Top Speed



CrazyDan

Well-Known Member
Joined
Jul 9, 2016
Messages
2,382
Doubt I"ll ever see 55 mph, would require I hit 9k rpm which isn't feasible at a 12.59:1 reduction (unless I get some serious fairings and windshield and go in a tuck downhill). 6th is great for cruising at 40 mph at 6500 rpm, but no real acceleration can occur in it.
 

ObseSSed07

New Member
Joined
May 28, 2019
Messages
2
I see a top speed of about 24mph on open flat road with no wind. I'm 218lbs and I run an 80cc stock setup tied to a Hyper Beach Cruiser. I have ordered a new stage II BBR Spark box, Thrust racing exhaust and a high compression head. I will check my mph after those are installed. By the sounds of the Youtube videos, I may need ear plugs too.
 

CrazyDan

Well-Known Member
Joined
Jul 9, 2016
Messages
2,382
I have a friend that's not very mechanically inclined. He bought a zeda motorsports engine that ran ragged as f***, and figured it was a trash motor. He sold it to another friend, and I helped him get the jetting right. That thing screams. The first owner didn't want to listen to me about elevation....moron... His house is at 2600', and the zeda motorsports engines are tuned basically right around sea level. Of course it's not gonna run right.... You can't fix stupid.
 

Robert Bianchi

Motorized Bicycle Vendor
Joined
Nov 3, 2017
Messages
66
I have a friend that's not very mechanically inclined. He bought a zeda motorsports engine that ran ragged as f***, and figured it was a trash motor. He sold it to another friend, and I helped him get the jetting right. That thing screams. The first owner didn't want to listen to me about elevation....moron... His house is at 2600', and the zeda motorsports engines are tuned basically right around sea level. Of course it's not gonna run right.... You can't fix stupid.
For sure. Some people just don’t understand
 
O

Otaku

Guest
All the stockers I have put together for people over the years have made about 35-38kays
Few mods detailed well on this forum, as well as disassembling the engine and cleaning it up.. every bearing pocket seems to be packed with swarf I have found.
as well as machining run-out off the bottom end
replace the Chinese approximation of a carb
and port matching the jug to the bottom end (transfer ports) they have a good 10mm step in some cases.
Skim the head a little..

again all well documented mods..

This made a bike for me that does 68.5 on the flat if I lie on the seat.. it is scary and even steel frames will not survive this long (ask me how I know) interestingly this 68.5 is the same speed that my bike will max out at bombing down a very long, quite steep hill with no engine engaged at all.. again.. scary.

I do not doubt the engine could be improved upon further than this, I do not doubt that more top end speed can be made at the sacrifice of torque and reliability but it really is entering the realms of motorcycle speeds and complexity to do this.. in most cases you can buy a used motorcycle for less that will be much more reliable and in some cases not attract the attention of the law (where applicable)
 
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