A Grim Grom Experience???

Discussion in 'General' started by b52bombardier1, Jun 23, 2015.

  1. b52bombardier1

    b52bombardier1 Well-Known Member

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    Hello,

    Not really grim, just what I considered to be a lack of performance. I took a test drive today on a yellow 2015 Grom and the best it would do on flat ground, not much wind and my 183 pounds aboard was 52 mph indicated. The bike had 17 miles on it so it's definitely not broken in well (at all) but I expected something a little faster.

    It got up to that speed with plenty of pep and going through the gears was also smooth as silk. But I rode to the dealer on my 72 Honda CL100 and it is a faster bike by about 3 mph indicated. Really shocked by that. I expected in the high 50's with my girth in the seat on the Grom. The good part of this deal is that the bike I would be trading would give me money back from the dealership and I ride home on a new Grom for free.

    For Ray - did you see significant improvements in speed as the engine got broken in?

    Rick
     
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  3. mini K1

    mini K1 Member

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    Lace up an 18" (like the CB had) on the rear of your CL and you'll widen the MPH gap on the Grom.
     
  4. Bevelsd

    Bevelsd Active Member

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    Not trading the CL100 for that Grom are you?
     
  5. b52bombardier1

    b52bombardier1 Well-Known Member

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    Hello,

    No, I'm keeping the CL. This would be a trade in of my 2004 BMW R1150RT. I ride it often enough to keep the battery charged and good fuel running through it but that's about it.

    An 18 inch CB100 wheel for more speed? Interesting. I will have to look into that.

    Rick
     
  6. Deoodles

    Deoodles Active Member

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    I have about 500 miles on it and you are correct Smooth as Silk. I have taken it to about 55 mph and I am not sure that 60 will ever be possible. I like it in the twisties of western NC. I have no buyers remorse and have read extensively on what people do to them. I can see a 183 upgrade some day. Not anytime soon though. It rides like a dream isn't broken in yet and is under warranty. Did I say I get ton of smiles (from me) when I take it out:)
     
  7. b52bombardier1

    b52bombardier1 Well-Known Member

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    Yes, I have seen the Power Commander mods among others but would have to wait until after the warranty is up.

    Rick
     
    #6 b52bombardier1, Jun 24, 2015
    Last edited by a moderator: Jul 17, 2017
  8. Adam-NLV

    Adam-NLV Well-Known Member

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    It's prob a heavier bike than the 72 CL, and it has EPA smog and down tuned for it too. A better CDI module, more aggressive timing tune-up and by passing the smog equip would help the top speed, no doubt.
     
  9. racerx

    racerx Administrator
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    At 183#, you're not exactly a heavyweight and nowhere near massive enough to account for that sub-par top speed. I can get 51mph riding two-up (~300# total combined weight) from my stock 110 Nice-powered CT70...in 3rd gear! There's only .2hp difference between the 125 Grom lump and the 110 Nice. This assumes that most owners have been truthful about their 60-65mph top speeds, more than plausible, imo. Due to the seating & handlebar positioning, a Grom rider is less of an airbrake than a CT70 rider. With similar hp on tap, the Grom should have an aerodynamic advantage.

    I'd get some more break-in miles on it, then take it back to the dealership and have it sorted-out, under warranty. The Grom EFI setup is alpha-n, not a whole lot more sophisticated than a carburetor, so it should be simple enough for a dealership mechanic (a.k.a. "parts replacer") to set right. Offhand, I don't recall what the actual issue is but, it's not been uncommon with the first two model years. When functioning correctly, the bone-stock setup works very well and should deliver 60-ish top speeds.

    As for the "smog equipment" that's basically a honeycomb catalyst-equipped exhaust, not that restrictive and easily excised, plus the EFI which, imho, more closely resembles a throttle body setup, of mid-1980s vintage. A number of riders claim that the stock airbox is the biggest restriction. (Hmmmm....where have we heard that before?:39:) Haven't seen anyone get what I'd call a significant improvement from an aftermarket ECU, on a stock motor. I have seen plenty with running problems that they were unable to solve for themselves. As with contemporary cars, low-restriction airfilters, exhausts and ECU tweaks are largely the stuff of urban legend...good for aftermarket vendors who sell these items and unlike to really hurt anything.

    Changing the sprocket combo, to give shorter gearing, supposedly improves high-speed performance, as the bike is slightly overgeared from the factory. Beware, however, that'll throw the speedo for a loop. The speed sensor is in the engine, so you'll need a speedo healer if you want the speedo/odo reading to be accurate.

    The place for an aftermarket ECU is on a modified bike, with higher compression and hairier bumpstick, added displacement and possibly a different head. That's who other can of worms. Unless you know what you're doing, EFI mapping still isn't ready for primetime.
     
  10. b52bombardier1

    b52bombardier1 Well-Known Member

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    Hello,

    I do not have the bike yet. Still thinkin'. I do like the suggestion above from "Mini K1" about a bigger 18 inch rear wheel on my CL100 from a CB100 bike. I bought a good looking wheel with nice chrome last night off Ebay and will proceed to make that swap. All in all, my reluctance at buying the Grom is directly tied to how very capable the CL100 bike is.

    I've also have a 120 sized main jet that I'm going to try for the CL100 versus the 110 standard main jet . Between the bigger wheel and the fatter main jet, I might eke out 60 mph on the CL100. So I'm actually headed away from the Grom deal for now.

    Rick
     
  11. Adam-NLV

    Adam-NLV Well-Known Member

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    There's are some video's of the Grom on YouTube, it looks pretty cool. Seems the pipe is constrictive, part of the emission regs. I'll bet getting a performance aftermarket one would be a good move. A EFI horizontal Honda 125cc from the factory is sweet. :)
     
  12. mini K1

    mini K1 Member

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    Rick,

    With a fresh set of points and check of tire pressure, I experienced 65 mph indicated on my CL100 K0, in a slight crouch. Actual speed was a solid 60 mph, as clocked by another rider on a sport bike.

    The larger rim/tire combo will also close the rear fender to tire distance on your CL... Have fun.


    -Doug
     
  13. racerx

    racerx Administrator
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    FWIW...

    I never thought we'd see the Grom reach the USA. It's cool to see it here and I hope it's a success. What's cooled my enthusiasm is the newness. It's the early-adopters that take the hits. Don't misunderstand what I'm saying. The machine has potential (as well as some of the same deficiencies), as did the Z50 & CT70 when they were the latest & greatest models. If anything, the situation mirrors classic musclecars vs the 2015 versions, faster and more competent, in stock form...with 45 years worth of R&D behind them, as well as cubic acres of plastic & cheesy detailing to satisfy the bean counters.

    Turning one of these bikes into a competent & comfortable 55mph cruiser costs about the same as turning a CT70 or Z50 into one. In another couple of years, it'll likely be possible to build one of these into a 90mph mini, that won't grenade...for a (substantial) cost. But, as with a new car, it's a depreciating asset for which agreed value insurance coverage is not available. Once a Grom reaches its first anniversary of leaving the dealership it's an $1800 machine. The collector market is at least two decades in the future. The bottom line, not-quite-ready-for-primetime and too much uninsurable risk...for now, imo. That will likely change, in time.
     
  14. b52bombardier1

    b52bombardier1 Well-Known Member

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    Wow. 60 mph true!! I think my bike is in a good state of tune and the spark advancer is free to move which is often suspect in my 90 CC bikes. It does not smoke and has good compression. So I don't know what could be holding it back but I do appreciate the advice.

    Was that with the 18 inch CB100 rear wheel and tire?

    Rick
     
  15. Adam-NLV

    Adam-NLV Well-Known Member

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    Must confess, it's the first I've heard about these models with the 125cc EFI and E-start being sold in the states. Not a big fan with the plastic fairings on the bikes but that's the modern look these days.

    I looked to see if a used engine is available and would think it would bolt up to the CT70 right?
    Here's one for $950 w/free ship!:4:

    14 Honda Grom MSX 125 Engine Motor Guaranteed 263 Miles | eBay
     
  16. WRXer

    WRXer Member

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    The Grom needs more gears badly. I don't understand a 4 speed on a small bore. I find it overpriced for what it is & the level of components it has. You can get a CB300 for a few hundred more that is actually a capable piece of transportation instead of just a toy.
     
  17. racerx

    racerx Administrator
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    They were released in the east about a year before the EU got them, we got them DF last; they're well into year #2 domestically. Most of the aftermarket stuff seems to originate in Thailand, where the original msrp was 2200.

    And no, not even close to plug & play; fitting one of these into a CT70 or Z50 chassis will involve major surgery. Look at the three-point motor mount setup. Dunno what you'd need for a working ignition, maybe just a CDI module. You'd likely end up retrofitting a carburetor. Notice that the EFI setup, in its entirety, is missing from the ebay listing. No idea what the ecu, throttle body & injector, plus the plumbing & wiring would cost...probably not worth the expense, for this application. There's also the not-insignificant matters of locating the the ecu and, I presume, a submersible fuel pump in a peanut-sized tank.

    I'd consider trying one of these, despite the need to use a carburetor (ugh), there are such retrofit kits sold for the Grom...if the motor mounts were Z50 pattern. Cutting-up a frame has been, and remains, a line I'd rather not cross. YOMD
     
  18. Adam-NLV

    Adam-NLV Well-Known Member

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    Dohhh... Just as well. I'd prob want to keep the fuel injection system and a pressurized fuel system and the electronic FI circuits would be a huge challenge to do on a Trail Bike and a PITA.... just a thought.:10:
     
  19. mini K1

    mini K1 Member

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    Yes, 18" rear rim set-up with a 300x18 Michelin Gazelle M62 and a 275x18 M62 on the front... Using stock sprockets.


    Doug
     
    #18 mini K1, Jun 26, 2015
    Last edited: Jun 26, 2015
  20. Deoodles

    Deoodles Active Member

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    Yes but it wouldn't be a toy. You have to remember that this isn't much bigger than a CT70. I think most Grom owners here in the states buy one to use as a toy. I use mine the same way I use my 70. The difference seems to be in its roadibility (is that a word?) It performs very well in traffic up to 45 or 50. So it can be used in a semi urban area quite comfortably. There are roads my 70 just shouldn't venture out on. The Grom can. That is where it shines for me.
     
  21. b52bombardier1

    b52bombardier1 Well-Known Member

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    Yes. That is exactly the way I feel about my CL100. These smaller bikes lean into turns so much more nimbly where my big bike feels like the Titanic without a rudder sometimes.

    I may yet pull the trigger and get the Grom but just haven't decided yet.

    Rick
     
    #20 b52bombardier1, Jun 26, 2015
    Last edited by a moderator: Jul 17, 2017

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