racetech fork spring spacer

[simpletty]

So I have ordered the 1.0kg/mm racetech springs, I am 225 in full gear. Was wondering who has an idea of where to start with the spring spacer length. Going to use 7wt oil and the recommended amount of 460ml in the forks. If anyone has perfected the length that worked for them I would appreciate it. Also what are you guys using to make the spacer as well. Thanks in advance

 

[zaster]

I was able to do all my mods myself so far but was very disappointed that racetech did not have moto specific instructions or how-to videos, so I had them installed.
I even contacted them for more specific info but just got a generic BS reply. Not sure I would use them again.

 

[Jeff Frazier]

I just did mine last night. I set the new spring next to the old spring, and measured the difference. Came out to exactly 3" in my case.

 

[Formula390]

The RaceTech spring lenghts differ as they come in either 250mm or 270mm. The TOTAL length, with springs and spacer, need to come to 350.5mm, +-3mm. The +- is for rider preference. Some riders like a little bit stiffer, some a little bit softer. Most of that is setup by the oil viscosity, but spring preload can make a little bit of a difference too. So, take your spring length (we'll use 250mm here in our example) and so it's 350.5mm (total length) - 250mm (spring length) == 100.5mm (spacer length). If you want a little bit more preload / stiffer, add in an extra 3mm, for a total of 103.5mm. If you want a little softer, then go with 97.5mm. This is assuming a correctly rated spring for your weight and application. I typically go with 1 over spring rate for racers than for street and occasional track day bikes.

The major adjustments in the stock front end on the RC is done with the fork oil viscosity. I typically start folks with 7wt. Some (Joey Clark) are running as high was 20wt!!! I eyes bugged out when he told me that, and It thought that was a bit nuts, but he's also putting it on the podium against some REALLY fast fuckers... so hey, do it! In general tho, 7wt is going to be pretty good. It's WORLDS better than the stock 4wt the bikes come with for us bigger riders flogging a little bike. The other advantage is, you can swap your fork oil without having to tear the front end completely apart!!!

Jeff, I doubt the difference came to (ahem, machinist here) EXACTLY three inches. 3 inches is 76.2mm. The stock springs are 345.5mm, and the stock spacer is 5mm (thus the 350.5mm) so comparing the 345.5mm springs to the 250mm springs SHOULD have resulted in a measurement of 3.759 inch... so color me perplexed.

 

[tecknojoe]

The major adjustments in the stock front end on the RC is done with the fork oil viscosity. I typically start folks with 7wt. Some (Joey Clark) are running as high was 20wt!!! I eyes bugged out when he told me that, and It thought that was a bit nuts, but he's also putting it on the podium against some REALLY fast fuckers... so hey, do it! In general tho, 7wt is going to be pretty good.

Yea my suspension guy tends to builds bikes very stiff. There's actually a lot of fast guys in our club that have been running 20wt in various small bikes. I have a very firm feel on the front end the way it is now, but i may try a lower viscosity at some point to see if I can get a tiny bit more stability when trailing off the brakes from 5% - 0%. That transition period makes me hold my breath some times, but it could just be the limitations of the small bikes in general. For reference, I'm 150lbs.

 

[cornerslider]

So I have ordered the 1.0kg/mm racetech springs, I am 225 in full gear. Was wondering who has an idea of where to start with the spring spacer length. Going to use 7wt oil and the recommended amount of 460ml in the forks. If anyone has perfected the length that worked for them I would appreciate it. Also what are you guys using to make the spacer as well. Thanks in advance

I'm 210 with gear, I got the 1.0 spring rate too. I ended up going with 3 - 1/8" spacers (after going longer and shorter) your sag won't be the same with the heavier springs. I just moved the forks up in the triples to compensate-


Sent from my iPad using Tapatalk

 

[simpletty]

1" schedule 40 abs pipe correct?

 

[Superpacman13]

It should come with either abs pipe or aluminum if you bought a race tech spring.

 

[stevieboy]

I used Racetech springs on a bike several years ago and the kit came with aluminum tubing. It was too short and I had to supply my own ABS.

 

[simpletty]

I used Racetech springs on a bike several years ago and the kit came with aluminum tubing. It was too short and I had to supply my own ABS.

Front end is off. Spring change this week. Rear shock will be done same
time as the front. Should handle like a champ

Some options to choose from

 

[stevieboy]

Did you end up getting another shock from Formula 390 or buy on your own?

 

[simpletty]

Did you end up getting another shock from Formula 390 or buy on your own?

Used core. Spring from local shop. Collar and spring shim from formula 390

 

[Formula390]

I used Racetech springs on a bike several years ago and the kit came with aluminum tubing. It was too short and I had to supply my own ABS.

RaceTech has "gone green" and isn't including the aluminum tube anymore even. They recommend schedule 40 ABS. 1" works great for the RC390.

 

[Superpacman13]

RaceTech has "gone green" and isn't including the aluminum tube anymore even. They recommend schedule 40 ABS. 1" works great for the RC390.

Well poop dang! I got mine not that long ago and just assumed it hadn't changed. Shows what I know.

 

[simpletty]

Ya ill pick some up and cut it to the appropriate length. Thinking I'll run motorex 10wto

 

[Jeff Frazier]

ok, i rode the bike this weekend (full pace testing at Circuit of The Americas), and i have a few opinions about my setup:

-1.0 spring
-7wt oil
-75mm spacer


The front dives a little too abruptly when jumping on the brakes. Matt was exactly right when he said that my spacer was too short. I will be going with new spacers at 95mm. This should load the springs more and cure the diving.

I also need to remove some oil, because the fork feels a little too harsh when fully compressed. I put 500ml of oil in each tube when I assembled them. I'll take measurements, and remove a little oil... Does anyone have recommendations on oil level height?

Also, I considered heavier oil, maybe 10wt. I'm sure it would work great at Circuit of The Americas (COTA) because it's so smooth, but all the of the tracks that we race at are bumpy and patchy... so, I will stay with the 7wt for now.

The next time I'll get to ride the bike will be at practice for my first sprint race on July 24th. I'll have more to report after that weekend.

Wish me luck!

 

[cornerslider]

I did the same set-up. I measured exactly 5 inches from top of oil, to top of the top of the fork cap. Seems okay, but I'm not really a suspension guru-