Brainstorm Base chassis for E trials bike build. ?

Discussion in 'Trials' started by MATTY, Mar 13, 2018.

  1. MATTY

    MATTY BORDER RAIDER

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    I have been contemplating building a E trials bike for close to two years now, i nearly got a Sherco 2001 off ebay but bike was sold through the back door so to speak.
    So asking the question here, what do the ADV rider trials collective knowledge base feel would be the best chassis as in an engine less rolling bike to use as a base for an E trials bike build.?
    I have so far just looked at Shercos because i have a sherco and thought any Engine ancillaries rad tank etc still on the donor bike i could add to my spares stock.
    But sadly the dead bikes seem to fetch near as much as running rough bikes and vi am tempted to look for a cheaper bike and re cover what money i can from selling the parts in a attempt to get the price of the project chassis lower.
    i know shercos and beta rev 3s well enough and a little on the 315 montessa but i have no knowledge on gas gas or other moderner trials bikes , so asking the question here rather than the electric bike section.
    What is a good chassis and are there any brands or models that command lower prices and as engined trials bikes are perhaps ungainly or with poor engine choices or some other mechanical reason they never cut it as trials bikes. Yet they had good suspension components and basic geometry and frames , and of course YOU FEEL these bikes would be suitable candidates to de commission as petrols and convert to An E bike trials conversion.
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  2. motobene

    motobene Motoing for 46 years

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    Well evolved designs tend to converge into a narrow pattern. In other words, all the bike brands have become very similar in design form.

    There are differences like 2 versus 4 strokes, and the Beta 2 strokes having the primary drive and clutch on the left and the final drive on the right, but you can get there doing custom work with any trials bike.

    Do you wish to retain the clutch and gear box like the latest GasGas and Mecatecno T12? If not, then you just need a motorless bike.

    However you go about this project, you'll face the same issues as anyone does, like how new a bike do I buy?

    If you buy a cheap older bike, you will have a cheap older bike plus all your time and money, just to attain the learning experiences of going electric.

    If you buy a newer bike, that begs the question of why not just buy a commercially available electric then dink around with that?
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  3. heffergm

    heffergm Long timer

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    I'd say any 'ol Sherco or GasGas. You'll have lots of access from the sides as well as the top with the split spar design, unlike with a Beta where access from the top will be tougher with the single spar backbone.
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  4. ivsforever

    ivsforever Adventurer

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    There is a guy in TX who converted a Yamaha TY175 to electric, he put the motor in place of the crankshaft and used the clutch and gearbox. Seems to work he rides it with the Austin CTTA trials club.
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  5. MATTY

    MATTY BORDER RAIDER

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    I thought geared and through the clutch but not necessarily the stock trials bike bottom end .
    The difference in price between a old sherco with a damaged or missing engine would be a lot less than a new E trials bike, and the motor and controls although not ideal could be found second hand wheel chairs golf carts and various industrial uses.
    I see what you mean old trials bikes, but this is all we use anyway, so a ten year even 16 year old sherco will do us ok for this project , i just got to thinking what else is out there besides beta rev 3 or shercos that might fit the bill.
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  6. MATTY

    MATTY BORDER RAIDER

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    I must admit the sherco appealed to me the most, but as i mentioned i dont know much about gas gas etc and i never really studied them that much.
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  7. MATTY

    MATTY BORDER RAIDER

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    Interesting its in use seems to be working ok, i think you could use virtually any bottom end that was similar weight and would physically fit the frame and maintain chain alignment and work angle for the swing arm pivot. Much better using the original bottom end if its still there with the bike, saves a lot of head scratching getting things to line up right to function properly, stock its all done by the factory and you can concentrate your efforts in to the electrification of the old bike rather than mixing and matching . .
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  8. DyrWolf

    DyrWolf Long timer

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    Perfect use for a 95 Fantic Section
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  9. 2whlrcr

    2whlrcr gooligan

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    :rofl
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  10. motobene

    motobene Motoing for 46 years

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    Seemingly lots of space in the crank well and flywheel enclosure for an electric motor.

    A tech challenge how to gear/do the primary drive. A chain-driven primary would be easier. Then again you'd have to ride all the sections ass end first!
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  11. MT 007

    MT 007 Been here awhile

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    Back in 2012 a couple of students at the local engineering school used an old TLR200 (reflex). Project came out pretty well but no clutch or gears - I suggested they do that as phase 2 of the project but it never happened. Their goal was to have it come in at the same weight as the gas version which they accomplished.

    [​IMG]

    [​IMG]
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  12. Ditch

    Ditch Long timer

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    Newer frames have very little space so designing the motor mount would be critical. Battery packs can be built to suit available space left over plus you will need room for the controller. With some proper redneck engineering I think a replaceable battery pack could be designed in, too.
    Lot's of info for bikes with more room in the electric bike thread and dedicated forums.
    I've been toying with converting an older ninja, etc. to electric for awhile, but haven't taken the plunge. With 65+ mpg out of my BMW it's hard to commit the money to a maybe I'll like it maybe I won't project.
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  13. motobene

    motobene Motoing for 46 years

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    The student bike has a chain-driven primary of 18/10 = 1.8, then no gearbox (like a 1:1 fifth gear), so no reduction there, then whatever the final drive is. That's way geared up compared to the overall ratios used with a gasoline engine.

    So if you borrow the primary, gearbox, and final drive from the typical trials bike, you have to use a higher RPM motor, or gear up between the motor and crank.
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  14. MATTY

    MATTY BORDER RAIDER

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    With regards electric motors it seems wheelchairs and golf carts offer the obvious choices for power plants but as anybody else any other ideas where second-hand motors could come from suitable for this job.
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  15. heffergm

    heffergm Long timer

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    I'd go golf cart any day. Those things are crazy with the restrictors removed! :)
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  16. MATTY

    MATTY BORDER RAIDER

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    Yes I think you're right wheelchairs could be a little bit underpowered I suppose compared to a golf cart. Only trouble I see with them is the price that quite expensive second hand being quite practical around smallholdings horse Paddock's excetera.
    With regards gaming in the primary side what about belt driven quiet less horsepower sap than a chain or gears.
    I accept there will be some work to do fitting a belt and not be necessarily practical in all cases but it's another option.
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  17. lineaway

    lineaway Long timer

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    Buy a used Oset and add a few mountain bike parts.

    Attached Files:

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  18. motodojo

    motodojo Been here awhile

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    Or you could buy a brand new e-bike for $800 less than the Oset 24.
    https://lunacycle.com/sur-ron/

    I don't know much about watts, amps, volts etc. Which has more power and range, the Oset 24 or Light Bee?
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  19. MATTY

    MATTY BORDER RAIDER

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    Looking on electric car conversion forums brushless Motors are the way to go, apparently more reliable long term I don't know if the mileage is covered in a trials bike could render brushless I luxury you don't really need. Anything new with me is totally out of it with regards finances I wouldn't spend it even if I had it.
    batteries seem to be the biggest issue if you read what is sad on the electric car forums I suppose a car sheer mass renders bigger batteres a must less so probably on a trials bike with it lower weight and low miles.
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  20. lineaway

    lineaway Long timer

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    Batteries is the whole problem. Watching Dad`s carrying back packs full of spare batteries is just lunacy to me.
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