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Cannon Racecraft Fork Springs

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I'm sure this has been covered in here before but I figured I'd bring it to the top for reference.

Cann Racecraft now has a part number for stock CRF150 and CRF230 fork springs.  They are as follows:

  • CRF150F - 27585 - 0.38, 0.40, 0.42, 0.44, 0.46, 0.48
  • CRF230F - 30597 - 0.40, 0.42, 0.44, 0.46, 0.48

The first two digits of the part number represent the spring diameter.  The last three digits of the part number represent the spring length.

 

Cannon can make these springs to any length you like.  For a bike with Race Tech Cartridge Emulators installed simply subtract 18mm from the length:

  • CRF150F - 27567 - 0.38, 0.40, 0.42, 0.44, 0.46, 0.48
  • CRF230F - 30579 - 0.40, 0.42, 0.44, 0.46, 0.48

They will make the springs for you either way.

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I didn't know they could do custom shorties for emulators. Calling them tomorrow. Thanks for letting us kmow.

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So I still haven't ordered a set of BBR springs so I can use only one for my 230....

If I order a set of Cannons,18mm shorter for my emulators, what part# for a pair of Cannons are equal to one stock spring and one BBR spring?

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So I still haven't ordered a set of BBR springs so I can use only one for my 230....

If I order a set of Cannons,18mm shorter for my emulators, what part# for a pair of Cannons are equal to one stock spring and one BBR spring?

 

That's a tough one because the stock forks springs are semi-progressive.  I say that because only the bottom few inches are at a rate of 0.21 kg/mm while the remainder are at a rate of 0.51 kg/mm.  The springs start at 0.21 kg/mm but when the bottom coils collapse and bind the rate goes up to 0.51 kg/mm.  This is why the top part of travel is so darn mushy.

 

Back in the 80s and 90s progressive springs were all the rage.  Today most tuners recommend straight-rate springs.  For a good estimate I'd go here:  http://racetech.com/ProductSearch/1/Honda/CRF230F/2009 and click on the "Calculate Spring Rates and Display Available Springs" hyperlink.

A lot of riders say Race Tech's calculations are a bit on the heavy side so you may want to consider that when using their site.  As a reference I believe many of the older XR200s and XR250s were equipped with 0.38 kg/mm fork springs.  For my 150 pound riding weight I got a recommendation of 0.42 kg/mm.  A 0.40 kg/mm rate sounds better given my experience BUT the CRF230 is a lot heavier than the old lighter XR200s and XR250s I'm accustomed to so it would need a bit heavier rate to compensate for the extra sprung weight.

 

I think you can only buy them in pairs so you may need to buy two anyhow.

Edited by VortecCPI
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Yes I'm aware that I will need to by two springs but since I can get them cut so there is no pre load with emulators that's way better for me.

It's just that I'm bottoming out to much with stock springs since my 230 is now making way more HP than when it was near stock. The Works rear shock is working just about perfect since John rebuilt it at the same time he did his magic on my 150 stock rear shock.

The 230 is not my most favorite bike because my 150 has cr85 forks with 40 springs.

With that said, the front suspension is perfect. But it's also 25lbs lighter than the 230.

I'm going to order a Hagon for my 150 because the rear, when it does bottom out, (not too much) It kills me.

So both bikes need some more suspension firmness but on opposite ends.

The problem I'm having is not knowing the what one stock spring and what one BBR spring would be equal to in a pair or non progressive springs.

Any ideas or educated guesses would really help a lot?

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That's a tough one because the stock forks springs are semi-progressive.  I say that because only the bottom few inches are at a rate of 0.21 kg/mm while the remainder are at a rate of 0.51 kg/mm.  The springs start at 0.21 kg/mm but when the bottom coils collapse and bind the rate goes up to 0.51 kg/mm.  This is why the top part of travel is so darn mushy.

 

Back in the 80s and 90s progressive springs were all the rage.  Today most tuners recommend straight-rate springs.  For a good estimate I'd go here:  http://racetech.com/ProductSearch/1/Honda/CRF230F/2009 and click on the "Calculate Spring Rates and Display Available Springs" hyperlink.

A lot of riders say Race Tech's calculations are a bit on the heavy side so you may want to consider that when using their site.  As a reference I believe many of the older XR200s and XR250s were equipped with 0.38 kg/mm fork springs.  For my 150 pound riding weight I got a recommendation of 0.42 kg/mm.  A 0.40 kg/mm rate sounds better given my experience BUT the CRF230 is a lot heavier than the old lighter XR200s and XR250s I'm accustomed to so it would need a bit heavier rate to compensate for the extra sprung weight.

 

I think you can only buy them in pairs so you may need to buy two anyhow.

After chatting with Richard, one of Cannon's suspension gurus, I'd suggest calling or emailing them yourself and not using RaceTech's calculator.

Strange that you were suggested 0.42kg/mm, that's what I ordered since I'm 25lbs heavier than you are.  I wonder if they knew the 230F has only 9.5" of fork travel (correct me if I'm wrong).  Shorter travel will increase the necessary spring rate.

 

It is also important to know, Cannon does not just cut the springs to length, apparently it is a much more elaborate process to change the length of a spring and maintain the rate, cutting a spring will change the rate, only a few coils cut off can increase it alot. 

 

I emailed Trish at Cannon over a month ago, she told me she was going to ask Richard what rate to go with and then I didn't hear from her for over a week so I went ahead and called them, spoke to Bob and ordered OE length in 0.42kg/mm.  A few days later Trish emailed to tell me Richard was back from vacation and that she wanted to have him call me to discuss what springs to go with.  I figured she had just forgotten about me or didn't like that I questioned the rate she suggested, I wish she had told me Richard was on vacation and wouldn't be getting back with me for a week or two.

 

I have the 0.42 springs here in my hands but will send them back to have Richard make them shorter.  I may go even shorter than 18mm off so I can adjust preload from 0mm with washers.  Apparently Zero or very little preload is very important and also requires for the spring rate to be just right and then the fork will be dreamy plush.

 

Richard also suggested welding/brazing closed the small rebound holes and re-drilling a single 1/16" hole in it's place and then running 5wt fork oil.

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Yes I'm aware that I will need to by two springs but since I can get them cut so there is no pre load with emulators that's way better for me.

It's just that I'm bottoming out to much with stock springs since my 230 is now making way more HP than when it was near stock. The Works rear shock is working just about perfect since John rebuilt it at the same time he did his magic on my 150 stock rear shock.

The 230 is not my most favorite bike because my 150 has cr85 forks with 40 springs.

With that said, the front suspension is perfect. But it's also 25lbs lighter than the 230.

I'm going to order a Hagon for my 150 because the rear, when it does bottom out, (not too much) It kills me.

So both bikes need some more suspension firmness but on opposite ends.

The problem I'm having is not knowing the what one stock spring and what one BBR spring would be equal to in a pair or non progressive springs.

Any ideas or educated guesses would really help a lot?

 

If you are bottoming hard at the front add more oil in 10cc increments until it stops.  Springs have little to do with bottoming resistance - Their purpose is to achieve proper sag.  Period.

Edited by VortecCPI

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So I need to set my sag on my 230 for the fist time ever, but I need a starting point so I don't end up buying multiple sets of springs.

All I'm asking is do you know approx or even an estimated guesstimate of what overall rate a stock spring is compared to a comparable straight rate spring. The same for a BBR spring.

Based on those #'s I can go from there.

Anyone have that information?

Edited by adnohguy

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So I need to set my sag on my 230 for the fist time ever, but I need a starting point so I don't end up buying multiple sets of springs.

All I'm asking is do you know approx or even an estimated guesstimate of what overall rate a stock spring is compared to a comparable straight rate spring. The same for a BBR spring.

Based on those #'s I can go from there.

Anyone have that information?

 

!!! EVERYTHING BELOW IS WITH RESPECT TO STOCK FORKS AND NO EMULATORS !!!

 

If I had to guess I'd say the equivalent average rate over the entire stroke is the average of 0.21 kg/mm and 0.51 kg/mm or 0.36 kg/mm.  However, since the lower rate is over a smaller distance the equivalent rate is possibly higher.

Taking the above into consideration, the equivalent rate over the entire stroke for one stock spring and one BBR spring is the average of 0.36 kg/mm and 0.53 kg/mm or 0.445 kg/mm.

 

That would be an average equivalent rate over the entire stroke, which doesn't do us much good because we need to consider just the first part of the travel to acquire proper static sag and race sag.  Given the sag measurements we've seen 0.445 kg/mm appears way too high.  Therefore...

 

The equivalent rate at he top of the stroke for one stock spring and one BBR spring is the average of 0.21 kg/mm and 0.53 kg/mm or 0.37 kg/mm.  Given the sag measurements we've seen 0.37 kg/mm appears way too low.

 

As a best guess I'd estimate the rate at the top of the stroke to be the average of 0.21 kg/mm and 0.36 kg/mm or 0.285 kg/mm.  Therefore the equivalent rate for one stock spring and one BBR spring is the average of 0.285 kg/mm and 0.53 kg/mm or 0.41 kg/mm.

 

Given the sag measurements we've seen 0.41 kg/mm appears pretty close.  One stock spring and one BBR spring gives me perfect race sag.  For my 200 pound buddy it's not quite enough.  Race Tech's calculator is telling me I need a 0.415 kg/mm rate and he needs a 0.455 kg/mm rate.  Seems like a reasonable sanity check to me.

 

I realize this doesn't answer your question but it's all I can offer.

Edited by VortecCPI
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One stock spring and one BBR spring gives me perfect race sag. 

 

ONE DAMN MINUTE ADMIRAL!

 

I swear you posted that one BBR spring gave you only like 1" of race sag.

Or was that with 2 BBR springs?

 

I think a critical aspect of our forks is the shorter travel than full on MX bikes.  The shorter the travel, the stiffer the spring must be.  This is where no preload really makes a difference as the fork will still be very compliant and plush on the small stuff but handle the big stuff as well.

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ONE DAMN MINUTE ADMIRAL!

 

I swear you posted that one BBR spring gave you only like 1" of race sag.

Or was that with 2 BBR springs?

 

I think a critical aspect of our forks is the shorter travel than full on MX bikes.  The shorter the travel, the stiffer the spring must be.  This is where no preload really makes a difference as the fork will still be very compliant and plush on the small stuff but handle the big stuff as well.

 

Negative.  That was with Race Tech Cartridge Emulators installed.  Without them everything was very good.  All the comments I made above are with respect to stock forks.  Great catch, though.  I modified the post accordingly.  Thank you.

The Race Sag with the emulators, one stock spring, and one BBR spring was ridiculously small.  The forks barely moved when the bike came off the kickstand.  The Static Sag was almost non-existent.

 

This is what gave my stock forks almost perfect Race Sag:

  • Two stock springs with two 3/4" spacers - No emulators
  • One stock spring / One BBR spring- No emulators
  • Two stock springs - With emulators

Although our bikes have less travel than newer bikes they are no different than the bikes of the 80s and 90s.

Spring rates have little to do with damping rates.  I suggest you get your hands on Race Tech's Suspension Bible.  The other thing you can do is call Bruce Triplett.  He knows these bikes well now (he rides a 230) so he can get you good data.

Edited by VortecCPI

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!!! EVERYTHING BELOW IS WITH RESPECT TO STOCK FORKS AND NO EMULATORS !!!

If I had to guess I'd say the equivalent average rate over the entire stroke is the average of 0.21 kg/mm and 0.51 kg/mm or 0.36 kg/mm. However, since the lower rate is over a smaller distance the equivalent rate is possibly higher.

Taking the above into consideration, the equivalent rate over the entire stroke for one stock spring and one BBR spring is the average of 0.36 kg/mm and 0.53 kg/mm or 0.445 kg/mm.

That would be an average equivalent rate over the entire stroke, which doesn't do us much good because we need to consider just the first part of the travel to acquire proper static sag and race sag. Given the sag measurements we've seen 0.445 kg/mm appears way too high. Therefore...

The equivalent rate at he top of the stroke for one stock spring and one BBR spring is the average of 0.21 kg/mm and 0.53 kg/mm or 0.37 kg/mm. Given the sag measurements we've seen 0.37 kg/mm appears way too low.

As a best guess I'd estimate the rate at the top of the stroke to be the average of 0.21 kg/mm and 0.36 kg/mm or 0.285 kg/mm. Therefore the equivalent rate for one stock spring and one BBR spring is the average of 0.285 kg/mm and 0.53 kg/mm or 0.41 kg/mm.

Given the sag measurements we've seen 0.41 kg/mm appears pretty close. One stock spring and one BBR spring gives me perfect race sag. For my 200 pound buddy it's not quite enough. Race Tech's calculator is telling me I need a 0.415 kg/mm rate and he needs a 0.455 kg/mm rate. Seems like a reasonable sanity check to me.

I realize this doesn't answer your question but it's all I can offer.

Thank you so much! This helps me tremendously. I appreciate your help.

I'm closer to your buddy's weight so I'm going to order a pair of 44's and go from there.

In your other postings you stated NO pre lode on the springs, correct?

So I will order 18mm shorter than stock.

Looking forward to riding with the upgrade!

Will report the results.

Guy

Edit: just ordered from "Bob" $140.00 a pair for a custom order (18mm shorter) 3weeks to complete + shipping time.

Edited by adnohguy

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Thank you so much! This helps me tremendously. I appreciate your help.

I'm closer to your buddy's weight so I'm going to order a pair of 44's and go from there.

In your other postings you stated NO pre lode on the springs, correct?

So I will order 18mm shorter than stock.

Looking forward to riding with the upgrade!

Will report the results.

Guy

Edit: just ordered from "Bob" $140.00 a pair for a custom order (18mm shorter) 3weeks to complete + shipping time.

 

Yes - No preload besides that which occurs during fork cap installation.  Every suspension tuner I've spoken with recommends no preload other than that.

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Thank you so much! This helps me tremendously. I appreciate your help.

In your other postings you stated NO pre lode on the springs, correct?

So I will order 18mm shorter than stock.

Edit: just ordered from "Bob" $140.00 a pair for a custom order (18mm shorter) 3weeks to complete + shipping time.

 

 

Yes - No preload besides that which occurs during fork cap installation.  Every suspension tuner I've spoken with recommends no preload other than that.

 

That which occurs during fork cap installation is still pre-load.

 

I do believe Bruce suggested 6mm of pre-load which is what the stock springs have with no Emulators under them.

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That which occurs during fork cap installation is still pre-load.

 

I do believe Bruce suggested 6mm of pre-load which is what the stock springs have with no Emulators under them.

 

Semantics, to a degree.  Let's just say the threads should engage with your fingers like they do on all XRs (and most other vintage bikes) I've ever worked on.  In other words, without having to push on the cap like a gorilla like we do when the emulators are installed with stock spring lengths.

When I talk about preload I mean that due to spacers or due to springs of improper length.  The 5 or 6 mm of preload we get by installing the fork cap is minimal.  That equates to about 4 or 5 pounds of preload with a 0.40 kg/mm rate, which is about 4% of the total load on the spring.

On the other hand, 6mm plus 18 mm (24 mm) equates to about 20 pounds of preload with a 0.40 kg/mm rate, which is about 20% of the total load on the spring.  That is quite a big difference.

Edited by VortecCPI

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Semantics, to a degree.  Let's just say the threads should engage with your fingers like they do on all XRs (and most other vintage bikes) I've ever worked on.  In other words, without having to push on the cap like a gorilla like we do when the emulators are installed with stock spring lengths.

When I talk about preload I mean that due to spacers or due to springs of improper length.  The 5 or 6 mm of preload we get by installing the fork cap is minimal.  That equates to about 4 or 5 pounds of preload with a 0.40 kg/mm rate, which is about 4% of the total load on the spring.

On the other hand, 6mm plus 18 mm (24 mm) equates to about 20 pounds of preload with a 0.40 kg/mm rate, which is about 20% of the total load on the spring.  That is quite a big difference.

Richard at Cannon stressed as little preload as possible, zero to 2mm if possible.  No preload allows you to run stiffer springs and still have a plush front end over the small stuff.

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