Oset 12.5 And 16.0 Prep Tips

[juanroberts]

I recommend putting Slime in the inner tubes (its the green goo sold for putting toinner tubes). On the USA's middle East Coast, there is a plant called Greenbrier that can creep on trails and has thorns. I did not have a problem with my own dirt motorcycle, but it was a real problem on my mountain bike until I bought inner tubes that had slime in them, and then the problem went away. I would not expect it to work as well on nail-sized thorns though.

[juanroberts]

I have installed batteries off an older version 16.0 on the 12.5. The only difference is that the old ones were 8a and the new ones are 10a and a little taller, so they are snug but also last a little longer. My son used to be afraid of the 12.5's power, and now he now loves turning that throttle, so the battery drains faster, but still lasts well over an hour on trails. What is funny is that he is still too small for a 50, yet can really ride this thing.

After nearly 2 years of riding the Oset 12.5, finally something broke: the throttle gave out. I was able to get a replacement sent to me right away and it is as good as new (Oset service remains A+) and I upgraded to spring-loaded footpegs for $20, which now work like a charm.

During the past 1.75 years, we rode the OSETs at least once a week and went through one 12.5 rear tire. So it got used about 100 times on mountain bike trails, for about 1.5 hours each time. Other than that, the only other costs have been related to chain lube and plugging in the charger. I used teflon-coated bicycle cables for easier braking. I wish gas bikes were this cheap and easy to maintain.

Edited November 6, 2008 by juanroberts

[brompton92]

Have you used an optimate to charge the batteries or do you charge them on the bike ? The reason why I ask is because I have bought a spare set of batteries for my sons Oset 16 (36 volt).

Also whats the score on the charging front as I didnt get a manual with mine due to it being a demo bike.

I have the 36 volt mains charger which has a red light on it whilst plugged in. Do I have to wait for this to turn green before the batteries are fuly charged ??

Or is it the lights on the throttle that turn green ??

[juanroberts]

>>Have you used an optimate to charge the batteries or do you charge them on the bike ?

No, I always charge them while on the bike.

>>The reason why I ask is because I have bought a spare set of batteries for my sons Oset 16 (36 volt).

Are you in SoCal? I would not mind trying it out.

>>Also whats the score on the charging front as I didnt get a manual with mine due to it being a demo bike.

I did not understand. It takes about 4 hours to charge them, but it depends on the use they got.

>>I have the 36 volt mains charger which has a red light on it whilst plugged in. Do I have to wait for this to turn green before the batteries are fuly charged ??

The light goes green on the 24V models' charger once the battery is fully charged. You do not have to wait if they are lead acid batteries, since they have no "memory", but you will get more riding time if you do.

>>Or is it the lights on the throttle that turn green ??

No, the throttle lights only indicate that the key is turned on, and they do not turn green. They are supposed to also indicate amount of charge on the batteries, but it only works once the batteries are so drained that it is already obvious. When under full throttle, the throttle lights tend to indicate battery drain a little earlier (they go down as throttle is applied towards the 3/4-end of the battery drain).

Here is an idea, hide batteries at the midpoint of a long trail loop and plug them to a solar panel charger.

[brompton92]

I am in the UK so test riding is not an option.

Thanks for the reply, It has answered my questions.

[yamadan]

Here's whats been done so far with Gavins..

Grips and end caps..

PW50 Grips and ODI moto grips..smaller than stock, and the end caps keep the impact off the throttle..

Did the bungee on the foot pegs, Thanks Juan!

Did a Shorter stem..

Carbon bars, feels like a pound of weight.

XTR Brakes, nice bite, ez pull..

Bumpers for the fork..

I was heavy in to Mountain bike racing, so these are "Just laying around" type mods..

The bike is awesome as it sits..

Next I need to do some paint.. But I need to pry Gavin off it first! lol

[juanroberts]

Dan,

On the bungees, I tied them to the front portion of the frame, because to each other did provid as much snap. I use cable from the footpeg to the front of the skidplate and then bungee to the frame tube above that.

I since bought OSET's spring-loaded footpegs and they work like a charm. Its the same footpeg, only dremeled in the center for a spring to fit in.

I used teflon-coated cables from a bike shop, lightly oiled them, and the brakes are easier now.

The handlebar endcaps are trick. I used a motor oil cap duct taped on the throttle side, and an inner tube as a sleeve on the other side, with tassles of course.

I would have thought a longer stem would be better. My daughter (and now son) always crouch so much to reach the bars on the 12.5 while standing, they have a hard time. I could be wrong. However, my daughter on the moment she moved up to the 16.0, could ride standing like a natural, and its bars are much higher. He is 3 and she is 5.

Nice aftermarket brakes.

John

[yamadan]

I ordered the pegs today.. along with a Black seat, extra set of Batteries.. He ran the bike completely out three days in a row over the Holiday!

I'll give the bike a bit of a "freshen up!"

I'll post pic's later..

The stem brings the bike in a "Moto" position.. for Gavin it fits fine.. In a couple years, I may be putting another one on..

I've been taking him to the track primarily, but now he's doing really well I may take him to a couple MTB spots.. just to check it out..

Big gravel is still really hard for him.. but he'll get it figured out..

Thanks!

Dan

[mikedufty]

The 16 appears to have two options for mounting the rear shock to the swingarm. Does anyone know if this is really what the extra hole is for, and in what circumstances the alternate hole would be used?

[motofire]

The 16 appears to have two options for mounting the rear shock to the swingarm. Does anyone know if this is really what the extra hole is for, and in what circumstances the alternate hole would be used?

I am not sure if that was the intent for that hole but you can use that mount hole. We tried it and didint notice much of a difference, though I am sure you can prove me wrong mathematically.

I was looking for a change in ride height because my son is small and at the time only 3. If your looking to lower the bike you can use a 12.5 shock. The best combo we found for him was a 16 shock with the 400# spring.

Edited January 5, 2009 by motofire

[mikedufty]

I wanted to modify my sons oset 16 pegs to spring back, but couldn't find any suitable springs or bungee at the shops. I then had a go with some old bicycle inner tube I had lying around. I cut across the tube to make a couple of loops like large lacky bands, then larksfooted them together through the frame and around the peg. Worked surprisingly well.

Not sure how long it will lasts but I've been using old tubes for tie downs for years and they seem to last pretty well.

I needed a bicycle spoke to tie help with threading the rubber through the frame and through itself.

See picture

[juanroberts]

he only weigh's 3.5 stone ... the chain sometimes comes off

I used a flat metal file to align the angle of the rear sprocket so that it was parallel with the front sprocket's (a long, slim piece of glass could also work). On the older 12.5 version, I also used washers in the rear to make sure the rear sprocket was flush with the front sprocket. Ever since, I adjust the chain tesioners screws with the same number of turns on each side (that way I do not have to check alignment everytime) and roll a screwdriver between the rear sprocket and chain to tension the system before tightening down the axle nuts. This whole process helped minimize the chain coming off unless its really loose, which is more of a problem on the 12.5 maybe because it has a warped rear sprocket. I also oil the chain every 4-5 long rides to keep its noise and wear down.

1 stone = 16 pounds

3.5 stone = 56 pounds

I went to Baja last week. My kids there were able to ride gas bikes there, and the wife followed around on the 16.0. OSETS are very versatile bikes!

[juanroberts]

I got taller aluminum handlebars at a mountain bike store for about $10. My son can now fully stand on the 12.5 without having to crouch down. This helped his confidence greatly.

[fastducs]

I took delivery of a new Oset 16 with the 36-Volt motor 2 days ago. The bike looks great, and the custom-welded frame is very solid - no complaints there. The power of a 36-Volt motor is impressive! This little bike can really go! But the first thing I noticed was that steering was notchy, which is usually an indication of an over-tightened steering stem. This is a typical problem of cheap Chinese-made bicycles (except Osets aren't cheap!) - EVERYTHING is over-tightened and under-lubricated. So the bike goes on the workbench and I took it all apart last night.

Sure enough, there is barely any grease in the steering stem bearings. Added some high quality waterproof grease, set bearing preload correctly, and now the steering is nice and smooth.

I move on to the front wheel, and it's the same problems. It had a bit more grease than the steering stem, but not enough IMHO. BTW, be careful with the wheel bearings - they are simple steel balls without a cage, so once you remove the axle, the balls will easily fall out. I loosened the axle, greased and re-set preload on wheel bearings, and now the front wheel spins pretty well. But now I notice the wheel is wobbly - oh well, I will true it later (assuming it's not the hub itself).

Move on to the swingarm. OMG! The swingarm pivot is a metal stem in a plastic bushing! My son rode the bike for 2 hours, and the metal stem was already galled. For a bike this expensive I expected needle bearings, or at least bronze bushings with reasonably close tolerances. Come on! It is the swingarm pivot - the most stressed pivot on any motorcycle! It was also badly over-tightened, which resulted in extremely stiff swingarm movement. There is also a hole drilled in the swingarm pivot boss. I don't know why it is there, but it is an invitation for water and dirt to get into the pivot and destroy it. I plugged the hole with silicone.

Rear shock had the exact same problems - over-tightened at both mounts and no lubrication anywhere. My son weighs less than 50 lbs, so I set fairly little preload on the spring, and I noticed that the shock spring preload collar got loose while my son was riding the bike. It really needs to have 2 counter-locking collars. After greasing all swingarm and shock pivoting surfaces and reassembling it without over-tightening I see a big improvement: the bike's rear suspension actually moves nicely. There is no damping of course (rear shock is just a simple spring) but all that stiction from over-tightening isn't a substitute for damping.

The front fork is stiff and wobbly - I suspect the clearance between telescoping tubes is just huge. I think I won't waste any time on it and replace the fork with a RST20 mountain bike unit mentioned elsewhere in this thread.

Chain was too tight and made quite a bit of noise when running on the stand. I loosened it a bit and sprayed chain lube on it - now it is better but not perfect. Drive sprocket looks a bit off center, which causes loose-and-tight spots in the chain. Maybe it's the motor axle itself - I didn't get into the motor, so I can't say at this point.

Brakes were easy enough to adjust, but be careful! The owners manual says that you can adjust back pad stop by turning it with an allen wrench from the back side of the caliper. The manual fails to mention that there is a hidden set screw which you must loosen first. If you don't, you will strip the pad stop.

My biggest complaint is the throttle. When speed limiter potentiometer is in its "maximum speed" position the throttle has a nice progressive response, except for a bit of a dead zone at the beginning. But as you reduce maximum speed with the pot, the dead zone becomes bigger and bigger. If your kid is a beginner then it makes sense to reduce max speed a lot, especially on this 36-Volt rocketship, but unfortunately it makes the throttle act almost like an on/off switch. I called Oset tech support about this issue. It is wonderful that in this day and age of off-shore tech support centers staffed by people who might as well be robots there are still companies like Oset that are staffed by real knowledgeable people that answer the phone! Talking to Mike at Oset made my day: he is knowledgeable, honest, and straight-forward. He explained that this throttle behaviour is a side-effect of the motor controller design. It is an off-the-shelf unit, so that's just the way it is. So the bad news is that apparently there is no way to remedy this problem without having a custom-designed motor controller.

[mikedufty]

I swapped the front brake lever on the 16 for a V-brake type lever. This has a bit less leverage than the standard levers, and I suspect is what the front disk brake was designed to work with. Seemed to improve the feel and operation of the front brake.