Front suspension fork
- Thread starter yuhr
- Start date
vanilla ice
1 MW
Most of them are aluminum which is less dense than steel. Most rigid forks are steel. You can get steel suspension forks if you're set on a front hub. Even with steel you probably shouldn't go high on power for a front hub.
Because of the aluminum fork, and it will break the fork. Due the aluminum casting easily break when the stress is applied. So, the steel fork is the best of the choice. There is also available in a steel suspension fork. If you are able to find it.
I own two bikes - 24" and 20" wheel - both are dual suspended, both are steel (unless magnetic Al was masquerating as Fe 
). Recenly I sold my old 26" dual-suspended bike, all steel. So, so far it was hard to find Al suspension fork .
And, BTW, my 20" bike is built like old fashioned BMX - its heavier than 24" (heavy gauge steel?), apparently designed for teens who consider jumping the curb a part of normal riding, as a warm up, before they start to do real tricks; it's just 7-speed full-suspension BMX. I am going to install an AmpedBikes DD SLA kit on it and use it as a moped, often with a trailer. I thought that with the rear kit too much rear weight (motor+SLA+myself) will unbalance the bike.
). Recenly I sold my old 26" dual-suspended bike, all steel. So, so far it was hard to find Al suspension fork .And, BTW, my 20" bike is built like old fashioned BMX - its heavier than 24" (heavy gauge steel?), apparently designed for teens who consider jumping the curb a part of normal riding, as a warm up, before they start to do real tricks; it's just 7-speed full-suspension BMX. I am going to install an AmpedBikes DD SLA kit on it and use it as a moped, often with a trailer. I thought that with the rear kit too much rear weight (motor+SLA+myself) will unbalance the bike.
dogman dan
1 PW
The other problem with suspension forks, is that some have no clearance for a motor, or at least some motors. gearmotors are often the widest, and very hard to fit into some suspension forks. The best clearance I have seen myself is the 9 c motors, or their lookalikes.
There is a type of steel suspension fork that looks like they simply pinched the end of the steel tube flat to make the dropout. One those forks, you can pinch them some more if you need to to make the space for a motor. The last 3" of those forks have nothing important in them, so squash em enough to use em.
The same thing is true of the cheaper steel suspension forks that do have a welded on dropout. Idealy though, look for forks that have the dropouts welded to the inside of the tubes, rather than centered. Look for the most distance between the tubes you can get.
There is a type of steel suspension fork that looks like they simply pinched the end of the steel tube flat to make the dropout. One those forks, you can pinch them some more if you need to to make the space for a motor. The last 3" of those forks have nothing important in them, so squash em enough to use em.
The same thing is true of the cheaper steel suspension forks that do have a welded on dropout. Idealy though, look for forks that have the dropouts welded to the inside of the tubes, rather than centered. Look for the most distance between the tubes you can get.
I've got a 407 front Crystalyte on a bike with front suspension with a steel fork and I've had no problems at all in the 2 to 3 years I've been riding. I'm also not even using torque arms - although I definitely should. When I was shopping for a bike I took a magnet with me to make sure I was getting a steel fork. I'm up to running 66.6v nominal with 20 amps and zipping around at 50kph+.
One thing I don't really like about the front hub is the weight up front. I find I have to lift the front and shift my weight towards the back when I'm going up sidewalks and bumps etc or I'll bottom out my shocks hard even if I'm only riding about 30kph. I'd really like to get a nice set of shocks but they're expensive and I'd be paranoid to leave my bike locked up when I'm shopping etc. It's a trade off.
One thing I don't really like about the front hub is the weight up front. I find I have to lift the front and shift my weight towards the back when I'm going up sidewalks and bumps etc or I'll bottom out my shocks hard even if I'm only riding about 30kph. I'd really like to get a nice set of shocks but they're expensive and I'd be paranoid to leave my bike locked up when I'm shopping etc. It's a trade off.
Thank you, electr0n,
I think I got it: I measured the front fork dropout distance and between its tubes above, on the suspension bike and on the regular 24'' one. The distance between dropout centers is 101 and 100mm. The difference is in geometry: Dropouts of suspension fork are formed by flattening the tubes, so pretty soon the distance between the tubes becomes progressively smaller. If the motor is as wide at its periphery as it is at the center, it might not fit. The dropouts of the regular fork are flat pieces of steel welded to the tubes and appear as continuation of its inner wall; therefore, 100mm distance is maintained to higher levels, although eventually the fork becomes narrower, as its tubes are not exactly parallel: the fork is wider at dropouts level than at the brake level.
I think I got it: I measured the front fork dropout distance and between its tubes above, on the suspension bike and on the regular 24'' one. The distance between dropout centers is 101 and 100mm. The difference is in geometry: Dropouts of suspension fork are formed by flattening the tubes, so pretty soon the distance between the tubes becomes progressively smaller. If the motor is as wide at its periphery as it is at the center, it might not fit. The dropouts of the regular fork are flat pieces of steel welded to the tubes and appear as continuation of its inner wall; therefore, 100mm distance is maintained to higher levels, although eventually the fork becomes narrower, as its tubes are not exactly parallel: the fork is wider at dropouts level than at the brake level.
dogman dan
1 PW
Should be easy to pinch down the tubes on squashed tube type steel suspension fork enough to clear the motor. DD won't need much if any, but a gearmotor will.
If you can get a vise, put the fork in the vise and squeeze down the tube till it clears the motor. If the vise is too weak, just clamp it hard and wiggle the whole fork and it will bend it enough. There is nothing in the last 3" of the pinched tube to damage.
I've also done it with two sledgehammers, one used as an anvil, and bash with the other. Awkward, but it will do the job.
I also ran thousands of miles with no torque arms on pinched tube forks. That kind of fork is cheapo, but strong as hell.
If you can get a vise, put the fork in the vise and squeeze down the tube till it clears the motor. If the vise is too weak, just clamp it hard and wiggle the whole fork and it will bend it enough. There is nothing in the last 3" of the pinched tube to damage.
I've also done it with two sledgehammers, one used as an anvil, and bash with the other. Awkward, but it will do the job.
I also ran thousands of miles with no torque arms on pinched tube forks. That kind of fork is cheapo, but strong as hell.
Hopefully, tomorrow I'll get a reply from AmpedBikes: I ordered DD rear kit, and last Wed they informed me that they do not have that kit in stock; probably "we'll get it within a week", They offered: 1. rear geared kit (at no extra charge), or DD front kit. I was surprised, as on AB website they say "Front kits cannot be used with suspension forks", both DD and geared. So, I wanted to get in touch with the boss, Danny, to get an advice from a pro. As a reply from him, I got only the company logo, no explanations. I don't want a geared motor - reliability is my priority; more (moving) parts - more trouble. As I understand, Sales Dept. handles my order. I'll try to get as much info from them re: motor shape and dimensions. I guess I'll be able to pinch the fork by a few mm; you are right, dogman, this fork is very strong, designed to withstand all abuse teens are capable of.
I'll keep you posted.
I'll keep you posted.
dogman dan
1 PW
Yeah, don't sweat it, a pinched tube fork can handle 1000 watts easily. It's the alu alloy forks that are easy to break just by tightening the nuts using the wrong washer.
I am still waiting for an answer from AB. I think I'll wait for a while and if they do not get my rear kit, I'll cancel the order (AB had a nerve to charge my credit card knowing that they do not have the kit! 
)and will order from EBK in Lambertville, NJ. It's more expensive but they have no limitations re: suspension forks, there is a dealer now within 5 mi from me and the total cost will probably be about the same - by the time I modify my front fork and butcher it in the process (my small vise is to week, so I have to buy a bigger one or go to a metal shop). And your review of EBK kit - I wish I read it before deciding to buy from AB.
)and will order from EBK in Lambertville, NJ. It's more expensive but they have no limitations re: suspension forks, there is a dealer now within 5 mi from me and the total cost will probably be about the same - by the time I modify my front fork and butcher it in the process (my small vise is to week, so I have to buy a bigger one or go to a metal shop). And your review of EBK kit - I wish I read it before deciding to buy from AB.
dogman dan
1 PW
One phone call can stop that credit card payment.
Of coarse. That charge should never have been made in the first place: they knew that they did not have the kit, just advertised it. And the price was higher than advertised one.
However, I'd rather get my original order. Later today I'll email them asking to send me my kit if they have it by tomorrow, or reverse the charge.
However, I'd rather get my original order. Later today I'll email them asking to send me my kit if they have it by tomorrow, or reverse the charge.
It was relatively fast: two days. I canceled the order and received refund notification from AB. 
I already ordered DD front e-Bike kit from Lambertville, NJ. No limitations. Just more expensive. Jason himself answers the phone, there is a dealer close to me, etc. And, once again, I confirmed the rule I made for myself: do not order ANYTHING from CA, no matter how cheap, if a similar product is available elsewhere. (Are they too close to Asia?) Just an example: while ordering online, I saw: 24" kits are temporarily unavailable. It's so simple 
Hopefully, I'll be riding my scooter in a week or so
I already ordered DD front e-Bike kit from Lambertville, NJ. No limitations. Just more expensive. Jason himself answers the phone, there is a dealer close to me, etc. And, once again, I confirmed the rule I made for myself: do not order ANYTHING from CA, no matter how cheap, if a similar product is available elsewhere. (Are they too close to Asia?) Just an example: while ordering online, I saw: 24" kits are temporarily unavailable. It's so simple Hopefully, I'll be riding my scooter in a week or so
Jason27
10 kW
yuhr you sound like a picky person. Amped Bikes charged your credit card to put you on top the waiting list. No need to get all worked up about it.
dogman dan
1 PW
No, no need to get worked up.
But paying money and getting it shipped immediately is prefered by most folks. It's near summer's end, and easy for even good vendors like Amped to run out of stock on some items. Likely he has stuff coming, but it comes by boat. No foul by Amped, but if you want it now you want it now.
But paying money and getting it shipped immediately is prefered by most folks. It's near summer's end, and easy for even good vendors like Amped to run out of stock on some items. Likely he has stuff coming, but it comes by boat. No foul by Amped, but if you want it now you want it now.
Perhaps I am.But: summer is ending soon. AmpedBikes might run out of kits by now. A decent merchant should inform its customers of this fact. In all likelyhood, I'll receive my e-Kit (ordered yesterday around 5 pm) this afternoon. I wasted a whole week because of AB deception. In my state, customers are not charged any money for being put on a waiting list. And advertising unavailable items is prohibited. Period.
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