Jump to content
Cobie Fair

Ask The Chief (Mechanic)

Recommended Posts

G'Day Stevo,

Interesting questions,

from what is printed in the mags and online, it seems that a lot of manufacturers over/under gear their bikes to pass noise tests.

With the 520 conversion, what's on it now?

is it for a street bike or a track bike?

How heavy,torquey and powerful is the bike?

180 rear tyre?

Cheers.

I use my bike both track and street. What I have: '02 Honda CBR600F4i, stock, with 525 chain, 16 and 46 tooth sprockets. I have almost 20K mi on the bike so it's probably time to replace the chain anyhow. I did just order Dunlop GP211A tires (190/55 on the rear, up till now using stock size of 180/55).

 

Speaking of noise, my muffler is stock, although I'm dragging it on some turns if I'm not really careful about my body position. Some guys think I need a new can, some think my rear shock needs to be replaced- if anyone has thoughts on this, I'd like to hear it. The way I see it is most after-market cans look just as big.

 

 

Any gain you would get from going to a 520/aluminum sprocket would be measured in 100ths of a second a lap, the rear sprocket will not last on the street like Steel either. Gearing on the hand you will notice seat of the pants. Depending on your track and skill level the idea is to tap out the gearing on the longest straight, It's not uncommon to see 600 one down in front and two to three teeth up on the rear. For you that would be going from a 2.87 to 3.26 final drive ratio, that's a big change.

 

I would change the pipe if you want your bike louder or the one you have becomes unserviceable. Even though an aftermarket pipe is lighter and may make a little power I like quiet bikes on the street and the trade off isn't worth it to me. If on the other hand it was just a track bike I would work it into the build simply to be able to hear my bike when others are close.

 

The shock if it's stock is WAY more important to address than the pipe. It you are running a stock shock and it hasn't been redone by a suspension guy by all means make that happen, the forks too. The difference is hard to explain but you will see your lap times go down immediately after having your bike set-up. If the shock has been worked then it will be time to step up to an aftermarket shock. A shock will be money you will never recover so be sure you get $1,000+ use out of it.

Share this post


Link to post
Share on other sites

Any gain you would get from going to a 520/aluminum sprocket would be measured in 100ths of a second a lap, the rear sprocket will not last on the street like Steel either. Gearing on the hand you will notice seat of the pants. Depending on your track and skill level the idea is to tap out the gearing on the longest straight, It's not uncommon to see 600 one down in front and two to three teeth up on the rear. For you that would be going from a 2.87 to 3.26 final drive ratio, that's a big change.

 

I would change the pipe if you want your bike louder or the one you have becomes unserviceable. Even though an aftermarket pipe is lighter and may make a little power I like quiet bikes on the street and the trade off isn't worth it to me. If on the other hand it was just a track bike I would work it into the build simply to be able to hear my bike when others are close.

 

The shock if it's stock is WAY more important to address than the pipe. It you are running a stock shock and it hasn't been redone by a suspension guy by all means make that happen, the forks too. The difference is hard to explain but you will see your lap times go down immediately after having your bike set-up. If the shock has been worked then it will be time to step up to an aftermarket shock. A shock will be money you will never recover so be sure you get $1,000+ use out of it.

It's hard find any 525 chain kit; 520 seems more common, and I did find a steel rear sprocket one where I can go up 1 in the rear and down 1 in the front. If you know of good places to look, let me know.

 

I don't like loud bikes and don't want to spend the money on the can unless I really need to. I'm due for level 3 this year and I think I will bring my own bike to school to work out the lean angle and position issues.

 

Last summer I had a guy set the suspension. He said the rear was pretty close and didn't change anything, but the front was off a lot and could only be adjusted to a point as the spring were too soft; I recently had them replaced with some Racetech .925 springs (stock on that bike was .66!). The stock rear is pretty close to what the Racetech website calculator says and I'm within a few pounds of the stock rider weight. So it could just be all the problems in the front, or maybe my rear shock is worn and needs to be replaced too. I haven't had a chance to ride with the new front to see how it will feel.

Share this post


Link to post
Share on other sites

Any gain you would get from going to a 520/aluminum sprocket would be measured in 100ths of a second a lap, the rear sprocket will not last on the street like Steel either. Gearing on the hand you will notice seat of the pants. Depending on your track and skill level the idea is to tap out the gearing on the longest straight, It's not uncommon to see 600 one down in front and two to three teeth up on the rear. For you that would be going from a 2.87 to 3.26 final drive ratio, that's a big change.

 

I would change the pipe if you want your bike louder or the one you have becomes unserviceable. Even though an aftermarket pipe is lighter and may make a little power I like quiet bikes on the street and the trade off isn't worth it to me. If on the other hand it was just a track bike I would work it into the build simply to be able to hear my bike when others are close.

 

The shock if it's stock is WAY more important to address than the pipe. It you are running a stock shock and it hasn't been redone by a suspension guy by all means make that happen, the forks too. The difference is hard to explain but you will see your lap times go down immediately after having your bike set-up. If the shock has been worked then it will be time to step up to an aftermarket shock. A shock will be money you will never recover so be sure you get $1,000+ use out of it.

It's hard find any 525 chain kit; 520 seems more common, and I did find a steel rear sprocket one where I can go up 1 in the rear and down 1 in the front. If you know of good places to look, let me know.

 

I don't like loud bikes and don't want to spend the money on the can unless I really need to. I'm due for level 3 this year and I think I will bring my own bike to school to work out the lean angle and position issues.

 

Last summer I had a guy set the suspension. He said the rear was pretty close and didn't change anything, but the front was off a lot and could only be adjusted to a point as the spring were too soft; I recently had them replaced with some Racetech .925 springs (stock on that bike was .66!). The stock rear is pretty close to what the Racetech website calculator says and I'm within a few pounds of the stock rider weight. So it could just be all the problems in the front, or maybe my rear shock is worn and needs to be replaced too. I haven't had a chance to ride with the new front to see how it will feel.

 

 

I think Tucker Rocky is the best place or parts unlimited, there are only a few co. who make steel sprockets. Your not going to notice much difference between 525 and 520. Those numbers are the key to the size of the chain. the first number 5 is the number of 1/8ths between the pins center to center or 5/8ths, .625". The second is the width with 20 being 1/4" and 525 being 5/16ths wide on the rollers.

 

On the suspension even though the springs are close for you most of the "feel" is the valve stack and the valve flow itself. "close enough" is never a place I would recommend stopping. I would have a good suspension shop work on the valving and get the springs in the right range. the 925 front rate should be good if you are 160 to 190. email me and I will give you a referal for a shop.

Share this post


Link to post
Share on other sites

On the suspension even though the springs are close for you most of the "feel" is the valve stack and the valve flow itself. "close enough" is never a place I would recommend stopping. I would have a good suspension shop work on the valving and get the springs in the right range. the 925 front rate should be good if you are 160 to 190. email me and I will give you a referal for a shop.

The previous owner of my GSXR had the forks reworked when he was doing track time. His body weight was about 165 (I need to email him to ask if this was with/without gear); my body weight is about 185 (without gear). Is this something I should consider reworking? And, as I think about it, I presume I should wear my gear (or a weight vest or whatever) so we're working with my riding weight rather than my street clothes weight?

 

The previous owner said he did not mess with the rear shock. Do you have a recommendation for priority of effort in reworking the rear shock? Or, is there a good replacement rear shock you could recommend (in the $500-$1k range)?

 

Thanks!

Share this post


Link to post
Share on other sites

unfortunately I think you will have to have the front at least looked at if not re-valved, The will be up to the discretion of whoever you pick to do the work. I do recommend that you choose someone who can support you at the track and help sort it out. It may take some time before you know what you need, more or less damping. You should be able to both ends worked on (sprung and valved) for less than the price of an Ohlin's and since your front springs are close that 100 off the bill right there.

Share this post


Link to post
Share on other sites

Hi Will,

 

Cobie suggested I bring this question to you, so here I am :). I'm trying to decide which oil to use for my next oil change. I'm planning to use a 10w40 full synthetic, and I'm wondering more about which brand. AMSOIL seems to have a good following, but so do many others like Mobil, Shell, and Castrol. I looked at some of the info posted at the AMSOIL website, and it is interesting reading at least. The other night I noticed a Sport Rider magazine ad for Silkolene Pro-4 (and with a CSS endorsement), and that raised my interest level. However, I found Silkolene is one of the more expensive brands at upwards of $20 per quart, and no one around here carries it, so I'd have to buy it through special order/mail order. Same deal with AMSOIL, although it's much more affordable at just over $10 per quart. Mobil 1 4T is available at a few local retailers for about $10 per quart. I was surprised to find I can get Honda HP4 from the Honda dealer for $7.50 per quart. I continue to read really good things about AMSOIL, and I was starting to lean that way, but... Anyway, please share your wisdom on oil :).

 

Thanks!

 

Share this post


Link to post
Share on other sites

Hi Will,

 

Cobie suggested I bring this question to you, so here I am :). I'm trying to decide which oil to use for my next oil change. I'm planning to use a 10w40 full synthetic, and I'm wondering more about which brand. AMSOIL seems to have a good following, but so do many others like Mobil, Shell, and Castrol. I looked at some of the info posted at the AMSOIL website, and it is interesting reading at least. The other night I noticed a Sport Rider magazine ad for Silkolene Pro-4 (and with a CSS endorsement), and that raised my interest level. However, I found Silkolene is one of the more expensive brands at upwards of $20 per quart, and no one around here carries it, so I'd have to buy it through special order/mail order. Same deal with AMSOIL, although it's much more affordable at just over $10 per quart. Mobil 1 4T is available at a few local retailers for about $10 per quart. I was surprised to find I can get Honda HP4 from the Honda dealer for $7.50 per quart. I continue to read really good things about AMSOIL, and I was starting to lean that way, but... Anyway, please share your wisdom on oil :).

 

Thanks!

 

 

 

 

while I only have my experience of one of bikes (03 Kawasaki)loosing the shaft that runs the water and oil pump ( unseen crash damage) at a latter school when running pinned in 6th on the back straight at Road America to draw from. The student noticed the temp warning light and looked down to see 248 flashing and shut the bike down. I knew it was bad and when the valve cover came off everything was black from the heat. I flipped the motor over and cracked the cases only to see all the mains still looking fresh? I took all the rod caps off and only one rod had any sign of a scuff! That is like those commercials where they drain the oil and do a dyno run! that engine ran at 12,000 RPM in top gear with no oil pressure and the bearing were fine! SOLD on Silkolene I am!

 

That being said the only comparative data i have ever found published was on Amsoil's site. They have different tests where you take rollers and races and drag them and test the pressure and wear. I have seen a few where they have used Silkolene Pro 4 and Motul 300V against their oil and they were all very close. Those test are just that, a very narrow focus and may or may not pan out in the real world.

 

I understand your final decision will come down to price point vs availability vs quality and asking a question about oil will bring out some much too learned opinions and put everyone to sleep. You asked my opinion and by my experience you will not go wrong using Silkollene, that's 11 years without an oil related failure!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...