New Oset Owner; Throttle Response

[samandkimberly]

Just got a new 36v Oset for my son and we love it! One small issue we have, though, is harshness of the throttle at very low speeds. It's not bad for general riding around, but it definitely makes practicing things like small circles a real challenge - I can only do them using a lot of brake to modulate speed instead of the throttle, and my kid can't do them at all. I've read elsewhere that this is just the way it is on this bike - it might be something we have to live with, and the rest of the bike is so good that we're certainly willing to do so. But we'd rather not - has anyone had similar issues and found ways to improve?

It really is a lot of fun, makes me want a grown up version.

Sam

[iansmitty]

This is Ian, of OSET. I hope it's OK to respond to this.

I'm well aware that when the bike is turned down, you have the 'dead zone' in the throttle. Then... on the 36v bike especially, you have quite a hard hit. The bike has so much torque it makes throttle control a little tricky for beginning riders. We recommend the 24v bike for beginners for this reason. Once you have the speed turned up all the way, the problem goes away, as throttle control gets better and the rider gets smoother. When you get there, the stock controller is really very smooth.

We're experimenting all the time of course, so I thought I'd fill you in on an option that you might like. Oliver has two bikes on the go at the moment, so we can compare parts. On one bike he's running a Kelly KDS36100 - a 36v, 100 amp programmable controller. You can see it on the Kelly site at http://www.newkellycontroller.com/index.ph...16f69ff101da49b . It's listed in US dollars at a mere $69, which is about 40 quid-ish. It's a fantastic controller. I'd love to get them for production, but they will barely budge on the price even for mass orders. The controllers come from China, and to send to the States, they charge another $30 or so.

I REALLY like this controller. It's small, so can fit in the same spot as the stock controller, is relatively easy to wire in, and best of all, is programmable from your laptop. You can set maximum current (torque), so you can calm the bike down as much as you like. It can be anywhere from pussycat to beast. You can also set the top speed. When you set to a lower speed, it doesn't have the dead zone at the start of the throttle movement. You can also choose how fast you want throttle response to be.

On Oliver's other bike - the one he's been on for years, and the one he favors every time (it's his old friend) we've got a pretty crazy setup. We have a Kelly KDS48200 - up to 48v, 200 amps! It's happy to run at 36v as well. I've got a 48v lithium battery pack that weighs about 6lb's in there (only good for a few miles), or 36v NimH packs (dangerous but good). We can run either way. With the 48v pack at 200 amps, the bike was insane. It was un-rideable. The power was ridiculous. It was probably the best splatter bike ever built. We programmed down the current to 45%, which is still super powerful but where Oliver wants it to be. When we run the 36v packs, we set the current higher. The cool thing about running at 48v is that the top speed comes from the volts... and we're up about 20mph on that bike, so he could tackle some pretty big hill climbs with a good turn of speed.

Sorry to be a little more expansive than needed! I hope that gives you some options. The stock set up is really smooth and nice once the rider can handle the full speed and develops good throttle control, but the 36v bike is not a beginner bike. The 24v is much more mellow, which is why we recommend that version for riders at earlier stages. Happy riding!

Many Thanks!

Ian.

[samandkimberly]

This is Ian, of OSET. I hope it's OK to respond to this.

Heh - this is like getting God to answer my questions about religion - thanks!

Then... on the 36v bike especially, you have quite a hard hit. The bike has so much torque it makes throttle control a little tricky for beginning riders. We recommend the 24v bike for beginners for this reason.

That's why it was so cruel of you to put the 36V on sale! I guessed that I was starting my son a little big, but I suffer from the "better to grow into power than suffer with limited potential" mentality - at nearly the same price I couldn't resist the 36V. That all being said, I was fully aware of what I was getting into and, as I originally posted, we all love the bike.

I'll take a look at the other controller - that seems like a very good option. Or I'll turn up the speed on the one we have. :-)

thanks,

Sam

Edited July 18, 2009 by samandkimberly

[samandkimberly]

I pulled the pin and ordered the 36100 controller from Kelley last night, and I'll post a review when I get it. Price was $69, plus $19 to ship to US, but after ordering it I realized that I was going to need the programming cable too - they charge a very reasonable 20.00 for that. Total bill was 113.00, not bad at all if you ask me. Having the ability to program top speed, throttle response, and more is a super bonus. I'm guessing the torque output will be a little better too. Ian - if you have pointers on wiring I'd love to have them, but I'm pretty good with this stuff so I'm sure I can figure it out on my own.

In the mean time I turned the power up on the Oset and played with it a bit while Elliott wasn't around. You're right - the response is much better when the speed is cranked up. In reality, I think I can find a happy medium between top speed and response with the bike as is, but now I'm really interested in the programmability the Kelley controller. Thanks for the tip.

Sam

[samandkimberly]

OK; got the new controller in two days! I took a closer look at the packaging situation on the Oset - the new controller is slightly larger, but very close in size to the original. I'm going to have to make up a bracket to fit but it's not a big problem; there is a lot of room to play with. Wiring would seem to be simple enough, though by no means blindingly simple.

The biggest issue I have is that I don't want to cut the wires in the system up, and I don't want to cut the wires on my perfectly good OE controller. Anyone have a spare bad controller kicking around that I can salvage the wiring from?

Sam

[juanroberts]

a Kelly KDS48200 - up to 48v, 200 amps

OK, I have the 36v OSET and just bought the KDS48200. Any guidance in terms of how to wire it, and program it, would be greatly appreciated. Also, where did you purchase the battery packs you mentioned?

Thanks!

John

[samandkimberly]

OK, I have the 36v OSET and just bought the KDS48200. Any guidance in terms of how to wire it, and program it, would be greatly appreciated. Also, where did you purchase the battery packs you mentioned?

Thanks!

John

I put in the smaller, 100a one. Installing the Kelley control is not rocket science but it does take a little care as it does not just drop in. You need to find a way to mount it to the frame (I used zip ties) in such a way that you can get to the programming end of the controller. I originally tried to make it a drop in exchange with the same connectors as the original (Ian was kind enough to send me a dead controller to pirate the wiring from) but you end up with a lot more connectors than you really need, and the standard Oset connectors are OK, but not the best - better to eliminate them and replace with the more robust ones that come with the Kelley. Wiring takes a little time to figure out, as there is no schematic for the Oset, and the Kelley diagram uses the main relay and throttle wiring differently - you lose the battery level monitor but gain an error LED. Overall, wiring up takes a few hours to do it right. Programming is relatively self explanatory once you've powered it up.

A few weeks after I installed this I started to have a problem with it stopping erratically. It turned out that, during my install I had loosened up some of the other power connections on the bike The electrical connections on the Oset are fine if you don't disturb them but don't stand up to a lot of wiggling around. Check them all while you have it apart.

As far as batteries - I don't know where Ian got his, but there are a lot of LiPo batteries on Ebay. But you can expect to pay nearly $500.00 for any of the modern battery types - a lot, but you're also goig to get 2x the capacity and 2x the life form these over sealed lead acid (sla) ones. As far as SLA, measure up your battery pan and then see what can fit - these might work:

http://www.batterywholesale.com/battery-st...tml?prodID=2818

Good luck. I like the Kelley controller a lot and I'm just trying to figure out what batteries to use myself.

Sam

[juanroberts]

The Dead Zone = I wrapped construction string a few times around the throttle and then tied it to the handlebars at the brake lever to eliminate the dead zone.

What is the dead zone? It is about 1/8 of the turn of the throttle when there is no response from the motor (typical when the governor is turned down for a smaller or beginner rider). This means the child has to turn the throttle a bit before the motor powers the rear wheel. The string trick made it so the throttle was already twisted by 1/8 of a turn, so as soon as my kids turned the throttle, the motor engaged. This made my kids a lot more knowledgeable as to when the motor would kick in, and much more sensitive to it, so that they could roll the throttle with much more finesse and effect a smooth power engagement.

I never had any problems with this setup, except for when the string came loose and the throttle and dead zone returned. That said:

--DO THIS AT YOUR OWN RISK--

[dsergison]

tying string is a bit cheesy.

you can change the travel by puting a tiny screw or a slug of epoxy etc... in the twist grip in the correct location to reduce the dead band.

it does require a bit of care.

and it does require you leave a TINY bit of dead band or the bike never shuts off.

-and should you manage to mess it all up really good, there is a particularly weird "feature"..... if the grip comes off, or rotates to far either way, the bike goes to medium/full throttle automatically.

so I'd say this is for the mechanically inclined individuals.

[juanroberts]

String allows for quick adjustments if you have kids of different sizes or levels riding. No, it is not cheesy, I used this for years with two kids. It works.

Your suggestions I already thought about many times over and could not figure out how to make them work, part of the reason for the risks you mention, and part because it is difficult to make an adjustment after the commitment was made. Have you tried them?

I actually did not tie the string, I would crimp/squeeze it by wrapping it in between the throttle and the brake lever assemblies and adjust the length while the bikewas on and the rear wheel was in the air, this before every ride.

[gwhy]

I think the throttles used are hall type, It may be possible to move the magnet or sensor in the throttle to get rid of this dead spot. I will have a look at one of the hall throttles that I have here to see how easy it is or indeed if it is possible. If its doable I will post some pic's. If they are resistive type throts then this is just a simple case of adding a simple resistor to the ground wire on the throttle connection.

[dsergison]

tying a string to the throttle string is certainly cheesy. but hey, to each his own.

I did modify mine. IT was extremely easy.

I'll elaborate:

#1 figure out how much dead band you want to eliminate. I suggest making some little marks on the grip where the throttle begins to respond. Note: you can't practically remove ALL of the dead band, you need some.

#2 take out little Philips screw holding on metal cover. this metal cover is the travel stop and runs in a slot on your throttle tube.

drill/tap a 4-40 hole in the grip tube for a 4-40 set screw. just long enough to give a new end stop for the metal tab to hit. not so long that it rubs the handlebar.

if you under do it, drill a new hole. if you over do it, drill a new hole, or grind a little off the metal tab.

I also packed a bit of epoxy behind the screw when I was done.

It is a Hall type. you cant move either part nearly as easily as you can just put in a new end stop. the magnet sits in a molded pocket. the sensor does too.

Edited April 5, 2010 by dsergison