An international forum for people interested in modern high performance road going sidecars. Forum Index An international forum for people interested in modern high performance road going sidecars.

 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Sidecar frame / suspension brain-storming
Goto page 1, 2  Next
 
Post new topic   Reply to topic    An international forum for people interested in modern high performance road going sidecars. Forum Index -> HPSidecar Technical Discussion
View previous topic :: View next topic  
Author Message
Bandit Bill



Joined: 31 Jan 2005
Posts: 202
Location: Hamilton, Ontario, Canada

PostPosted: Tue Jul 12, 2005 2:51 pm    Post subject: Sidecar frame / suspension brain-storming Reply with quote

Howdy all..

Been a little since i last posted, been riding way too much to sit down at a computer for too long Smile

Just had my first real long ride, appx 1000 km's on roads different than the local ones - It was at the Parry Sound Sportbike Festival, firmly in the frost zone, so the roads are somewhat rougher (not recently paved ones anyway) and heavily crowned and patched, particularly at the top of rises and in corners.

These roads presented new challenges - My rig is simply built too low.
I've bevelled the sidecar swinging arm low point into a 45 Deg angle, and i snapped the two rear-most body mount bolts clean off behind the nuts, dragging them on the pavement. The only thing i have done to modify the ride height of the sidecar, is to mount it in a slight nose high position relative to the horizontal.

I can't help but think an extra 1-2" of additional ride height would be the cure-all for what scrapes the undercarriage.

Additionally, when pushing the rig through a corner, the rig has a tendancy to 'slew' the nose of the sidecar, it feels like the sidecar wheel tucks, and wants to wash out. I guess this could properly be defined as 'oversteering'. The stock Hannigan sidecar rim can mount a maximum of a 145R12 series tire. At the same time that the rig oversteers, or basically washes out the sidecar wheel, the rear wheel of the tends to get light, which aggrevates the situation in that it feels like the rig could spin out if the situation continues. Backing off of the throttle momentarily, is sufficent to stabilize the rig. Additionally, the sidecar suspension arm is of a leading design, vs a trailing design - as such, the leading arm connection is welded to the bottom of the frame rail, vs inline with the frame, which is contributing to the grounding out of the lowest point of the swingarm pivot point. The whole design from the swingarm, shock tower, right down to the VW sourced wheel hub/brake rotor is fairly crude, both in form and function, and i can't help but think that it needs a total rework.

Preliminary thoughts of a rework, basically come down to building a new sidecar frame from scratch. I'd retain the basic Hannigan sidecar 4 point design, with the sidecar frame extending upwards alongside the bike for the top two strut mounts. I'd want to change the leading design of the sidecar swingarm to a trailing design - it seems to me to be a design better suited to handle rougher roads, vs forcing a leading design to go over the bumps abruptly. Going to a wider series tire, would increase traction on the sidecar wheel, while increasing the size of rim that the rig uses to a 14-15" would increase overall ride height of the lower portions of the frame. Of course, increasing the width and diameter of the sidecar wheel, along with the redesigned sidecar suspension will require the sidecar body/fender well to be substantially tubbed out, in order to accomodate the larger components while still retaining the exterior lines of the sidecar. Going to a trailing swingarm design would also flatten out the angle at which the swaybar lays across the frame of the sidecar - as it is now, it's at a relatively steep angle across the frame, which isn't the most effective for a swaybar to work.

What i need from y'all, is a little advice on what i should be looking at to utilize, in terms of off the shelf, or even wrecking yard automotive components. What would work best? 14" or 15" rim size? should i up the width of the sidecar tire to the same 185 series that is already on the motorcycle? Should i stick with the same basic swingarm design, or should i look into perhaps an A-arm design, which is a little more compact fore and aft, but bulkier in intrusion into the sidecar body?

Suggestions, photo's, ideas, etc. gratefully appreciated.
_________________
Homebrew '99 Suzuki Bandit 1200 / '88 Hannigan Comet
'78 Honda CT70 playbike
http://www.chairintheair.ca
Back to top
View user's profile Send private message Send e-mail
bmcsheehy



Joined: 22 Jan 2005
Posts: 977
Location: Massachusetts USA

PostPosted: Tue Jul 12, 2005 5:56 pm    Post subject: Reply with quote

Isn't this fun. Laughing
I build my own chassis for one of Hannigan's sidecars too.
At the time I bought it they didn't offer a trailing arm, now they do.
Good luck. I used traditional swing arm design on mine.
_________________
Bill
High Performance Sidecaring... ...There is nothing "HACKED" about it.
2006 ZX-14 / HANNIGAN HP.
2011 Concourse / California Friendship III.
1936 Ford Fordoor Humpback
www.Yankee-Engineering.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Bandit Bill



Joined: 31 Jan 2005
Posts: 202
Location: Hamilton, Ontario, Canada

PostPosted: Tue Jul 12, 2005 6:00 pm    Post subject: Reply with quote

bmcsheehy wrote:
Isn't this fun. Laughing
I build my own chassis for one of Hannigan's sidecars too.
At the time I bought it they didn't offer a trailing arm, now they do.
Good luck. I used traditional swing arm design on mine.


I was just browsing through your picture directory, when the topic reply notification came through my email, lol.. your piccy's will help lots i think.

What wheel, brake/hub assembly did you utilize in your fabrication?

If i'm gonna have to modify the sidecar body to tub it out, i'm thinking i'd also be wise to dish out the rear sidecar body trunk area, and fab in a gas tank into the rear frame area and kill multiple birds with one stone.
_________________
Homebrew '99 Suzuki Bandit 1200 / '88 Hannigan Comet
'78 Honda CT70 playbike
http://www.chairintheair.ca
Back to top
View user's profile Send private message Send e-mail
bmcsheehy



Joined: 22 Jan 2005
Posts: 977
Location: Massachusetts USA

PostPosted: Tue Jul 12, 2005 7:35 pm    Post subject: Reply with quote

Spindle is Chevy Nova, Caliper is GSXR, rotor is accura, wheel is Civic.
Then I fabricated a swing arm and backing plate to hold it all together.
Thinking
I would find the wheel you want to use, then try to find a spindle with the right bolt pattern. Then the only thing left would be to add a rotor and caliper. Piece of cake.
Motorcycle Happy
_________________
Bill
High Performance Sidecaring... ...There is nothing "HACKED" about it.
2006 ZX-14 / HANNIGAN HP.
2011 Concourse / California Friendship III.
1936 Ford Fordoor Humpback
www.Yankee-Engineering.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Bandit Bill



Joined: 31 Jan 2005
Posts: 202
Location: Hamilton, Ontario, Canada

PostPosted: Wed Jul 13, 2005 2:38 am    Post subject: Reply with quote

bmcsheehy wrote:
Spindle is Chevy Nova, Caliper is GSXR, rotor is accura, wheel is Civic.
Then I fabricated a swing arm and backing plate to hold it all together.
Thinking
I would find the wheel you want to use, then try to find a spindle with the right bolt pattern. Then the only thing left would be to add a rotor and caliper. Piece of cake.
Motorcycle Happy


When you say spindle by Chevy Nova, I assume you mean the classic muscle car or the relatively brief and ignominious late 80's rebadged Toyota/Chevrolet Corolla/Nova? Smile

Being a Civic wheel, i assume it's a 14" that takes a 185/55R14 OEM (off the top of my head)?

Thanks
_________________
Homebrew '99 Suzuki Bandit 1200 / '88 Hannigan Comet
'78 Honda CT70 playbike
http://www.chairintheair.ca
Back to top
View user's profile Send private message Send e-mail
swaybar2002



Joined: 26 Jan 2005
Posts: 380
Location: Central Pa.

PostPosted: Wed Jul 13, 2005 6:25 am    Post subject: Reply with quote

As far as spindles go there is a huge selection out there that will work. I have utilized the rear spindles off of a Dodge K car numerous times as they are a simple bolt on spindle with a flat backing plate. (Plus they are easy to find and snag off a junk car).There surely are other car spindles that mount in similar fashion that could be used. Th ebolt pattern on the hubs that I had used were 4x4 although they did make a five bolt hub as well.
In reading what you wrote I am curious about a couple of things though Bill. You do have a lighter bike matched to a heavy sidecar. This alone may magnify the tendency of the rear wheel to get light ,or 'unload' in hard left handers. One way to assist in corecting this from happening is to increase lead. How much lead are you running now? Have you been able to play with using more lead? Another factor that is basically adjustable is the size of your swaybar. When the effects of cornering are acting as you described is the rig still corning fairly flat or is the sidecar side dipping and the rear suspension rising up? Getting someone to stand on the side of the road and watching you in a left hander may be a good idea. (If they understand the dynamics of cornering enough to see what is happening of course).
Personally I prefer an oversteering rig far above one that pushes , or understeers in a turn. The fear of oversteer produced by a total unloading of the rear suspension is of course that the sidecar nose can be jammed into the pavement or the bike's rear wheel can actually leave the ground. In extreme cases the bike has actually flipped over the sidecar. Fun meter reading? Zero!
I suppose what I am saying is there just may be other factors invloved here that can possible tune in your handling better without going to the extremes you mentioned. (Lead increase and possibly swaybar sizing). Note: You can also play with pre loading the swaybar and see if that helps but I kinda feel a lead increase may be the solution. I think the rig shown on Roger's site doing the 180 spin (bat turn) had a 15" lead on that Moturist sidecar. Watch that video a few times and notice the forces acting on that rig as it spins. It is also a heavy bike so the rear will not lift as easliy as a light one.
Our ratty old XS1100/ Motorvation is a lighter bike with a heavy wide sidecar. Even Without the swaybar on it it can be pitched into a left hander to put it into an oversteering situation under braking and powered through the turn in that fashion will very little dipping of the sidecar nose. That is IF your timing is right for the conditions. This is a shaft drive bike which would actually magnify the problem you have with you chain drive due to the jacking efect of the driveline. I think I am running 12" of lead on the thing. It still will understeer coming off of a turn if th einitial entry to the turn was botched.
Just some thoughts Bill. Hope to see you at the RON DEE VOO.
_________________
Claude Stanley

Founder: Internet Sidecar Owners Klub
http://autos.groups.yahoo.com/group/SCT/

2007
I.S.O.K Sidecar RON-DEE-VOO III ..
First full weekend in August!! Thursday through Sunday!!
Weikert, Pa ..more details coming
Back to top
View user's profile Send private message Send e-mail Visit poster's website Yahoo Messenger
bmcsheehy



Joined: 22 Jan 2005
Posts: 977
Location: Massachusetts USA

PostPosted: Wed Jul 13, 2005 10:30 am    Post subject: Reply with quote

Quote:

When you say spindle by Chevy Nova, I assume you mean the classic muscle car or the relatively brief and ignominious late 80's rebadged Toyota/Chevrolet Corolla/Nova? Smile

Being a Civic wheel, i assume it's a 14" that takes a 185/55R14 OEM (off the top of my head)?

Thanks


Yes, mid 80s Nova. the civic wheel is a 15". I would recommend a 15 inch tire and wheel package because there is more performance tires available in 15.

I also agree with Claude, before you go through the effort of building some thing else, you may want to play with the set up you have. Different shock and spring settings, tire pressure too can make a difference, lead, etc.

Sounds like you do need more ground clearance.

I am also set up with 15 inches of lead.
_________________
Bill
High Performance Sidecaring... ...There is nothing "HACKED" about it.
2006 ZX-14 / HANNIGAN HP.
2011 Concourse / California Friendship III.
1936 Ford Fordoor Humpback
www.Yankee-Engineering.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Bandit Bill



Joined: 31 Jan 2005
Posts: 202
Location: Hamilton, Ontario, Canada

PostPosted: Wed Jul 13, 2005 2:06 pm    Post subject: Reply with quote

Thanks for the advice Claude, i'll recheck the lead i have at this point - I can't remember what i had it set at for the life of me, but it is greater than 10" overall. I'll be limited as to what i can set it to over what i have it now, or the swaybar will no longer fit in place. The tendancy to pitch over in corners was markedly reduced when i put the LL front end on the rig, there is still a bit of sidecar body roll evident in cornering, but again the swaybar setup cured most of that - A rig is all about compromises, for the most part i find. One suspension issue i do have is with the rear suspension - it's somewhat too soft still - I put an 850 lb spring on the rear last year, but i'm betting it'd benefit from an upsizing to a 950-1000 lb spring.

As an aside, i took a wander around the SMART car lot again today.. funny how i keep returning to that car for parts ideas.. The front wheel assemblies used are 145/55R15 series tires, the spindle assemblies are quite compact - I'm going to take a tape measure to the diameter of the tire, but if push comes to shove, it potentially might make a good alternative to the 145R12 on the sidecar without having to totally punch out the interior of the sidecar to tub in a new wheel well. Wouldn't address the possible need for more width of tire to increase footprint on the sidecar side, but it would assist in overall ride height, which is the major concern at this point.
_________________
Homebrew '99 Suzuki Bandit 1200 / '88 Hannigan Comet
'78 Honda CT70 playbike
http://www.chairintheair.ca
Back to top
View user's profile Send private message Send e-mail
zentime



Joined: 22 Jan 2005
Posts: 831
Location: Massachusetts USA

PostPosted: Wed Jul 13, 2005 2:33 pm    Post subject: Reply with quote

Bill, I would take a serious look at how much rebound dampening you have on your rear shock. You mentioned you have a heavier rear shock spring plus you have a swaybar. You may not have enough rebound dampening to compensate for the increased effective spring rate on the back. Without enough rebound dampening, when you pitch your rig to the left the heavier spring rate in the back will cause the rear of the bike to rise rapidly causing some of what you are experiencing.
_________________
CBR1100XX/EZS
1973 MotoGuzzi V7sport

will August ever come............
Back to top
View user's profile Send private message Visit poster's website
swaybar2002



Joined: 26 Jan 2005
Posts: 380
Location: Central Pa.

PostPosted: Wed Jul 13, 2005 7:24 pm    Post subject: Reply with quote

zentime wrote:
Bill, I would take a serious look at how much rebound dampening you have on your rear shock. You mentioned you have a heavier rear shock spring plus you have a swaybar. You may not have enough rebound dampening to compensate for the increased effective spring rate on the back. Without enough rebound dampening, when you pitch your rig to the left the heavier spring rate in the back will cause the rear of the bike to rise rapidly causing some of what you are experiencing.


Thanks for mentioning that Bill (Zentime bill) . This is a really critical issue and may just be the solution. Adding even more spring rate as metioned earlier on the rear could make the situation even worse if the rebound dampening is lacking now. Remember that spring is trying to lift the rear of the bike all the time. When cornering forces are introduced to 'help' it do so it is glad to accept them. Yes, the swaybar theroretically will compensate but only to a point, dependant upon it's own spring rate. The spring rate of the sidecar suspension, of course also comes into play.
One 'backyard' way to experiment with this would be to limit the rebound of the spring from it's present sag setting at rest. This (Food for thought only...I can't beleive I am saying this) could be done with a strap of some kind that would not allow the spring to unload(REBOUND)very far. It would still compress under 'bump' but rebound would be limited. Running a strap would work or even a small diameter cable from shock eye to shock eye. Bracketry would be required of course but it would be simple. Then after this is hooked up try a left hander and see what happens. Remember that the strap itself will be trying to pick up the rear wheel so procede with caution.If the rear wheel does actually come off the ground things begin to happen quickly and you have little control, at that point , of the outcome from a drivers standpoint..proceed with caution. Do not try to run full bore into a turn and 'give her a pitch' to see how it works. If you do be sure to have a friend with a video camera on duty! Your suspension travel on rebound is limited. Note that 'tying down' the left rear on roundy round stock cars was a popular trick for years before we knew better.
As far as increasing lead goes (and this is only more food for thought). You may be able to lengthen the swingarm on the sidecar and move the body forward accordingly if needed.(it is a leading and not a trailing swingarm) This will ,of course, give more leverage onto the sidecar spring from the wheel and make it feel softer, how much I do not know. Maybe doing this would allow the swaybar to stay as is??
I concur, to a point, about increasing ground clearance but if your experiments work out to provide a decent plan of attack you may not need to raise it much, if any, at all.How much do you have now? I have seen some Hannigans that had trouble pulling out of a gas station with out bottoming the rear of the body.
All of this is only food for though of course. If ANYONE tries this stuff and ends up on their head it was their sole decision to try it...close cover before striking,coffee is hot do not spill in lap, not to be taken internally, use saftey goggles,do not lay hand on burner it may be hot after stove is turned of....and so forth.Everyone say : D I S C L A I M E R three times.
_________________
Claude Stanley

Founder: Internet Sidecar Owners Klub
http://autos.groups.yahoo.com/group/SCT/

2007
I.S.O.K Sidecar RON-DEE-VOO III ..
First full weekend in August!! Thursday through Sunday!!
Weikert, Pa ..more details coming
Back to top
View user's profile Send private message Send e-mail Visit poster's website Yahoo Messenger
Ralph



Joined: 27 Jan 2005
Posts: 588
Location: Lexington, Ky

PostPosted: Thu Jul 14, 2005 1:27 am    Post subject: Reply with quote

Laughing hehe dam Bill you are so smart, I wish I has thought of that. Worship
_________________
"So Soon Old & So Late Smart"
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Bandit Bill



Joined: 31 Jan 2005
Posts: 202
Location: Hamilton, Ontario, Canada

PostPosted: Thu Jul 14, 2005 3:53 am    Post subject: Reply with quote

Before i went on my ride this evening, i went over the suspension on the bike a bit - I moved the rebound setting on the rear shock up 2 clicks, bumped the front up to maximum rebound setting. I didn't mess with the sidecar suspension at all.. it's a simple air shock.. and went for a ride.

Rig didn't seem to pitch and rattle over rougher/washboarded pavement as badly as last night (I run a 'circuit' over the same roads every 2nd evening or so) It seemed to settle into corners a little better, not quite as prone to get as nervous if it hit a bump/pothole with the rear wheel.... or it could just be a figment of my imagination, and i was just riding like a prissy little Nancy this particular evening.

I measured sidecar lead when i got home - 12" dead on. A little conservative going by your guys figures i guess - I do remember originally setting the lead, figuring that i needed to compensate a bit for the overall mass of the the sidecar nose forward of the sidecar wheel, in figuring out the rigs relative balance point under braking/Maneuvering. For the same reason of pitch clearance, I set the sidecar nose high, with the result that the rear mount bolts on the sidecar frame/body only clear terra-firma by 1 1/2" - The rear corner of the sidecar swinging arm is even less, about 3/4-1" total. Perhaps i need to look at resetting the altitude of the sidecar nose back down towards the horizontal again, since it isn't nose-diving as it did with the stock telescopic front suspension.

Before I'd go to the measures that you suggested to move the lead forward and change sidecar frame mounts, Claude, i think i'd try out a 4" over Bandit rear swingarm extension - i've got two spare Bandit swingarms kicking around Smile - Thats something to contemplate for the winter, I think.

I've set the Mercedes (also SMART car dealer) parts dood in his wretched little cubical to the grim task of putting together a parts list/cost estimate for the sheer heck of finding out what the core components for a 15" wheel setup using SMART car components on the sidecar would come to - perhaps the $$ quote will scare me off the whole idea for a little while Big Grin
_________________
Homebrew '99 Suzuki Bandit 1200 / '88 Hannigan Comet
'78 Honda CT70 playbike
http://www.chairintheair.ca
Back to top
View user's profile Send private message Send e-mail
zentime



Joined: 22 Jan 2005
Posts: 831
Location: Massachusetts USA

PostPosted: Thu Jul 14, 2005 12:33 pm    Post subject: Reply with quote

Ralph wrote:
Laughing hehe dam Bill you are so smart, I wish I has thought of that. Worship


Smile well, I was thinking about Bandit Bill's problem and wasn't coming up with any ideas for him. Then I remembered and went and got my honorary hillbilly hat, so affectionately presented to me in Maggie Valley, put it on and then amazingly ideas began to just flow out of my head! Big Grin
Aspiring Hillbilly
_________________
CBR1100XX/EZS
1973 MotoGuzzi V7sport

will August ever come............
Back to top
View user's profile Send private message Visit poster's website
docmike



Joined: 27 Jan 2005
Posts: 630
Location: Eastern NC

PostPosted: Thu Jul 14, 2005 12:55 pm    Post subject: Reply with quote

Postie Bill,

Quote:
Spindle is Chevy Nova, Caliper is GSXR, rotor is accura, wheel is Civic

Question

How is it that the Accura rotor fits a Nova spindle. Did you spend days in a junkyard trying rotors on spindles? Are they all so standard that they're interchangable? Is it a matter of sitting down with a micrometer and a bearing catalog? Or is it the machinist version of the old biker with the Indian motor in a late model HD frame who told me if you have a cutting torch you make anything fit in anything?

(This has been bothering me for days, but this was the first time I've had a spare minute to type it in.)

Mike
_________________
Mike Currin
93 BMW K1100RS / EML Speed 2000
89 Honda GB 500 (6,700 miles, all original except tires)
67 Triumph 650 chopper
92 Suzuki GS500 (eldest son)
Back to top
View user's profile Send private message
Bandit Bill



Joined: 31 Jan 2005
Posts: 202
Location: Hamilton, Ontario, Canada

PostPosted: Thu Jul 14, 2005 1:39 pm    Post subject: Reply with quote

docmike wrote:


How is it that the Accura rotor fits a Nova spindle. Did you spend days in a junkyard trying rotors on spindles? Are they all so standard that they're interchangable? Is it a matter of sitting down with a micrometer and a bearing catalog? Or is it the machinist version of the old biker with the Indian motor in a late model HD frame who told me if you have a cutting torch you make anything fit in anything?

(This has been bothering me for days, but this was the first time I've had a spare minute to type it in.)

Mike


Tinkerer's Maxim #1:

Anything will fit with a big enough hammer.

Tinkerer's Maxim #2:

If it won't fit, it weren't no good anyway.
_________________
Homebrew '99 Suzuki Bandit 1200 / '88 Hannigan Comet
'78 Honda CT70 playbike
http://www.chairintheair.ca
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    An international forum for people interested in modern high performance road going sidecars. Forum Index -> HPSidecar Technical Discussion All times are GMT
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group