A forum for owners of Yamaha TTR250 trail and enduro bikes!

Rtw1day · Veteran Member

Brake upgrades

mossproof · Super Guru

TTR front brake is well known for being an absolute b**tard to bleed properly, but even then, it might be a bit more spongy than some you've ridden. A new braided hose helps, but if you're planning on changing it all soon I would just run some fresh fluid through and see what happens - it doesn't often get changed.

The rear brake is usually plenty to lock the wheel so definitely try some fresh fluid.

I assume all the pins and pistons are clean and free moving and there's nothing contaminating the pads (wd40 being a favorite if the PO sprayed it around liberally before parking it up for a while!)

Rtw1day · Veteran Member

Yeh, so spongy the front end, I normally take off the entire brake system to bleed to ensure all the air gets out of any pockets if I replaced a line. I inspected the calliper & pins, all looked good, scuffled up the disk & looked at the pad.

i Just came off a dirt bike with a 300mm front disk, so it’s definitely not the best at stopping

TTRfan · Super Guru

I can lock up my front wheel on tarmac if I pull the lever hard enough wink

A braided cable certainly sharpens up the brake but, for trail riding in the UK, the last thing you want is a sharp front stopper when riding on loose and muddy surfaces. I much prefer a gentle progressive brake.

Just my point of view biggrin

Brian

Jeff B · Senior Member

Well said Brian. I totally agree. Yamaha designed this bike as a "soft" enduro bike. It is awesome as a light, woods and single track trails bike but still very stable and capable for street riding. Is it perfect? Of course not, but it is great at what it was designed for. Even though it was designed to be soft, it can be adjusted for user preference. My only tweak for the front forks was to rebuild them and use 10w fork oil and soften the compression adjustment to 14 clicks out. The steering is responsive and no longer feels vague. With the rear shock and suspension rebuild, the bike feels very balanced for moderate speed technical trail riding now. I also find the rear brake too sensitive for soft dirt and use engine braking instead.

There are plenty of other bikes available for those who want something more aggressive. My DRZ400S has very crisp front brakes which are great on the tarmac but are difficult to not lock up in soft dirt and mud. I prefer my DRZ400S on the tarmac but prefer the TTR250 offroad.

mossproof · Super Guru

Rtw1day wrote:
Yeh, so spongy the front end, I normally take off the entire brake system to bleed to ensure all the air gets out of any pockets if I replaced a line. I inspected the calliper & pins, all looked good, scuffled up the disk & looked at the pad.

Yep. hang the master cylinder up so there's no bend in the hose and the highest point is the reservoir. Then squeeze the caliper piston back in to force the last bubbles out.

Alternatively it's finger exercises wink Start by squeezing a tennis ball. When that gets too easy move up to a baseball/cricket ball (depending on your nationality!), and when that's mastered you can finish on a snooker ball

Or just ride faster. Enzo Ferrari didn't believe in efficient brakes smile

Rtw1day · Veteran Member

Any ideas on what the weak point is on the front brakes?

I’m going to fit a yz250f master I have so I can run the gytr lever that I’m used to & love, & install a braded line, maybe new pads

Any thoughts on if there will be a noticeable change? I will have to check the cylinder size to see if they are the same

mossproof · Super Guru

Smaller cylinder = more pressure for the same force applied, I think, = better brakes. (Somebody check my workings!!)
If the banjo bolt is the same, you could experiment with all sorts of master cylinders.
New sintered pads would have been the first thing I'd change...

Rtw1day · Veteran Member

mossproof wrote:
Smaller cylinder = more pressure for the same force applied, I think, = better brakes. (Somebody check my workings!!)
If the banjo bolt is the same, you could experiment with all sorts of master cylinders.
New sintered pads would have been the first thing I'd change...

I believe your right, smaller master will provide more pressure at the requirement of a longer range,

i believe the YZ masters are the standard 13mm, not sure on the TTR

TerryK · Super Guru

I find the brakes are good & only the traction between the tyre & surface the issue, too strong & all you do is lock up but in saying that my WRR is a little better. You may want to check the brake pads, if the brake material is hard or the disc gone hard it will reduce the friction.

Rtw1day · Veteran Member

I just find them very spongey, & require all fingers & the full range of the lever to brake hard, all the way to the bar sometimes, & I’ve adjusted the lever out as far as it will allow, I roughed up the disk to shave off some of the pads but that made little to no difference

TerryK · Super Guru

Rtw1day wrote:
I just find them very spongey, & require all fingers & the full range of the lever to brake hard, all the way to the bar sometimes, & I’ve adjusted the lever out as far as it will allow, I roughed up the disk to shave off some of the pads but that made little to no difference

Reverse bleed the brakes, push fluid into the caliper & up to the res.

I use short levers ( 2 fingers ) & find them good, can lock up if I wish

TbirdX · Veteran Member

I've always found the brakes on mine to be very good. I'd go so far to say excellent really.

It's a very personal thing of course but I can dive the front forks under hard braking without locking up (I've never tried to actually lock the front for obvious reasons!!) and can lock the rear at will.