for the fact that after 50 years riding motorcycles and bicycles with the front brake on the right, this is going to take a long time and then, when I finally master the new brake setup, it's going to cause problems when I'm riding my motorcycles. So, I've come to the conclusion I need to swap them so the front brake is on the right. I can't believe how hard it is to make such a simple mental adjustment, but right when I think I'm getting it, and I need to brake suddenly, yep, I'm confused all over again - it's really awful and a little scary.

I think the brakes are Shimano BR-MT520 4 Piston (not sure if that also identifies the master cylinders too or not). I've never had an MTB with internally routed brake lines, so I don't know what's involved in switching these around and whether I need to buy new components to make it work or not. The eMTB shortage caused me to buy the bike from a shop hundreds of miles away and I don't really want to take it back there. I'm hoping I can do it myself.
 

militantmandy

Well-known member
Jan 18, 2022
399
369
Tweed Valley, Scotland
Forgive me if I am being a moron. But in my head, you would just disconnect hoses from levers and swap over. They may need bled after though. My Decoy came set up front brake left (mad considering it came from YT Mill in UK), but with codes you can just flip them. I eventually rerouted the hoses to tidy up. It was a bit fiddly, but not too bad really.
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
I'm hoping that's the case. I know how to bleed motorcycle brakes but I've never worked on MTB hydraulic brakes. My previous MTB bike was the first one with hydraulics and I replaced it with the Scott eMTB before I needed to service the brakes. It was a Specialized S-Works without internal routing, and I just flipped the handlebar units over and that was that!
 

Tim1023

Well-known member
Aug 25, 2020
660
584
Hamburg, Germany
I've got the standard Shimano SLX M7120 four piston brakes that came with my comp. The shop swapped the lines over when I bought the bike. Just a five minute job, they said. Didn't cost me anything. Didn't ask further questions.

"Moto" is standard in the UK and what I was used to, but it's the other way round here in Germany. The use of brakes, especially in an emergency, is so instinctive, I didn't want to have to relearn.
 

flash

E*POWAH Elite World Champion
Patreon
Nov 24, 2018
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Wamberal, NSW Australia
I'm hoping that's the case. I know how to bleed motorcycle brakes but I've never worked on MTB hydraulic brakes. My previous MTB bike was the first one with hydraulics and I replaced it with the Scott eMTB before I needed to service the brakes. It was a Specialized S-Works without internal routing, and I just flipped the handlebar units over and that was that!

Yep. It's easy. You'll need Shimano mineral oil, allen keys (2.5mm), a small shifting spanner, a bleed kit (for shimano) and ten minutes. Just be very careful not to contaminate the pads/ rotors. You should only need to bleed the lever end though so it should be OK to leave the pads in. Just remember the front pads and rotor are directly below the levers!!. Other wise a bike shop can do it for a half hour service fee.

Gordon
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
I've got the standard Shimano SLX M7120 four piston brakes that came with my comp. The shop swapped the lines over when I bought the bike. Just a five minute job, they said. Didn't cost me anything. Didn't ask further questions.

"Moto" is standard in the UK and what I was used to, but it's the other way round here in Germany. The use of brakes, especially in an emergency, is so instinctive, I didn't want to have to relearn.

I can't imagine what the justification is for any company or country to standardize the front brake on the left on a bicycle considering motorcycles in all countries have standardized it on the right. Who can justify this in a way that makes more sense than "it's just the way it's been for years, it's convention". That doesn't fly with me considering that motorcycles are very often ridden by the same parts of the population that ride bikes. Even at age 15, when I got my first motorcycle, I knew I would have to switch my bicycle brakes to match (because the motorcycle can't be switched due to the need for a clutch and throttle.

I dunno, maybe most bicycle riders just squeeze both brakes at the same time and if they hear skidding noises they just release both of them and try again? In other words, they don't worry which is the front and which is the rear? You know, a car has only one brake control for front and rear, LOL! On a motorcycle it would be unthinkable to not know which brake the right lever operated.

Back in the day of cable operated brakes, with the cables not integrated in the frame, it was no big deal to flip them over. Even then, I wondered why bicycles didn't follow the motorcycle convention.
 

Tim1023

Well-known member
Aug 25, 2020
660
584
Hamburg, Germany
I can't imagine what the justification is for any company or country to standardize the front brake on the left on a bicycle considering motorcycles in all countries have standardized it on the right. Who can justify this in a way that makes more sense than "it's just the way it's been for years, it's convention". That doesn't fly with me considering that motorcycles are very often ridden by the same parts of the population that ride bikes. Even at age 15, when I got my first motorcycle, I knew I would have to switch my bicycle brakes to match (because the motorcycle can't be switched due to the need for a clutch and throttle.

I dunno, maybe most bicycle riders just squeeze both brakes at the same time and if they hear skidding noises they just release both of them and try again? In other words, they don't worry which is the front and which is the rear? You know, a car has only one brake control for front and rear, LOL! On a motorcycle it would be unthinkable to not know which brake the right lever operated.

Back in the day of cable operated brakes, with the cables not integrated in the frame, it was no big deal to flip them over. Even then, I wondered why bicycles didn't follow the motorcycle convention.

Yup. I find it bizarre myself. But the brain is an amazing thing. It seems to understand that different behaviours are needed in different circumstances. Have you ever noticed that the number pad on your phone is upside down compared to that on your computer keyboard and calculator? It's not jarring at all to move between them. I guess riders in afflicted countries have a similar brain setting for riding with / without peddling.

Also re bike brakes in Germany: the majority of "normal" bikes that people ride around on, especially as kids use reverse pedal brakes. Fucking lethal if you're not used to it. Simply horrible.
 

MOTO13

Active member
Sep 16, 2020
335
381
Elkhorn, Wi
I rode and raced MX for decades and I hate the front brake on my right hand on bicycles. My Magura's were that way and I simply swapped the hoses. To me the rear brake being on the right makes so much more sense when riding a bicycle. It's like the rear brake on a motorcycle being on my right foot. Just makes more sense to me to brake that way. If I ride an emtb with a right front brake...I'm probably going to crash. Maybe I simply rode bicycles enough over my life to have it never be an issue with the rear brake on the right.
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
Yup. I find it bizarre myself. But the brain is an amazing thing. It seems to understand that different behaviours are needed in different circumstances. Have you ever noticed that the number pad on your phone is upside down compared to that on your computer keyboard and calculator? It's not jarring at all to move between them. I guess riders in afflicted countries have a similar brain setting for riding with / without peddling.

Also re bike brakes in Germany: the majority of "normal" bikes that people ride around on, especially as kids use reverse pedal brakes. Fucking lethal if you're not used to it. Simply horrible.

I assume these kids bikes also have a front hand lever operated brake these days? My first kids bikes had no front brake, but I would consider that child endangerment now.

After a lifetime of motorcycling (and I still ride motorcycles on the road), as well as having ALWAYS switched my front bicycle brakes to the right-hand lever, I am not finding the brain adept in reconfiguring, pedal powered or not. It's the same reflexive reaction regardless of equipment. I thought I could switch back and forth (and I gave it a very serious effort) but I can't, at least not without reverting to instinct in the heat of the moment when I need to grab either or both brakes. It's become hard-wired into my reactions and I've almost crashed at speed a couple of times because of it. At age 58, that is not going to end as well as it would have at 35 or 40 years old.
 
Last edited:

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
I rode and raced MX for decades and I hate the front brake on my right hand on bicycles. My Magura's were that way and I simply swapped the hoses. To me the rear brake being on the right makes so much more sense when riding a bicycle. It's like the rear brake on a motorcycle being on my right foot. Just makes more sense to me to brake that way. If I ride an emtb with a right front brake...I'm probably going to crash. Maybe I simply rode bicycles enough over my life to have it never be an issue with the rear brake on the right.

Are you left-handed? Or is front brake on the left simply what you learned first?

The front brake has the most stopping power, by far (due to forward weight shift) and also requires the best modulation since things happen more quickly when you lock up the front tire. So, I can understand why a left-handed person might want the front brake on the hand that has the most dexterity and control.
 

MOTO13

Active member
Sep 16, 2020
335
381
Elkhorn, Wi
I use my rear brake a bit more than my front when riding my emtbs. I kind of trail brake with both brakes in turns, but usually use my rear brake to assist in fast turns, like a MX bike...kind of skidding the rear at times. I am not left handed but I am fairly ambidextrous, but I never liked a right hand front brake on a bicycle for some odd reason. On a MX bike, it's natural to have a front right brake. I can switch from emtb to MX bike with no problem. IDK, in my mind, the way I ride, it just never made sense on a bicycle to have a right front brake.
 

RickBullotta

E*POWAH Elite World Champion
Jun 5, 2019
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USA
Yep. It's easy. You'll need Shimano mineral oil, allen keys (2.5mm), a small shifting spanner, a bleed kit (for shimano) and ten minutes. Just be very careful not to contaminate the pads/ rotors. You should only need to bleed the lever end though so it should be OK to leave the pads in. Just remember the front pads and rotor are directly below the levers!!. Other wise a bike shop can do it for a half hour service fee.

Gordon

I would also replace the barbs/olives if you're swapping hoses. It *probably* won't leak if you don't...but it could.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
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Chichester, W.Sussex, UK
I would also replace the barbs/olives if you're swapping hoses. It *probably* won't leak if you don't...but it could.

I took the not-so-nice Shimano MT420 levers off my Rail and replaced them with my very-nice Shimano M6100 levers no probs. Didn't replace any olives, no leaks, simply did a top bleed and all good. If they don't leak no point in replacing anything. (y)
 

flash

E*POWAH Elite World Champion
Patreon
Nov 24, 2018
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Wamberal, NSW Australia
I would also replace the barbs/olives if you're swapping hoses. It *probably* won't leak if you don't...but it could.

For a straight swap, I wouldn't bother. It's rather unlikely unless you damage something when the levers are from the same Shimano family and brand new. I've not had any problems when doing this on several bikes. I've not heard of bike shops having issues and here as our brakes are Moto as standard we do it quite often.

If doing this on old systems or with upgrades outside the same group, then yes, I think it's advisable.

Gordon
 
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Jurassic

Active member
Subscriber
Jul 22, 2022
236
243
Helensburgh, Scotland.
I've detached hoses at the lever end on Shimano brakes and not even had to bleed them, they've been fine (whilst refitting brakes to a new frame with internal cable routing). Just be careful and try to make sure that the hoses don't drop down when they're uncoupled. Also definitely don't pull the levers until you've hooked them up again!
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
Thanks for all the help and tips to give me the confidence I need to tackle this myself. I must say, you all made it sound very easy. I've ordered a Shimano brake bleeder kit and hopefully I can find some good how to guides with regard to disconnecting/reconnecting the hydraulic lines.
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
To do it correctly there is more to the story. You need to reroute the rear brake hose to exit the frame on the left side of the bike.

Thanks, yeah, I surmised that. I keep looking at it, think about diving in, and then I say, "Nah, I think I'll go for another ride instead!"

I get it that it's not too involved but now I'm thinking I want to trim three or four inches off the lines as they are really long from Scott. Is there any reason to leave a bit of extra (besides the obvious avoiding of strain from turning the bars)? And do I really need the special line cutting tool or can a careful surgeon do it with a sharp utility blade?
 

TurboJoe

Member
Jul 11, 2020
21
11
San Jose, CA
Utility blade works find, just cut square. I would not cut until you reroute. It was not that big of job on my 2020 Turbo Levo SL. Your bike is sold in places that require the front brake to be on the right, correct? So it must be possible.
 
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MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
Utility blade works find, just cut square. I would not cut until you reroute. It was not that big of job on my 2020 Turbo Levo SL. Your bike is sold in places that require the front brake to be on the right, correct? So it must be possible.

Yes, Scott's are made in Switzerland which I think must be front brake/right since it's Germanic? In any case, I'm sure they are sold in Germany too. But what do you mean "it must be possible"? Is it even in doubt that the hydraulic lines can be swapped? Maybe you mean possible to re-route? Yes, it looks like that's not a problem.
 

TurboJoe

Member
Jul 11, 2020
21
11
San Jose, CA
Utility blade works find, just cut square. I would not cut until you reroute. It was not that big of job on my 2020 Turbo Levo SL. Your bike is sold in places that require the front brake to be on the right, correct? So it must be possible.
Have you removed the battery
Yes, Scott's are made in Switzerland which I think must be front brake/right since it's Germanic? In any case, I'm sure they are sold in Germany too. But what do you mean "it must be possible"? Is it even in doubt that the hydraulic lines can be swapped? Maybe you mean possible to re-route? Yes, it looks like that's not a problem.
Yes, reroute. Looks like if you remove the battery you would be able to reroute. On my SL it was remove the TCU for access.
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
It is possible the front brake hose will be too short to put to the right side.
Fortunately, it's a cheap item.
 

Pdoz

E*POWAH Elite World Champion
Feb 16, 2019
1,112
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Maffra Victoria Australia
I can't imagine what the justification is for any company or country to standardize the front brake on the left on a bicycle considering motorcycles in all countries have standardized it on the right.

Front brake on left is a weird driving on the. wrong side of the road thing - enlightened countries have the front brake on the right. Would you like a picture of my daughters scott genius to see how MT520's and the scott suspension cables are routed in a normal country?
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
It is possible the front brake hose will be too short to put to the right side.
Fortunately, it's a cheap item.

I'll probably be cutting both of them since Scott made them so long. I suspect they made them extra-long to accommodate buyers who immediately wanted to install a longer and taller stem and/or really wide bars. But I can't imagine anyone needing anywhere near as much hose as they came with. And, yes, I do understand they need plenty of slack, it's just that there is more than enough hose. And I have an X-Large frame so it's kinda odd.
 

MountainBoy

Active member
Mar 4, 2022
231
212
Washington State, USA
Front brake on left is a weird driving on the. wrong side of the road thing - enlightened countries have the front brake on the right. Would you like a picture of my daughters scott genius to see how MT520's and the scott suspension cables are routed in a normal country?

That's super helpful to offer a photo but I think it's pretty straight-forward looking so I should be OK. Currently, I have three cables going into the left side of the frame (one of them is the rear brake from the right handlebar) and two going into the right side of the frame. When I swap the rear brake hose to the left bar I'll have three entering the right side of the frame and two entering the left.

There are little cable guides sitting flush in the frame that guide the cables into the frame and clamp them. It looks like I just need to swap the left for the right so the three cable guide is on the right side of the frame and the cable guide grooves should still be orientated properly after flipping them.

Thanks for offering though!
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
I'll probably be cutting both of them since Scott made them so long. I suspect they made them extra-long to accommodate buyers who ...
My left-front was much too long too.
I suspect it was laziness, cutting the tube is an extra step in assembling :)
 

Pdoz

E*POWAH Elite World Champion
Feb 16, 2019
1,112
1,206
Maffra Victoria Australia
There are little cable guides sitting flush in the frame that guide the cables into the frame and clamp them. It looks like I just need to swap the left for the right so the three cable guide is on the right side of the frame and the cable guide grooves should still be orientated properly after flipping them.

Thanks for offering though!

It looks like scott just leave the back brake cable on the left and the spaghetti system sorts things out

6B3A0514-B50C-4F81-8427-6B61792495F6.jpeg
E614295D-B426-4D27-A567-4965DF51780B.jpeg
 

Pdoz

E*POWAH Elite World Champion
Feb 16, 2019
1,112
1,206
Maffra Victoria Australia
That doesn't look very sorted. isn't it up to the local bike shop to set up the lines?

It looks messy but works, none of the lines catch in use, nothing rattles or rubs, and she isn't concerned by aesthetics.

We bought the bike from a large franchise that has zero pride in quality control. I always intended to tidy up the mess, but it's 3 years later and I have 3 kids- so a fleet of mountain bikes / dirt bikes / water craft and taxi duties.....

IF I was to spend shed time , I'd remove the cable to the forks, shorten the dropper cable, and possibly route the rear brake line on the right -but life is short
 

BeBiker

Active member
Aug 26, 2020
700
421
Belgium
If it were 1 or 2 cables being somewhat weird, it should already been done.
But this is such a mess that you don' even start :)
 

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