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Discussion Starter #1 (Edited)
Not sure if anyone else has done something like this but i figured id post up my new clutch setup and mod. In classic ND4 fashion i like to make things reliable so here we go. (you can skip below the second === to get the mod)


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Backstory: I finally rounded out my bbk with a finbro superhead that i ported n polished up myself. Things are running amazingly good. The other day i missed a shift between first n second at WOT, wound it out to 12.5k and dumped it back into 2nd and was appalled at how much clutch slip there was, probably around 1.5-2 seconds before it fully grabbed (this was with EBC "10% stiffer" springs and the stock clutch plate). So i set out to get ye ole standard billet clutch plate and much stiffer springs.

I ended up with this

Honda Grom/MSX125 Billet CNC Clutch Plate Kit [WCR] - $49.99 : The Sic Shop, Stunt Parts Store

with 6 finbro springs. 67ish shipped for a nice billet piece and 6 MUUUUUCH stiffer springs.

So the other night i popped it in and took her out for a spin. Clutch grab was INSANELY better, lever pull not any worse than my other motorcycles, but you can actually clutch up a 2nd gear wheelie with ease now and full rev limit clutch dumps have almost zero slip.

Then i took a shit, and a shower, which allowed me to think (this is never any good).

This billet plate has identical tabs for all 6 spots which include a hole for one of the 3 stock bolts. I never liked how 3 of the springs were not captured by a bolt on either a stock or aftermarket clutch plate especially considering how much stiffer these new springs were. So i decided to change this.
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The stock pressure plate has 3 of its 6 spring standoffs threaded for 3 M6x1.00 x 20mm flange bolts. The other 3 standoffs just so happened to be already drilled with the right sized hole (a smidge under 5mm) to be tapped for M6x1.00 threads. In combo with my new billet plate that had each spring tab with a hole in it, things could work out well for a 6 bolt clutch. So i pulled the side cover back off. Pulled the clutch out of the bike so I could tap the predrilled unthreaded holes with an M6x1.00 tap i borrowed from a buddy. Went to the hardware store n picked up 3 M6x1.00 x 20mm flange bolts and then bolted everything back together. Now every spring is properly captured. There is no extra stress on the ears of the clutch lifter plate caused by springs not being properly captured and i feel much better now.

I did not take any pics of the disassembly or tapping process, but any clutch disassembly video will show you how to get to be able to pull the pressure plate out. But here is the final product. 3 OEM bolts and 3 new bolts properly holding the clutch all together in one big happy grippy family.

6BoltClutch.jpg
 

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Good to know they won't have to be drilled out anymore before running a tap through it. Seems like a common sense mod that anyone with an aftermarket plate should be doing.

Thanks for doing this before I bought mine... think I'll be doing the same thing considering how often I drop the clutch!

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Discussion Starter #4
Good to know they won't have to be drilled out anymore before running a tap through it. Seems like a common sense mod that anyone with an aftermarket plate should be doing.

Thanks for doing this before I bought mine... think I'll be doing the same thing considering how often I drop the clutch!

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Only some of the aftermarket plates have 6 identical ears that will allow this. Lots only have 3 holes drilled through them and 3 spots to recess the bolt heads. That stated, when considering a clutch lifter plate, getting one with 6 holes like i did has its benefits.
 

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I’ve been considering doing this quite some time now. Just haven’t had a real need to do it. Though I’ve got my hands on 6 of the busa springs and from what I heard(well, seen tests on Facebook), they’re by far the stiffest that’ll fit in a Grom. Also have my RSC on order. When it comes in I plan to do this mod.
 

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I’ve been considering doing this quite some time now. Just haven’t had a real need to do it. Though I’ve got my hands on 6 of the busa springs and from what I heard(well, seen tests on Facebook), they’re by far the stiffest that’ll fit in a Grom. Also have my RSC on order. When it comes in I plan to do this mod.
If the Hayabusa Springs are a lot taller than the stock springs, its not going to work because they'll bind before the clutch is fully disengaged. When you lock the three clutch plate bolts down, you'll hardly see a gap between the coils of the spring. Once you put the clutch cover back on, you'll know immediately when you go to test it out. Your clutch lever will have a bit of "play" then feel very stiff...don't try to force it.

HOWEVER....If it works, let us know! Share the part number.
 

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Discussion Starter #7
^ yup what solidjohnny says. I actually ordered a set of the busa springs and they are too long, They are almost at coil bind just sitting in the clutch with the plate tightened, let alone when them further compress to disengage the clutch.
 

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I got them off a guy on Facebook (Pistol Pete I think was the name) that has been using them in his Grom. Even had them on a spring scale comparing them to stock and ebc springs. Spring height looks same as stock. I’ll post the part number when I get home later this evening.
 

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I got them off a guy on Facebook (Pistol Pete I think was the name) that has been using them in his Grom. Even had them on a spring scale comparing them to stock and ebc springs. Spring height looks same as stock. I’ll post the part number when I get home later this evening.
It would probably work great if they are cut down to the right height. I thought about it, but it would've been too much effort for me to make the cut end look nice.
 

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Discussion Starter #10
I got them off a guy on Facebook (Pistol Pete I think was the name) that has been using them in his Grom. Even had them on a spring scale comparing them to stock and ebc springs. Spring height looks same as stock. I’ll post the part number when I get home later this evening.

while they might be same or similar height their wire diameter is MUCH bigger which creates the coil bind
 

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Busa (part# 21413-24f10)
29.8mm long
2.28mm wire diameter

Stock
27.72mm
2mm wire diameter

Hmm, guy said he’s been running them for a while now. Though after measuring, I could see their size being an issue. Glad they were cheap, $13 for all 6. I wanted to try them out of curiosity anyways. I’m already running 6x kitaco 60% springs on the stock clutch pack(with 24,4** miles on them) and it grips nice an tight!
 

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Busa (part# 21413-24f10)
29.8mm long
2.28mm wire diameter

Stock
27.72mm
2mm wire diameter

Hmm, guy said he’s been running them for a while now. Though after measuring, I could see their size being an issue. Glad they were cheap, $13 for all 6. I wanted to try them out of curiosity anyways. I’m already running 6x kitaco 60% springs on the stock clutch pack(with 24,4** miles on them) and it grips nice an tight!
That looks like it would work. That's a pretty good deal for just $13!!! Let us know how it works. I was looking into the Kitaco springs myself.

Thanks for posting up the part number. I noticed it was for the 1999-2000 Busa. I think I only looked at 2001 and newer busa springs, and they're much longer.
 

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Finally got to ride with my rsc lever. I can finally pull the clutch comfortably(though still on the stiff side) with just my index finder. Used to use my middle finger(mostly) and my index finger. Thats with the 6x 60% kitaco springs(on stock clutch pack with 24,533miles on it and a drow sports spring plate) and I really like the way it feels right now. Not gonna be swapping the springs too soon. Gonna throw in a SMR 6 plate clutch pack in at the same time. Should have crazy reliable kung fu grip for a long time.

I go guess long story short. The kitaco springs are nice. All six is very stiff on the stock lever, everyone that tried it on my bike side it was too stiff. With my short rsc lever it’s still stiff but not too much. Most people would probably just run 3 of them, unless of course they prefer a stiff snappy clutch.
 

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I ordered this and my clutch plate only has holes drilled on 3 of the tabs instead of 6. It looks way different than the one pictured on their website.
 

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Discussion Starter #16
I ordered this and my clutch plate only has holes drilled on 3 of the tabs instead of 6. It looks way different than the one pictured on their website.

Its funny i actually ordered the one with holes in only 3 tabs and they sent me the one with 6.... at first i was pissed but then went hey this works out way better. Call them up and say you wanted the one with 6 holes.
 

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Its funny i actually ordered the one with holes in only 3 tabs and they sent me the one with 6.... at first i was pissed but then went hey this works out way better. Call them up and say you wanted the one with 6 holes.
Yeah I thought about it. I've got a kitaco cover and oil pump ready to be installed so I don't really want to wait on getting a new one. I may drill it out myself or just say f*#k it and run with three.
 

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Discussion Starter #18
Yeah I thought about it. I've got a kitaco cover and oil pump ready to be installed so I don't really want to wait on getting a new one. I may drill it out myself or just say f*#k it and run with three.

You could do that too. Wouldnt be terribly hard to get the holes mostly centered, and really you could just go one size bigger so you have a lil wiggle room.... the bolts themselves will thread into the clutch pressure plate after you tap them so no worries on getting stuff perfectly centered.
 

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You could do that too. Wouldnt be terribly hard to get the holes mostly centered, and really you could just go one size bigger so you have a lil wiggle room.... the bolts themselves will thread into the clutch pressure plate after you tap them so no worries on getting stuff perfectly centered.

Well I was a moron and tried to tap the holes with the clutch assembly still on the bike. Ended up breaking my tap off in one of the holes. Took the clutch apart and tried to drill it out with no luck so now I've gotta get a new pressure plate. If anyone else does this be sure to tap them off of the bike!
 

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Discussion Starter #20
Well I was a moron and tried to tap the holes with the clutch assembly still on the bike. Ended up breaking my tap off in one of the holes. Took the clutch apart and tried to drill it out with no luck so now I've gotta get a new pressure plate. If anyone else does this be sure to tap them off of the bike!
I actually tapped mine on the bike as it holds the pressure plate very well (had to take it off to clean the tapping flakes) You gotta be slow and methodic with a tap. 1/4 turn of cutting, back off a full turn. fully pulled the tap out of the holes probably 4x per hole to clean the tap and re lube with some oil.
 
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