Topic: Braking Question (1981 Honda CB650C)

[F16Viper68]

I was able to take my first ride on a Honda CB650C I've been working on for the past three months (link in signature).  I have a question about the front brakes.  During my test rides I wasn't very impressed with the feel/effectiveness of the brakes.  They don't seem to be biting nor can I come close to locking up the front tire. I know this is bad but you at least know you're getting a good bite.

I've rebuilt the calipers, new EBC pads, cleaned the rotors, bleed with a Mighty Vac, and burned off the crap on the rotors by riding the brake a bit.  Standard stuff. 

The master cylinder is from a 2008 V-Strom so I'm wondering if maybe it's not getting enough pressure down to the calipers?  I can easily squeeze the brake lever to the throttle grip.   

Maybe I'm expecting too much from a thirty year old bike?

Dave...

[grcamna2]

Did you do a search here for that chart I saw about the MC to caliper ratio ?...I've seen it here when other folks had brake questions a few weeks ago.. do you have S.S. braided brake lines ? & sometimes it takes just a bit of time to bleed all the air bubbles(the small bubbles rise through the small bleed hole in the MC)from the system.

[RustyStuff]

I was able to take my first ride on a Honda CB650C I've been working on for the past three months (link in signature).  I have a question about the front brakes.  During my test rides I wasn't very impressed with the feel/effectiveness of the brakes.  They don't seem to be biting nor can I come close to locking up the front tire. I know this is bad but you at least know you're getting a good bite.

I've rebuilt the calipers, new EBC pads, cleaned the rotors, bleed with a Mighty Vac, and burned off the crap on the rotors by riding the brake a bit.  Standard stuff. 

The master cylinder is from a 2008 V-Strom so I'm wondering if maybe it's not getting enough pressure down to the calipers?  I can easily squeeze the brake lever to the throttle grip.   

Maybe I'm expecting too much from a thirty year old bike?

Dave...

Something is wrong with them. On the stockers on my bike, you cant easly squeeze the lever enough to touch the grip.

[F16Viper68]

Did you do a search here for that chart I saw about the MC to caliper ratio ?...I've seen it here when other folks had brake questions a few weeks ago.. do you have S.S. braided brake lines ? & sometimes it takes just a bit of time to bleed all the air bubbles(the small bubbles rise through the small bleed hole in the MC)from the system.

Yeah, I've been wondering if the V-Strom master cylinder is the root cause of my issues.  It could be air, maybe I'll order a bleeder bolt for the master cylinder.  Can't hurt.

Dave...

[F16Viper68]

I was able to take my first ride on a Honda CB650C I've been working on for the past three months (link in signature).  I have a question about the front brakes.  During my test rides I wasn't very impressed with the feel/effectiveness of the brakes.  They don't seem to be biting nor can I come close to locking up the front tire. I know this is bad but you at least know you're getting a good bite.

I've rebuilt the calipers, new EBC pads, cleaned the rotors, bleed with a Mighty Vac, and burned off the crap on the rotors by riding the brake a bit.  Standard stuff. 

The master cylinder is from a 2008 V-Strom so I'm wondering if maybe it's not getting enough pressure down to the calipers?  I can easily squeeze the brake lever to the throttle grip.   

Maybe I'm expecting too much from a thirty year old bike?

Dave...

Something is wrong with them. On the stockers on my bike, you cant easly squeeze the lever enough to touch the grip.

Ok, thanks for the input.  I have the OEM master cylinder 95% rebuilt.  I just need to find new screws to hold the reservoir on.  You'd think they'd been easy to find...not quite.   

[RustyStuff]

I was able to take my first ride on a Honda CB650C I've been working on for the past three months (link in signature).  I have a question about the front brakes.  During my test rides I wasn't very impressed with the feel/effectiveness of the brakes.  They don't seem to be biting nor can I come close to locking up the front tire. I know this is bad but you at least know you're getting a good bite.

I've rebuilt the calipers, new EBC pads, cleaned the rotors, bleed with a Mighty Vac, and burned off the crap on the rotors by riding the brake a bit.  Standard stuff. 

The master cylinder is from a 2008 V-Strom so I'm wondering if maybe it's not getting enough pressure down to the calipers?  I can easily squeeze the brake lever to the throttle grip.   

Maybe I'm expecting too much from a thirty year old bike?

Dave...

Something is wrong with them. On the stockers on my bike, you cant easly squeeze the lever enough to touch the grip.

Ok, thanks for the input.  I have the OEM master cylinder 95% rebuilt.  I just need to find new screws to hold the reservoir on.  You'd think they'd been easy to find...not quite.

Slightly off topic, but did you use a Honda Rebuild kit, and if you did, was the Secondary piston installed, or if not, how did you do it. Trying to install mine, the Little, flower shaped spring on the front of the metal piston, cut the Rubber piston, Hopeing it will work, because I don't want to have to buy another $$ kit.

[F16Viper68]

I was able to take my first ride on a Honda CB650C I've been working on for the past three months (link in signature).  I have a question about the front brakes.  During my test rides I wasn't very impressed with the feel/effectiveness of the brakes.  They don't seem to be biting nor can I come close to locking up the front tire. I know this is bad but you at least know you're getting a good bite.

I've rebuilt the calipers, new EBC pads, cleaned the rotors, bleed with a Mighty Vac, and burned off the crap on the rotors by riding the brake a bit.  Standard stuff. 

The master cylinder is from a 2008 V-Strom so I'm wondering if maybe it's not getting enough pressure down to the calipers?  I can easily squeeze the brake lever to the throttle grip.   

Maybe I'm expecting too much from a thirty year old bike?

Dave...

Something is wrong with them. On the stockers on my bike, you cant easly squeeze the lever enough to touch the grip.

Ok, thanks for the input.  I have the OEM master cylinder 95% rebuilt.  I just need to find new screws to hold the reservoir on.  You'd think they'd been easy to find...not quite.

Slightly off topic, but did you use a Honda Rebuild kit, and if you did, was the Secondary piston installed, or if not, how did you do it. Trying to install mine, the Little, flower shaped spring on the front of the metal piston, cut the Rubber piston, Hopeing it will work, because I don't want to have to buy another $$ kit.

Sorry I haven't gotten that far, I have the kit (non-Honda) but I haven't installed it yet. I was really hoping the V-Strom MC would work.   

Below is a picture of the guts of my master cylinder.  I'm not sure what you mean by secondary piston.  Maybe yours is different. 

[RustyStuff]

Ah, it appears that Mine has a completely different design for the Master Cyl, Honda sure changed alot in 1 year.

[cb650]

Yes the 81 custom and 82 sc had dual disks so the M/C is diff from all other 650"s.
I would think the v storm would work but might just go with the original.

[F16Viper68]

Yes the 81 custom and 82 sc had dual disks so the M/C is diff from all other 650"s.
I would think the v storm would work but might just go with the original.

I was wondering if the dual disc had prompted a MC change.  Thanks for confirming. 

You'd think the V-Strom MC that was designed for two calipers/four pistons would be able to handle two calipers/two pistons.  Crap that thing was handling eight pistons (upgraded the calipers on my V-Strom) for a while but I felt it was a bit mushy so I upgraded the MC on my V-Storm which is why I had the OEM laying around.

I'll see if I can find the screws up town and get the original MC installed.

Dave...

[grcamna2]

I have had a struggle finding those size screws also; found the thread pitch & screw diameter alright but couldn't find ones locally that were long enough.

[F16Viper68]

I have had a struggle finding those size screws also; found the thread pitch & screw diameter alright but couldn't find ones locally that were long enough.

I gave up and ordered them from BikeBandit.  I needed a new horn so I just threw those in there too.

Dave...