Friction Drives Vs Chain Mounts????

Discussion in 'General Questions' started by chefbuzz, Jul 26, 2009.

  1. chefbuzz

    chefbuzz New Member

    Hello Folks,

    I have been looking into building a motorized bike for about two weeks now ever since I saw a guy in town (Ann Arbor, Michigan) with one. He had a chain mounted engine with a frame mounted gas tank.

    The question is Chain mounts and friction drives????

    I am leaning toward the friction drive side because it looks really easy to install and I am not very mechanical. I also like the idea that I can move the friction wheel off the tire to ride the bike normally. The drawback seemed to be less power on hills. Ann Arbor is a little hilly and I weight 220.

    I am looking into the 50cc titan from

    I am a newbie to all of this and I was hoping for some advise and feedback between the pro's and con's of a friction drive motor bikes.



  2. moped-dan

    moped-dan Guest

    Hey buzz,

    I was thinking about chain and friction drives too but in the end I went with a staton inc friction kit. I was worried about the hills and the rain, especially because I got the 33cc Robin Subaru engine. Now that the engine is starting to break in, its really gotten better and more smooth. I can keep up with most mopeds around here which is good enough for me. It gets me up most hills but the really steep ones I have to help the engine out a little bit, which is fine but if you have lots of hills I would reccomend a 50cc instead like the Titan or the Honda. Overall im real happy with the friction, I think the downsides of it are over hyped and with a good tire rain shouldnt be much of a problem. Here is a thread with a nice setup for the money: Good luck with whatever you choose.
  3. Porkchop

    Porkchop Member

    Keep doing your homework until you make sure which system you want. They both have their pros and cons. I have a brand new frame mount engine kit that's never been used. I ordered it and before I received it I decided I wanted a friction mount kit. I ended up with the kit from Assembled it and had it in the road in less than an hour, and this was my first build. I had a Harbor Freight 52cc 2 stroke (2.2HP) to start with. It currently has a Honda GX35 4 stroke 1.6 HP which I do not like becasue of the lower power/perfomance. Not knocking Honda. Everone knows they're great engines. I just don't like the low power.
    As far as the Titan, click the link below. Poster's name is s_beaudry. He's done several builds. His last one is the same friction drive kit I'm using and he put the Titan 50 on it. He has had nothing to say but good things about that engine. This is also at least his second friction drive kit from BMP. You, him and I are about the same weight. Check out his post and look at the photos he has attached. Talk to him. He's a good guy and I'm sure he'll help you. I to am thinking about a Titan.
    As far as a Honda 50, there might be crank shaft and clutch issues involved with mounting that particular engine on a friction mount. Compare photos of the Titan and the Honda with each other and you'll see the difference. There might be a quick bolt on solution for the Honda. That's all I know about it right now. Welcome aboard, good luck and hope this 'lil tid bit of info helped !
  4. Porkchop

    Porkchop Member

    I'll sacrafice riding in the rain, which I have no intentions of doing anyway, for the simplicity and reliability of a friction drive any day.
  5. Happy Valley

    Happy Valley Active Member

    As a wise member of MBc once said to me:
    "Everything in life is a trade off, the trick is getting what's right for you at any particular time and place."

    Picking up on what you've described:
    FDs are easy to install if you don't want to get too involved in mechanics. (Many here find chain or belt drives equally easy to install because mechanical ability is second nature and tinkering something they enjoy.)
    Most FDs do lift off the tire and restore the bike to it's original freewheeling mode.
    IMO there is no inherent drawback with FDs having less power on hills. Power on hills on any MB under the same load and riding conditions is related to engine output and gearing. With a FD, gearing is a product of drive spindle diameter. The most commonly available FD kits are singlespeed so again there are trade offs with gearing choice IE low gearing/small roller equals a better climbing ability on hills but sacrifices top speed. The question you have to answer is how fast do you want to go or how much pedaling up hills do you want to do?
    For me the main drawback of FDs is riding conditions. They are best suited to riding on dry, paved road surfaces. As you move away from that condition things become problematic though there are some limited measures one can use to mitigate those problems. No doubt though, all steel drive spindles lose traction on wet tires. Will you ride in thee rain? Probably not much but for me the issue is riding on wet roads after rain or when heading out on a day when it's clear and showers pop up along the way or riding between showers.

    Chain drive has the most adherents I'd guess. Many simply like a bike that looks like a motorcycle and wouldn't own anything else, though rear rackmounted chain drives are of course available. Positive drive train connection is certainly an advantage of chain drive in all weather conditions, and chain drive offers various drive train and numerous variable gearing choices as well. The ability for chain driven MBs to freewheel in a bicycle's original freewheeling mode is less universal however, though there are ready made solutions available that address that as well.

    When you think about how you want to get power to the ground it effects immediate decisions but also extrapolates into further consequences.
    For example with chain drive, if you mount the engine in the frame or behind the seat might effect engine choice and that might effect drive train decisions and how and where you attach the secondary sprocket and how/if the bike is able to freewheel.
    With FD you would do well to think about riding conditions, if you'll want to ride in wet weather, off-road, or in the winter.

    I hope some of this helps and I don't mean to complicate your decision, more offer some consideration that goes into it. There is much more info on these subjects here for the taking, a little reading and research into the archives offers a ton of insights. Best of luck with your bike.
  6. Esteban

    Esteban Active Member

  7. 5-7HEAVEN

    5-7HEAVEN Guest

    I like friction drive. I make the sacrifice of riding in the rain.

    I ride to work, rain or shine.:jester:
  8. mlcorson

    mlcorson Member

    I have a rack mounted 35cc R/S engine Staton chain drive on a heavy Schwinn Skyliner bike, total weight I guess 65lbs. I weigh about 155. I recently bought a BMP friction drive 35cc R/S engine and put it on a Specialized hybrid. That bike weighs about half what the Skyliner weighs. The friction was very easy to install and performs and handles beautifully. Honestly, if I could only keep one bike, I'd opt for the friction, so much simpler, and operates really well on a light bike. I've noticed almost no difference in power transfer. Maybe a little more peddling up before accelerating. For your weight, I would hear what others have to say about a larger engine. I hope this helps.
  9. chefbuzz

    chefbuzz New Member

    Thanks for all of the great feedback.

    I am almost sure that I am going to build the same bike as Steve from

    It is pretty much exactly what I was thinking about building, a friction drive with a titan engine on a cruiser bike.

    Rain seems like an issue, but I don't ride my bike in the rain much anyway. The Titan engine, I figure will solve for the power issue.

    I think I would want to upgrade to a 1 gallon gas tank down the road.

    I also like the idea of a four stroke because I can simple fill up at a gas station without mixing oil.

    The idea was to order from for the engine and for the kit.

  10. Porkchop

    Porkchop Member

    It's not just rain, it's a wet tire period. For instaqnce, if you're cruising down the road and you run through a wet spot and you're tire gets much wet at all, the roller will slip momentarliy until the tire gets dry enogh to create enough friction between the tire and roller. To me that's no big deal. Doesn't happen to often. Ask 5-7heaven how he gets his to go in the rain. As far as a larger fuel tank for the Titan, you might have an issue there. I understand those engines have a gravity feed fuel system, menaing the bottom of your fuel tank needs to be higher than the carb on the engine. What I mean about you might have an issue there is finding a larger fuel tank that will not stick way up in the clouds.
    Did you notice the tank on the Titan is located on top of the engine ? Ibought a ;arger tamk for my bike a few months ago. Engione is onme side of the mount anmd tank hangs on the other side. I fabed a bracket and drilIled 2 holes through the channel and bolted it on. Don't let this scare you, I'm just trying to give you a heads up. Steve's the man to talk to. Check out the attached photos. Sorry, I don't have detailed photos of the bracket before I mounted it on my bike. The tank holds 3/4 gallon. I found it on eBay for like $12.00 shipped !

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    Last edited: Jul 28, 2009
  11. chefbuzz

    chefbuzz New Member

    Another development.

    I was looking on craigslist and found this motor bike ad

    It is a fully built frame mount with a new bike for $400.

    My FB build will be 200 for engine and 200 for the kit not including a 100-200 bike. ($500-600)

    My original thought with a friction drive was that I would build it myself. The engine mounts seemed like too much mech work for a novice, and I figure I would have to pay extra to have someone build it for me bring up the cost.

    Now I find that a couple of bike shops in the area are offer fully built bikes for the same price as the bike and the engine kit. They get both the bike and the kit wholesale, so the labor is free. The result is that I "could" get a fully built engine mount bike for the same as building it myself.

    What to do, what to do.

    One thought that stands out is burns. The guy I met in town who had a engine mount bike and let me test ride it had a crazy burn on his leg from riding with shorts. I also did not like the fact that I would have to pedal start the engine. I needed like a 100-150 feet of flat road just to start it.

    And legally speaking, engine mounts look a lot like an actually motor cycle. I don't really care either way for a faux motor cycle look. Do engine mounted bikes get pulled over because they look like a motor cycle???

    The other thought here is that if I do go with a FD, I always can change bikes. A fully built engine built will be a done deal.

    Going to KMart to look at bike.

  12. norm1950

    norm1950 New Member

    I have the titan 50cc from and its great I get 35mph
  13. MikeSSS

    MikeSSS New Member

    Straton friction drive, with R/S 33.5cc, on a mountain bike, Gotham tires.

    I got caught out in a heavy rain, pushed the roller into the tire a bit more and could ride at 14 mph through the water. I did pedal lightly but the bike brought me home.

    I recommend not riding in the rain, the bike gets filthy and the water is bad for the hub and bottom bracket bearings. Water borne dirt gets in the clutch too and it sounds bad when you roll the bike to park it.
  14. darwin

    darwin Well-Known Member

    All about choice, FD is a fair weather kit in my book. Folks that say they ride in the rain and snow successfully with no problemos must have bribed Murphy, I refuse too.