Servi handling
Stiff and twitchy
-
- Member
- Posts: 58
- Joined: Wed Jul 06, 2022 1:12 am
- Bikes: 1970 Servi
1998 FLHT - Location: Usa
- Has thanked: 33 times
- Been thanked: 5 times
Servi handling
I already know that servi's aren't built for speed or handling. Mine has 3 motorcycle tires with about 22# each. It is stiff and tippy and twitchy. I have read that 12# is recommended, but that just seems very low. I would like to know about anybody's experience with psi and tire differences like car tires (?)
To make any improvement, just in case I need to make a sudden, evasive maneuver without trashing this thing. Thanks in advance to the more seasoned professionals!
To make any improvement, just in case I need to make a sudden, evasive maneuver without trashing this thing. Thanks in advance to the more seasoned professionals!
-
- Senior Member
- Posts: 1608
- Joined: Fri Oct 03, 2008 2:57 am
- Bikes: Pan
FLHP Evo
E-H Super X
Chubble head hack
Servi-car
Topper(s)
Model 64D (Hey its got 3 wheels!) - Location: Indianapolis
- Has thanked: 406 times
- Been thanked: 367 times
Re: Servi handling
It's just the nature of the beast. My 65 doesn't care to be sporty either. I have Avons on it, and run around 20 in them. 12 Does sound too low, but it boils down to what the tire manufacturer states are safe ranges, and what risk you're comfortable with. And I think you've already been advised that for handling and safety, the front fork on a servi is in a permanently raked position, similar to that of a side car equipped big twin of the era.70 servi wrote: ↑Mon Aug 01, 2022 12:53 pm I already know that servi's aren't built for speed or handling. Mine has 3 motorcycle tires with about 22# each. It is stiff and tippy and twitchy. I have read that 12# is recommended, but that just seems very low. I would like to know about anybody's experience with psi and tire differences like car tires (?)
To make any improvement, just in case I need to make a sudden, evasive maneuver without trashing this thing. Thanks in advance to the more seasoned professionals!
-
- Senior Member
- Posts: 581
- Joined: Wed Aug 13, 2014 8:27 pm
- Bikes: WLA
- Has thanked: 58 times
- Been thanked: 145 times
Re: Servi handling
The WLA/ WLC was recommended with 1.8#...maybe it helps your Servi to be less bouncy..?
-
- Member
- Posts: 58
- Joined: Wed Jul 06, 2022 1:12 am
- Bikes: 1970 Servi
1998 FLHT - Location: Usa
- Has thanked: 33 times
- Been thanked: 5 times
Re: Servi handling
I will try less psi, i was hoping to hear that somebody is running bias ply car tires on back, yes the fork is in the longer position, all good there, after finding the stem nut detached! I dont find the rig bouncy and when i can spend more miles riding than testing, i will get more tolerant of the handling.
No wonder we dont see any "Trike Races".
No wonder we dont see any "Trike Races".
-
- Moderator
- Senior Member
- Posts: 8414
- Joined: Sat Nov 15, 2008 4:09 am
- Bikes: Multiple H-D, Ducati, BMW, Triumph, BSA,...
- Has thanked: 484 times
- Been thanked: 2958 times
Re: Servi handling
Car tires work on trikes and sidecars because they never lean so there are not issues with sidewall flex, etc. Trikes are inherently bad handling beasts. they worked fine for meter maids at 10MPH but are really stressed at 50MPH on an open road. Low pressure in the front tire will make the handling even heavier. A functioning steering damper is a must.
-
- Senior Member
- Posts: 1608
- Joined: Fri Oct 03, 2008 2:57 am
- Bikes: Pan
FLHP Evo
E-H Super X
Chubble head hack
Servi-car
Topper(s)
Model 64D (Hey its got 3 wheels!) - Location: Indianapolis
- Has thanked: 406 times
- Been thanked: 367 times
Re: Servi handling
Putting the square profiled Shinko on the back of my sidecar rig has made flying the car a bit trickier...
-
- Member
- Posts: 58
- Joined: Wed Jul 06, 2022 1:12 am
- Bikes: 1970 Servi
1998 FLHT - Location: Usa
- Has thanked: 33 times
- Been thanked: 5 times
Re: Servi handling
Follow up: on my latest local test ride loop i ran 18# in all 3 tires. Much less oversteer, and handling is improved, and on my next drive, after gas tank lining and clutch repair, I will experiment more with the PSI.
-
- Senior Member
- Posts: 1500
- Joined: Tue Aug 03, 2010 7:10 pm
- Bikes: 1937 U big flathead, 88" stroker, dual port, big cams, pop-up pistons
- Location: Lynbrook, New York
- Has thanked: 32 times
- Been thanked: 387 times
- Contact:
Re: Servi handling
Two choices for the fork (using OEM parts)
1. Fork stem not parallel to the tubes (permanent in G, adjustable in sidecar)
2. Everything else (stem and tubes parallel)
1. Reduces steering effort by shortening trail, which is the self-centering characteristic. Result is less stability at speed, like a shopping cart.
2. Require more shoulder muscles to operate but more stable at cruising speed.
Raking the neck increases both stem angle and trail, steering becomes very heavy, very large turning circle.
A combination of a raked neck plus raked trees can give close to normal handling with severe fork angle.
1. Fork stem not parallel to the tubes (permanent in G, adjustable in sidecar)
2. Everything else (stem and tubes parallel)
1. Reduces steering effort by shortening trail, which is the self-centering characteristic. Result is less stability at speed, like a shopping cart.
2. Require more shoulder muscles to operate but more stable at cruising speed.
Raking the neck increases both stem angle and trail, steering becomes very heavy, very large turning circle.
A combination of a raked neck plus raked trees can give close to normal handling with severe fork angle.
-
- Senior Member
- Posts: 698
- Joined: Mon Feb 23, 2009 5:24 am
- Bikes: 1945 UL
1947 EL
1948-ish Pan
1991 FXLR
2007 FXDB Street Bob - Location: Snohomish, WA
- Has thanked: 22 times
- Been thanked: 35 times
-
- Senior Member
- Posts: 5327
- Joined: Tue Oct 31, 2017 1:00 pm
- Bikes: 1950 Panhead, Resto-Mod
1968 90", 5 Speed Shovelhead,
1984 Home Built Custom Evo 100" Bagger - Location: Knoxville, Tennessee
- Has thanked: 2801 times
- Been thanked: 2159 times
-
- Member
- Posts: 12
- Joined: Thu Apr 12, 2012 10:21 pm
- Bikes: 1956 Servicar, 1932 VL
- Been thanked: 1 time
Re: Servi handling
I run around 22 lbs in rear and whatever the tire calls for in front. Now running 36lbs in front on modern Dunlap.
-
- Senior Member
- Posts: 1500
- Joined: Tue Aug 03, 2010 7:10 pm
- Bikes: 1937 U big flathead, 88" stroker, dual port, big cams, pop-up pistons
- Location: Lynbrook, New York
- Has thanked: 32 times
- Been thanked: 387 times
- Contact:
Re: Servi handling
A certain minimum psi is needed in the rear tires to combat wear, oversteer and high temperature, but since the entire chassis is unsprung (rigidly mounted to the axle) any bump at all throws the axle up in the air, and you with it. Use the lowest safe pressure.
In addition, the higher the psi in the rear the worse a single-wheel bump, which makes the bike dart to one side, in extreme cases it will try to change lanes.
In addition, the higher the psi in the rear the worse a single-wheel bump, which makes the bike dart to one side, in extreme cases it will try to change lanes.
-
- Member
- Posts: 58
- Joined: Wed Jul 06, 2022 1:12 am
- Bikes: 1970 Servi
1998 FLHT - Location: Usa
- Has thanked: 33 times
- Been thanked: 5 times
Re: Servi handling
Thanks Buster and Kitabel for any and all info, the steering damper is in place and so far I havent needed to turn it downward. My original concern, while having too much psi at that time, was the firmness of the ride especially while in a turn, which is improved with less psi. I believe the manual says to use 12#, which just seems wierd to me but then again so does the 18# i am running. It will be a while before I take another ride on my usual test loop, which is hilly and curvy.
-
- Moderator
- Senior Member
- Posts: 8414
- Joined: Sat Nov 15, 2008 4:09 am
- Bikes: Multiple H-D, Ducati, BMW, Triumph, BSA,...
- Has thanked: 484 times
- Been thanked: 2958 times
Re: Servi handling
Be aware that the 12psi is for old style rayon cord tires in use at the time, which had very stiff sidewalls. Nothing at all like modern production tires. Get modern ones soft enough and they will fail when in a most inopportune time, like the middle of a turn.70 servi wrote: ↑Tue Aug 30, 2022 10:22 pm Thanks Buster and Kitabel for any and all info, the steering damper is in place and so far I havent needed to turn it downward. My original concern, while having too much psi at that time, was the firmness of the ride especially while in a turn, which is improved with less psi. I believe the manual says to use 12#, which just seems wierd to me but then again so does the 18# i am running. It will be a while before I take another ride on my usual test loop, which is hilly and curvy.