New BMP Combo Drive and Jackshaft Kit

Discussion in 'Dealer Advertisements' started by BMP, Dec 4, 2010.

  1. BMP

    BMP Motored Bikes Sponsor

    The new BMP Combo Drive is finally here! We have redesigned our friction drive kit to allow for conversion to chain drive. With our new belt powered or chain powered jackshaft kit you can easily and affordably convert to a quality chain drive setup. With the belt powered jackshaft the gear reduction is 2.86:1, and with the chain powered jackshaft the reduction is 3.38:1

    With this versatile system the engine does not have to be removed and bolted on the opposite side of the engine channel when changing from friction drive to chain drive, the entire unit will simply be rotated 180 degrees (with friction drive the engine will be on the left side, and with chain drive the engine will be on the right side) don't even need to remove the drive roller from the drive shaft when converting to chain drive.

    With chain power there is some chain noise, but with belt power the system is virtually silent and very smooth. There is very little drag when pedaling with either system, almost a non-factor. The kit comes with a belt/chain guard that covers the system nicely. The kit is well balanced with the weight of the engine on one side and the pulleys or sprockets on the opposite side. The kit comes with 2 extension brackets for the quick release skewer that bolt to the engine channel. The chain tension is quickly and easily adjusted with the quick release skewer. The chain sprocket as well as the entire unit can adjusted laterally for proper chain alignment.

    The belt, sprockets, and pulleys used on the jackshaft kit are readily available here in the USA from many different manufacturers and vendors (or from us). This is helpful if you ever need to replace parts or wish to change gear reduction. The kit is versatile in what it can support for those of you who are more experienced or are interested in is an excellent building platform. With the chain powered jackshaft it has room for a larger 2nd sprocket if you desire more reduction than 3.25:1. For example, if you switched to a 30 tooth second sprocket this would make the gear reduction 3.75:1. There are many possiblities.

    We have been test riding this quite a bit and it has exceeded our expectations. Please check out our website at for more details and pictures of this exciting new kit. Attached are a few pics.

    Attached Files:

    Last edited: Dec 5, 2010

  2. ballermj23

    ballermj23 New Member

    nice!!! Look fantastic... Now you have taken your kits to another level.
    Last edited: Dec 5, 2010
  3. BMP

    BMP Motored Bikes Sponsor

    Thank you ballermj23...we are very excited about the new kit, especially because it rides even better than we thought when we first drew up the plans. I know you sent me a PM regarding comptability if you have our old friction kit. Since it will be a common question I figured I'd answer it in public.

    Unfortunately if you have our old kit you will not be able to use the jackshaft kit. One of the main changes was the addition of another set of bearing holes in the engine channel for the jackshaft, as well as making it 11" instead of 10". We also made the drive shaft longer to accomodate the pulley/sprocket and added a set screw flat.

    The only way you can upgrade is to get the new engine channel, plus you would need the longer drive shaft. Although this is not ideal, you can probably use the old drive shaft even though it is a little short.....this is because it still has enough length to grab the set screw on the pulley or sprocket, you would just need to file out a set screw flat.
    Last edited: Dec 5, 2010
  4. 5-7HEAVEN

    5-7HEAVEN Guest

    Awesome, man. That is the best thing you could've done to the kit.

    How do you tighten/loosen the belt or chain, from engine drive to jackshaft?
    Last edited by a moderator: Dec 5, 2010
  5. BMP

    BMP Motored Bikes Sponsor

    The 21" V-Belt used is a perfect fit, no tensioner is needed and you cannot adjust the tension. To install it you need to have the engine pulley secured to the drive shaft and the larger pulley in hand. Next you place the belt around both pulleys, then pull it tight and slide it on the jackshaft - it can be a little tricky at first but once you do it a few times it's easy.

    As of now no tensioner is used on the chain jackshaft either....the chain fits well without it. The current sprocket combo is 8 teeth/27 teeth. There is a chance we may change that combo...if so we may need to add a chain tensioner
  6. 5-7HEAVEN

    5-7HEAVEN Guest

    This kit has a LOT of potential!
  7. occchopperfl

    occchopperfl Member

    Hey Jim,

    I just bought your fd kit a month ago. (im from Palm Coast, FL btw)
    The kit came delivered on time and promised. (still in box, not installed)
    Thank you!

    Congrats on your new chain/belt jackshaft adapter!

    I think my engine channel is 10", -
    is there anyway I can get the new fd kit with 11" engine channel to fit your new chain/belt jackshaft adapter?

    Thank you. :)

    Sorry Jim, Maybe a PM or email would have been more appropriate?
    Last edited: Dec 6, 2010
  8. BMP

    BMP Motored Bikes Sponsor

    Hi Jerry,

    Since you haven't installed the old kit I can exchange it for the new design if you can wait a few weeks. Right now I have limited stock and need to save them for sales.....I didn't want to manufacture too many this first run in case we had to make any changes to the new engine channel (it turns out we don't right now). We will probably run out of stock soon and it will be the end of this month before we have plenty in stock. I can do it then....if that doesn't work for you I would be able to give you a really nice deal on the new design when I have plenty of stock.

    Thanks and let me know
    Last edited: Dec 6, 2010
  9. occchopperfl

    occchopperfl Member

    Thanks Jim,

    No worries, i'll follow your lead. New kit for the new year!

    Thanks again Jim!

    For those of you who dont know, Jims contact info at BMP is:

    Please email your questions to

    Mailing Address
    c/o Formula Bicycle Engines
    936 Red Mill Rd.
    Greenville, New York 12083 USA
    Telephone: 518-772-4592
    Last edited: Dec 6, 2010
  10. lowracer

    lowracer Member

    The new kit is looking great & I'm sure will attract many avid MB fans for its versatility.
    Happy Holidays,
  11. cpuaid

    cpuaid Member

    Now this is what I've been waiting for! We need some estimated max speed for the the most popular engine configurations with the stock wheel sprocket. Wondering if I can use my 28T wheel sprocket with this setup, may need to install some kind of tensioner pulley to keep everything in proper alignment. Perhaps the belt/chain setup is the safest way to go in case of chain misalignment?
    Last edited: Dec 6, 2010
  12. 5-7HEAVEN

    5-7HEAVEN Guest

    You will not be able to use that 28t sprocket. The resulting gear ratio would be too high.

    Max jackshaft ratio = 3.75:1.....
    28t wheel/8t jackshaft = 3.5:1.....
    3.75 x 3.5 = 13.125:1.....too high.
  13. BMP

    BMP Motored Bikes Sponsor

    Check the website, it has a table with estimated speeds with different size wheel sprockets. Most stock sprockets that come with the Import kits are 44tooth. With the belt jackshaft this would give you a 15.7:1 gear ratio, and with the chain jackshaft this would give you an 18.6:1 ratio. No belt tensioner is needed with the current belt/pulley combo, but if you were to go to a different combo you may need a tensioner. I've attached a couple of photos of a belt tensioner that can be added if needed.....the same concept can be applied for a chain tensioner as well.

    Attached Files:

  14. cpuaid

    cpuaid Member

    Very informative data from the BMP website on the jackshaft ratio / max speed. Looks like this is a very well engineered drive system that won't cost you an arm and a leg. My congrats to BMP on a very user friendly drive system and I will definitely be placing an order. Small question slightly off topic. Why doesn't BMP offer a 1-1/2" steel roller for the friction drive kit any more? I thought it was available at one time in the past.
  15. BMP

    BMP Motored Bikes Sponsor

    We never had a 1.5" steel roller but we did have a 1.5" urethane roller. It is a stock part you can get from (part #2475K32). We stopped offering it because a few people had it shred up on them. Also, they slip instantly if they get even a drop of water on them, much worse than a steel roller on wet roads. They are offered in different durometers, soft to hard....we used the hard one, but maybe a softer one may have worked better. I didn't have any problems with it myself on dry roads, but I only put about 100 miles on it. It would cost you about $30 plus shipping if you ever wanted to test it out.
  16. happycheapskate

    happycheapskate Active Member

    Thanks BMP. I don't have your kit yet but I have been helping promote it because you made the product I wish I'd bought in the first place, and you make a product in USA.

    I am saving small change and gift $ to buy one in the future. I already have the hybrid/comfort bike for it. I'm just waiting!

    I really like the new chain-driven wheel setup! I LOVE Lawn and Garden and industrial trimmer engine equipment so this is a strong related interest. I think these 2 kits are set to start a transportation revolution in America, as long as Big Brother doesn't jump on it and tax the # out of it.

    Can't wait to buy.
  17. happycheapskate

    happycheapskate Active Member

    I have a technical question. If a bicycle uses a 11-34 tooth cassette on a standard shimano mtn bike wheel, can the chain drive of the BMP kit be made to turn the 34 tooth cog, if 1 or 2 other cogs are deleted by spacers so the pedal chain does not conflict with it? I know it will still have a slight drag from the clutch maybe, but at least it can free coast, and eliminate the LH drive cog system.
  18. BMP

    BMP Motored Bikes Sponsor

    Hey Happy,

    With the price wars that you see happening in this Industry it is tempting to have the kit outsorced and made in China....we are proud to say that our kit is still made in the USA. Of course there will always be a few components that are imported (bearings, quick release and maybe some hardware), but the core components are made here in the USA (clutch drum, channel, drive shaft, frame bracket, drive roller).
  19. BMP

    BMP Motored Bikes Sponsor

    It can be setup to run the large sprocket on your cassette but this would make the pedals turn also, requiring you to pedal along all the time...not something you want. I think that's correct? Actually now I'm confused....anybody else know?
  20. happycheapskate

    happycheapskate Active Member

    Front Freewheel Cranksets, adapters, and various chainwheel sizes, sold here, separately (e-bike store)

    SICK bike parts also has Front Freewheel cranksets for SQuare Taper Bottom Brackets. (SICK is awesome! )

    I'm mostly interested because of these two ideas:

    A person in a state with certain clauses in the motor bicycle laws is not required to use pedals, if the bike is under certain CC and is actually a bicycle frame and wheels. I am trying to remember what state now, will look in the forums, or someone can chime in. This would allow a RH drive side and use of common wheel parts, with a freecoasting hub.

    A person who wants to pedal full time anyway can use it like this:

    Yes, it would be true in this application. If the engine is small like 32cc, and the automatic clutch is still used, it shouldn't be a problem, because pedaling full time would work well on some applications, especially since you say it can be pedaled with the engine off, correct? 2 cycle engines used for this will have a fast throttle response, so letting off the gas lever would disengage the clutch nearly instantly. A dual kill switch setup with thumb buttons for each hand would be effective for a safety measure. Extra care would have to be taken to let off the gas when changing speeds.

    Someone on this forum once modified a Shimano hub or a shimano freewheel to use a standard BMX freewheel in place of a lockring or smallest cog. This would eliminate the multi speed ability though, but would allow use of spacers to create a place for the motor chain to fall into if it ever derailed due to the motor quick release bracket loosening.

    I would use this on a bike with BMX pegs so I could start the bike, then ride on the pegs like a sport bike. With a short crank like 160-175, you shouldn't have to worry about grounding out the pedals.

    The front freewheel cranks sold for shift kits could also be employed. This would leave one with ONE motor speed gear, and various pedal speed gears (minus deleted gear for space to prevent chain rub). This would be IDEAL for me because I live in TX where the multi speed motor/shift kit is not legal, as far as I know. It would also be a perfectly fine setup for anyone. With pedal speeds, you can always crank your feet on the hills to power up, then coast for the downhill and flats.
    Last edited: Dec 8, 2010