speed and rpm check

Ghost0

New Member
Mar 7, 2008
764
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0
Bellingham, WA
I just use a regular bicycle computer "speedometer". Don't have a tack but you can get one for about $50. Google "tiny tach".
 

ibcnya

New Member
Oct 29, 2008
220
0
0
Concord NC
I get my friend to ride his scooter beside me...he clocked me at 45 today, and walked him on takeoff. His scooter is a 50cc and he said I cheated because i could peddle to get speed quicker
 

tylerlough

New Member
May 28, 2008
109
0
0
Mishawaka, IN
I use a $10 bicycle computer for my speed, it even tells me the air temperature. I don't really worry about RPMs, I just pull the clutch in when going downhill. My max estimated RPM is 7200. I wouldn't do that with a needle bearing engine though.
 

m0ck5

New Member
Jan 26, 2009
16
0
0
jefferson city missouri
I use a $10 bicycle computer for my speed, it even tells me the air temperature. I don't really worry about RPMs, I just pull the clutch in when going downhill. My max estimated RPM is 7200. I wouldn't do that with a needle bearing engine though.
if its not needle bearing what other options are there, where does it go, where can i get the upgrade and how much does it cost?
 

tylerlough

New Member
May 28, 2008
109
0
0
Mishawaka, IN
This is all in regards to the happy time 2-stroke engines.
When I say needle bearing, it's the wrist pin bearing which connects the piston to the connecting rod. Some engines using a bushing bearing in place of the needle bearing. A high quality needle bearing is superior to a bushing when it comes to wear. But the cheap bushing can take higher engine speeds than the low quality needle bearing used in some engine. A needle bearing doesn't need as much oil as a bushing so that is why the needle bearing is seen a superior.
If the needle bearing holder were to fail, the engine would be basically destroyed. An easy way to destroy the needle bearing holder would be to over rev the engine going downhill.

It is difficult to tell what type of wrist pin bearing you have unless you take to cylinder off or you could ask the seller. As for switching bearing types, I've never done it and don't know how much it would cost.
Here is a picture of a wrist pin bushing:
http://motorbicycling.com/f30/bicycle-engine-total-tear-down-391.html#post3236
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
The bearing and bushing are NOT INTERCHANGEABLE.

Just thought I'd clear that up.

I have a thatsdax needle bearing engine that will get run this spring, and I am already doubting it's longevity based on what I've read.

Now back OT- I check my speed with my GPS, accurate and reliable.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
Oh yeah, the max is in the 7000+ range, but these engines (99% anyways) do not like to be revved out that hard.

That's not what they are made for.
 

Retmachinist

New Member
Oct 21, 2008
637
0
0
Urbandale Ia
I was thinking the same thing Joe. These engines with their crude specs. are certainly not made for many 7000 R.P.M. bursts. I don't want one flying apart when I am cruising out here on the blacktop. Could really ruin your day. Specially since I can't get myself to wear one of these cheesy helmets.

John
 

jasonh

New Member
Jun 23, 2008
1,590
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36
Longmont, CO
My old bushed motor was definitely more rev-happy than my new needle-bearing motor. That's ok though, that's what extra torque is for :) (which this one seems to have plenty of)

I have a cheap analog bike speedo that is only accurate up to about 20-25mph. Reads 40 at 35. I verify with a GPS, but that's not an every day thing.
 

tylerlough

New Member
May 28, 2008
109
0
0
Mishawaka, IN
I like this speedometer from amazon.com for $10. All the functions are useful except for the calories burned function, something tells me it doesn't apply to motored bikes.
schwinn speeedometer
Off topic: If you want free shipping you could order this comfy seat I had on my previous motor bike. (my dad now uses the seat)
.bf.