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Discussion Starter · #1 · (Edited)
Hi All and Harris, <GRIN>

I hope I am not out of line posting this question in this forum, it is kind of a technical question but it does concern safety stopping distance issues.

I have a 2003 FXSTSI with 28,000 miles on her. I recall looking at the specs on my Springer, on the Harley Website in 2003, about stopping distance comparisons on all the different Harley models.

All the 2003 models "with a full load" including the Sporster, stopped at approx 160 feet from 60 mph, except for the Springer, which stopped at approx 18 feet farther "if memory serves me right" approx 178 feet.

Now the springer was the only bike in 2003 with a 1 piston front break caliper, all the other 03 models had a 2 piston front break caliper.

I am told by my dealer that the Springer front end is approx "3" times heavier than the other models front ends, with the 21 inch front wheel, and this is the reason for the head bearings needing adjusting and finally replacement after X number of miles.

I know this because I need the head bearings now on my bike with 28,000 miles.They can't be adjusted any further and need to be replaced. The bearings are cheap approx $30.00 but the labor will be approx 2 1/2 hours at $60.00 an hour.

Now my Question:

If the front end is 3 times heavier on a Springer, and the greatest stopping power on a bike is the front break, when the front break is properly applied and the weight transfer takes place going toward the front of the bike, why would the Springer with a "heavier front end" take a longer distance to stop? I am also told front tire size is not an issue.

Here are weights I found
2003 SOFTAILS:

2003 Harley-Davidson
FLSTS/FLSTSI Heritage Springer
Vehicle Weight In Running Order (unladen) 741.0 lbs. (337.0 kg)

2003 Harley-Davidson
FLSTC/FLSTCI Heritage Softail Classic
Vehicle Weight In Running Order (unladen) 738 lbs. (335.0 kg)

2003 Harley-Davidson
FLSTF/FLSTFI Fat Boy
Vehicle Weight In Running Order (unladen) 705 lbs.(320.0 kg)


Start 21 inch front tire my bike first
=============================================================
2003 Harley-Davidson
FXSTS/FXSTSI Springer Softail
Vehicle Weight In Running Order (unladen) 694.0 lbs. (315.0 kg)

2003 Harley-Davidson
FXST/FXSTI Softail Standard
Vehicle Weight In Running Order (unladen) 672.0 lbs. (305.0 kg)

2003 Harley-Davidson
FXSTB/FXSTBI Night Train
Vehicle Weight In Running Order (unladen) 672.0 in. (305.0 kg)

2003 Harley-Davidson
FXSTD/FXSTDI Softail Deuce
Vehicle Weight In Running Order (unladen) 672.0 lbs. (305.0 kg)

By the way I put on an after market 4 piston break calipers on my Springer from day 1.

Please advise.

Thanks

John G
 

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jguarnieri said:
Hi All and Harris, <GRIN>



Now my Question:

If the front end is 3 times heavier on a Springer, and the greatest stopping power on a bike is the front break, when the front break is properly applied and the weight transfer takes place going toward the front of the bike, why would the Springer with a "heavier front end" take a longer distance to stop? I am also told front tire size is not an issue.


Please advise.

Thanks

John G
Hi John-

I have practiced numerous braking exercises on my Glide in both Harris' training program, as well as in the ERC course.

I will tell you what I know. Perhaps it will be of some help.

First and foremost, buy the book Proficient Motorcycling, By David L Hough

There is an entire chapter that goes over braking in great detail.

Secondly, In my "motor training begins series" there are 3-4 posts on the braking section available for you to read, today. click on page 6-7.

They say the front brake provides 70% of your bikes topping power. In reality, I would say the front brake provides close to 90% of your bikes stopping power.

Please keep this simple fact in mind.

When, not if, you find youself in a situation that requires immediate braking, you will never rise to the occassion. You will only sink to your level of motor training. Thus, it won't matter what kind of bike your on. If you do not know how to use your front brake, you could be in some serious trouble.

Please the read the motor training threads...everything you need to know is right there.

good luck :)
david
 
G

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John,

The heavier front end would not have any effect on the time the weight transfer takes. Instead it merely adds to the total weight of the bike. As you can see, your bikes weight is well within the range of softtail's weights. although 22 pounds heavier than the others withthe 21 inch front wheels, it's lighter than the Heritages and Fat Boys. The differences in weight listed would not appreciably affect stopping distance. Also, the narrower 21 inch tire would not cause a change worth mentioning.

You hit on the cause of the longer braking distance in your question. The single piston caliper. A 2-piston causes more friction between the brake pads and the disc, thus more efficent braking. If you have replaced the single-piston already you have negated this problem. Now the only key is your braking skill.

Any time relative braking distance is discussed, it is "threshhold braking", or maximum braking with the wheel still rolling. Particularly on a motorcycle, this take a lot of practice to consistently acheive. A skid lengthens braking distance on any vehicle - and of course is usually disasterous on a motorcycle. If you has a car manufactured in the '60s, that had four-wheel drum brakes, and another car of similar weight with the most advanced brakes available today, you would of course have a much shorter "stopping distance" specification on the new car. However (if you defeated the new car's ABS), and put both cars into a locked wheel skid, their braking distances would become equal. This is because you're no longer dealing with the controlled application of friction between the brake's friction surfaces, but merely friction between the tires and road, battling the momentum of the car's weight and velocity.

So, to summarize. By upgrading the brakes on your motor you've negated the mechanical deficiency in your case. They key now is to practice braking so that you can gain the advantage you've paid for.

Harris
 

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Discussion Starter · #4 ·
Hi Harris,

Thanks for your reply. I'm glad the 4 piston caliper will work for me.
I'll be practicing my stops in mid March if the weather breaks in Buffalo NY
 

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I did some tests for Ferodo brakes about 33 years ago riding a Norton. That was with drum brakes. Achieved a stopping distance (with a bit of practice) of 99 feet from 60 MPH. If that bike could do it, so can yours with it's discs. Practice!
 
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