- Joined
- Feb 15, 2013
- Messages
- 1,903
don't think the freehub body engagements will last long under high motor power..
LMX P2 : Freeride trials motorcycle frame development
- Thread starter bzhwindtalker
- Start date
gwhy!1
100 kW
nor me , but will have to wait and see... I think it will be a much more solid drive train if the rear sprocket were fixed, i.e no freewheels in the system. it will also give a far better throttle response.
bzhwindtalker
100 kW
crossbreak
1 MW
With normal 4:1 reduction the motor should not have enough torque to do any damage to the freewheel. 150Nm is not a problem
still i would lock it before even mounting a sprocket
still i would lock it before even mounting a sprocket
- Joined
- Feb 15, 2013
- Messages
- 1,903
don't think any motor rpm reduction is planned for this build..
since max torque is desired for trials..
http://endless-sphere.com/forums/viewtopic.php?f=28&t=57668&p=860244&#p860244
since max torque is desired for trials..
http://endless-sphere.com/forums/viewtopic.php?f=28&t=57668&p=860244&#p860244
crossbreak said:
MitchJi
10 MW
efMX Trials Electric Freeride said:
Half of 8.36, is roughly 4 to 1.
grindz145
1 MW
built by someone who clearly understands what a bike needs to look like to be ridden hard.
bzhwindtalker
100 kW
r3volved
100 kW
damn you...I need a new job 
and a friend who can weld
Looks great! Is it operational?
and a friend who can weld
Looks great! Is it operational?
bzhwindtalker
100 kW
Nope yet. I hope to have a rolling/painted chassis by the end of the week. the whole frame needs some cleaning and the swingarm is not fully welded. Next up : wiring, finishing up and learning to ride the beast
r3volved
100 kW
How does the weight, dimensions and geometry compare to your last LMX so far? That LMX#1 looked like it had a really comfortable riding geometry
bzhwindtalker
100 kW
The P1 was quite good since I mooved the footpegs but this one will be very similar, only with higher seat and a more relaxed head tube angle. So steering should be less twitchy! With the improved control the kelly and thumb throttle should provide, along with the weigth reduction, especially in the rear wheel, and the reduced inertia, the riding experiance should be vastly improved Now the only variable for me will be the motor performance... I may run 18s at first because I got a terrible deal on 10ah lipo cells, if they perform OK i will probably setup a second pack
Now the only variable for me will be the motor performance... I may run 18s at first because I got a terrible deal on 10ah lipo cells, if they perform OK i will probably setup a second pack 
standfast
100 W
You are doing a fantastic job on this. I really like the style of the bike. How is the 420 sprocket adapted to the bicycle hub? I have been trying to figure that bit out.
bzhwindtalker
100 kW
I'm adapting a new front sprocket and going full #219 13/60 geraring that should top out at about 65kph in 20s
standfast
100 W
Hi @bzhwindtalker!
This is by far the best Electric Vechicle I've ever seen. I would really like to build a similar one, altough I wonder how much do you think it would cost? I'm sorry if this is a bit OT, but I'm new here on the forum and your LMX P1 and your LMX P2 looks like exactly like my dream ebike. That's why I'm asking you how much you think a similar build like yours would cost. I've got a maximum budget of 3500€ and 1 month of 24/7 time. What would you say, would that be able to get a similar bike like you?
I'm really good with CAD and electronics, but I can't weld. I know a place that could weld it for me for some €€€, so maybe I could make the whole bike in CAD and then hand in exact instructions to them. Or would you recommend to buy a welder and learn it?
I've read a bit and it looks like you were planning to build some frames. Maybe I could buy a frame from you instead? How much would you charge for that (if you would do it)?
Thank you on beforehand man, you're the boss.
//Mr. Sweden
This is by far the best Electric Vechicle I've ever seen. I would really like to build a similar one, altough I wonder how much do you think it would cost? I'm sorry if this is a bit OT, but I'm new here on the forum and your LMX P1 and your LMX P2 looks like exactly like my dream ebike. That's why I'm asking you how much you think a similar build like yours would cost. I've got a maximum budget of 3500€ and 1 month of 24/7 time. What would you say, would that be able to get a similar bike like you?
I'm really good with CAD and electronics, but I can't weld. I know a place that could weld it for me for some €€€, so maybe I could make the whole bike in CAD and then hand in exact instructions to them. Or would you recommend to buy a welder and learn it?
I've read a bit and it looks like you were planning to build some frames. Maybe I could buy a frame from you instead? How much would you charge for that (if you would do it)?
Thank you on beforehand man, you're the boss.
//Mr. Sweden
bzhwindtalker
100 kW
Standfast, this is a custom made kart sprocket carrier made from a karting one (about 30e new) that was re-machined to fit the freewheel hub. I will have to adapt cassete cogs on each side to transmit the torque to the freewheel hub.
I am not too concerned about the freewheel breaking but time will tell
this thing should torque quite a bit..
I had various issues on the last work sessions I put into the project, with the shock hitting the swingarm (I had to cut the traction struts, will weld them back wider)
Also the fox van I brougth has a way too soft spring for the leverage ratio I have, so I ordered a new spring of double the spring rate. it is the heavyest so I hope it will work :|
I also had to do a cutout in the frame near the pivot to accomodate the chain, it would have fit but was a lil tight now there is plenty of clearance. Next frames will use a water cut bracket there.
Finnaly, the rear subframe would hit the wheel when 80% compressed. Tha's already 200mm rear travel so I think I went a bit fat on the leverage ratio
MrSweeden, I am indeed considering building some frames as a small scale production. This first P2 frame is helping me making some very good progress on the design, I feel like you can't design evrything in CAD Time is runing fast but this one is almost done.
As far as pricing goes my initial studies show that a 650€ asking price for the first batches may be doable.
This would be for the bare frame without the battery box and without paint, but that would be a very good base to build you dream bike upon. I will need some testing time on the bike before starting this phase, to work out bugs and see if the drivetrain is living up to the expectations but i'm quite confident on this point!
The bike should be rideable this weekend so we'll know soon enougth
Adam
I am not too concerned about the freewheel breaking but time will tell
this thing should torque quite a bit..I had various issues on the last work sessions I put into the project, with the shock hitting the swingarm (I had to cut the traction struts, will weld them back wider)
Also the fox van I brougth has a way too soft spring for the leverage ratio I have, so I ordered a new spring of double the spring rate. it is the heavyest so I hope it will work :|
I also had to do a cutout in the frame near the pivot to accomodate the chain, it would have fit but was a lil tight now there is plenty of clearance. Next frames will use a water cut bracket there.
Finnaly, the rear subframe would hit the wheel when 80% compressed. Tha's already 200mm rear travel so I think I went a bit fat on the leverage ratio
MrSweeden, I am indeed considering building some frames as a small scale production. This first P2 frame is helping me making some very good progress on the design, I feel like you can't design evrything in CAD
Time is runing fast but this one is almost done. As far as pricing goes my initial studies show that a 650€ asking price for the first batches may be doable.
This would be for the bare frame without the battery box and without paint, but that would be a very good base to build you dream bike upon. I will need some testing time on the bike before starting this phase, to work out bugs and see if the drivetrain is living up to the expectations but i'm quite confident on this point!
The bike should be rideable this weekend so we'll know soon enougth
Adam
If your designing with CAD it is a simple task to check the suspension travel against shock movement and tailor the linkage to achieve the desired ratio. Surely this is one of the main purposes of CAD to eliminate prototype errors. It is also easy to position the pivots and mountings so that each inch of wheel travel moves the shock a little more than the previous inch to create a rising rate, this can be achieved to a small degree without an additional linkage. If your shock travel is too small not only will the spring be too soft but the damper may not have sufficient adjustment to achieve enough damping of the suspension from such small movement, which will be made all the more difficult with the addition of the stiffer spring. A better solution would be to move the lower shock fixing further away from the swingarm pivot.
I have just made a new spring top support cup for my shock which also hits the bump stop slightly earlier limiting the shocks stroke to 2", this equates to 6" of wheel movement, using this travel I can accommodate wheels up to 26" and 29er's with another spacer in the shock. To achieve this ration the shock bottom mount is 1/3 of the swingarm length from the pivot. Simples!
Sorry for the rant Adam, I am really liking what your doing and want to see you create an amazing bike, for 8" of suspension travel you really need to ensure the whole shock stroke is utilised to get any level of wheel control. And I know you will need that control with your riding ability!
CAD is not just to make pretty pictures.
I have just made a new spring top support cup for my shock which also hits the bump stop slightly earlier limiting the shocks stroke to 2", this equates to 6" of wheel movement, using this travel I can accommodate wheels up to 26" and 29er's with another spacer in the shock. To achieve this ration the shock bottom mount is 1/3 of the swingarm length from the pivot. Simples!
Sorry for the rant Adam, I am really liking what your doing and want to see you create an amazing bike, for 8" of suspension travel you really need to ensure the whole shock stroke is utilised to get any level of wheel control. And I know you will need that control with your riding ability!
CAD is not just to make pretty pictures.
bzhwindtalker or Adam, that's your real name right?
Really cool that you'll maybe be making some of these frames.
650€ Sounds like a great price, I'll definitely be standing in the line for buying one
I'm pretty new to this ebike thing, so I don't really know what's the best place is for buying the different parts. Maybe you could make a parts list of what parts your bike consist of, and link to some good sites that sell those parts or similar. I'm thinking on, for example the wheels, saddle, motor, esc and such. That would be really valuable to know later on if you start producing some of these and I buy one
Again, really cool project. Looking forward to see how it looks when it's completed. I'll be following this thread day and night
Tench, yes CAD has some really great and advanced features, and it could really help a lot. I agree with you, but also with Adam. I think you have to try it out to be 100% sure on a design. All angles and data values may look perfect in theory, but you can't know for sure until you've tried it
//Mr. Sweden
Really cool that you'll maybe be making some of these frames.
650€ Sounds like a great price, I'll definitely be standing in the line for buying one
I'm pretty new to this ebike thing, so I don't really know what's the best place is for buying the different parts. Maybe you could make a parts list of what parts your bike consist of, and link to some good sites that sell those parts or similar. I'm thinking on, for example the wheels, saddle, motor, esc and such. That would be really valuable to know later on if you start producing some of these and I buy one
Again, really cool project. Looking forward to see how it looks when it's completed. I'll be following this thread day and night
Tench, yes CAD has some really great and advanced features, and it could really help a lot. I agree with you, but also with Adam. I think you have to try it out to be 100% sure on a design. All angles and data values may look perfect in theory, but you can't know for sure until you've tried it
//Mr. Sweden
standfast
100 W
What's the advantage of having the freewheel? Why not just lock it?
bzhwindtalker
100 kW
Tench said:
Don't get me wrong I'm not totally flying blind. I studied my lapierre blue FR geometry and tried to improve on my P1. I did some calculations and the bike as it is has about 230mm (9") of rear usable travel with a leverage ratio of 3,2. Fox states that up to 3.25 is OK. That's using all of the shock travel (73mm).
With a 700lbs spring I should have the recomended 20-30% recomended sag. So it's only a matter of getting the rigth spring fitted and shock set-up. I get what you are saying with the expodential spring curve, will look into it more closely, I'm sure minor ajustements could help a lot. Then there is always some deviations from CAD to the final product... So a test mule is essencial in my developpement process.
Mr Sweeden,
Yep my real name is Adam, Bzhwindtalker has been my screen name sine my kitesurfing days haha!
I have a parts catalog/ list with estimative prices I could share, but it needs some work (not ready yet). I'll let you know !
Sandfast, there is no advantage to having a freewheel, in fact engine braking is quite usefull for riding, but I tried in the past to weld one and it never held correctly, so IF it breaks, then i'll try this!
bzhwindtalker
100 kW
Progress
I resolved clearances issues, changed the shock spring, mooved the rear subframe mounts higher up to clear the full suspension travel.
Head tube angle 68° resting, 65° loaded with my weigth
Looks good to me. I also received my 13t 219 sprocket but fitting it to the motor won't be easy...
I resolved clearances issues, changed the shock spring, mooved the rear subframe mounts higher up to clear the full suspension travel.
Head tube angle 68° resting, 65° loaded with my weigth
Looks good to me. I also received my 13t 219 sprocket but fitting it to the motor won't be easy...
