36 replies to this topic

[petrg]

My 7 yr old has just got an Oset 36v, which I can't keep him off, which is great.

But the take off from a standstill is really jerky!!! I have researched this, and it appears this is a common issue. I have turned the potentiometer up to max, and it makes no difference other than increase the top speed of the bike, which is great, but we still have the jerky throttle.

This makes riding at slow speed, which is the idea of a Trials bike, very difficult. I have been advised to buy a programmable speed controller from Kelly Controllers in the US.. Surely if Oset know of this issue, the programmable speed controller should be supplied with the bike???

Has anybody any feedback after changing there speed controller to a Kelly programmable one?

Cheers

[frogger]

http://www.trialscen...ottle-response/

Edited by frogger, 10 January 2012 - 09:12 PM.

[petrg]

Frogger

Have seen that link before. Thanks anyway..

[frogger]

I have the same issue as you. I need a fix too.

[petrg]

Frogger

The fix is to order the Kelly controller. I just wanted to hear from those that have fitted one, before I spend my hard earned cash on one.. As if the 36v Oset wasn't expensive enough!!!!! Great bike, just let down by the throttle and old tech on the batteries.. Li-po is next, once the throttle is sorted.

Regards

[frogger]

I am going to call Oset tomorrow for help on which controller to buy exactly and how to fit. Will post whatever I find out.

My 8000mah lipo's are ordered. Should make a nice 16000mah pack. I'll post up my results on that too. I need to get the snatchy start sorted because the lipo's will bump the voltage up a bit so my fear is the snatchyness will be exaggerated.

[Pete_Scorpa3]

I have a 2012 model 36v and the throttle operates just like a normal trials bike, it is smooth and linear. My daughter can control the slowest turns with no problem. What year is yours? Perhaps there has already been an upgrade that can be fitted?

Pete

[frogger]

Mine is brand new. Bought 3 weeks ago. My son who is almost 9 has no problem with the throttle, he is used to a KTM 65 2stroke but even then I can still see the rear wheel spin when he opens the throttle. It's when my daughter who is 5 and is very inexperienced tries to ride it that it's a big problem. I know the 36v is designed for more experienced riders but it should still be ultra smooth, no reason for snatchyness.

Edited by frogger, 11 January 2012 - 12:01 AM.

[gwhy]

You dont need a kelly controller to fix this problem, but you do need to know what is causing the problem before you can fix it. Is the snatchy throttle only at the very start of the throttle travel i.e when pulling away or for example if your riding at 1/4 throttle and then twist some more do it still snatch or is it more controllable from 1/4 throttle up ?. I expect the kelly control has a soft start built into it which do smooth out the throttle from a stand still but it will introduce a delay in the throttle in doing so which is also not very good trials. I would fit a magura pot throttle first, Hall throttles are ok but they are not consistant.

[petrg]

My sons Oset is a brand new 36v bought 2 weeks ago from my local dealer.

My son is an experienced rider having had a CrF 50 and then a Cobra 50( similar to KTM 50 ), so he is not intimidated by the power!!

It is the initial bite of the throttle, ie: the position from a standstill to actually a position were the bike starts moving, it's either on or off!!! No good for trials. When the bike is moving the throttle action isn't perfect but is manageable.. But it's still need sorting were the power is from and off position to on..

Regards

[gwhy]

frogger, on 10 January 2012 - 09:11 PM, said:

http://www.trialscen...ottle-response/

I just read through this post and did not know that the kelly controller was only £40, a magura pot throttle is around £50 so it will make sense to go with the kelly for a quick fix, or you could either try another hall throttle or put a simple rc circuit inline with the throttle signal ( this will take a bit of experimenting with to get the sort of throttle response that you want ) this will no allow really fast changes in throttle output but ramps the throttle voltage up over a preset time ( you need to be aiming for around 1/4 to 1/2 second ramp time the lower the better) the cost will be about 50 pence and involves just 2 components a resistor and a capacitor. If you wanted to try this I could work out some initial values for you to try.

[frogger]

Spoke to Ian today and he re-iterated that the 36v was designed to work this way so that kids can get good drive off the bike to loft the front wheel up and get over obstacles. I can see that with my boy, he loves the kick.

But... For my little girl it's an issue and my lipo upgrade will make the problem worse so Ian did recommend trying the Kelly controller. He said they had very good results with it.

Very helpful, Ian said he will try and help me through the wiring if I decide to buy it. I have decided to hold off for a bit, complete the lipo upgrade and give my little girl some more time on the bike to see how it goes. In a weird way I actually think it might teach her more sensitive control with the throttle but time will tell.

Edited by frogger, 11 January 2012 - 11:09 PM.

[Dave Horne]

For those of you who don’t know me, I ran the Yeadon Guiseley Oset Cup in 2011. So I’ve seen first hand the issues some beginners have with the power delivery of the 36V bike. (Especially if they haven’t previously ridden a 24V bike).

What I’ve found is, the kids who perceiver and put the time in, will master throttle control. If you take a look at our Oset Cup films posted on YouTube, you can see first hand the bikes are very capable of running even in very wet conditions, once skill level improves. In my opinion, if your child is struggling with controlling wheel spin on the standard set up, upgrading to Lithium’s is probably not the best option at the moment. My kids are so lite, they need the extra weight of the lead batteries, to help stabilize the bike.

We’ve also tried a controller and found the power delivery is delayed and creates more issues than it resolves. My eldest has ridden a couple of adult easy trials this winter and wouldn’t have had a hope of getting up some of the steps with a delayed throttle.

I would always advise beginners start on the 24V bike and only upgrade once they’re using that bike to its full potential. The way second hand values are at the moment, you’ll probably get your money back on a 24v anyway.

[gwhy]

I over come this problem with my powerfull e-bikes ( they are not osets ) by making a throttle interface that allows the programming of the throttle resolution at different points with in its travel( throttle mapping ) so there is no delay introduced , this works very well as it was a big issue for very slow riding control, the more powerfull the bike the more of a problem it becomes. There are quite a few controllers out there that have soft start options ( delay in throttle ) but how well these work will depend on the controller design.

[frogger]

Dave Horne, on 12 January 2012 - 12:13 AM, said:

We’ve also tried a controller and found the power delivery is delayed

Hi Dave, thanks for joining in. I totally get what you are saying, hind sight is a wonderful thing. For those of us that don't have first hand experience of the bikes and further more 2 kids at different ages and experience levels it seemed (to me at least) the most logical option to buy a bike that both can ride and will enjoy so I opted for the 36v. I bought a 2 week old bike from another member on here because he wasn't impressed with the range of the bike and decided to opt for a Beta 50 instead so I didn't have the benefit of a salesman's guidance in a shop. I probably should have bought a 24v for my daughter and waited for the Oset 20 for my son. Oh well...

Do you mind sharing which controller you tried? I have heard someone else say the Pico Amp from Germany felt like nothing more than a delayed throttle but not heard that being said about the Kelly. Was it the Kelly controller you tried?

As far as the Lipo upgrade goes, I am doing for 2 reasons, range and simplicity. The pack I am building should at least double the range or more. I am very familiar with Lipo's, have a charging station setup and so for me it's actually more hassle having to worry about charging up additional lead acid cells. I do realise however that it will make the initial jerk a bit worse because of the increased voltage but I am still set on changing to lipo. No choice now the cells are already on their way from Hong Kong!