OP
@rusty_rope avatar
UTC

Addicted
Vespa GTS 300 Super
Joined: UTC
Posts: 916
Location: London, UK
 
Addicted
@rusty_rope avatar
Vespa GTS 300 Super
Joined: UTC
Posts: 916
Location: London, UK
UTC quote
I need some help please! I've finally realised that I could do with some better brakes, but with my fly being relatively new on the market it's hard knowing what fits and what don't.

Ideally I just want to upgrade the callipers and not the hydraulic lines (is that even possible?)

Some pictures of how the stock ones are situated:
Rear Looks pretty tight
Rear Looks pretty tight
Front
Front
@dougl avatar
UTC

El Macho
0/0
Joined: UTC
Posts: 9052
Location: Porto 4050-570
 
El Macho
@dougl avatar
0/0
Joined: UTC
Posts: 9052
Location: Porto 4050-570
UTC quote
Probably not really possible, as you are unlikely to find any upgrade parts. Just an opinion though, I could be quite wrong. More than likely, though, is if you need better brakes, then you need to change your scooter... It's only when you get to big bikes, that you find common parts, where upgrades are more possible. Brembo make a kit for the GTS I believe.
@willie_b avatar
UTC

Ossessionato
'20 300GTS Super Tec '09 250 GTSie '75 Rally 200 '79 P200 '09 Stella 221
Joined: UTC
Posts: 2610
Location: Midway, Kentucky
 
Ossessionato
@willie_b avatar
'20 300GTS Super Tec '09 250 GTSie '75 Rally 200 '79 P200 '09 Stella 221
Joined: UTC
Posts: 2610
Location: Midway, Kentucky
UTC quote
Upgrading to Sintered pads will enhance the capabilities of your scooters braking. It's probably doubtful that anyone is offering upgraded braking components, but I would check to see if Stage 6 offers anything.
@super-fly avatar
UTC

Molto Verboso
Vespa GTS300ie
Joined: UTC
Posts: 1291
Location: essex united kingdom
 
Molto Verboso
@super-fly avatar
Vespa GTS300ie
Joined: UTC
Posts: 1291
Location: essex united kingdom
UTC quote
Whats the problem with the brakes
My old fly125 had the same front calipar and a rear drum brake & that was fine .

The same front & rear brake calipars where fitted to my gilera runner st200 and the brakes worked real well on that

Also both calipars are fitted to most of the piaggio/vespa/gilera/derbi range of scooters including the gts300
@socalguy avatar
UTC

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
 
bodgemaster
@socalguy avatar
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
UTC quote
The stock brakes on our Fly are very respectable and it only has the disc in front (rear is drum). It's a relatively light scooter - the brakes have no trouble hauling it to a stop. If you want to do some handling mods, consider upgrading to Biturbo shocks.
@oopsclunkthud avatar
UTC

Banned
3:5
Joined: UTC
Posts: 9053
Location: San Francisco
 
Banned
@oopsclunkthud avatar
3:5
Joined: UTC
Posts: 9053
Location: San Francisco
UTC quote
I would not try and improve the rear in any way at all.

The front caliper seems to be the same as the GTS but the disk looks smaller like the LX. Depending on the master cylinder used for the front there may be an easy way to add quite a bit more force to the front.

The GTS uses a 12.7mm master, if the fly uses that then the braking force would be about the same as the GTS. Assuming that's all the case switching to the LX master (11mm) would increase the stopping force by about 30%.
@dooglas avatar
UTC

Veni, Vidi, Posti
GTS 300ABS, Buddy 125, Buddy Kick 125
Joined: UTC
Posts: 13508
Location: Oregon City, OR
 
Veni, Vidi, Posti
@dooglas avatar
GTS 300ABS, Buddy 125, Buddy Kick 125
Joined: UTC
Posts: 13508
Location: Oregon City, OR
UTC quote
super-fly wrote:
Whats the problem with the brakes
I'm with "super-fly". For a bike of that size, weight, and power - what is wrong with the front brakes?
@socalguy avatar
UTC

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
 
bodgemaster
@socalguy avatar
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
UTC quote
oopsclunkthud wrote:
I would not try and improve the rear in any way at all.

The front caliper seems to be the same as the GTS but the disk looks smaller like the LX. Depending on the master cylinder used for the front there may be an easy way to add quite a bit more force to the front.

The GTS uses a 12.7mm master, if the fly uses that then the braking force would be about the same as the GTS. Assuming that's all the case switching to the LX master (11mm) would increase the stopping force by about 30%.
That is very interesting info. If the LX master does have a smaller piston - assuming it will fit under the Fly's headset without interfering with anything - switching to it would be a great mod.
@madison_sully avatar
UTC

Veni, Vidi, Posti
MP3 500, GTS 250 (both 2008 MY), 2013 Piaggio BV 350, 2014 Can Am Spyder RT
Joined: UTC
Posts: 7666
Location: Madison, Wisconsin
 
Veni, Vidi, Posti
@madison_sully avatar
MP3 500, GTS 250 (both 2008 MY), 2013 Piaggio BV 350, 2014 Can Am Spyder RT
Joined: UTC
Posts: 7666
Location: Madison, Wisconsin
UTC quote
Based on the pictures, it looks like you brake harder with the rear than the front brakes. You can see machining marks on the front rotor still, where the pad makes contact. The rear rotor shows no such machining marks.

Are you left handed by chance?

I would think moving to sintered pads for the fronts may help, but only after bedding them in to the rotor. Beyond that, swap front and rear hydraulics if you are indeed stronger in your left hand. Gripping the brake lever more out toward the end would help increase stopping force too.

If none of these work or are unappealing, the smaller diameter piston would increase stopping force, but keep an eye out for squishy brakes; that smaller piston will displace less brake oil, so your caliper will have less throw and could cause the brake lever to bottom out on the handlebar.
@super-fly avatar
UTC

Molto Verboso
Vespa GTS300ie
Joined: UTC
Posts: 1291
Location: essex united kingdom
 
Molto Verboso
@super-fly avatar
Vespa GTS300ie
Joined: UTC
Posts: 1291
Location: essex united kingdom
UTC quote
If you want to spend some money on improving safety I would replace the factory fit cheap CST ( cheng sing tyres ) with some Michelin city grips
OP
@rusty_rope avatar
UTC

Addicted
Vespa GTS 300 Super
Joined: UTC
Posts: 916
Location: London, UK
 
Addicted
@rusty_rope avatar
Vespa GTS 300 Super
Joined: UTC
Posts: 916
Location: London, UK
UTC quote
Madison Sully wrote:
Based on the pictures, it looks like you brake harder with the rear than the front brakes. You can see machining marks on the front rotor still, where the pad makes contact. The rear rotor shows no such machining marks.

Are you left handed by chance?

I would think moving to sintered pads for the fronts may help, but only after bedding them in to the rotor. Beyond that, swap front and rear hydraulics if you are indeed stronger in your left hand. Gripping the brake lever more out toward the end would help increase stopping force too.

If none of these work or are unappealing, the smaller diameter piston would increase stopping force, but keep an eye out for squishy brakes; that smaller piston will displace less brake oil, so your caliper will have less throw and could cause the brake lever to bottom out on the handlebar.
Wha? emoticon I am in fact left handed. Before I got my rear pads changed I was only ever using rear because the CBT centre drummed it into me that front brakes are very dangerous so I was scared of using them.

Since the pad change (few weeks ago) I finally realised that I needed to change my braking, And now I use majority of my braking with the front.

The main reason why I'm asking for calliper upgrades is because both levers are loose and have a lot of travel (spongy - yet i've bled both lines with 500ml in each just to make sure there's no air), I prefer levers solid and more responsive - is this a calliper upgrade or down to something else?

Thanks for the suggestion for sintered pads, i'll get them asap along with a torque wrench.

Cheers guys!
@baudler avatar
UTC

Foiled
300 - 'Red' Primavera
Joined: UTC
Posts: 1321
Location: Rock Hill, SC
 
Foiled
@baudler avatar
300 - 'Red' Primavera
Joined: UTC
Posts: 1321
Location: Rock Hill, SC
UTC quote
Polini makes a disc brake. Several brands make rotors. Upgrade the brake line as well. SIP has all these parts on their website.
@gtdespatchcourier avatar
UTC

Molto Verboso
GTS 300ie
Joined: UTC
Posts: 1687
Location: Sunshine Coast, Australia
 
Molto Verboso
@gtdespatchcourier avatar
GTS 300ie
Joined: UTC
Posts: 1687
Location: Sunshine Coast, Australia
UTC quote
Giving your brakes a good clean can improve stopping power by up to 11%.
@dooglas avatar
UTC

Veni, Vidi, Posti
GTS 300ABS, Buddy 125, Buddy Kick 125
Joined: UTC
Posts: 13508
Location: Oregon City, OR
 
Veni, Vidi, Posti
@dooglas avatar
GTS 300ABS, Buddy 125, Buddy Kick 125
Joined: UTC
Posts: 13508
Location: Oregon City, OR
UTC quote
Rusty rope wrote:
Before I got my rear pads changed I was only ever using rear because the CBT centre drummed it into me that front brakes are very dangerous so I was scared of using them.
Normal braking is about 60% front wheel, 40% rear wheel. Braking with only the rear wheel is very likely to result in a low side fall. The front brake is your friend if you really expect to stop.
Rusty rope wrote:
The main reason why I'm asking for calliper upgrades is because both levers are loose and have a lot of travel (spongy - yet i've bled both lines with 500ml in each just to make sure there's no air), I prefer levers solid and more responsive - is this a calliper upgrade or down to something else?
If both your brakes feel "spongy" I'd say the first step is still to be sure you have no air in the brake lines. How much experience do you have at servicing brakes? If you are new to this and don't have the proper equipment such as a miti-vac brake bleeder (vacuum pump brake bleeding tool), I'd seek help with bleeding before considering a major rebuild or replacement of the brake calipers. Sintered pads won't hurt of course, but you still need to be sure the lines are clear of air first.
DoubleGood Design banner

Modern Vespa is the premier site for modern Vespa and Piaggio scooters. Vespa GTS300, GTS250, GTV, GT200, LX150, LXS, ET4, ET2, MP3, Fuoco, Elettrica and more.

Buy Me A Coffee
 

Shop on Amazon with Modern Vespa

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com


All Content Copyright 2005-2025 by Modern Vespa.
All Rights Reserved.


[ Time: 0.0240s ][ Queries: 4 (0.0171s) ][ live ][ 327 ][ ThingOne ]