408 Front Mounting. Did I goof it!

[RayB]

Ok,

I think I have goofed up my Crystalyte 408. I think I over tightened it on the front forks and now the right nut will tighten up, reach a certain resistance and keep spinning without tightening all the way. The weird thing is the threads look normal but it wont let me tighten it up to a reasonable amount of torque. I dont think I have stripped the threads so its a bit weird. Here is a picture of the mounting thus far.

At the moment it is snug.. but not overly tight IMO. The left side has been fine. I hope I dont need to reorder a new motor to Japan. That would kind of suck..

Thanks,

Ray

 

[Jeremy Harris]

Sounds like the nut thread has stripped, rather than the thread on the spindle. Take the nut off and look inside, I expect you'll find that the thread looks a bit ragged and torn. In my experience, standard Chinese made nuts often seem to be made from very soft steel.

The good news is that you should be able to find a new nut locally if this is the problem. The thread is a metric fine pitch, 12mm diameter x 1.25mm pitch (a standard M12 nut is coarse pitch, 1.75mm, so won't fit). Metric fine pitch nuts are common on Japanese made motorcycles, so should be available where you are.

Jeremy

[edited for typo]

 

[dogman dan]

Idealy a nut has slightly softer metal than the bolt, so you have stripped the nut. Lucky you! Rethreading an axle can be done too, but it's a pain.

For sure, on a front hub, anything less than perfect is unacceptable unless you like using your health insurance. ( if you have any)

 

[dnmun]

the axle steel will also strip so people should not depend on overtightening the new nut to compensate for the lawyer lips not being filed off, and lack of a torque arm. remember that half the threads are already missing on the flat sides of the axle. make sure in any case that you know the threads are the proper match and fit snuggly, but not binding when it turns.

looks like you have justin's C washer which along with the flat washer has used up a lot of the threads on the axle already.

bill has had his C'lyte axles strip already, but they are bent too.

 

[Drunkskunk]

The axle is cut threads, and they can't handle much torque. 20-30 pounds. As was pointed out, half the threads are missing on the axle since it has the flats, so its only half as strong. If you did just strip the nut, you got lucky.

I can also see you aren't running a torque arm on that side. Since the intergity of the axle is already in question on that side, you need one.

 

[chet]

I have a hub with 12mm 1.00pitch. Try finding that.

 

[RayB]

Great replies... thanks guys... good point, I guess I probably have just stripped the nut. I will have to check after work today. I will try to source some new ones locally. Luckily, I am going to Canada next week for a visit so will order up the torque arm, spare axle , and if they are available nuts from ebikes.ca just to keep some spare parts available.

On another note. I am going to put on the torque arm but the motor came with two washers on each side, and a thin piece of metal that seems like it is intended to take the place of a torque arm in a way. It is shaped to the axle and has a tab that fits into the bottom of the dropout perhaps kind of like a lock washer that you will see with some internal hubs. After I get the torque arm I am thinking just to ditch these as the torque arm should do a much better job I am guessing?

I knew someone would mention the lawyer tabs not being filed off. I am going to try to get my hands on a file to do just that. Just not had the time yet. I am not riding the bike yet so want it right before I start using it. Any suggestions on files to use? This is a first for me.

Thanks.

Ray

 

[fifthmass]

Ray,

Your motor is installed incorrectly in a way that no one has mentioned yet.

If you look at the 'metal axle' side of the motor (as opposed to the 'teflon bushing' side) you will see a flat milled onto the larger diameter axle portion that protrudes about 1/2" out of the motor case. This flat is visible in the photo in your first post. This flat is meant to slip into the drop out and provide additional torque resistance. I know this is the case because I have a 408 motor too. From your photo it looks like this flat area is not recessed into your drop out.

With regards to the lawyer lips please keep yourself safe and do not file them off and use the same fork. You may have insufficient metal left in the dropout. Buy a new fork without any lawyer lips. Many ES members including myself swear by the rigid Surly chromoly forks.

Be safe
Bill

 

[dnmun]

i agree the axle flats do not seem to have bottomed out in the dropout, as though something is keeping them out.

maybe some better pictures.

filing the lawyer lips flat does not weaken the dropout. you should also file the bottom end of the dropout to take out some of the shoulder out of the dropout and even off the back side of the axle so it seats as far down in the dropout as possible. you want the bottom of the dropout to be almost square and the threads on the back side of the axle filed down so it seats like a square with no slack at the bottom so it cannot rock back and forth in the dropout.

if you leave the lawyer lips on you need to talk to justin and get his C washers, otherwise there is no way to tighten the nut and have it seat properly. i thought everybody knew that.

i thought you had justin's C washer which was pushing the nut out so far, guess i cannot make out any of those parts. you gotta have a real torque arm though. the little torque washers are for bikes with long enuff dropouts that the tab will fit in the dropout to keep the axle from turning but most or all western bikes have small dropouts and it never works. i am gonna weld an arm on my torque washer at the right place to make it into a torque arm on 2 of my builds in progress now.

 

[adrian_sm]

i agree the axle flats do not seem to have bottomed out in the dropout, as though something is keeping them out.

Looks like the axle was jammed into the dropouts, without lining up the milled flats.
Thw wheels axle should just slide in to the dropouts.

This would also explain the stripped nut thread. If you didn't realise the threads of the axle were jammed into the drop-puts, and kept doing up the nut because it hadn't seated down to the shoulders of the milled flat yet, it would definteily strip threads.

 

[Sacman]

I got a Front 408 as well. Yes the shoulder (or fatter part) of the axle should be flush against the inside of your forks. Something looks to be preventing it from doing so like dnum and fifthmass said. File out only enough of your forks to allow the flats of the axle to fit thru and so the shoulder pushes up flush to the inside of the forks.

On the outside of the forks, some forks have an indentation (lawyer lips i believe they're called) where the round washer fits into to prevent the axle from sliding out of the dropout. On top of the round washer next is where you place those funny looking (anti-spinout plates) that look like small torque arms. They're not as good as torque arms but they're better than nothing. They're okay for use with a 408 running at 36V with at 20A controller. Any higher power and I'd definitely get a real torque arm. The bent tabs should be facing downward and pointing toward the motor. I notice on your picture that your round washer preventing your anti-spinout plates to rest flush againt your forks. Either your washer is too thick or it is not seated flush insid the indentation (lawyer lips) of the fork. Get a proplerly sized washer (diameter and thickness).

 

[dnmun]

sacman, the lawyer lips are protrusions that curl out on the end of the dropout forks and are like 2 prongs standing outside the surface of the dropout. the circular indentations are also present sometimes, but not always. if you have the indentations for the locking ferrule nut then you have to use one of justins C washers inside the indentation. or if you can find a small enuff washer, but not likely to find one that small.

i have seen the indentations on my neighbor's Surley road bike. i have never had a bike with the indentations, but some had the lawyer lips sticking out and flat dropouts. if the indentation is not too deep i would try to file it flat if i could get enuff (dropout) meat on the nut and depend on the torque arm to hold it. file just enuff to get the nut to have a full flat surface to seat on all the way across.

that's how i got my goldenmotor. the guy before me did not realize he had to file the lawyer lips off and the nut was just held onto the top of the lawyer lips bumps and the axle spun off the first time he rode it. that was the goldenmotor i pushed the new 12G phase wires into and replaced the hall sensors. that's why i try to get people to file them off so they don't have a twist off too.

i really really try to square the inside shoulder of the dropout too. file the shoulders of the dropout almost square to match the larger diameter of the axle shaft, and file the threads of the back side of the axle too so it goes as deep as possible into the dropout and keep it tight and rigidly locked into that 'square' end. but just the threads inside the dropout, not further out on the axle where the nut runs.

 

[RayB]

Thanks again guys,

Ya, I am going to order up some Surly LHT forks and grab them when in Toronto next week. Not sure if these have lawyer lips or not but if they do I will get my mechanic buddy to file them off while in Toronto before coming back to Tokyo.

I will also put on the torque arm I am going to order from ebikes.ca. Further to this, I figured the notched fat part/non wire side of the axle was supposed to go flush but it would not fit into my dropouts no matter what I did, hopefully the LHT forks will be easier.

Whats everyone using for RIMs on the 40x series motors, I mean for non crystalyte wheels that is. I think these rims are garbage so am thinking of building it into something like a Mavic A719. I guess a lot of people are using the Sun Rhyno rims for their wheels and 13g spokes....

Anyways thanks again and I wont be riding this thing until I can get it mounted properly. I will post another pic once its all done just to make sure I got it right

 

[fifthmass]

Thanks again guys,

Ya, I am going to order up some Surly LHT forks and grab them when in Toronto next week. Not sure if these have lawyer lips or not but if they do I will get my mechanic buddy to file them off while in Toronto before coming back to Tokyo.

I will also put on the torque arm I am going to order from ebikes.ca. Further to this, I figured the notched fat part/non wire side of the axle was supposed to go flush but it would not fit into my dropouts no matter what I did, hopefully the LHT forks will be easier.

Whats everyone using for RIMs on the 40x series motors, I mean for non crystalyte wheels that is. I think these rims are garbage so am thinking of building it into something like a Mavic A719. I guess a lot of people are using the Sun Rhyno rims for their wheels and 13g spokes....

Anyways thanks again and I wont be riding this thing until I can get it mounted properly. I will post another pic once its all done just to make sure I got it right

Ray,

If the lawyer lips are just the two bumps (about 1mm high) you can easily file them off without compromising the dropouts. Surly forks actually have these bumps. I did not realize those were lawyer lips until now. I filed them off both my forks no problem. OTOH if the dropouts have an actual circular recess for a QR hub you should not use that fork with a motor. That is only my opinion. Justin at ebikes.ca sells a C-washer that fills the circular well. Some guys here trust them, some don't.

Be safe,
Bill

 

[RayB]

I ordered a load of things from ebikes.ca this morning including those c washers you mention. Even if I dont need them on the surly it will be good to have for future use. i.e. move the motor to my wife's bike.

I also noticed they have new front axles also so ordered one incase I strip the current one or do further damage to it.

I also ordered a long haul trucker (surly) fork and if as you say the lawyer lips come on these I will get it filed off by a buddy.

I am still nervous about putting a front motor on the thing but guess it should be safe once everything is installed properly.

Next project somehow getting the battery mounted inside the frame triangle instead of on the rack.

 

[dogman dan]

Anything less than perfect on a front install is suicide. You are on the right track. Once you get it right, you can totally stop worrying.

The c washers are a good idea, but something like bmx forks, with perfectly flat dropouts is best. The torque washers can be discarded when you have good torque arms to replace them. Often the torque washers need a touch with a file to fit right, or even the tab bent in further. For sure, anything that is not right HAS to be solved. None of the fit issues explain the stripped nut though, unless the axle threads are a reallly really poor fit on the nut. So your new axle may come in handy if you can't find nuts that fit the axle threads better. It totally sucks that by now with ebikes popular in the west, such quality issues still exist on motors for export. It may be fine for sale in china, but dammit, we demand better.

 

[RayB]

Hi dogman,

You bring up something that I just noticed in your post. From pictures I have seen I have thought most people only use one torque arm. Do people think its better to use 1 on each side? Or should 1 suffice. I guess more would be better but I am just curious if the correct way is to infact implement 2 of them.

Thanks,

 

[dogman dan]

I dunno really, still no torque arms on my bikes after 5000 miles. I rely on a perfect fit and tight nuts on my front hubs. I don't have high amp controllers. Usually one is enough though. Some use two for higher power motors.

 

[RayB]

Ok,

So, I have rectified many of my problems I think. But have another query about the torque arm being placed to the front instead of the back.

First, here is a pic of the new mounting. Axle and nut are now ok I have a replacement from ebikes.ca. The axle is fitting flush against the fork now, with a c washer for the lawyer lips issue, then the torque arm and finally the nut. I think this should now work well. Here is a pic of both the mounting and also of how I am considering putting the torque arm. If I place the torque arm behind the fork I can not use fenders. Is it a must for the torque arm to go behind the fork? If so, I will do without fenders I suppose but would prefer to have them. But of course I prefer front teeth to fenders so if I must, than I must.

I guess on the wired side of the motor it is still good to use the lock ring.

Thanks....

 

[Sacman]

On a torque arm like that you use a stainless steel hose clamp to secure it to the fork. When you do this it is typically best to place the torque arm on the side of the fork that puts TENSION on the hose clamp when the motor turns the wheel. This means placing the torque arm on the side of the fork that faces toward the rear of the bike (or toward the rider).

 

[torker]

I have been following this cause I run a front 9c motor and I actually put it on a te clone with an old mt. bike fork. I wanted to mount it on my EZ-Rider but it has the lawyer lips and I wasn't sure how to do it safely. Looks like you are on the right track with the new parts. I wonder if you could use a small ubolt on the fork and run another heavy strap between that and the torque arm. Hope you get riding soon..

 

[RayB]

oh, yes sorry. I do have something to lash the torque arm to the fork. I have just held off on doing it yet to see what peoples feelings were on the positioning of the torque arm. Then I will finalize it and install it.....

 

[torker]

Well Sacman is right. The motor will try to rotate backwards in the dropout under power and forward during deceleration. Ideally having the torque arm inline with the fork and locked down so no rotation either way would be best. But, the fit of the motor in the dropout is the most important and the torque arms are your "just in case" extra measure.

 

[RayB]

oh sorry, I did not see Sacmans reply. Thanks, now that makes sense. I do have the hose clamp but just had not put it on yet. So, I moved the torque arm to be mounted in back of the fork and attached with the clamp. To get around the fender mount problem I just used a plastic zip tie to secure it. Here is the final install pic.

 

[Sacman]

Good! You got the torque arm on the correct side of the fork. Keep it on that side of the fork but you could also try flipping that arm over and face it the other way to see if you get a better fit.
Then pass the steel hose clamp thru that long narrow slot (or is it already passing thru the slot, it's hard to tell from your picture).