What HP/size are your motors?

[impression]

2.58hp happy time 66cc

7kg bike
7.5kg engine

60kg rider.

 

[duivendyk]

The key is hill climbing requirements,with a small displacement (below 50cc) engine any hill with more than 4% grade would require lower gearing which may cause you to overrev on the flats unless a variable drive is available (gear box,CVT or deraileur).Engine torque (pulling power) is pretty much proportional to displacement,so a 100cc engine has about twice as much pull as a 50 cc one.Small but powerful engines like the R460 get their high relative output mainly from rev capability.The torque on it peaks at 8-9 krpm and max power is at around 10k.I think a 200cc engine is an overkill,tempt one into going too fast,my guess is around 75-100 cc is optimum,without a variable drive, 50+ with one.Weight is only important really in hilly terrain,or with small engines 35 cc or less,and less so with variable gearing.The case for larger displacement is also one of durability,the life expectancy of an engine that runs wide open a lot of the time is usually reduced quite a bit,esp those without forced cooling (over heating) and of Chinese origin,mainly because of lower construction quality.

 

[ENO]

My 13 year old has nearly finished the OCC Stingray Chopper and we put a 70cc motor in it..I am wondering if I have let him have too much power wnd speed even though the bike is heavy. Then again a 48cc (legal) would have probably been to slow and not have enough grunt to compensate for the weight of the bike and rider..He could always go light on the throttle and secretly have the extra power if he needed it..Of course if the boys in blue (OZ) pull him over the sticker will say 48cc...Anyone have some info on speeds with this bike and motor...Anyway in about a week or so we will find out...Bit concerned about our "Fred Flintstone brakes" but am seriously thinking about adding some discs on the front for the required stopping in a hurry...Thanks ENO

 

[5-7HEAVEN]

You love your son.

Install the disc brake, place a governor on the engine.

 

[duivendyk]

I forgot to mention my ride,Mitsu TLE 43 Staton, NuVinci,I don't get much over 20mph in the hills and blind curves around here , on the back roads in the Piedmont of Virginia.This is a place were brakes are as important,if not more so, than the means of propulsion,as I have had occasion to find out.Front disk and rear calipers.

 

[Irish John]

Honda 50cc 4-stroke on a Schwinn Deluxe 7 weighs a lot but drives like a motorbike. Top speed 55 km\hr on flat
HuaSheng 50cc on Schwinn Alloy 7 much lighter with top speed of 52 km\hr on flat. Changed engine to Honda and top speed is 59 km\hr on flat but the revs are way too high so it cruises nicely at 53 km\hr on the flat dropping to 30 km\hr on big hills.
I weigh 86 kilos in summer and 88 kilos in winter cos of heavy goose pimples.
HT 70cc 2-stroke on Merida Kalahari top speed 38 km\hr but after 2 minutes of that you need to replace the piston rings, gaskets and bottom and top bearings. It costs about $1 per kilometer if you factor in the true cost of running the HT. No kidding I'm serious.

 

[bamabikeguy]

I'm running a 25cc Robin-Subaru on my 26" comfort bike. It tops out at 25 mph. Once at 30. I don't want to or need to go faster than 20 mph.
When I do a desert run with lots of wind, I put on the 35cc Robin-Subaru. Both are GEBE systems. They're more long-distance runners than sprinters; they can go all day.

That's what I'm interested in, I've done my long hauls on the 2 strokes, Zenoah and Tanaka, and next months 1,000++ miler will be on the Robin/Subaru 35.

Has anybody done any cross country distances with one of these yet? And have any insights?

Or would I be better off switching the Tanaka 33 on to the recumbent?

 

[ENO]

Thanks 5-7 in Hawaii and "Top of the mornin to ya" John..
John as you live in OZ I was wondering if you could give me some info on getting hold of disc brakes to suit the OCC Stingray chopper front wheel in NSW and the costs...I know there are a necessity as those little rubber things we have now can disappear as quick as a goose bump when friction is added....Thanks ENO ..PS..5-7..Ill get back to you to scratch your brains on governors (and I dont mean the ones that looked after convicts)..Thanks

 

[Zev0]

That's what I'm interested in, I've done my long hauls on the 2 strokes, Zenoah and Tanaka, and next months 1,000++ miler will be on the Robin/Subaru 35.

Has anybody done any cross country distances with one of these yet? And have any insights?

Or would I be better off switching the Tanaka 33 on to the recumbent?

I have both the RS and the Tanaka 33. If I was going to take a ride like that it would definately be on the 2 stroke. I'm not an expert by any means, but I've heard and read that the 2 stroke would be more ideal for that kind of ride.

 

[bamabikeguy]

I have both the RS and the Tanaka 33. If I was going to take a ride like that it would definately be on the 2 stroke. I'm not an expert by any means, but I've heard and read that the 2 stroke would be more ideal for that kind of ride.

I'm getting kind of spoiled on the decibel diff and the torque.

I've put maybe 500 break in miles since Dec., changed the Mobil 1 oil three times, and planned to carry along a 13 toothed drive gear to swap out once I hit the flatlands.

Yesterday I did maybe 70 miles, thinkin' and thunkin' all the way.

Glad to have someone also using both types to compare notes.

The Tanaka could easily do 250 miles in a day, do you think the Subaru could do 200?

Edit: noticing the post above, and I'll chime in on the "4 stroke/torque" debate and say first, all my R/S installs have been on 21 speeds and above.

On those bikes, a R/S 35 will outrun a Tanaka 33 on a 7 speed bike, in a 3 mile or more race.

The Tanaka will zip on straightaways, but with the 21 speed getting the jump on hills, that torque in the 4 stroke is PLENTY pleasant.

And that is another reason why I think the R/S might do a long haul, because the recumbent isn't a 7 speed, and I can help it any time I choose.