its now a e-motorcycle

[Craigh85]

What kind of weights in a striped rolling chassi ? It sure looks light.

[gwhy!]

What kind of weights in a striped rolling chassi ? It sure looks light.

its around 42kg, when I had it running with the small out runner with 10ah of battery it had a total weight of 51kg but this was a little to heavy for the poor old tiny motor.

[drewjet]

So what motor are you planning, how much battery, and what top speed?

What is the typical wet weight of a gas trials bike?

Will you be able to be lighter or about the same with your conversion?

Sorry for all the questions. but I have never done trials before, and it sure looks to be fun, and as long as you are not trying some of the really crazy stunts, it seems relatively safe, as the speed is not real high. There just isn't a lot of info on this forum, and I haven't got the time for other places.

[gwhy!]

So what motor are you planning, how much battery, and what top speed?

What is the typical wet weight of a gas trials bike?

Will you be able to be lighter or about the same with your conversion?

Sorry for all the questions. but I have never done trials before, and it sure looks to be fun, and as long as you are not trying some of the really crazy stunts, it seems relatively safe, as the speed is not real high. There just isn't a lot of info on this forum, and I haven't got the time for other places.

A modern ( newer ) gas bike will be a bit lighter than the one I have ( with gas engine) which is around 75kg-80kg ready to ride.
After conversion with around 30/40Ah worth of lipo it will be around 60kg ready to ride. Top speed will be around 22mph ( but I have a few plans to make it 2 speed and try to gear it even slower ) the plan is to use 2 outrunners on a common shaft ( If I can make it fit to save space) Im estimating about 7kw at this speed should be enough to have some serious fun. Its about one of the safest and cheapest forms of motor sport to get into and I love it. Its more of a personal challenge rather than competing directly with others and you only ride what you feel comfortable doing and your skill set. When I had it running before with only 2.5kw @ 22mph it was usable as a beginners bike but You need more power once you start needing to pop the front wheel over stuff.

[drewjet]

Thanks for the input, it seemed about what I thought, but far better to get info from someone who knows than me guessing. Do you really think you need 40 AH worth of battery? My uneducated guess would say that due to the low speed and not always being on the power that 15 to 20 would be enough, but again that is why I am asking as my experience level is zero.

I was thinking of an Astro 3220, as I have a spare right now, It is good for 7 to 10KW bursts so with an optical sensor from Burtie, I think would be the ticket.

Again thanks for your insight into this

[gwhy!]

40ah will be over kill to lug around on the bike and I will prob only use 10ah worth on the bike at a time which should be enough. Yes most of the time you will only be pottering around at about 5-10mph but if there is a long hill climb ( at full throttle ) with a couple of stop/starts on the way then this will really bite into the battery also the very short bursts of power needed for popping the front wheel over stuff even you are still only travelling at walking pace, these all add up. My bike in the OP would do approx 10mins of constant demanding trial sections with 10ah or travel about 6-8miles for normal offroad riding ( mx style ) with 10ah so even the trials stuff is very slow, its very intense on the batterys. Putting this into perspective when competing in a trial there are around 40 sections that are marked on and each section will be about 1-2min long everything else will be just riding offroad style.

[cyclesguff]

Hi,

I've just joined endless-sphere and am amazed at some of the builds. I'm very interested in your trials bike build. My beta rev3 is possibly going over to electric, this will be the first time I have done any e-bike/moto build so any advice and tips would be be greatly appreciated.

Stay upright

[gwhy!]

Hi,

I've just joined endless-sphere and am amazed at some of the builds. I'm very interested in your trials bike build. My beta rev3 is possibly going over to electric, this will be the first time I have done any e-bike/moto build so any advice and tips would be be greatly appreciated.

Stay upright

Hi and welcome to es,
umm rev3 to electric very nice, the rev3 has always been my bike of choice. I have the sherco as it was a very cheap bike to play around with and being a steel frame would be easy to weld lugs and stuff to if needed. The only problem with the rev3 is the petrol tank, being part of the frame it takes up valuable space. I am messing about with a "one mount fits all" universal fitting solution at the moment. Some tips: aim for a total weight of the bike ready to ride at about 60-65kg ( should be easy to do with the rev ) think about what the top speed needs to be ( aim for 25mph for 95% of trials stuff, if you can get it upto around 30 would be better for long climbs ). you need to be looking for a min 3-4kw power for easy route trials and 5-7kw middle route and 7kw+ for hard route stuff ( but this really depends on the weight of the completed bike) . you will get around 8 sections on a middle route and the commutes inbetween ( as long as the commutes are not to far/long ) on about 10Ah ( think about swapable batterys instead of carrying all the batterys on the bike at the same time this saves weight and unnessasary power wastage ) .

[cyclesguff]

Hi,

Thanks for the advice and the universal fit sounds very interesting. I was also thinking about the issues of the petrol tank and aluminium frame. The beta is a good runner and tidy bike, so it might be worth selling it and buying a gas gas, sherco non-runner as the basis for the project. I don't compete in trials, but am lucky enough to have an old quarry close to my house for pottering about. Noise can also be an issue, so a 'quiet' bike seems like the way to go.

[bzhwindtalker]

I started riding trial style stuff lately, I really like it! My next bike will definitely be geared more towards trial. However keeping pedals on a E-trial sucks :/ I feel like it limits the bike, but loosing pedals means loosing a lot of legitimity to ride on protected trails and do rock climbing on the seafront... Decisions, decisions..

[gwhy!]

I started riding trial style stuff lately, I really like it! My next bike will definitely be geared more towards trial. However keeping pedals on a E-trial sucks :/ I feel like it limits the bike, but loosing pedals means loosing a lot of legitimity to ride on protected trails and do rock climbing on the seafront... Decisions, decisions..

I did start to try and ride cycletrials for a while but I just could not get the whole pedal thing , its another thing that you need to think about when tackling a obstacles ( the pedals need to be in the right plane to clear it ) , its something I have thought long and hard about to have or not to have pedals. I was toying with the idea to have quickly removable pedals just so I can ride to a playgound and remove the pedals once I got there, but now I am going for a full blow trials bike as I have 2 other e-bikes ( with pedals ) that I can just have a play on if I want to, and the full blown trials bike is only weighing around 60kg will will be more than light enough to fit onto a heavy duty cycle carrier for the car to transport it about.

[deVries]

I just wanted to put my 1,000th post "here" in honor of gwhy!

Any offerings for ES coming anytime soon? This Summer or Fall?

[gwhy!]

I just wanted to put my 1,000th post "here" in honor of gwhy!

Any offerings for ES coming anytime soon? This Summer or Fall?

I may have a couple of new things to show you guys Soon

[gwhy!]

not much to show, but I thought I will post a pic of the bike as it stands at the moment, this is just setup to test the strength of the chains, sprockets and mount. so there is nothing really new here ( at the moment ) but over the next couple of weeks this should change as long as everything holds up to the abuse that it will get in the testing with 3kw. This was the mk2 version, the bearing housings on the jackshaft give up on mk1 after only 500 meters of testing ! at least the mk2 have survived the initial testing of pulling wheelies and bunny hopping

left side_1.jpg (68.23 KiB) Viewed 444 times

[bzhwindtalker]

Damm this looks so strange! big bike, small motor... is that a 6374?
Just to know, how much does such a rolling frame cost?
I guess it weigths something between 40 and 60kg? it's still not too much considering you have a bombproof frame to bash around at 40kph with really good torque.

I'm waiting for videos

[cyclesguff]

wow, I'm looking forward to seeing more, hopefully soon.

Is the chain from a bicycle?

[deVries]

This was the mk2 version, the bearing housings on the jackshaft give up on mk1 after only 500 meters of testing ! at least the mk2 have survived the initial testing of pulling wheelies and bunny hopping

That bike looks like a monster with no engine.

Is mk2 a different design than mk1 or just an upgrade to resolve the bearing issues?

Plenty of room for lots more batts.

Look'n good gwhy!

[gwhy!]

Damm this looks so strange! big bike, small motor... is that a 6374?
Just to know, how much does such a rolling frame cost?
I guess it weigths something between 40 and 60kg? it's still not too much considering you have a bombproof frame to bash around at 40kph with really good torque.

I'm waiting for videos

yes a 6374. The bike as it stands weighs 52kg . Rolling chassis are rare but can be bought from anything from £200 up or you can get a running bike for around £600 up ( depending on age and condition ) then sell the engine and exhaust and all the other bits and pieces that you dont need( a good engine would sell for around £200+, and other bits and pieces for another £150. I have plans to be putting around 6-8 kw through it, now this will really bring it to life don't get me wrong its fun to ride as it is with just 3kw.

wow, I'm looking forward to seeing more, hopefully soon.

Is the chain from a bicycle?

its a kart chain and sprockets.

This was the mk2 version, the bearing housings on the jackshaft give up on mk1 after only 500 meters of testing ! at least the mk2 have survived the initial testing of pulling wheelies and bunny hopping

That bike looks like a monster with no engine.

Is mk2 a different design than mk1 or just an upgrade to resolve the bearing issues?

Plenty of room for lots more batts.

Look'n good gwhy!

just a upgrade for the jackshaft and bearings. loads of room for more battery's

[gwhy!]

This weekend I done some more testing ( well me and my son ) and was just pottering around on halve throttle to see how hot the motor and controller would get, the current limit on the controller was set for around 75A @ 48v. The motor got hot but survived 10mins of continuous riding on halve throttle as in these to small vids. These vids are not very dramatic but as I was out testing the bike I thought I would take a bit of vid. The bike is geared for a top speed of around 22mph and feels very under powered at this power level, I tried the bike geared for 30mph and it would still pull reasonable well but no good for anything off road but would be usable for road use.

[bzhwindtalker]

It does indeed look under-powered... considering it weigths that much. It looks like it needs x3 the power to me!

[gwhy!]

It does indeed look under-powered... considering it weigths that much. It looks like it needs x3 the power to me!

In the vids is only at about halve throttle so it has a little more grunt than shown but If my calculations are right, 7kw should make it come to life , I need to remake the mount for the jackshaft/motor as there is not enough room ( since the bearing mods ) to fit the extra motor , In theory I can put upto 14kw of motor/motors into it all in the same space so there there will be plenty of options for more power.....

[GCinDC]

more closeups!

[gwhy!]

I managed to do a bit of work on the new jackshaft.

jackshaft_mk3_1_s.jpg (103.18 KiB) Viewed 1293 times

jackshaft_mk3_fitted4_s.jpg (146.44 KiB) Viewed 1293 times

[bzhwindtalker]

#219 chain? I love this stuff

[deVries]

Hey Gwhy! Look'n good.

That two piece mated vertical looking thing is giving me a "hard-on"...

What is it??? The Big ?