scottwitting

Run time obviously depends on type of riding, as a guide I can get my 22kg son on his 16 two thirds of the way round the Sherwood red mountain bike trail before a battery change is required. This is about 5 miles. My understanding of C rating is that you multiply the capacity (8Ah say) by the C rating (15's about the lowest) to give a current that the battery is comfortable being used at. So this gives 120 amps. Given that the Oset 16 is fitted with a 40 amp fuse I reason that the current rating of the battery is never going to be a limiting factor! These batteries are designed to be used in a quadcopter type thing that will drain the battery in minutes, not half an hour like on an Oset. No BMS, just train the child to tell you when a light's gone. I'm not aware of a plug and play BMS that is suitable. Parallel charge. After a ride (down to two lights ~ 37v) I storage charge the batteries if they're not going to be used for a while and then fully charge (balance charge every time) a day or two before riding. I'm no expert but this seems to work and keeps my battery's quite well balanced. Hope this helps, sorry for the delay replying.

I have run two 36V Osets on Lipos for while now, a 16 and a 20 lite. I use two 5s 8000mAh batteries in series, so 10 cells, 37V nominal. The throttle lights drop from three to two lights at a convenient 37V so you, or the child, know to change batteries then. Bike operates fine with these.

If you don't fancy the LiPo route then invest in some new lead batteries. If your existing batteries are relatively old they'll have gradually reduced in capacity over time, new batteries should give a noticeable increase in performance. Best value way is not to buy batteries from Oset but to search eBay for the right size/voltage/capacity batteries as these will be significantly cheaper.

We've been round Sherwood mountain bike trails a few times with no bother. Also ride in local parks and woodland with no issue. Even riden past a policeman on a woodland footpath - he was more interested in the bikes than telling us off! As others have said, remain responsible and you should get very little bother. At the risk of diverting the thread, the place we've had most objection to the boy's riding has been trials! Don't get me wrong, I fully appreciate the club's potential insurance implications for letting non entered riders ride and how relations with landowners can be damaged if an incident occurs, but it's also in a club's interest to promote the sport to the riders of tomorrow! Fortunately more and more clubs have a conducted route now but kids are riding from as young as two and can't compete until they are four!

Not blaming the bike already are you?

Most people doing serious trials with a 20 upgrade to the 'competition rear wheel set' - £159 through Oset (http://osetbikes.com/gb/parts/wheel-sets/ also through Trials UK but a bit dearer - http://www.trialsuk.co.uk/products/oset-rear-competition-trials-wheel) This comes as standard on the 20 Racing and gives you a 3" wide rear tyre (same as TY80 rear tyre I believe). Think it comes with a security bolt so you can run at 2psi or less for best grip. Don't think you can simply buy the wider tyre and fit to the standard rim, although I haven't personally tried!

After having my thermostat fail during a trial, nearly boiling my bike and not being able to finish, I now carry a small link wire (6mm male spade each end if I remember right) that can now be quickly used to link out the thermostat and make the fan run all the time. I also run the bike up to temp and watch for the fan cutting in after each wash off and carb clean.

We have an 'old type' 2011 12.5. This has been a great bike for both our boys to learn on. It's biggest weakness, in my opinion, is it's sharpness, it is quite aggressive and doesn't have any throttle response adjustment (just top speed). This hasn't been a major issue though. You can get a tidy one like this for £400 to £500 if you keep an eye on eBay. The other slight issue was the chain constantly coming off. This has been improved since I put new chain and sprockets on, but I still feel the chain was a little to small gauge for the bike. Oh, the plastic chain guard soon gets smashed too. I think (not 100% sure about chain size on Eco) these three issues have been rectified on the 2015 12.5's which are pretty much a complete re-design. If I was buying one now I'd probably go for the Eco, think most of the upgrades on the racing just add a bit more bling. In my opinion there is no need for disk brakes if you keep the V and band brakes well maintained. The band brake is very good, neat & tidy, effective and low maintenance. I wouldn't hesitate to buy a used one, they're fairly simple to maintain and repair if needed and hold their value quite well. Have fun!

Great! Thanks for that, found those on a map so should give her a few to go at. How about the Sunday? Any idea where we'll be heading?

I think I squashed the batteries on the side so that may have been it. I have a Hobby King X120 charger, it's the touch screen type that gives quite a lot of info whilst charging. I balanced charged each battery individually at 6 amps (so less than 1C). I do balance charge my other batteries but thought with this being the first charge I'd do them one at once. The bike is fitted with a 40 amp fuse so obviously won't pull anywhere near the 10C the batteries are rated too. Yes, I'm now removing batteries from the bike when not being used and storing in fire safe bags in a safer place (how much are lipo batteries effected by cold? Could you store them outside during winter nights, or would this do damage?). I charge in a sealed metal box in a 'safe'ish corner of the garage with a smoke alarm mounted above. 'Never leave unattended whilst charging' - is this practical? Does this just mean be in the house, or stay in the garage!!

I thought I'd share a recent near miss I had with some lipo batteries whilst attempting to convert our little lads 12.5 from lead to lipo....... After running a 36v (pairs of 5s batteries in series) 16" bike on lipo for a while with no problems I decided to get some for the young un's 12.5. Went for some of these http://www.hobbyking.com/hobbyking/store/__56843__Multistar_High_Capacity_6S_8000mAh_Multi_Rotor_Lipo_Pack.html which, after careful measuring, seemed like they would fit nicely. Once they arrived I taped them together, wrapped them in some 8mm foam and duct taped them up. Trying them in the bikes battery tray they were a good fit, just dropping in under their own weight. I put them on charge whilst I got to work soldiering up a harness. One charged fine but the other never seemed to want to finish, one cell would not go above 4.18v. In the end I stopped the charge myself. Next I attached the parallel lead and went to fit them in the bike again. This time they were a tighter fit, as if the batteries (or one) had swollen a bit. I was just easing them in when there was quite a loud and#39;pop' and smoke started to be emitted. My first reaction was to step away but then I realized what might be happening so grabbed the bike, wheeled it outside and ripped out the batteries. Within less than 30 seconds there were three foot high flames coming from the packs, which after several more minutes burnt out leaving a smoldering pile of ash, see pic below. I'm still not certain what caused this, the batteries weren't punctured or impacted in any way. The force I was applying to the batteries at the time was probably similar to a small child standing on them, not excessive in my view. I'm quite certain the battery that and#39;popped' was the one that failed to charge properly. I'm progressing this with Hobby King to see what they say and hopefully get a refund. Looking back I feel extremely lucky not to have destroyed the bike or the entire garage. The foam base in the battery tray melted and there was a bit of smoke dust on bits of the bike, but no real damage. I'm going to be much more careful in future how I store and charge these batteries! They are great when working ok, but can obviously go badly wrong!

Hope I got in then!? Sent entry quite early so if it's first come, first served I might be ok! Will the route or section group locations be available anywhere in advance? My wife and boys (2 and 4) will be hoping to watch if there are some easily accessible groups. She likes to know where she's heading before hand.

Good job our girls are doing a top job of representing GB then!

I've had a sit on one that young Dominic Horne rides. Apart from suspension settings (I'm 6ft 3, 14 stone, compared to his 4 stone ish!) it felt like I could have comfortably ridden it in sections. Dom rides it well, seen it zip up quite a steep climb (which my old boy on a TYZ struggled with - technique...). And apparently it will be fitted with a more powerful motor than the prototype has. It all looks proper too, neat finish & components. Think this will bridge the gap for youngsters to full size bikes. Will they ever have to use a clutch?!

Hi gwhy, thanks for the reply. Impressive device! Sounds ideal, with it having variable throttle maps and power/speed settings would it replace parts on the Oset (controller?) or could it just plug in-line and perform the soft cut off function? How much do you sell them for if you don't mind me asking? I've been looking at some speed controllers on HK (like this http://www.hobbyking.com/hobbyking/store/__29665__Turnigy_dlux_80A_HV_Brushless_Speed_Controller_OPTO_UK_Warehouse_.html) . Some seem to feature a programmable soft cut off function, but also do more than I require. They also have three output wires (for connection to a brushless motor) so I'm not sure how that would work with just the two wires on the Oset? They also have an input from a receiver which I guess sets the speed. I'm unsure what this would need to be fed with to see a permanent 'throttle fully open' signal, if that makes sense.

Similar to wackston above, after making good use of the valuable info in this thread, I've successfully converted a 36v 16" to LiPo's (two 5s in series in various capacities). All very positive, the weight saving and the ability for LiPo's to maintain voltage even at high current draw really transforms the bike. My one remaining issue/fear is running the batteries too low. 37v corresponds to loosing the first throttle indicator light, so I've tried my best to train our 4 year old (& Mummy) to stop riding at that. However, sometimes he gets carried away chasing other kids around, I'm absent riding the adult trial and Mum is off the ball. A couple of times I've had batteries down as low as 13v (5s) but luckily seemed to have recovered them ok with no lasting effects. I've just got some of the 'beepers' that wackston mentions so will see how they go. However, ideally, and this is my question, does anybody (gwhy!) know if it is possible to get a device that you can connect in line which measures voltage and ramps down current between two levels (say 37 and 36v in my case)? Hopefully this would give the feel of SLA's dying and leave it impossible for said child to run the voltage below 36v. I guess you may be able to get low voltage cut offs, i.e. get to specified voltage and cut power off completely. However, I'd not be comfortable with this as it's most likely to happen whilst drawing max current when part way up a hill, having dangerous consequences for the rider! If something is available it needs to be reasonably simple as my background is mechanical, not electrical! Cheers Scott

Thanks for the replies Steve, we ended up meeting family/friends on both days of the weekend so no chance for a trial, maybe next year! Managed to get a good bit of Oset riding in on the many mountain bike trails of the new forest though, so a good time was still had! Cheers Scott

Cheers Guys, will discuss with 'her who must be obeyed' and see if we can squeeze anything in!

Hi, we're heading down to the New Forest for a weeks camping (near Ringwood) on Thursday. Taking the lads Oset. Does anybody know of a club/event this coming weekend nearby that would cater for an E class rider?

I have two Osets for our boys (aged 2 and 4) and a Sherco for Daddy. The Osets are fantastic for getting kids into riding. I didn't ride a bike until I was about six, yet our eldest is popping wheelies and competing in trials at just four! The fact they are simple (switch on, rev and go) and can be ridden anywhere (local parks) mean the kids can get hours and hours in practicing in places that just wouldn't be possible on a petrol bike. I also love the low maintenance of them - hose wash off, dry a bit, oil up, check chain tension and you're ready to go again. Much easier than stripping a carb off. Good sealing of electrics would result in an electric bike you could fully submerge, drag out and ride away, no plug out, upside down draining of an engine! Oset will soon release the 24" version which will just about bridge the gap to the adult EM. I predict there will be a whole generation that will avoid petrol and just carry on with electric to adulthood, avoiding having to learn to use a clutch. I agree with the comments about lack of second hand adult electric bikes, if I could get a second hand EM for £2k I'd have one, can't justify £5.5k when that would get me a new, highly developed factory version of a petrol bike. It's not really about the environmental fuel impact, you'll always burn more fuel transporting the bike to the trial! It'd be great to go riding with the boys in the local woods on a full sized electric, although I do believe it wont be long before the law catches up and these are banned too. Imagine dozens of EM's tearing up a Peak District bridal way, the argument that it's just a mountain bike with a motor wouldn't hold up long!

3.00 by 12 pit bike tyres fit. Search for Oset tyres and pay £35 or this (http://www.ebay.co.uk/itm/Pit-Dirt-Bike-3-00-12-Tire-Tyre-300-12-SDG-Wheel-Knobbly-12-12-Inch-Rim-80-100-/171821951624?pt=LH_DefaultDomain_3&hash=item280162ea88) is identical for £15. I ordered the expensive one, realised it's just a cheap Chinese pit bike tyre and found the cheaper one. They're a bit tight to fit and a bit heavier, but you can run them virtually flat and they seem to give much better grip. hillary - you prompted me to search for the sections in the ACU handbook, see that copied below. For a start it says E class is small wheel, yet the Oset 16 has 16" wheels front and rear? Does this mean E class riders must ride a 12.5? As for the tyre section, I've just tried to apply it to the new pit bike tyre, the only bit it seems to fail on is the "blocks must be parallel with or at right angles to the tyre axis". Surely nobody is going to stop a 4 or 5 year old from riding because they have the wrong tyre!! D Class Medium wheel 80cc, and Electric up to 7 bhp measured at the rear wheel D Class Small wheel 50cc Mono and 80ccTwinshock, and Electric up to 2 bhp measured at the rear wheel E Class Small wheel Electric powered machines up to 2 bhp measured at the rear wheel Wheel sizes Standard Wheel – 21" Front – 18" Rear Medium Wheel – 19" Front – 17" Rear Small Wheel – 16" Front – 14" Rear The above is based on the wheels of combustion engined machines using motorcycle tyres.If other wheels are used as on current Electric powered machines then the outside diameter (total circumference) of the tyre must not exceed that of the corresponding tyre size Tyres. Only tyres which conform to the following specification may be used. All tyres will be measured mounted on the rim inflated to a pressure of 14 lbs/sq.in, and must have a nominal aspect ratio of 100/100. Overall width (O) measured at wheel spindle height must not exceed 115mm. (Refer to diagram). Tread depth (A) must not exceed 13mm. All tread blocks in the same circumference must be of the same depth. The space between the tread blocks ( must not exceed 9.5mm across the tyre or 13mm in a circumferential direction ©. The space between the shoulder blocks (D) must not exceed 22mm. The space across the tread (E) must not extend completely across the tyre measured at right angles to the tyre wall unless broken by a block. All main tread blocks must in principle be parallel with or at right angles to the tyre axis. (Tyre must have the samea ppearance if reversed and conform in principle with these diagrams). The tyre surface must not be fitted with any subsequently mounted elements such as anti-skid devices, chains, etc. NB: Only tyres available from commercial sources and complying with these dimensions are permitted in competitions. Where the event uses the public highway, tyres must be manufactured to comply with European Tyre & Rim Technical Organisation and have the relevant markings.

Hi zamboni9, Can't comment for your location, but my experience of buying batteries (lead) for a 12.5 24v Oset is that you get the best price if you buy ones that are just sold as 'batteries' not 'Oset batteries'. Know the size and capacity and search for that on eBay. Think the last pair of batteries I purchased were about £35, compared to £60+ if I'd gone via Oset....sounds like you've done the same with the charger. LiPo - agree with s1vwl, LiPo's make a huge difference to the bike. Weight saving and the fact they maintain their volatage at high current draw means the bike zips up hills much better with Lipo. However, also agree with gwhy, to be fully safe you need a very good understanding of the risks and how to use/care for the batteries. Because I'm tight I went down the Hobby King plus loads of reading route (lots of great info on here, alot supplied by gwhy - thanks!) instead of paying for somebody else to do the thinking and sell me shrink wrapped plug and play solution. I would like to know what is contained in the Boost packs that takes all this thinking away from the user! I suspect Oset haven't gone down the LiPo route themselves yet because of the risks and the fact the bikes would no longer be 'ride until they die then plug in' anymore.

Good on ya! Best of luck getting back into riding. What other motor sport can three generations compete, possibly on the same sections? I'm in a similar position, except being the middle generation. Our four year old boy is just getting going on an Oset and Grandad still plods on on bikes that are often older than me! Can't wait for the day when we can all ride the adult route together! I remember as a 10 year old being very pleased with myself if I'd beaten the sixty odd old timer at our local club. The beauty of trials, not too expensive and you can make a comeback at any age. Enjoy and keep those feet up!

Observers would have free use of internet/Facebook during the trial! Observers could also have a profile/log on so riders could debate if it was a stop or just a dynamic pause after the trial....... Agree, the cost could be prohibative for the smallest of clubs, also agree with the point about not all riders being IT savvy, but as time went by more would sign up. Pre 65 trials could still be marked on slate....

See this website - http://www.britishworldtrial.co.uk/shop/4587790221