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Julian

Top 10 Front Suspension Mods

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Julian

Prompted by some recent dissatisfaction with my front suspension which I will explain separately, I researched a lot of articles and forum posts on the topic. I found the information to be very scattered and quite a lot of contradictions, and I wanted to bring it all in one place in a structured way. This is not a recommendation rather a summary of available options. If I missed something, got something wrong or you have something to add, let me know in the comments and I will update it here.

1. Add more oil of the same viscosity
What it does: Softens or prevents bottoming out under heavy compression e.g. if the springs are too soft for your weight. The air gap inside the fork acts as a progressive spring - the less air the harder it is to compress it. 
Difficulty: Easy. Can be done with the forks on the bike just need to remove the caps, add small quantities of oil at a time and test.
Cost: Almost free, only need a little bit of fork oil.


2. Install fork caps with preload adjustment
What it does: allows preload adjustment on the stock or aftermarket springs. The same thing can be achieved by switching between spacers of different lengths but the screw adjustment is more convenient.
Difficulty: Easy. Can be done with the forks on the bike.
Cost: $25-$60 when bought separately, they come included with some spring kits

3. Cut the spacers down 10-15 mm
What it does: Reduces fork spring preload therefore allowing more static sag. That in turn lowers front ride height and decreases the trail and wheel base (slightly). It's routinely recommended by Dave Moss but it seems that some aftermarket springs (Ohlins, Race Tech) are shorter than stock, therefore achieving the same result.
Difficulty: Easy. Just need to be able to cut a pipe or have a friend who can do it. Alternatively you can replace the spacers with shorter metal ones or cut shorter spacers from PVC pipe.
Cost: free if you do it yourself

4. Raise the forks 8mm in the triple clamps
What it does: Easier to steer? Lowers the handlebar and changes the geometry of the bike ever so slightly. Dave Moss recommends this together with points 3, 6 and sometimes 1(cut spacers, raise the forks, change oil to higher viscosity and sometimes add more oil).
Difficulty: Easy. It is done with the forks on the bike.
Cost: free

5. Replace springs and spacers with aftermarket ones
What it does: Allows the rider to choose a spring rate that is better suited for their weight or preference (softer or harder). In theory the aftermarket springs could have tighter tolerances or be more durable. Some manufacturers have shorter than stock springs (Ohlins, Race Tech), different spacer length, may include caps with preload adjustment and they may recommend different oil levels and viscosities so points 1, 2, 3 and 6 also come into play.
Difficulty: Easy. Can be done with the forks on the bike.
Cost: $80-$250 for a pair of aftermarket springs

6. Replace fork oil with higher viscosity
What it does: increases both compression and rebound damping. Actual viscosity may vary between manufacturers for the same rating (Bell Ray said to be thicker than others). Some users report a harsher ride overall.
Difficulty: Medium. The forks need to be removed from the bike.
Cost: oil and potentially labor if done by a shop.

7. Install gold valve emulators
What it does: makes compression damping tunable, rebound damping remains unchanged. Rebound damping can be changed with different viscosity oil.
Difficulty: Medium. The forks need to be taken apart and bigger or additional compression damping holes drilled. The valve emulators need to be fished out every time a compression damping adjustment is needed but that can be done with the forks on the bike. 
Cost: $200 for the emulators and adapters + work + maybe shipping

8. Install aftermarket fork cartridges
What it does: allows for separate function and tunable compression and rebound damping, either through shims or remotely with adjustment screws in the fork caps.
Difficulty: Difficult. Fork internals need to be replaced and they might need to be sent to the manufacturer or a tuner. Needs to be repeated if making changes to the shim stacks.
Cost: $600+ for the cartridge kit + labor + shipping

9. Complete front forks or front end swap from R6 or other bikes
What it does: Higher quality complete front ends are transplanted onto the MT-07. This can include larger diameter forks, upside-down forks, brakes, tunable suspension etc.
Difficulty: Difficult. Depending on the chosen front ends, multiple mods and compromises might be necessary to make it fit.
Cost: 1000+ depending on the make and model, if new or used etc.

10. Change the rear shock
What it does: Technically this is not front end related, but users have reported improved front end operation after upgrading to aftermarket rear shocks set correctly for their weight.
Difficulty: Medium. Requires replacement of the stock rear shock but it can be done by the owner.
Cost: $500-$1500 for an aftermarket rear shock + labor if done by a shop.

Edited by Julian
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Triple Jim

#1 is incorrect.  The oil level is always above the damping/valving parts of the fork, so they're always completely submerged in oil.  Adding oil can't make them change their damping.

Adding more oil of the same viscosity reduces the air space, causing the air pressure to increase faster on fork compression.  This raises the effective spring rate, which would be similar to installing stiffer springs.  Since the air volume inside changes quickly with fork compression, it's non-linear, so it behaves like progressive springs.  If a fork is bottoming out under hard braking, for example, adding oil can stop that, but it's due to the higher effective spring rate, not increased damping.

 

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M. Hausknecht

Great job Julian! Here are my initial thoughts, for what they are worth.

 

1. Adding oil does not change damping, either rebound or compression. What it does is reduce the space for air in the fork so that under significant compression of the fork the compressed air acts as a bottom out spring. So, if your fork is bottoming too harshly and readily, adding sufficient oil will soften the bottoming or prevent it outright because of the sudden ramp up in effective fork spring rate caused by the compressed air in the forks.

3. Changing the length of the spacer in each fork changes the preload on the spring but it doesn't directly change anything else. Shortening the spacer will, therefore, reduce fork spring preload and should result in more static sag at the front. The increased static sag should bring with it a lower front ride height and a slightly steeper steering head angle. If you change the fork preload and at the same time raise or lower the forks in the triple tree, you can keep the same geometry and front ride height you started with notwithstanding the change in preload. Keep in mind that changing spring preload does not change the spring rate; it merely changes the length of the spring at a given load on the spring. Dave Moss's suggestion to shorten the fork spacers is based on his view that an unladen motorcycle (no rider) should cause the fork to sag (compress) by around 5mm or so.

4. Raising the forks in the triples reduces front ride height, increases the steering head angle, and shifts some weight from the rear tire to the front tire. The motorcycle will want to change direction more readily and with less effort; it will also be accordingly less stable in a straight line. Whether you want more agility or more stability is a personal choice that should be based on the kind of riding you do and what you prefer. 

5. The springs are what holds the bike up. If you and your bike are 30 or more pounds heavier or lighter than the loads for which the stock springs seem intended by the manufacturer (sometimes hard to understand what the manufacturer intends), you should consider changing the springs accordingly. With the proper springs for the combined weight of you (and any passenger) and the bike, and your riding style and environment, you can have the desired unladen sag and laden sag, operate the suspension within the middle of its travel (where it works best), and avoid bottoming out the suspension with consequent loss of traction. Springs and their preload work together, so changes to fork spring rates should also include changes in preload (via spacers or adjustable fork caps).

6. With the stock forks, heavier weight oil increases both compression and rebound damping and lighter weight oil reduces both types of damping. Cheap damper rod forks like the 07's often benefit from more damping for race track use where the extra control over chassis movement is welcome and the loss of compliance matters little because the surface is smooth(er).  

7. Gotta love Race Tech's Gold Valve emulators! See here for what they do and how: https://racetech.com/page/title/Emulators-How They Work . If you are patient and understand what you're doing and what you want, the combination of emulators, correct springs, preload spacers (or adjustable caps), fork oil viscosity, and fork height can create an excellent front suspension. The only real disadvantage is that adjustment, especially of damping, is time consuming because you need to remove and adjust the emulators and perhaps change the fork oil viscosity. 

8. If you want or need quick easy damping adjustability, fork cartridges  are your only option (short of all new forks). I have Ohlins cartridges on my race bike and I'm reasonably pleased with them. Compression and rebound adjustments are done externally with wrenches,and  preload is adjustable with the fork caps. If the manual adjustments and oil viscosity changes don't get you what you want, the shim stacks that control separately compression and rebound damping can be changed (this requires specialized tools and sophisticated knowledge; so you'll want to work with an experienced suspension tuner who understands how to get you what you want). 

9. The final front end option for an 07 is to install R6 forks (and brakes) with suitable triples. The stock forks flex a bit, especially under heavy braking, which is the primary reason for going to R6 forks rather than merely installing cartridges in  the stock forks. The R6's bigger discs and radial mount calipers also generate more braking force with less effort than the stock pieces. If you're handy with tools, this isn't a tough swap but you'll want to start with a complete R6 front end (wheel, brakes, front master cylinder, clip ons, etc.) and then get a suitable triple tree, as an example:      https://www.robemengineering.com/product-page/fz-07-mt-07-adjustable-triple-clamps-50mm-forks . The R6 forks are adjustable for preload, and rebound and compression damping,  but can also benefit from reshimming or aftermarket cartridges.

10. Yes, it can be difficult sometimes to isolate fork problems from shock problems. An underdamped rear shock can cause all sorts of problems for the front of the motorcycle. The stock shocks also wear out fairly quickly, providing still less damping and offer little (rebound damping since '18, I think?) or no adjustability beyond preload. I think reasonable people could disagree over whether to upgrade forks or shock as a higher priority.

I think two other items are worth mentioning. First, for track use with the stock forks, consider aftermarket triple clamps to get the trail and fork angle you want for both quick turn in and reasonable stability in a straight line. Second, the shock "knuckle" isn't ideal for track use; too much progressivity and not enough swing arm angle. See, for example: https://www.robemengineering.com/product-page/fz-07-linear-linkage .

 

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shinyribs

I'm going to try to be brief , but don't take this as being condescending or rude. Everybody has a different budget, and sometimes you ain't got the budget you used to have last year. I build tons of my own stuff because I'm cheap, and also because I'm not rich. 

That's aside, I've tried all sorts of bandaids on suspension stuff. The guy on the internet who spent $28 on fork oil and eBay preload caps and "completely transformed!!!!"  his bike is lying to you. Perhaps not out of malice, maybe he really thinks it's better. IMO Dave Moss's "fix" for our "DANGEROUS" forks lands firmly in that category. Look at your own post. #2 Add preload. #3 Remove preload. Which is right? They can't both be right. 

There's no harm in tinkering. Go for it and have fun. 99% of the time the improvement you were looking for will cost you something on the other side of the coin.

If you want it right, you know what you've got to do. It doesn't have to costs thousands to be real good, but it's not gonna be free. And when it's right, you'll kick yourself for not doing it sooner. I spent ages band-aid'ing bikes. I bit the bullet and did it right a while back. It's eye opening. Now, I just bought a new bike recently and immediately went out and ordered proper suspension for it. When you know the difference, you'll not have the patience for fiddling with internet fixes anymore. 

 

Good luck on your journey ✌️

Edited by shinyribs
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seven
20 hours ago, shinyribs said:

If you want it right, you know what you've got to do.

@shinyribs I don't know specifically so I am curious what your opinion of what options you consider proper fixes? Is a full swap like the R6 front end required or would you consider cartridges to be a proper.

I generally believe that "you get what you pay for" but have to admit that it is hard to filter out the "completely transformed" comments we can see on forums/internet.

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Weeksy
20 hours ago, shinyribs said:

I'm going to try to be brief , but don't take this as being condescending or rude. Everybody has a different budget, and sometimes you ain't got the budget you used to have last year. I build tons of my own stuff because I'm cheap, and also because I'm not rich. 

That's aside, I've tried all sorts of bandaids on suspension stuff. The guy on the internet who spent $28 on fork oil and eBay preload caps and "completely transformed!!!!"  his bike is lying to you. Perhaps not out of malice, maybe he really thinks it's better. IMO Dave Moss's "fix" for our "DANGEROUS" forks lands firmly in that category. Look at your own post. #2 Add preload. #3 Remove preload. Which is right? They can't both be right. 

There's no harm in tinkering. Go for it and have fun. 99% of the time the improvement you were looking for will cost you something on the other side of the coin.

If you want it right, you know what you've got to do. It doesn. And when it's right, you'll kick yourself for not doing it sooner. I spent ages band-aid'ing bikes. I bit the bullet and did it right a while back. It's eye opening. Now, I just bought a new bike recently and immediately went out and ordered proper suspension for it. When you know the difference, you'll not have the patience for fiddling with internet fixes anymore. 

 

Good luck on your journey <img src=">

Fwiw I've had mates run round track in the fastest group with nothing but a shock on his mt07.

I won't be changing anything and will run in the middle group.

Im not convinced this bike needs more than a shock. Many people read rubbish on the internet then get it done.

Nothing wrong with it. As for the "you'll know" well yes it may feel nicer but you won't necessarily use it or go any quicker on the roads or track. 

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shinyribs
5 hours ago, seven said:

@shinyribs I don't know specifically so I am curious what your opinion of what options you consider proper fixes? Is a full swap like the R6 front end required or would you consider cartridges to be a proper.

I generally believe that "you get what you pay for" but have to admit that it is hard to filter out the "completely transformed" comments we can see on forums/internet.

I've done front end swaps, but I certainly wouldn't not on this bike. The stock geometry is so good, why mess with it. 

I replaced my shock immediately. Major improvement and I happily rode like that for the next few years. The fork was never really offensive, but it was harsh compared to a good shock. I messed around here and there with different oils and spring spacers, but there were no real results. Any thicker oil just makes the fork even more harsh. 

 

After a few years of not spending any bike money I decided to splurge on the forks. I went with Ohlins cartridge kit, but there's cheaper options. Since the fork was never offensive like the shock was, I kinda felt like I was wasting money, and ultimately I was worried that the kit would make the bike too racy and ride hard. It ended up being perfect. The eye opening part was how much better the bike cornered with the front end fixed. I'm not talking about racing or track days, I'm just talking about daily riding on back roads. 

The shock is really bad, the forks are decent. When they're both right, it's damn surprising how good it feels, but I could live with an 07 with just a good shock. 

 

 

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Julian

Thank you for the suggestions guys, keep them coming and I will try to work them into the first post.

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klx678
On 11/7/2021 at 1:49 PM, shinyribs said:

I'm going to try to be brief , but don't take this as being condescending or rude. Everybody has a different budget, and sometimes you ain't got the budget you used to have last year. I build tons of my own stuff because I'm cheap, and also because I'm not rich. 

That's aside, I've tried all sorts of bandaids on suspension stuff. The guy on the internet who spent $28 on fork oil and eBay preload caps and "completely transformed!!!!"  his bike is lying to you. Perhaps not out of malice, maybe he really thinks it's better. IMO Dave Moss's "fix" for our "DANGEROUS" forks lands firmly in that category. Look at your own post. #2 Add preload. #3 Remove preload. Which is right? They can't both be right. 

There's no harm in tinkering. Go for it and have fun. 99% of the time the improvement you were looking for will cost you something on the other side of the coin.

If you want it right, you know what you've got to do. It doesn't have to costs thousands to be real good, but it's not gonna be free. And when it's right, you'll kick yourself for not doing it sooner. I spent ages band-aid'ing bikes. I bit the bullet and did it right a while back. It's eye opening. Now, I just bought a new bike recently and immediately went out and ordered proper suspension for it. When you know the difference, you'll not have the patience for fiddling with internet fixes anymore. 

 

Good luck on your journey ✌️

That's kind of what I did.  I got an Ohlins used from a member here and went with the Matris valve/spring kit.  I figure it has to be an improvement over the stock stuff after several thousand miles.   Plus it was a new bike and I could finally afford to do the stuff.   Like the full exhaust that does nothing very noticeable for performance, but looks and sounds how I want , and changing out the headlight bucket and mount along with filling the rear fender and fitting a better looking tail light on the XSR.  I can do what I want for a change for the most part.   

 

I'd rather have Jeff Palhegyi's DT07 street tracker though❣️  Wish Yamaha would take a chance on a similar, but affordable street tracker.  No hedging on the bodywork and look, make it a decent tribute to the DT07 flat trackers.  I know they can't do exactly the same stuff, but they could come close with some good bodywork on the XSR and a set of 18/19 wheels.  Ah, but I know I'm just dreaming.  

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PMT-07
On 11/8/2021 at 3:58 PM, shinyribs said:

I've done front end swaps, but I certainly wouldn't not on this bike. The stock geometry is so good, why mess with it. 

I replaced my shock immediately. Major improvement and I happily rode like that for the next few years. The fork was never really offensive, but it was harsh compared to a good shock. I messed around here and there with different oils and spring spacers, but there were no real results. Any thicker oil just makes the fork even more harsh. 

 

After a few years of not spending any bike money I decided to splurge on the forks. I went with Ohlins cartridge kit, but there's cheaper options. Since the fork was never offensive like the shock was, I kinda felt like I was wasting money, and ultimately I was worried that the kit would make the bike too racy and ride hard. It ended up being perfect. The eye opening part was how much better the bike cornered with the front end fixed. I'm not talking about racing or track days, I'm just talking about daily riding on back roads. 

The shock is really bad, the forks are decent. When they're both right, it's damn surprising how good it feels, but I could live with an 07 with just a good shock. 

 

 

Sorry to revive this thread, but I’m curious because I’m looking to make some suspension changes. The mt07 is my first bike, and I have nothing to compare this too. I’m a heavy rider approx 250 and 6 foot. Do you believe that a lot of the suspension issues are the shock mainly? I feel like the front is “bouncy” so when I brake im feeling like a bull trying to push me off. I could see that being the rear shock as well. Im curious if I could get away with just the shock and get to the forks later. It’s a 2019 mt07

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mossrider

100% correct. The bulls ass is coming up and booting you in yours. Do the shock and put heavier fluid and possibly a preload shim in front and you'll be amazed at the difference. Finish the fork when/if you feel a need. 

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shinyribs

Yes, I still believe the shock is the big offender. Us heavier guys really need fork springs though( new shock will come with a proper spring) There's a lot of comfort when the springs are right. Overloaded springs bottom out easier and you feel that more than you realize. I'm pushing 240 all geared up. Respringing bikes is just a reality I've come to accept. 

 

 

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PMT-07
Just now, mossrider said:

100% correct. The bulls ass is coming up and booting you in yours. Do the shock and put heavier fluid and possibly a preload shim in front and you'll be amazed at the difference. Finish the fork when/if you feel a need. 

Thanks for this. Excuse my ignorance with the shim, what exactly is required with this?

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cornerslider
On 11/7/2021 at 9:24 AM, M. Hausknecht said:

 

7. Gotta love Race Tech's Gold Valve emulators! See here for what they do and how: https://racetech.com/page/title/Emulators-How They Work . If you are patient and understand what you're doing and what you want, the combination of emulators, correct springs, preload spacers (or adjustable caps), fork oil viscosity, and fork height can create an excellent front suspension. The only real disadvantage is that adjustment, especially of damping, is time consuming because you need to remove and adjust the emulators and perhaps change the fork oil viscosity. 

 

 

I second this! I've run Racetech emulators on several track bikes over the years (I still have them on my wife's R3). I ran them on my FZ-07 from 2017, until last year. They are a good product, but a little "generic"... By that I mean a 41mm emulator works in every bike with a 41mm fork tube. It's up to the owner to set the right spring, at the right tension on the valve. You also need to drill extra holes in the OEM dampener rod. Specific to the FZ/MT-07, you also need to buy a dampener rod "adapter" to adapt to the emulators. It's more labor intensive than I would have expected, but I was happy with the net result. I would say it got me to about 80-85% of what a properly set-up cartridge fork would provide.

Last year I switched to the Traxxion Dynamics AR-25 kit. I had heard good things, so I thought I'd give them a try (I also put my "old" emulators from my FZ-07,  in my wife's street R3) 😎. At any rate, I bought this kit: 

AR-25-Damper-Rod-Kit2.jpg

Drop in Damper Rod Kit. Combines damper rod and cartridge technology for superior bump absorption, traction, and control.

The kit is only slightly more money than the Race tech kit (with fork springs, emulator valves, and adapters). Traxxion Dynamics has been around a long time, and really know their stuff!!! You order the "kit", that comes with EVERYTHING you need right out of the box. The fit and finish was outstanding! You order it to your weight, and riding style. Traxxion Dynamics handles the rest!!!. They improved upon the Race tech idea, and made it MUCH easier. They incorporated the valve directly into their provided dampener rod. They even provide the proper oil in the kit to suit your provided riding style. Right out of the box, it was better than my Race tech set-up. I can honestly say the AR-25 kit, it got me about 95% of what a properly set-up cartridge fork would provide. I'm a 52 year old track day rider.... 95% is plenty good enough for me. I'm not chasing championships/points. I just enjoy lighting fuel on fire, and destroying tires 🤣-

 


""W.O.T. until you see god, then brake"

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cornerslider
Just now, PMT-07 said:

Thanks for this. Excuse my ignorance with the shim, what exactly is required with this?

It's just a slightly longer "spacer" at the top of the fork tube (right underneath the caps on the fork legs). You can cut your own out of 1" PVC pipe available at your local hardware store (seriously).... I've heard that people increase the length by 10mm. I never added them, as I have proper straight-weight  fork springs. I did add some preload adjusters to replace the OEM fork caps. They provide +/- 5mm to the preload. Honestly, I've never really need to mess with them much? Hope that helps-


""W.O.T. until you see god, then brake"

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