turner dhr + hs3540 - soon to be Hubmonster! pics!

i had the opportunity to use my friend's shop the past couple days. i managed to make a set of dropouts for my turner dhr so i could put my hs3540 on to it until i get the rest of the parts for the hubmonster build (only renders now: http://endless-sphere.com/forums/viewtopic.php?f=3&t=48380 ). i will admit that this isn't the most conventional or ideal method, but it seems extremely solid - hopefully i wont have any problems with axle twisting now. overall i am very happy with the way it turned out and doesn't seem much heavier than my previous build. the handling, especially offroad and in snow and ice is much better! also it is much more enjoyable and comfortable to ride. the bag was cut in the middle to make it a saddle type bag for batteries in both sides. i really like this bag - the width doesn't bother pedaling much and i fell more in control with my legs/knees holding the bike.

Lol, looks a bit excessive but i see how that works.
This would be a good solution for putting a 20" wheel on the back of a bike designed for 26".

lol it is a bit excessive, but i figured id do the best i could with what i had. the original rear wheel was a 26, but im running a 24 now. i think 20 would work as well but i might want a smaller front then as well. maybe 20 in the rear and 24 in the front would work well.

also, i got the rear brake set up and new cables for both. silky smooth and very good stopping power!

[youtube]YPq8YAoXi_c[/youtube]

sorry for the camera shaking...i will have to find a way to stabilize the camera better. part of the reason is it was filmed with my phone

the other reason is i cut out some trail riding after 2:42 where the camera got loose without me realizing it

[youtube]lIYSz1Utn8g[/youtube]

after this video i put on my rennen 52t chainring



now i can actually pedal faster than 17 mph =)

good on ya for trying something different. looks like a bit more length from rear axle to suspension piviot and therefor , more travel. and longer wheel base. is it steel or aluminium? spring washers or nylock nuts?
looks great, although the drop outs are a bit ugly but i love that over kill style.

the dropout was made using 3/16" steel. im not sure what kind exactly. they are a bit ugly, but it definitely seems to be holding up - no problems so far. this was a somewhat unplanned build - when i had an opportunity to use a shop and the free metal i realized i could be riding this bike as an electric bike; instead of just having it sit in my room. because the dropout is slightly lower, i guess there would be slightly more travel. the wheel base and the geometry are almost the same because i only lowered the dropout and am using a 24" tire instead of 26".

i was trying to tighten my spokes/adjust my disc brake because my tire and wheel were both rubbing slightly. imagine my surprise when i saw what had happened! i am just thankful that i was riding slow because of the rubbing!

where the axle sheared, it is slightly twisted. the patterns of the axle in the first picture are hard to see, but they also seem to twist or swirl. as you can see, it broke about 1/8" after the start of the recess for the wiring.

i have been running 20s with about a 50 amp limit. there have been some timing/syncing issues with my sensorless crystalyte controller - this might have been part of the problem. if you go full throttle, the motor will lose sync and lock up or jolt for a fraction of a second. however, this happens very rarely. i have never taken the bike off jumps (other than the occasional curb) and only have done very moderate offroading - but mostly street riding.

i do have about 7000 miles on the motor so im not completely disappointing...but im sure you guys know how this kind of stuff can be frustrating. has anyone else managed to break a hs3540 axle or replace one? is it possible to fix or is it basically trashed?

do you think there may have been an angle of force going through the axle from your crazy diy drop outs? i just broke a hub plate gear thread OFF the motor (ht3525) after 100km , i think it may be my rediculous clamping torque arms stressing the axle making it bow slightly and creating constantly changing force from the bearings as the wheel spins. maby you had something simalar?

good effort breaking that fat axle, warning to anyone that opens the wire channel in the axel.

there might have been some weird forces from the dropouts...i did have to force the motor in the dropouts a bit (there are about 1/8 too narrow). i didn't think this was too much of a concern. this was probably one of the things that was actually still holding the motor slightly in place while riding with a broken axle! also i see what you are saying about the changing forces on the bearing/axle. my wheel was also a bit out of true - i have been putting that off for too long - this could have cause some added stress as well, as the wheel spins under load.

i have been thinking about how i want to do my next set of dropouts. i used kiwi's dropouts as a starting point as far as what i was going after/what has worked in the past.





there is still a bit to figure out (the model is a bit old/dimensions aren't exact). i plan to get exact measurements, fix the model and hopefully have a template made in the next few days. once i'm finished with this semester at school (about 2 weeks) i will have time to make the actual dropouts with the help of my friend and his cnc!





the three holes near the middle of each dropout are for metal pins to hold everything together. the holes are 1/4".

Those drawings always look so cool to me. I wish I could create something like that for my bikes.

That first video got quite fun at around 2:00 after all that traffic nonsense . I love popping in here to watch some good videos. It's giving motivation to work on my DH bike.

hey, that's a cool looking build. bummer about the axle! i think the xlyte axles are a bit soft, softer than 9C's. and i can't imagine how you'd fit the axles in if the slot is 1/8" narrower. how did you wedge it in? i would not be surprised if that caused some stress on the axle, esp since the dropouts are only 3/16".

i think the best thing is to clamp them in, but not squeeze them to death.

also, were the dropouts perfectly lined up? i use kiwi's, and after installing them, i ran a fine file on the inside to make sure they were lined up properly, otherwise, a slight offset could stress the axle once it's tightened down on.

not sure, who knows. not criticizing, just thinking out loud. there have definitely been other axles, not a ton, but some, notably: neilp's 5304 axle snapped after 5700 miles the amount of work he's gone through to replace it has been extensive, enough so i know i'd never bother attempting it!

regarding the new design, looks good. but how wide is your frame at the dropouts? do you have that much room to spare on the inside? i guess you must, considering your bolt design fits the same way?

anyway, good luck!

Unfortunately, these axles aren't the strongest to begin with

What i found is that i needed a really, really, really wide torque plate on mine, otherwise the axle started being cut by my chromoly dropouts. They must be using a particularly weak metal..

i redesigned the dropouts and played around with some CAD (cardboard aided design - lol). there were some changes between the cardboard and computer model...and still a bit of work making exact measurements/making sure everything will line up perfectly. i finish up my classes today so hopefully in the next week (after i order some steel) i will be able to cut and make these.

finally got my ebike back up and running and damn it feels good! crystalyte hrs3553 with a crystalyte 18 fet (4115 fets with a modded shunt). on the test run i hit close to 7000w at somewheres around 40mph! i was running a hs3540 previously and was only seeing peaks of 5-6kw. not quite sure why/how or if this motor is really more powerful but it sure seems like it! (it might just be because its been too long since ive ridden an e bike =P ) ill have to verify the settings on my CA are still correct for the shunt..which there should be no reason they aren't. my Ah seems fairly accurate but ill double check with my chargers.

ill try to post some pictures in the next day or two. im pretty happy with the way it turned out, turner dhr downhill bike and a pelican 1200 for the batteries looks pretttty clean

for the dropouts i ended up just making a rectangle piece of 1/2" steel with slots. this is bolted through the axle with 20mm bolts and also through the frame with a 1/4" bolt to prevent the plates from spinning or moving at all. also i drilled through the slot and put a bolt just below the axle. not quite a pinch dropout as it doesnt tighten the slot much(as far as i can tell) but it will prevent it from getting any bigger (by the axle twisting) or prevent the motor from sliding back out - which i can't see happening because the slots are ridiculously tight as they are and the force of sitting on the bike should prevent the motor from moving back out.

it will make more sense once i have some pictures for you guys but i don't have a camera so ill have to use a friend's.

so i had the bike out just a few minutes ago. was about 3/4 a mile away from my house...accelerating and passing a car doing about 35mph. i see a small hump in the road coming up...i debate whether or not to slow down (i think naahhh ill be good with dual suspension). all of a sudden - WHAM! i drop about a foot in the rear. still riding straight no problem i brake and pull off to the side of the road - only to find to my utter amazement that my rim has complete detached itself from my hub motor. not a single spoke still attached.

i dont have a camera of any sort but will try my best to get a friend over and take some pics for you guys :lol: its actually almost a work of art. with all the spokes bent in the same direction around the rim :lol:

in the meantime this picture best explains the damage although not at nearly the same power as luke's "bike"




the problem clearly was the way the rim was laced...which (in all honesty) was a bit sketchy to begin with - but i didn't ever imagine anything like this happening (maybe a single spoke or a few at most). it was done at a lbs but in a somewhat crude manner. instead of using proper 12ga spokes (the correct size for the motor - but too big for the rim) or using a tapered 12ga to 13ga spoke (so it would fit correctly in both rim and hub) - a 13ga spoke was used with brass washers on the inside of the motor flange to prevent (or so we thought) the spokes from pulling through. im definitely gonna have a talk with them and see if i can get it laced up for FREE and PROPERLY this time. luckily (as far as i can tell) nothing was severely damaged. the rim is fairly scuffed up and possibly out of true - its hard to tell now as i haven't taken it apart yet - and don't have the time/ambition too atm. frankly im kinda pissed haha. the motor is also scuffed but appears to not have taken any severe damage.

Glad you're OK!!

Now, waiting in excitement for carnage pics

jansevr said:

a 13ga spoke was used with brass washers on the inside of the motor flange to prevent (or so we thought) the spokes from pulling through.

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WOW... never seen that. amazing! glad you're ok!!!

Awesome work!! Woot!! I love wheel good wheel carnage!

Yeah, nice work.

Did the spokes actually break or just pull through?
That looks like something I'd like to avoid.

fechter said:

That looks like something I'd like to avoid.

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Amen to that!

Tom

What gauge spokes were you using?

The holes in the hub flange look big enough for 11g (2.9mm) or even thicker.

When rebuilding, I'd suggest drilling new holes between the existing ones that snugly fit 13g (2.3mm) or whatever you end up replacing with. Proper spoke tension of 100kgf+ is also crucial.

none of the spokes actually broke. it seemed to have been a chain reaction with them all pulling through in about half a second. definitely would be avoidable with the proper spokes or better washers. the brass washers that the bike shop used to lace the wheel were probably the most thin and weak washers i have ever seen.