eBike-Specific Forks?

[richmpdx]

Russell - yes the ezee forks have a 1/8" thick torque plate that is fixed to to the fork with 2 bolts.

Rich

 

[cell_man]

Reply to Cell Man. The cheap steel forks from the 1" headset bikes I rode for 5000 miles never bound up, they were too floppy to have that problem.

I just yesterday was installing a motor on a Rockshocks dart 1 fork, and found I put too much spreading force on it, the motor was a bit too wide. After I got it on there, the shocks were stuck. So I can see that with a better shock, everything about the fit must be perfect. But I dout the motor pulling forward is any worse than the forces a fork encounters when dropping off or climbing up a 16" ledge, so I doubt the motor tourqe would be as big an issue as the initial fit.

The shock I'm using is binding on the front due to the torque of the motor. If I put the brakes on and put the opposite rotating force onto the lower, it will free up. Anyway it's a real cheapo fork, was just wondering if this is common.

Have some better models on their way, including forks for e bike. The E Zee fork mentioned above is just a Zoom fork. They can be had a lot cheaper than that too Edit: any additional torque plate will be an E Zee addition, it will not be standard Zoom part AFAIK.

 

[dogman dan]

None of the ones I used, same or similar to the zoom fork were binding on me. but they only had 40mm of travel, and the extra weight on the bike would squash em down to about 20 mm left of travel. So maybe if they were binding, I never noticed. They did work on big bumps, since you'd definitely know when the bottomed out.

With other forks on other bikes that had not been made for a suspension fork I had some issues. The chopper like rake that resulted when I put the long fork on a regular bike would cause the fork to respond a lot less than it should have. It would tend to lift the wheel rather than move the shocks.

 

[PeteCress]

(was duplicate post, needs tb deleted)

 

[PeteCress]

Yeah Pete, if the washers are laying at an angle on the lawyer lips, the result is usually a loosening of the nut, followed by a spinout. Though the torque arm should save your bacon and keep the wheel on the bike, the dropouts can still be damaged by the spinout. The space under the oversise washer is the problem, and the washer will eventually deform into the gap allowing the nut to get loose.

It's really crucial to have all the washers and stuff lie flat on the dropouts, front or rear motor.

So, to spin it another way (no pun intended....): the makers or distributors are selling us equipment not only with the wrong-sized washers, but wrong-sized washers in a place where the misfit could realistically kill or maim the rider - as with a front fork failure at speed on a setup where the rider did not take the initiative to install torque arms.

Seems like a bolt-on ebike kit that doesn't bolt on out of the box is a major problem - especially when it comes with instructions that emphasize the importance of those anti-spin washers that don't have a snowball's chance in hell of fitting the standard MTB fork dropouts that probably 98% of the purchasers will put the kit on.

I've called two retailers on this and both of their reactions were what I would call blase'.

It seems to me like this is a very big deal.

Are those statements too strong? If so, what am I missing?

Washer-wise, my plan is to:

• Lose those thick anti-spin washers (the ones where people have to take a hammer and punch to make the anti-spin tabs engage in whatever forks they are made to fit) since there's no hope of making them perform their function.
• Replace above-mentioned washers with washers that fit within the lawyer lips.
• Check tightness on axle nuts periodically.
• If they seem tb showing any tendency to loosen, set them in red LocTite.
• Use two torque arms (right now I've got two, but am only using one bc the other contends with the disc brake mount.... ordered a couple of arms that connect to the fender eyes instead of hose clamps...

 

[Russell]

Yeah Pete, if the washers are laying at an angle on the lawyer lips, the result is usually a loosening of the nut, followed by a spinout. Though the torque arm should save your bacon and keep the wheel on the bike, the dropouts can still be damaged by the spinout. The space under the oversise washer is the problem, and the washer will eventually deform into the gap allowing the nut to get loose.

It's really crucial to have all the washers and stuff lie flat on the dropouts, front or rear motor.

So, to spin it another way (no pun intended....): the makers or distributors are selling us equipment not only with the wrong-sized washers, but wrong-sized washers in a place where the misfit could realistically kill or maim the rider - as with a front fork failure at speed on a setup where the rider did not take the initiative to install torque arms.

Seems like a bolt-on ebike kit that doesn't bolt on out of the box is a major problem - especially when it comes with instructions that emphasize the importance of those anti-spin washers that don't have a snowball's chance in hell of fitting the standard MTB fork dropouts that probably 98% of the purchasers will put the kit on.

I've called two retailers on this and both of their reactions were what I would call blase'.

It seems to me like this is a very big deal.

Are those statements too strong? If so, what am I missing?

Washer-wise, my plan is to:

• Lose those thick anti-spin washers (the ones where people have to take a hammer and punch to make the anti-spin tabs engage in whatever forks they are made to fit) since there's no hope of making them perform their function.
• Replace above-mentioned washers with washers that fit within the lawyer lips.
• Check tightness on axle nuts periodically.
• If they seem tb showing any tendency to loosen, set them in red LocTite.
• Use two torque arms (right now I've got two, but am only using one bc the other contends with the disc brake mount.... ordered a couple of arms that connect to the fender eyes instead of hose clamps...

Pete,

The issue of the motor fitting in the dropouts and dealing with “lawyer lips” is something most folks doing a front motor conversion face and the solutions are fairly straightforward and well documented on this forum. On my first build I decided to simply file the protrusions off. With hand files it took a bit of work but I considered it part of the job (On the second bike I kept the lawyer lips and modified the torque washers).

Perhaps your expectations going in were a bit high which I'm sure is not helped by statements made by vendors that an e-bike conversion can be done in less than an hour. Before I converted my first bike I read this forum for months, I read the information at the various vendor sites and I planned in advance how I would execute the conversion. I bought a "kit" but never expected it to be an afternoon job, in fact between the waiting for parts and customizing it took somewhere around 6 weeks to complete. The time however was well spent as the bike worked perfectly from day one.

For me and many others on this board this is an ongoing hobby and the challenges are part of the fun. People who want a turn-key system with most of the bugs worked out would probably be better off buying a ready-made ebike like one from eZee for example.

Some kits ARE getting better as a few sellers who are committed to E-bikes work to refine their offerings. Perhaps the kits should include several sets of filler washers to fit various forks along with at least one torque arm. Maybe one day the “perfect” kit will be available along with the perfect battery and mounting system however you do have to remember that we are converting bikes which were never meant to be motorized and those bikes come in a wide variety making the perfect kit difficult to build especially when keeping the price low is a major priority.


-R

 

[dogman dan]

I agree Pete. The kits should fit all bikes, or at least most bikes. And likely they do. The inclusion of poorly fitting tourqe washers in a kit that comes with a toruqe arm is a mystery to me though, the torque arm makes the torque washers redundant. So they should supply a smaller washer that spaces the tourqe arm out past the lawyer lips. But the reality is that 90% or more of these kits go onto beach cruiser or other cheap bikes that have no problems with the washers. On the huffys, roadmasters, next, pacific, schwinn, and pacific bikes at the big box store the motors fit fine.

What you want Pete, is the C washers from Ebikes-ca. I just got some and they are just the ticket for use instead of the oversize tourqe washers.

 

[PeteCress]

The issue of the motor fitting in the dropouts and dealing with “lawyer lips” is something most folks doing a front motor conversion face and the solutions are fairly straightforward and well documented on this forum. On my first build I decided to simply file the protrusions off. With hand files it took a bit of work but I considered it part of the job (On the second bike I kept the lawyer lips and modified the torque washers).

Perhaps your expectations going in were a bit high .....

They were certainly higher than what I encountered.

I would agree that our slice of ebikes is basically an enthusiast's market.

But I would severly fault any retailer for not explaining up-front and in detail the issues around fork slot size, motor axle size, lawyer lips, and to one-size-definately-does-not-fit-all anti-rotation washers.

Dogman's observation about use on beach cruisers and other cheap bikes suggests that my representation of the percent of buyers affected is way high. But if his 90% figure is on the money, that's still one out of ten customers affected.

Informing buyers of that issue would not increase the cost of the product. It would be limited to a one-time expenditure of the dealer or distributor man-hours spent documenting those issues in writing for their customers.

I don't see it as either reasonable or responsible to sell something like this and then let the buyer - no matter how enthusiastic - take the risks mentioned in this thread until they stumble on the Endless Sphere forums.

Seems to me like a bunch of lawsuits waiting to happen.

 

[Russell]

The issue of the motor fitting in the dropouts and dealing with “lawyer lips” is something most folks doing a front motor conversion face and the solutions are fairly straightforward and well documented on this forum. On my first build I decided to simply file the protrusions off. With hand files it took a bit of work but I considered it part of the job (On the second bike I kept the lawyer lips and modified the torque washers).

Perhaps your expectations going in were a bit high .....

They were certainly higher than what I encountered.

I would agree that our slice of ebikes is basically an enthusiast's market.

But I would severly fault any retailer for not explaining up-front and in detail the issues around fork slot size, motor axle size, lawyer lips, and to one-size-definately-does-not-fit-all anti-rotation washers.

Dogman's observation about use on beach cruisers and other cheap bikes suggests that my representation of the percent of buyers affected is way high. But if his 90% figure is on the money, that's still one out of ten customers affected.

Informing buyers of that issue would not increase the cost of the product. It would be limited to a one-time expenditure of the dealer or distributor man-hours spent documenting those issues in writing for their customers.

I don't see it as either reasonable or responsible to sell something like this and then let the buyer - no matter how enthusiastic - take the risks mentioned in this thread until they stumble on the Endless Sphere forums.

Seems to me like a bunch of lawsuits waiting to happen.

I dunno about 90% being low-end bikes but both of mine were not.

When I was converting my first bike a year ago I had the same discussion about fitment with Justin at ebikes.ca. He told me about the eZee kit which included filler washers but that he could not obtain them otherwise. We also discussed the possibility of him offering "C-washers" which is something he eventually did. He did say what was holding him back was the cost to have them made and the fear they would not sell therefore if you want to support someone who does work for change then buy some of his washers. You have to remember that the kit sellers are not some big corporations with deep pockets they are entrepreneurs trying to run a small business that has a good deal of competition. I think the washers and torque arms should be included with the kits however price competition is pretty fierce on the low-end stuff so adding cost hurts profitability and robs them of the chance to sell the accessories at a higher mark-up. Jason at E-BikeKit, where you purchased your kit, has added a torque arm and internal washers as standard equipment and perhaps he can be convinced to include filler washers as well or at least offer them to folks who need them. Drop him a line :wink:

-R

 

[dogman dan]

Could be a lawsuit happening. More than one poster here has commented that front hubs, in general , are lawsuits waiting to happen. And as the ebike catches on, a lot more people will want to put a motor on a nicer bike. The 90% figure I pulled out of thin air may already be much lower. Of ES members, probobally 90% are putting a motor on a nicer bike.

 

[PeteCress]

The spoke calculator at ebikes.ca has the 9C numbers input for you, just enter the ERD of the rim (Rhyno Lite 26" = 548mm) and you get the result (168mm, for 16mm nipples instead of 12mm reduce by 3mm to 165mm).

http://www.ebikes.ca/SpokeCalc.shtml

What is your confidence level in the 548 number?

I'm using the procedure described in the SpoCalc spreadsheet (available at http://www.sheldonbrown.com/rinard/spocalc.htm) and coming up with 554. 6mm seems tb something like the diff between considering and not considering the thickness of the nipple heads.

The diff in spoke length is significant: 160 via SpoCalc.

OTOH, I'm one of those people that can mess up a wet dream. When we'd test each other's software at the electric company I used to work at, my nickname became "The Kiss Of Death".....

 

[Russell]

The spoke calculator at ebikes.ca has the 9C numbers input for you, just enter the ERD of the rim (Rhyno Lite 26" = 548mm) and you get the result (168mm, for 16mm nipples instead of 12mm reduce by 3mm to 165mm).

http://www.ebikes.ca/SpokeCalc.shtml

What is your confidence level in the 548 number?

I'm positive about it since that's what the manufacturer says it is. :wink:


http://www.sun-ringle.com/contentpages/mtb/rims/allmountain.php5



-R

 

[PeteCress]

I agree Pete. The kits should fit all bikes, or at least most bikes. And likely they do. The inclusion of poorly fitting tourqe washers in a kit that comes with a toruqe arm is a mystery to me though, the torque arm makes the torque washers redundant. So they should supply a smaller washer that spaces the tourqe arm out past the lawyer lips. But the reality is that 90% or more of these kits go onto beach cruiser or other cheap bikes that have no problems with the washers. On the huffys, roadmasters, next, pacific, schwinn, and pacific bikes at the big box store the motors fit fine.

What you want Pete, is the C washers from Ebikes-ca. I just got some and they are just the ticket for use instead of the oversize tourqe washers.

FWIW, here's what I did:

• Took a Dremel tool to the torque washers to make them into faux "C" washers that fit within the lawyer lips
• Replaced the hose-clamp torque arms with Renassiance's arms that anchor to the fender eyelets. (sort of unrelated... but it looks a lot cleaner and makes wheel removal significantly easier. Hopefully they're still strong enough...)

 

[John in CR]

Ebike specific forks...Sorry but no such thing exists unless you want to be restricted to pedal speeds. With a front hub, If you're considering going for performance and require suspension, then you need to just accept the weight penalty and use those meant for motorcycles. Maybe you can get away with some $1k forks designed of downhill, but you're still going to need steel sleeves at the bottom for proper dropouts.

Can you get away with something for bikes with a front a hub? Yes, many do, but the suspension doesn't really work properly, and you better be alert for the very beginning of issues. Just today I heard a new squeak up front. An inspection to locate the source revealed that a crack developed between the head tube and the bike frame. I don't even want to think about what could have happened if I ignored it. Keep in mind that yes I ride fast with plenty of weight, so the stresses are greater than most, but I don't have a front hub motor, much less regen, and that's with a steel bike frame, headset, and forks. Needless to say the next build with even higher performance will be motorcycle parts up front.

Cyclist types might scream about the extra weight, but once you add a motor, 5-10 extra pounds is nothing unless you have a regular situation that you need to lift the entire bike to go on a bus rack, or fold up to go on the train.

John

 

[dogman dan]

Yeah, but you haul ass John. No suprise your frame breaks. Pretty damn amazed mine hasn't. Sure as hell hasn't been from me baybying anything.

I'm only about 30 miles into riding on aluminum suspension forks with a 9c motor. So far so good, and the suspension works fine. But it hasn't allways been that way, this time I finally got the right combintation of parts on one bike. When I bunny hop, this bikes suspension sucks it up perfectly balanced front and back. I feel safe enough with the perfect fit the c washers gave me and double torque arms.