DiamondBack - Dillenger Ebike Conversion

Discussion in 'Dillenger Forum' started by TDMModels, Sep 9, 2015.

  1. TDMModels

    TDMModels New Member

    I completed my ebike conversion of a 30 year old Diamondback Response Sport mountain bike.
    I went with the Dillenger 350w kit with the 26v 10ah battery kit after doing a review of available electric bike kits. I like the Dillenger kit because it had the frame mounted battery (No rear rack), plus it had 5 level pedal assist. I should have done a little more reading/research before installing the hub motor on the old bike. It had a RockShox aluminum fork and after about 15min of riding the fork failed (fortunately at a stop sign). I was naive and did not know that that was unsafe unless you have dual toque arms. Dillenger should really have a WARNING on the web site regarding the use of a front hub motor on an aluminum or allow fork and recommend torque arms if you want to do it.

    I ordered a Surly Troll steel fork and installed it along with two (2) torque arms (I know it's overkill but I don't have to think about a failure). Installing the Dillinger kit was fairly easy on this bike accept for the pedal assist ring. This bike had an aluminum pedal crank that was slightly larger than the the sensor ring. I solved the dilemma by filing down a flat spot/groove on the crank and removing all the "fins" on the
    pedal assist ring. I also had to enlarge the diameter of the ring to fit over the crank groove. I then epoxied the ring to the crank and it lined up fine.

    As part of the upgrade on this old bike I had to replace the old gear shift levers with new and installed a new Shimano Acera v-brake on the front fork. The Surly fork had about 1.8" longer dropout - crown distance compared to the old RockShox. I wanted the handlebars higher for a more comfortable ride
    and replaced the old straight handlebars with a 4" rise set... all of which made the bike much better to ride.

    I live in a hilly community in central Arkansas and the addition of electric power really makes bike riding more feasible now. I've gone on a couple 10-15 mile rides and the 350w motor + peddling gets me up, down and around with not much effort. Assist Level 3-4 will get me going as fast as I can peddle and seldom need more than 3-4 gears.

    All in all I am very pleased with the Dillenger kit and have would recommend it to others.
    The only exception being that they really do need a warning about using the front hub motors on aluminum or alloy forks without torque arms OR recommend installing on steel forks only.

    myEbike4.jpg MyEbike7.jpg MyEbike6.jpg MyEbike1.jpg MyEbike3.jpg MyEbike1.jpg MyEbike3.jpg
    Tara D. likes this.

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  3. SQN

    SQN Member

    Interesting! I'm currently debating between the new Dillinger 350w and 1000w kits. I'm curious what the top speed is on your bike, and how fast you can cruise at consistently on flat roads. Yours is similar to their Arc 350w system, but not entirely the same.
  4. TDMModels

    TDMModels New Member

    I have not ridden it that much, but if I put it in top gear and assist level 5 I can get 25mph without much of sweat.
    20mph is no problem on middle chain ring and assist level 3.
  5. SQN

    SQN Member

    That's nice to hear! If you can get 25mph without much effort, what then do you think would be the top speed you could attain consistently while peddling?
  6. George S.

    George S. Well-Known Member

    I had a bike with a really cheap aluminum suspension fork and decided to just swap it out for a Surly steel fork. I like the front hub, but it creates a lot of stress.

    Don't know if you have any pictures. They say they will crack or break, not bend. I trust the Surly, but also use a torque arm. That was lucky that it broke like that.
  7. maui_rider

    maui_rider New Member

    Interesting, I would like to know more on your Rockshox fork failure, where exactly did it break and do you start off by peddle, throttle only or a combination of both? Reason why I ask is I just installed my Dillenger 350w 11amp front wheel kit just a 6 days ago on my old school Gary Fisher Joshua with Rockshox Jet front suspension. I specifically use this bike in the foothills of California with my Miniature Pinscher riding along with me for 5 to 10 miles each ride and need to know what is not safe about the Rockshox? I communicated with Dillenger about the usage of the front wheel setup, battery mount and sent them pictures of my bike and they seem to be quite confident that I would not have any issues, so I am surprised to read your post.

    I have since put 55 mile on my kit with a Buddy Rider attached and my 11lb dog in seat, what a blast for both of us. With this kit I can climb a 7% grade with no problems and very little to moderate effort using peddle assist level 3, I 'm not going fast but it is truly no sweat climbing the hill. I can easily sustain 20mph on the flats using level 4 and I was capable of short spurt runs of 31mph with my moderately hard bike effort, but ran out of gear and was spinning. The miles I got on my first charge with one bar left on the indicator was 27 miles, not bad for a hilly area and my 11lb dog along for the ride, I think I could have gone another 5 miles easily.

    One important thing to note is watch your spokes they will come loose and you need to re-tension them, mine were very loose after the first 10 miles and required tightening and minor truing. Also, watch for nuts and bolts becoming loose as well, the battery cradle has a few small screws and nuts holding together the metal base and plastic controller body, you will see what I'm taking about when you remove the battery from the cradle. Use lock-tite on your mounting screws those become loose too.

    Overall this is a great affordable kit, well thought out with the controller integrated into the cradle/battery and a powerful enough system to handle the hills when called upon and just a no clutter system. I only use the PAS, I purchased the thumb throttle but I never use it, the PAS is awesome and BTW I did have the same issue as you did with the PAS but just drilled some holes in it and tie wrapped it to the crank arm. I never thought I'd own an E-bike as I am an avid road bike rider with two carbon Cervelo's one being a time trial bike. I just bought this kit on a whim to get more miles of riding with my dog after work and weekends and can now ride in the 100 temp days without overheating. But of course SAFTY first, will my forks fail too, I need to ride careful in the meantime would hate to crash with my dog onboard.

    For those of you on the fence on a E-bike kit, this is a good one, practical and easier on the wallet. Good Luck to you all and Fun Riding!

    Maui_rider (that's my dog)
  8. TDMModels

    TDMModels New Member


    My Response Sport had Rockshox aluminum forks. I installed the front hub motor and did an easy ride of about 10 miles.
    This was all on smooth pavement. As I rolled up to a stop sign I was barely rolling and applied the front brake.
    The bike fell forward and when I looked down I saw the back side of the dropout had snapped off. More than
    likely, it had cracked during the last part of the ride and the small bit of force from the application of the brake broke it off.
    I am VERY fortunate... I had been going as fast as 27 miles per hour just a few minute prior. If the fork would have snapped
    at any other speed, rather than just barely rolling I would be in the hospital for sure with a smashed face, broken bones or worse.

    After this happened, I contacted Dillinger support and they claimed they had never seen a failure with a 350w hub motor.
    I then did some google searching for "broken suspension fork and front hub motor" and found several photos and links.
    I went to endless-sphere.com and found many threads of others with broken front forks. They all said never put a front hub motor
    on an aluminum or magnesium dropouts with out two (2) torque arms installed.

    I needed to order a new fork and after much research I could not find a single suspension fork that didn't have magnesium lower dropouts.
    Magnesium is weaker than aluminum. I looked on other ebike kit web sites and on several they had disclaimers that said do not install on anything
    but steel forks.

    I did not want to worry about magnesium forks so I bought a steel fork AND a couple torque arms.
    Now I can ride with peace of mind and will still check the steel forks for fatigue cracks from time to time.

    Thanks for the tips and suggestions on maintenance and locking things down. Will do.
    I agree with you that the Dillinger front wheel kit is a complete package and makes your bike look like a factory built
    E-bike. The rear rack battery mount puts a lot of weight behind you and it appears to rattle and shake as you ride.
    Like you, I like the fact that the controller is built into the battery. Also, the battery can be replace from more than source
    if it degrades.
    Tara D. and J.R. like this.
  9. J.R.

    J.R. Well-Known Member

    Amazing! A picture is truly worth a thousand words.

    Thanks @TDMModels for posting, very helpful!
    George S. likes this.
  10. George S.

    George S. Well-Known Member

    It's interesting. Dillenger had a Kickstarter early in the year for a 350W front motor. I asked about a torque arm, with the kit they were offering and got this back:

    Dillenger Pty Ltd says:
    Hi George, we can include a torque arm for sure. It's something we were thinking about for the 350W kits but if you decide to support us please just leave a note on the order and I'll make sure you will be sent a torque arm or 2. The batteries we use in most of our batteries are made by a company called Headway. They're very well known in the industry. The type of cell is 18650 2200mAh Li-ion. They're a super reliable and very safe cell which are the major considerations for our project.

    If you have any other questions, please let me know :)



    A couple of months later I bought a MAC kit. It will put out a lot of watts, to get up hills. But the Dillenger kit sounds like it is pretty solid. Paul, who sold me the MAC, recommends a torque arm or plate, but they aren't included in the kits. He sells the Grin arms at good prices.

    The steel lends itself to inspections, as I understand it, since it will bend and round over, more than break. I've taken the front wheel off for inspections, just to get a sense if anything was going wrong.

    I like the way the front wheel handles, except for loose stuff. It balances OK with a rear battery. I had a rear hub and changing a tires is a major problem. My front hub is very easy, though there is a fair amount of stuff to disconnect.
  11. maui_rider

    maui_rider New Member

    Thank you so much for the reply and photo, now I fully understand. With aluminum being soft, magnesium being a porous material and dynamic forces being applied to the drops with axel torque and front wheel braking that is a weak point given the material of the forks. I inspected my forks to look for signs of stress cracking and wear on the drops and so far they look ok. I do not have torque arms installed but I am going to order two of them tonight through Amazon and will have them in a few days. In the meantime the bike will be ridden very slowly and with caution. I may decide to move this kit to my old school Diamond Back Apex with all chrome moly steel frame and forks but I will see how the torque arms work. It is a scary thought to have a fork failure while riding at speed. Thanks again for sharing and SAFE RIDES.

  12. Tara D.

    Tara D. Administrator

    Nice review of your conversion and thanks for sharing about your suspension fork failure. I'm glad to hear you were barely moving when this happened!
  13. TDMModels

    TDMModels New Member

    I've ridden about 75 miles now over the last week since finishing my build and have some further thoughts/info about the Dillinger kit.
    I am quite impressed with the performance of the 350w front hub motor. So far I've been riding in assist level 3 or 4 but on occasion I've
    clicked it up to level 5 to get up some steeper grades. I've posted a couple graphs of a 12 mile ride. You can see from the elevation plot that
    I am riding on some fairly hilly up/down streets. At level 5, the digital readout indicates the motor in putting out a little over 500 watts when
    working hard. On level 4 it shows and output of 300 watts. Regarding top speed, on a flat, I have a hard time getting faster that 28 mph.
    I can't peddle faster than the motor is helping. (I have a 21 speed bike).

    Below is the elevation profile of a 12 mile ride. Total climbing on this ride was 2307. Average speed over that distance/terrain was 14.4 mph. Max speed according to GPS was 37mph

    Below is the speed graph over the same route.

    Below is the route shown on a topo map.

    After this ride which took a total of 48 minutes the battery voltage was showing two bars under load and three bars on cruising.
    Most of the riding was in top gear 3 - 7, drop to 3-6 or 3-5 as needed. On the steepest grade I had to drop to 2-2 and assist level 5.

    If I would have tried this same ride without an hub motor I would have had to really work hard and would have had to use "Granny gear" or
    even walk the bike to make a couple hills. With the 350w hub motor I was able to do the entire route and get home without breaking a sweat.
    I saw one biker on the same route really pumping hard. I thought about flagging him down and tell him about the virtues of an e-bike.
    Maybe another day :)
    George S. and J.R. like this.
  14. J.R.

    J.R. Well-Known Member

    Very compelling comments! All too often it seems people looking into ebikes want to be seen as a cyclist, but have the motor power of a moped/scooter. My experience mirrors yours, I climb some serious hills and do a lot of miles. Your experience shows what an electric bicycle can do.
  15. George S.

    George S. Well-Known Member

    I'm happy with that situation. After 4 months of climbing hills and studying my watt meter, I think it's fine to stay within the 'generally accepted' laws, around 750 watts. I could live with 500 watts. The difference between 700 watts and 500 is the difference between 14 mph going up the steepest hills around here, versus about 11 mph.

    Karl wrote a comprehensive piece about power and kit bikes. It's definitely worth reading. His point of view is nicely straightforward. "Enough" is being able to climb a 10% grade at 20 mph. He gets into some nice detail work on the various choices, like windings and wheel sizes, but it's basically DD hub vs geared vs mid-drive.


    I'll disagree with Karl to the extent that going from 500 watts to 1500 watts, to climb a 10% grade at 20 mph is maybe putting the cart before the horse. Top speed on a flat road is a contentious area, but I won't ever use 1500 watts on a flat road to go around 35 mph. I would buy a gas motorcycle or scooter, to do that.

    I find the big part of the motor around here is going into the wind. Suddenly a 15 mph speed takes decent pedal power and 400 watts. Adding 400 watts does a lot for a bike when my normal power is about 100 watts. Let that sink in.;)

    The people who are gravitating toward a lot of power would do well to read what Karl is saying. You can push all these ebike motors too hard. You want one that matches what you are trying to do, whether it is speed or hill climbing, etc.

    The low power stuff is not straining anything, and a more basic bike will work pretty well. The battery will give more miles per watt consumed.
    Tom on 101 likes this.