Caught short on a Commando

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komet

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Bought a '71 Roadster 'cos it looked great and I could touch the ground when stopped. It's currently stripped down to sort a few things. The seat foam needs replacing, problem is that the new one is higher. I've had suggestions ranging from:

A: fit an 18 inch rear wheel, get a machinist to reduce the stanchions by an inch (at the top), plus 1/2 inch shorter rear shocks.
B: replace both wheels with 18 inch rims.
C: thicker soled boots, trainer wheels etc.

So was wondering if A is viable, if so what about spring length and would there be enough clearance with the mudguard? Haven't seen any pix of a bike with an 18" front wheel so don't know if this would look silly with a standard mudguard. I could get the new foam cut down but the original seat was uncomfortable so prefer not to. Norvil sell shorter stanchions but wouldn't be cheap to freight to New Zealand. I don't weigh much or go flat out like the good old days, but don't want to upset the handling. Any ideas?

Cheers,
Graeme
 
are you related to HOBBIT,gee i thought that most commando's were rather low to the ground as is??? :wink:
 
would agree with fullauto about the corbin seat komet,,its the way to go,,how tall are you? i have a corbin on my bike and im only 5'11 and touch the ground easily..
Fullauto said:
Don't butcher the poor critter. Buy a Corbin seat and you'll love it.
Click to expand...
 
Get the seat re done by a professional bike seat upholsterer. And use good foam so it can be lower.
I have Mk3 with 18" wheels, it's not that much lower.
2 pics, same bike, different frocks,,,

Caught short on a Commando


Caught short on a Commando


OR when all else fails,,,,,

Caught short on a Commando


graeme
 
"A: snip ........ get a machinist to reduce the stanchions by an inch (at the top),.........."

LOL Ditch the guy who suggested this.....
Staunchion length does not determine ride height, the damper length and spring length are the items that do this.
shortening the tube will only raise by 1" where the lower bush sits in the leg!
 
An 18" rear wheel will only gain you less than 1/2". A whole 1/2" if you do the front wheel too.

The front suspension is challenged enough, better leave it alone. But as Dave says, shortening the spring and the damper rod my get to where you need to be. I may be wrong about this too, so check it out before you do it.
This will change the dynamics of the spring but you probably will not notice it. Also, if you go to far with this and you add an Old Brits Oil Pressure guage, your fender will hit the bottom bolt of the steering triple tree.

Another option is to get a shorter rear shock. If you do this, check for clearance and drive chain for tightness. This might be the easiest thing to do.

Yet another (not cheap) option is to change out the triple tree to a clamp type. You can then dial it right in to your needs, ala BMW lowering system. But again, the fender may bang the bottom the triple tree.

It will also be a real bitch to get it up on the centerstand.
 
hi komet, i hear where ya coming from. at 5ft6 theres no way im getting both flat on the floor at once, just the toes. a good thing with mine is the rh gears as the road cambers down to the brake side. so at least i can get one on the floor. though if the corbin seat is lower i might have to get one :)
 
pvisseriii said:
snip But as Dave says, shortening the spring and the damper rod my get to where you need to be. I may be wrong about this too, so check it out before you do it.
Click to expand...

It is the damper BODY (not rod) and spring that determine the ride height.
You could use atlas staunchions and damper bodies to acheive lowering. however remember the atlas damper caps are 26 tpi not 28 per commando.
this would gross approx 1-3/8" lowering
No idea about the fender clearance on compression though.
 
Whoa! Keep it simple as suggested by GRM.
If it was fine with the old seat, than all you have to do is cut down the new seat to match, either do it yourself or have a professional do it. No point in messing with the geometry of the bike and spending oodles of cash.... well, you'll spend oodles of cash on something soon enough.

If you cut it down yourself, remember that width will make almost as much difference as height. If you narrow it, by taking a bit off the top corners where your thighs sit, your legs will be allowed to drop down more, rather than being spread out.
At the shop I worked at we used to cut down a couple seats a week, mostly for dirtbikes but it's all the same. You don't have to remove much to make a big difference.
A good old cheese slicer or one of those electric meat slicers will work wonders.
 
What does CNW do to get their bikes lower? It looks like they put a shorter shock on, notice the swing arm bends up a little.

Caught short on a Commando


Dave
69S
 
I've never meet a Corbin Commando seat I like to sit on for very long, though I like the lower Corbin on my SV650 as it lowered my 6'2" height on bike for more comfort and fling security. If'n it was mine I'd cut 1.5" inches off the fork springs and add 1.5" very weak spring just to take up the clatter slack then put on 11" or less rear shocks. May tend to bottom forks more so would plug and more the damper holes up for soft indefinite bottoming. Be alert to tipping too far and scrapping of course.
 
GRM,my wifey wears stillettos on the Crazy Creature and I wipe melted rubber marks off the peashooters all the time with paint thinner on a rag. Like I'm gonna tell her to take those off. The best advice I can give here is to put on a French beret and a smock and wield an electric carving knife with gusto keeping the shape of your own butt in mind when attacking/building.You are all artistes in your own right and your ass is GOD. Firmer is better than soft, women and your butt know.
 
Lowering its going to wear out the exhaust pipes . side stand etc .

A flat sheet of alloy with the edges folded / rolled down over the seat rails , with a cut out for the spine .
Let in a U the other way up , flanged edges riveted , or weld . That high density chip foam a inch & a half thick , with squishy stuff over that if you dont want it looking flat .Keeping the front edge no wider than the rear of the tank .

But , if you slide forward and to the side , you find a comfortable ' at rest ' position , if you must ride iin town . :lol:
 
It's easy to fix stuff when you are spending somebody else's money.

Shorter shocks are easy to install and easy to get back to stock if desired.
Corbin seats are considered by many to be a selling feature.

I would invest in both but would also talk to Matt at CNW as he will have advice on what works for him.

The 18" rear wheel will only shorten the bike if you select a tire that is smaller in overall diameter than stock. This gets screwy because you might end up with a flat profile or a skinnier tire. They are narrow enough now. This is also not inexpensive and has a doubtfull return.

There is lots of clearance on the rear mudguard so unless you are short AND fat I doubt you will bottom it out in normal riding conditions with a shorter shocks.

Russ
 
Yes the answer is to reupholster with modern foam and take an inch to an inch and a half of height out of the seat, don't change the fork stanchion height
There are stepped seats available out of the UK for exactly that purpose, slightly higher pillion position and you don't slip back to the middle of the seat
Mike
 
Hey, thanks for all the advice. Wheel rims and tyres are in good order so didn't really want to spend money on them, guess modding the seat would be the best way to go. I'm 5 foot 6 and the current seat height is just tolerable. Commandos, early '70s Bonnies, even a friend's BSA 250 Starfire is high, seemed silly at the time to limit sales to taller people. Came home once and found my Norton owning flatmate had written on a pallet I used to reach things: For boys who want to be men.
 
I used to stand on a cinder block to throw my leg over the rail when learning to ride my first bicycle which had 26" wheels. Back then we called them "English" bikes. I remember painting that bike frame blue with a brush when I was a kid - my first resto? Even at 5' 10-1/2" my feet are just barely flat on the ground when sitting on my '72.
 
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