wake no brake

[freelancethink]

83 xs400rk with 7K+ miles

i am unable to get the front wheel to lock up entirely and go into a skid. the bike has a single disc brake up front so getting the wheel to lock up should be possible. i've only had the bike a few months and i am just getting around to making it rideable so it's not as though the brakes were ever good and have deteriorated over time.

i tried bleeding the front brake to no avail. tried adjusting the brake lever to engage the master cylinder earlier. no avail.

i am considering adding some steel braided lines but what i really want is to have the brake stop quicker. there is meat on the brake pads and no air in the brake lines but at best the front brake feels wooden and doesn't provide much feedback or bite.

any suggestions on the cheapest options for improving my bike's braking capabilities are appreciated.

sean

 

[Tombo]

Stainless lines make a GIANT difference. Brakes are worth it. While you are there, rebuild caliper, replace piston seal. Probably $100 to know your brakes are safe!

 

[freelancethink]

i agree that good brakes are worth it and can make my own steel braided lines for $15-20. Tombo: do you have a link to where i can buy a piston seal? as far as a rebuilt caliper, what parts does this entail and do you have a link for where i can buy parts?

 

[Tombo]

Freelancethink -

You gotta do your own searches - I know some other yamaha bikes share the caliper up front - but since I don't have a disc on my xs (plus it's a sohc older model), I am not familiar. I have heard it might share the caliper with an xj650 (but you need to do your own verification.

Here's a link to powersportsplus.com with your bike input to the system. I noticed they have a master cylinder rebuild kit for about $50, and you can buy a whole piston assembly (with the two piston seals) for about $50 as well. More than I expected.

I actually just chimed in because I just did the caliper, master cylinder and switched to stainless lines on my old xj6y50 maxim (xj maxim uses a very unique caliper caliper that pivots on a vertical axis) and it went from zero to hero! I can lock the front wheel if I want to, just as you desribe.

 

[16VGTIDave]

You WANT the front wheel to lock? That is the LAST thing I'd want. Once the front wheel is locked, the next things to happen are road rash, pain and damage.

The harder the front brake is applied, the more weight is transferred to the front. This increases traction of the front tire, making it harder to lock the wheel. When/if it locks, you have lost all control of the bike and your only option is to completely release the brake to get the wheel turning again. I know that my reflexes are not fast enough to recover from this before the bike goes down...

I have semi-metallic pads (unknown brand), and otherwise stock front brake system. I can fully compress the forks and get the rear suspension completely unloaded with a hard application of the front brake. If I had the guts to clamp harder on the lever, I'm fairly certain I could get the rear wheel off the pavement before bad things started to happened, but I go to great lengths to avoid this.

If you really think a front lock-up is desirable, I'd suggest testing on a bicycle and a soft surface. I've done this on my MTB (accidentally), and can tell you that it isn't something I wish to repeat. At the least, you will get bruised and scraped, but you are more likely have dislocated joints or broken bones. On a motorcycle, probably much worse...

Dave

 

[Tombo]

16VGT -

I don't the the OP wants it to lock because that's how he thinks he can get better stopping - but from my interpretation, he is using it as a describer for his brake power. I am doing the same. Proper motorcycle braking means that you apply brake slowly at first to transfer weight to the front wheel, so that more force can be applied. I took for granted that the OP understood this.

I come from DH mountain bike racing - and in that world, me and my collegues will use describers like this to explain how one brake system might be better than the next. I can slam on the front brake of my dh bike and manujal on the front wheel easily, or if I transfer my weight to the back, I can let my front wheel skid. And from where I'm stsnding, it does help to define whether you hhave good braking power.

All your points are valid, but I think you are placing your own assumptions of our intentions.

Ps - if you can't recover from a front wheel skid, then you should take a class. It was covered in my motorcycle saftey course - and my girlfriend who has almost no bicycle experience and only riding motorbikes for 3 months when we took the course together learned to recover from it on first try.

 

[16VGTIDave]

16VGT -

I don't the the OP wants it to lock because that's how he thinks he can get better stopping - but from my interpretation, he is using it as a describer for his brake power. I am doing the same. Proper motorcycle braking means that you apply brake slowly at first to transfer weight to the front wheel, so that more force can be applied. I took for granted that the OP understood this.

I come from DH mountain bike racing - and in that world, me and my collegues will use describers like this to explain how one brake system might be better than the next. I can slam on the front brake of my dh bike and manujal on the front wheel easily, or if I transfer my weight to the back, I can let my front wheel skid. And from where I'm stsnding, it does help to define whether you hhave good braking power.

All your points are valid, but I think you are placing your own assumptions of our intentions.

Ps - if you can't recover from a front wheel skid, then you should take a class. It was covered in my motorcycle saftey course - and my girlfriend who has almost no bicycle experience and only riding motorbikes for 3 months when we took the course together learned to recover from it on first try.

I didn't try to interpret what the OP was trying to say, I took it as it was written. Sorry if that was incorrect. If the OP had said they wanted better brakes, or a firmer feel to the lever, that would have induced different response.

I'm going to stick with my opinion that a front wheel lock-up is a bad thing. A 400+ pound motorcycle is not nearly as easy to control as a 30 pound MTB when things go wrong. The time it takes to get a relatively heavy wheel to resume turning is an eternity when it happens. With all the hazards we encounter on the road, and the speeds we travel, thinking proactively about safety is a must.

For what it is worth, I was taught that it is better to apply the front brake hard initially and then ease off as the pads warm-up and bite harder. The momentum of the front wheel, and the sudden weight transfer will prevent it from locking. But only do this in a straight line, not when turning.

With regard to handling a front wheel skid (not a lockup), just last night I was turning left from one road to another and found that someone had dumped a load of dirt right where I wanted to apex. I didn't see it until after I was committed to the turn. Most of the dirt had been swept off, but enough was left on the road to cause my front wheel to loose grip and begin to slide out. I was no longer applying the front brake, and was lightly on the rear brake while beginning to accelerate when the front started to go. I was able to recover, but ran wide and almost ended up at the edge of the road, which would have ended badly... I'm sure I could have handled this better than I did, but my reactions were good enough to salvage the situation.

Dave

 

[Tombo]

You are right not to interpret, my mistake. And certainly, I would not recommend the locking of a front brake if you can avoid it (unless training to control front wheel lock up).

Glad you got out of the situation described!

As far as braking - if you apply the front brake hard at first, you have higher likelihood of causing the front wheel to lock up or skid. It's all physics. If you grab lots of brake right away, the front wheel will not have as much weight on it (reducing friction and traction). If you ease on to your brakes, feel the weight shift to the front (and your suspension to compress a bit), then there will be more weight on the front wheel. It happens very quickly - and once your suspension is dipped and weight is transfered, you can, in optimal road conditions, put quite a bit of power into the front before losing traction (in fact, if going in a straight line, you are more likely to "endo" than to skid the front wheel).

You may already be braking this way without knowing it - but if you are not, I suggest you learn this technique and change your habits. Perhaps one person told you that heavy breaking right away is correct - but the Motorcycle safety course teaches differently - and I bet if you searched the net for braking technique that the community would agree with my suggestion.