Honda Pacific Coast ipcrc Archives

Title and Body Title Only	All Words Any Word Phrase
Author:
Search Start Date:
Search End Date:
Sort Order	Newest Posts First Oldest Posts First
Sources to include:	Both Yahoo Groups and List Server Only Yahoo Groups Only Older List Server
OR Message ID:

6 speed transmission project ...
Written by spacetiger_j... on 5/11/2012 at 01:44 am

The intent is to get lower RPM at cruising speed. Stock is ~4,000 RPM at 60; at
70 you are closer to 4,600 RPM.

You can swap to the VT1100 and RPM ~10%. I think this a good cost effective
change. The only down side is this changes the overall gearing so every thing is
about geared 10% taller.

Some ride with a taller tire (140/90-15). That reduces the RPM at cruising
speed too and it does so across the RPM range. Another low cost way to do this.
I don't know if there is someone doing both. If so, that would be a significant
drop in RPM at 60+ and much slower acceleration.

I'd like to see if there is a way to reduce the RPM at cruising speed via an O/D
but, retain stock gearing so there is no loss of acceleration in gears 1-5. It
will take a bit of elbow grease... but I think it will be worth it if I can get
the gear ratios worked out.

Jerry

--- In ipcrc@yahoogroups.com, "Jerry" <sanae.ej@...> wrote:
>
> So its taking forever to get the parts in, so I thought I'd get an early start
on the upcoming winter project - getting a 6 speed transmission into the PC.
>
> Okay, technically, it is a 5 speed transmission with overdrive. Point is, it
is 6 forward speeds.
>
> The donor bike is a 86 VT700. From 1984-1987 this bike came with a 5 speed +
OD transmission. The VT800 followed with only a 4 speed but was tuned for more
torque/HP and the 5+1 TX was deemed not necessary. Our PC800 followed in 89 and
had a 5 speed TX. In my research of this engine line, I found many common parts
between the VT700/800/PC800 engines, not so much with the VT1100 because of the
difference in power output. I then started looking at the price of parts on
ebay for the VT700/800 and found them to be surprisingly reasonable. The 5+1
transmission cost $35 and included free shipping. I found an engine case for
the VT800 and VT700 for a little over $100, so I thought this was a reasonable
cost to try and see if this swap was doable. I have a spare PC800 engine.
>
> I will have to do a bit more research on other gearing changes it might make
sense to do as I will try to mod the engine a bit for a little more power. I
will have to map out the overall gearing ratios so I get a match so the new 5th
geat matches the PC5th gear giving me a true 6th or O/D gear.
>
> So, I will do play with this project a bit between parts delivery as I work to
get the PC rideable. I will finish the transmission swap on the spare engine
and once done, swap engines in the PC during the winter.
>
> :-)
>
> Jerry
>