[mattallac]

This is not a how to , just some good info so you dont waste your $. I called race tech for some front springs last week (150.00 ouch ) , and they never sent them . Today I called them and a sales guy said the front forks are a pain in the ass and 200.00 in special tools and a press are needed . That is the truth . For about 350.00 (springs 150.00 , fork disassembly and reassembly 125.00 fork oil 1 pint 30.00 and disassembly of the lower fork legs 50.00 ) they will do the job . I told them that I needed more info before I sent my forks out ( are you putting heavier oil in the forks to compensate for the stronger springs , are you changing the fork oil height , etc ) After waiting 30 min on the phone I talked to the engineer and he said he is gonna make fully adjustable cartridges that will be released 2 months or so for now .The moral of the story is if you want forks that really work , wait a few months and have them done all together rather than doing it twice for more money .Im 205 lb and the front suspension is way to soft for me , the stock fork spring rate is .4 and for my weight i need a .65 rate .If you just do the springs dont expect any miracles its a check valve system that is used for fluid transfer , much like a ktm 50cc motocross bike . Hope this helps everyone

 

[Nefariousd]

Forks springs will help the bottoming issue. I'm having some wound next week by a company that did all the springs for my mini SUMO bikes. The springs are $100 and they'll do any weight you want.

The check valve system can be manipulated with oil weight, but not completely controlled.

I for one won't be spending a bundle on this bike, it costs less than the forks that were on my GSXR. I'm saving up for the next big Awesome at the end of the month FZ9 here I come!

 

[Highsider989]

I agree. I've ripped my Grom around hard. I'm 200+ with gear and even on shitty roads don't think the stock suspension is terrible. It's a mini. The forks although soft do control huge bumps. I could change my mind once I put my good tires on the bike.

 

[mattallac]

The rear shock IMO is pretty good , but the front is shit , I bottom my front shocks out around corners and its a pretty crappy feeling . I dont know the terrain in VA but in northern cali. we have a lot of hills with twists and turns . Nefariousd , will your guy sell springs to the public < if so id be interested . Race tech wanted 116.00 for the springs and 55.00 to cut them to fit ( that was last week ). now 150.00 is the new price .

 

[Highsider989]

I'm a very experienced rider and lived in the east bay for over five years. I think you need to be smooth with the grom. I will give a full review after I hit the mountains with leathers on.

 

[mattallac]

so your still living in the east bay , or you use to live in the east bay? My friend and I are also pretty experienced riders about 20 years a piece . Control on this mini can be a safety issue , its fun to push in the twisties and fast enough to actually hurt you .

 

[Nefariousd]

Nefariousd , will your guy sell springs to the public < if so id be interested . Race tech wanted 116.00 for the springs and 55.00 to cut them to fit ( that was last week ). now 150.00 is the new price .

Yes, I'm going to send him a spring next week after I teach this weekend and use the bike for demo's. He said he'll have mine back in 7-10 Business days. Once he has the dimensions he can make any rate that will fit within reason.

I might try to measure the spring here on my press, but I sold all the stuff associated with doing it. I used to do RaceTech and Traxxion Dynamics stuff when I had the shop.

How were you able to determine the stock ones were .4's ?

 

[mr_e]

Changing the volume of oil in the forks to create a bigger air pocket might be a good idea too...

 

[mattallac]

Racetech told me the stock rate . Adding more fluid volume usually makes the forks stiffer , the stock fork oil is 10w , 20 or 30w should do the trick with a stiffer spring If I go the cheap route

 

[Cadimanjd]

Yeah mine were killing me on these crappy Vegas roads so my buddy and I drained the forks and refilled them with a 75w gear oil. It was $6 for a bottle of it and now the ride is amazing now. Now all I need to do is the rear shock.

 

[Eurobeaner]

Lol Jesus. Goodbye seals! 75 is way way way way too thick for forks. 30w would have done much better. Maybe even 40w if you could find it. But 75 is terrible

 

[mr_e]

Yeah mine were killing me on these crappy Vegas roads so my buddy and I drained the forks and refilled them with a 75w gear oil. It was $6 for a bottle of it and now the ride is amazing now. Now all I need to do is the rear shock.

Your buddy didn't do you a favor there FYI.

 

[Cadimanjd]

I guess we'll see. He's done it several times and never had any problems.

 

[mr_e]

Check this thread out...
Motor Oil for fork oil? - Bob Is The Oil Guy

3rd post on the page by wileyE.

Dude was tuning microvibrations out of the flux capacitor on his trials bike and went anal on oil viscosity in his garage. He timed how long it took to run 50cc's of various types through a container with a .140" hole in the bottom. Recording his results.

Gear Related:
---------------------
Stihl Chainsaw Bar Oil 2006 97s
Valvoline 85W140 Gear Oil 83s

Valvoline 10W40 Motor Oil 57s
Unilube Synthetic 75W-90 Gear Lube 50s
Belray Gear Saver 80 weight 50s
Citgo Chrysler Spec 7176 ATF 41s
Valvoline Dexron III ATF 26s (a great option for
eliminating clutch
drag in trials bikes)

Suspension:
---------------------
Bel-Ray High Perf. Fork Oil 10 weight 21s (same oil as 7 weight)
Bel-Ray High Perf. Fork Oil 7 weight 21s (same oil as 10 weight)
PJ1 Fork Tuner H.V.I. 5 wt. 16s
Bel-Ray High Perf. Fork Oil 5 weight 14s
Golden Spectro 85/150 2.5 wt. Very Light 13s (a petroleum/synthetic
cartridge fork oil)
Stock Paioli Fork Oil from Factory, Used 12s
Honda/Showa SS7 shock oil 5 weight 12s
Fox Racing Oil 5 weight J26 12s
Maxima Zero-Fade Light Shock Fluid 5 wt. 11s (white bottle)
Maxima High-Perf. Light Shock Fluid 5 wt. 11s (black bottle)
Stock oil out of a Boge shock 11s

Isopropyl Rubbing Alcohol 9s
Justice for Corrupt Powerful Politicians 11.76 Gigaseconds

He even noted how long 50cc of rubbing alcohol took to run through the same rig.

Compare any of the gear oil times to the fork oil times. Then look at the 75w gear oil and compare it to any of the 5w(stock) fork oils.

Here's another good one on fork oil
Ride Reports and Other Drivel: The Secret World Of Fork Oil

 

[rkwfxd]

Mr e - clif notes?

 

[rkwfxd]

Yeah mine were killing me on these crappy Vegas roads so my buddy and I drained the forks and refilled them with a 75w gear oil. It was $6 for a bottle of it and now the ride is amazing now. Now all I need to do is the rear shock.

Interesting. I would never have thought to use motor oil or gear oil. So the ride is "amazing" now - can you give us some details/ Stiffer, softer, bottoms more less what?

thanks

 

[Cadimanjd]

Interesting. I would never have thought to use motor oil or gear oil. So the ride is "amazing" now - can you give us some details/ Stiffer, softer, bottoms more less what?

thanks

Man I really like the feel now. I'm 6'5" and like 280 so the forks would dive and bottom out over almost any bump in the road
and now they soak up bumps in the road. They go down slower and give some good feeling to the bike.

 

[daddysmut]

Yeah mine were killing me on these crappy Vegas roads so my buddy and I drained the forks and refilled them with a 75w gear oil. It was $6 for a bottle of it and now the ride is amazing now. Now all I need to do is the rear shock.

:concern:

:concern:

whoa.....never heard of anyone doing this before

 

[mr_e]

Mr e - clif notes?

In a nutshell, gear oil and fork oil are not the same type fluid. They aren't even measured on the same scale. They have different characteristics at different temps and pressures.

Not an apples to apples comparison, but 75w gear lube through above dudes test rig took 50 seconds to drain.
5w fork oil, what comes stock in Grom forks took around 11-14 seconds to drain.
Rubbing alcohol took 9 seconds.

Introducing gear oil to the fork valves is going to lead to unpredictable behavior of the forks.

 

[rkwfxd]

Man I really like the feel now. I'm 6'5" and like 280 so the forks would dive and bottom out over almost any bump in the road
and now they soak up bumps in the road. They go down slower and give some good feeling to the bike.

Thank you.