Help! I want to go uphill

Discussion in 'General Questions' started by rjones, Oct 27, 2008.

  1. rjones

    rjones New Member

    I need help. I have built two motorized bicycles since April of this year. The first a frame mount Honda gxh50 with a Grubee gearbox on a Schwinn cruiser frame. The second I put together this week, a RAW 50cc 2 stroke. The typical chinese HT motor as far as I can tell.

    I live in the Blue Ridge mountains near Boone, NC. The elevation is 4700 ft. In other words I live in hilly terrain. I started with 44T sprocket which was useless anywhere but on flat surface. I traded my 44T for a 56T and things were better. At least I could go to town and back on the paved road without too much pedaling but there was still no way it would go up my driveway and some of the roads around here without me doing most of the work. I was at my brother's a few weeks ago and he gave me an old schwinn exercise bike that had a 65T chainring which I immediately saw as my next rear sprocket. I drilled the 9 holes and installed. I thought I would be able to climb any hill a car would go up but was wrong again. It was better but still not enough. I installed the HT engine yesterday and put the rear wheel with the 65T on. The kit came with a 44T so I figured the 65T would climb a tree. Wrong again. I thought the Honda was weak. it reminded me of the Honda when I had the 44T on it. I had to pedal up all but the slightest of hills.

    Has anyone else living in the hills had this trouble? Is there a remedy to this problem? I don't care about speed as much as pulling power. I'm thinking about a 24" wheel next.. Any suggestions would be appreciated. Some of you may be thinking the hills here are steeper than they are. I can pedal up my driveway on my old Motobecane Mirage. I haven't had a car yet that wouldn't come right on up the to the house. BTW I weigh 190 lbs.
     
    Last edited: Oct 27, 2008

  2. TWalker

    TWalker Guest

    shifter kit
     
  3. I think you just need to wait until the engine is broken in. On mine there was a drastic increase in power after a couple of tanks of gas. I also dont need to go fast and am running a 50t rear sprocket with a 48cc engine. Good luck....
     
  4. rjones

    rjones New Member

    help with hills

    thanks for the quick reply. I heard the HT motors got better after break-in. Got my fingers crossed.
     
  5. Hmmm.....could be that your altitude is sapping a fair amount of power too....Have you read your sparkplug to see how the mixture is (You may be running rich since you are so high up)....

    Break in will help BUT I would imagine that even the small HT engine should have enough power to motivate the bike up some degree of hill with the 44T...

    Hope this help you.

    Andrew
     
  6. I was just curious to see how much power would be lost due to altitude and on several sites people seemed to say you will have approximately a 20% loss of power due to your 4700' of altitude...

    Even though the engine is small, a stock geared engine should be able to pull some minor hills without problems....I mean when you went to 65T you should have been able to climb pretty steep hills with relative ease (not fast tho because of the low gearing).....

    Despite the "newness" of the engine I would suspect something is "up"......Unless you are used to riding a Ninja or something! ;-O

    Andrew
     
  7. wanger

    wanger Guest

    these bikes are pedal assist u need 2 use your pedals
    on a cruser u only have 1 gear try ur setup on a mountain bike then u will b able 2 pedal with it with gears [not shifter kit] 2 keep momentum
    shifter kits my mates bought they have sold on.
    when trying 2 climb hills have not found rite and all that was said by person above was use a different front chainring on cranks increased size but all this will do is increase the load u have 2 put at the pedal crank
     
    Last edited by a moderator: Oct 27, 2008
  8. rjones

    rjones New Member

    going uphill

    I don't think the "shift kit" (if it's the jack shaft kit Sick Bike Parts is selling) would gear bike any lower than it is. As far as my pedal gearing it is mountain bike gearing. I have a 28/38 chainring with a seven speed cassette on the rear. The frame is a Schwinn Deluxe 7. I don't want to pedal. Why bother with an engine if you have to pedal. The advertisements don't say anything about having to pedal, other than starting off. I probably do loose about a third of a horsepower to the altitude. I changed the main jet to one for 4000 to 8000 ft. It runs better on the top end. Still doesn't have any low end grunt. The HT seems to have a little more chugging power but just when I think it's starting to really pull there's nothing left. I am use to a ninja but I do know the difference between 20 and 2 hp. I bought two of the RAW motors I tried them both. I thought I'd build one to sell. I guess I put about 10 miles on each. They pretty much feel the same. I checked the plug after and it was dry but dark. I wish I knew for sure that there wasn't anything wrong with the engines.

    Thanks for all the replies
     
    Last edited: Oct 27, 2008
  9. wanger

    wanger Guest

    your post said it all
    GO AND GET A MOTORBIKE
    NOT A MOTOREDBIKE
    PEDDELING REQUIRED ESPECIALLY UP HILLS
    dont know who told u no peddling required
     
    Last edited by a moderator: Oct 27, 2008
  10. 5-7HEAVEN

    5-7HEAVEN Guest

    What you want is a 6.5hp push trailer attached to your bicycle.
     
  11. rjones

    rjones New Member

    going uphill

    I don't remember seeing anyone on those 2 hp mopeds pedaling. Some don't even have pedals. How can they weigh a hundred lbs. or more, go 30 mph and handle hills just fine. Yeah I know some of them have 2 speed transmissions but some of them don't. Is there some magic gear ratio that as soon as you add that final tooth to your back sprocket you can go uphill without pedaling? Like I said I don't care much about top speed. I would be content with 15 to 20 mph or maybe even less if I could get up a hill. I would go bigger but the law says no more than 50cc and 2 hp. I think my question was basically how can I make my HT go up a hill or for that matter how can I make my Grubee/Honda go uphill. From the way the vendors advertise you would think you could pull stumps with that 4 stroke powerhouse. :). I know I could get a moped for about the same amount of money or less than I already have invested in motorized bicycles but it wouldn't have the style or fun factor that a frame mounted engine on an American style cruiser does. One comment I've heard more than any other is that "It sure looks better than a moped". Sorry I'm so wordy I'll try to stay off soap box. If anyone knows the magic tooth number please send me a pm. I didn't mean to stir up indignation from some members.
     
    Last edited: Oct 28, 2008
  12. wanger

    wanger Guest

    alot of people think motor no pedal i have had these bikes for 2 years and believe me need 2 pedal up hills only on straights flats capable 40mph [65km]yes 36toothh sprocket
    up hills 44 with pedal assist no problem
    48 or 52 have not tried
    by the way i ride pushbikes all the time and i might have the leggs for it i am able 2 ride approx 100 km a day on my cross contry mountain bike
     
  13. HoughMade

    HoughMade Guest

    rjones,

    I have the same 4 stroke setup described. You are dealing with more altitude and apparently bigger hills that I do. On a couple of the largest hills I deal with, if I get a run up, say 35 mph, I will crest the hill between 20 and 25 mph- 48 tooth sprocket. However, if you have to start on hills or take them on without building speed- you are going to have a tough time.

    On the 4 stroke, what are you using for gearbox lube? Also, are you using the governor? If so, get rid of it.

    As for mopeds and scooters- one word- transmission.

    As for "pedal assist" that's up to the user- I think of mine more as pedal start and a place to rest my feet. The gearing on the Sick Bike parts kit can get it real low depending on your bike. You could also play with the jackshaft gears to get it lower.
     
    Last edited by a moderator: Oct 28, 2008
  14. rjones

    rjones New Member

    going uphill

    I run a 50/50 mixture of gear oil and Lucas oil stabilizer. I've found that it is just thick enough to quiet the gearbox down a little and it makes the clutch work better than anything else I tried and I think I tried about everything. I've bypassed the governor. The throttle goes to wide open. I put the 4000 to 8000 ft high altitude main jet in the new carb I replaced just in case. The Honda runs much better, especially at high rpms.

    I live about 3 1/2 mi. from town. The first 1/2 mi. is the gravel road I live on. The rest is a two lane state highway. The continental divide is in the middle so it's basically uphill halfway there and uphill halfway back. With the 65T sprocket the Honda does it without pedaling. It slows down to about 20 or 25 right before the top but makes it over without too much strain. The only problem is the driveway. It's about 500 ft. long I'm moving at the bottom when I start up but not fast because there's a hairpin curve first thing. I can help it up by pedaling but it seems hard on the clutch and it's very hard to balance the power between me and the motor. I usually just get off and walk along side. The HT seemed to about the same but lower rpms much lower top speed with big sprocket. I think I'm going to put that 65T sprocket on a 20" wheel just to see what will happen.
     
  15. HoughMade

    HoughMade Guest

    Sounds like not getting a run is the problem there- no way around it, though. That 20 inch wheel will really up the torque, but top speed will be really low.

    I used to use the 50/50 mix, but over time, the clutch was slipping. Is your gearbox gets so hot that you can't lay your hand on it, yours is slipping too. It may not be, but it is a possibility. When mine slipped, it did not slip 100%- it would still propel the bike forward, but under heavy load (like a hill) I did not get the power I think I should have.
     
  16. rjones

    rjones New Member

    uphill

    What do you use in your gearbox?
     
  17. HoughMade

    HoughMade Guest

  18. rjones

    rjones New Member

    uphill

    Thanks I'll try that
     
  19. duivendyk

    duivendyk Guest

    You need a gearbox with different ratios (at least 2) or a CVT.If you gear low enough to get up steep hills,you will be way overrevving the engine on the flats.I live in the Blueridge too near Lynchburg.I opted for a NuVinci drive + a Mitsu 43 cc 2 stroke.This works well on hills,the rear hub has a 3.5 ratio (0.5 to1.75).This can tackle steep hills but is quite pricey and for rack mount only (so far).Check with David Staton,www.staton-inc.com he might have come up with something for frame mount.
     
  20. rjones

    rjones New Member

    uphill

    Yeah I guess I'm going to have to bite the bullet and fabricate some kind of Jackshaft like the SBP system with a freewheel front sprocket so I can use a transmission on rear wheel. Problem is I think it's illegal in NC.
     
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