Convert Single speed Specialized into Pedelec?

[tapash]

How easy and practical to convert a lightweight single speed/fixie bike to an ebike? What are the advantages & disadvantages? I am aiming to keep the weight as less as possible thus this approach...

 

[flecc]

It's practical, but if a fixie probably best to only have throttle control to help avoid the feeling of your legs being driven at times with some pedelec types which could be unpleasant. Personally I think a single speed with freewheel would be better for being comfortable with the combination of motor drive and pedalling.
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[tapash]

It's practical, but if a fixie probably best to only have throttle control to help avoid the feeling of your legs being driven at times with some pedelec types which could be unpleasant. Personally I think a single speed with freewheel would be better for being comfortable with the combination of motor drive and pedalling.
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Thank You.
I have one freewheel in mind, Fitting a Oxydrive 13AH model, would it be a overkill? considering its a road bike? Maximum width of tyre i can fit would be limited.. isnt it?

Rear frame dropout/rear spacing of this bike I am talking about is 120. I didnt see any reference guide about this in oxydrive website though.

 

[flecc]

I was thinking of a front hub motor conversion. That 120 mm is too narrow for most motors in the rear, they generally need 135 mm, but that's with a derailler set of sprockets, so without that and leaving off the odd spacer/washer might trim that width need slightly. Rear frames can often be stretched to some extent too.

I can't say on the tyre width without knowing the bike, they vary quite a lot. Sometimes the height to the fork crown is a tyre size limiter too, not just the width.
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[tapash]

I was thinking of a front hub motor conversion. That 120 mm is too narrow for most motors in the rear, they generally need 135 mm, but that's with a derailler set of sprockets, so without that and leaving off the odd spacer/washer might trim that width need slightly. Rear frames can often be stretched to some extent too.

I can't say on the tyre width without knowing the bike, they vary quite a lot. Sometimes the height to the fork crown is a tyre size limiter too, not just the width.
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Its specialized Langster.

 

[flecc]

Its specialized Langster.

I don't know that personally, but from the illustrations it's not the most suitable for conversion, very much an all-out dedicated fixie. The blind front fork end isn't ok for mounting a hub motor and the tyre size is likely to be somewhat restricted at both ends.

So either a rear hub motor if one can be found to fit that 120mm, or alternatively if the bottom bracket is fairly standard, a crank motor kit.

My knowledge on what's available in those two types is limited, but hopefully others will know some that suit.
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[trex]

beautiful bike but not easy to convert with that flip flop rear hub and narrow fork:

 

[mfj197]

In many ways a fixie would make a good lightweight conversion as you get the electric assistance at lower speeds partially negating the need for lower gears. However I'd have to agree with others - the Langster doesn't look an easy conversion. Also if you're looking to keep the weight down (good idea on a bike like that) I'd steer clear of the Oxydrive kit which, whilst being good, is definitely not a lightweight. It weighs more than half of your entire bike, at over 4kg. I'd probably look at something like a Q75 in the forks for that application, although yours are carbon (but that might not be a problem with a Q75).

Michael

 

[bateman]

I tried and ended up getting another bike. See last few posts of http://www.pedelecs.co.uk/forum/threads/cyclotricity-kit-review.19793/

 

[tapash]

Thank you all for your input. First of all, looks like i have to forget about Langster.

Re: Q75 kit seems not available in UK. So need to forget about that too.

From the begining i was not so inclined using the conversion kit, due to the complexity of it. And after reading baseman's thread I am glad that I have started this post.

I guess I better off buying a readymade bike... But thank you all in this forum. You Guys have been the most helpful I am glad I bumped into this forum.