Lowering Clearance ?

I have read a bunch of posts about how to lower a Commando. Matt's post about lowering either 1", 2", or 3" was very informative.
But there is one thing that bothers me about several of the posts. It seems that some guys are okay with the rear tire hitting the fender and the front fender hitting the triple clamp if the bike is heavily loaded ( I would be more concerned about the fender hitting the frame downtubes. )
I read comments about not overloading the bike to keep this from happening. I would not consider in any way to have a set up like that. I read all of these posts looking for definite info regarding lowering equally front and back and whether there would be clearance problems. I didn't find any. Maybe I missed it. Before I order my new one inch ( or more ) shorter fork tubes and one inch ( or more ) shorter shocks I will make mock up shocks (out of wood) and figure out where the forks will end up, then check tire clearance when shocks and forks are at full compression. Allowing interference when heavily loaded is just sloppy engineering ( or really no engineering).
If any one knows this info I would appreciate it. It would save me a lot of work.
The question is: how much can a Commando be lowered ( equally front and back ) with stock wheels and tires and still not bottom out?
Incidentally, to lower bike one inch you would have to shorten suspension units more than an inch because they are not vertical. The suspension units are actually the diagonal of a right triangle.
Thanks

If you lose suspension travel, you change the handling The squat at the rear as you accelerate, changes the rake at the steering head to give positive feeling. The dive in the front as you brake changes the rake and determines the stability. That is why the bike is difficult to turn, if you brake while in the middle of a corner, and why it feels accurate when you accelerate.

Not sure of your reasons to lower the bike but from my experiences in the 70's and early 80's when I used to ride hard I spent a lot of time pulling the exhaust in to try to avoid scraping on the ground. You re talking of lowering by up to 3". Would have thought this would severely decrease your ground clearance for cornering. I think that I am right in saying there was a lower frame available at one stage, may be for production racers. Not sure what else was altered or if removal of standard exhausts is what is needed to gain ground clearance.

Commandos don't handle to good with shorter shocks on the back, ground clearance is also a problem, what commando do you have,the interstate has a very wide seat etc, when my commando was a fastback I cut the ears off that Go either side of the tank and I cut the seat foam down with a step in the seat,it was very comfortable

Depends if you are short or you just want the "look".

Pulled the Titanic off the work table to clean up yesterday and rolled it outside the garage (1st time in over a year) and was marvelling at how low the chassis looks without any tank or seat. If I were too short to reach, the first thing I would do is look into a lowered seat. Slamming a Commando for looks would probably ruin it's character on the road.

I had Matt lower (1") both of my CNW builds. Ground clearance when cornering was my biggest problem. Was constantly hitting the pipes and foot pegs in corners. Matt uses a stock 19" front wheel, but an 18" rear, but clearance of the fender and frame components was never a problem

I had Matt take build 119, my Interstate, back to stock suspension. The problem with hitting the pipe or pegs went away (for the most part, I still like riding a little aggressive sometime) I left build 99 with the 1" inch lowering kit on it. 99 has become my wife's bike and she needs the bike a little lower. When I ride 99 I have watch lean angle

acotrel said:

If you lose suspension travel, you change the handling The squat at the rear as you accelerate, changes the rake at the steering head to give positive feeling. The dive in the front as you brake changes the rake and determines the stability. That is why the bike is difficult to turn, if you brake while in the middle of a corner, and why it feels accurate when you accelerate.

Click to expand...

Agree. Unless you are very short of leg length, it is best to leave it stock.

Slick

If you are going for a "low" look heed the advice about grinding exhaust, sidestand, footpegs, etc. If the reason is that you are inseam challenged go have a shoe repair service add an inch or so to your riding boots. Yes, you'll look a bit like Frankenstein when you walk but you'll avoid a whole lot of potential issues with your Norton. When I worked for BMW motorcycles this was always my first suggestion to those that wanted to lower their bike. A local shoe guy would do the lifts for $60. If it didn't work out he'd return the boots back to stock for $20 provided that it was within a 60 days. About 70% of the customers stuck with the lifted soles.

I found that using slightly shorter rear shocks made the bike almost impossible to get on the center stand.
Rolling the rear tire over a 1" thick piece of wood made using the center stand easy again.

I changed the wheels on my Triton from 19 inch to 18 inch so I could fit better rubber. The first thing I noticed was I could not get around corners so fast because I started grounding the footrests more when I wasn't even trying.

HARLEYS are for low'rin, Cdo's are for corn'rin

Commandos were designed for 19" wheels in my opinion changing anything from wheel size to suspension length is a mistake and taking the bike from its orginal design, but then again I change the whole design of my Commando.

Ashley

Function dictates the shape the bike takes. In the end, it is what works best that matters. Commandos were not just dreamed up out of somebody's head. 'Racing improves the breed'. If you look at a modern bike then try to copy the design changes onto a Commando, you are probably kidding yourself. The modern concept is completely different. It'dbeinteresting to know how much suspension travel the 961 has - a lot, or does it just look like it ?

If you are just going for the "look", I can't help but reiterate what Ashley just said.
If you are having an issue with reaching the ground like I did, you might consider just re-shaping (shaving with an electric knive) the seat foam. The stock saddle is both wider and taller than it needs to be, at least for my skinny ass.
I'm still using the stock seat pan, but if I were any shorter, I'd get someone to make up a fiberglas pan and get even lower.

How do the Corbin seats go in this regard ?

Sorry that I can't help with the measurements you are looking for. Neither of my Commandos have stock suspension dimensions. And the other posts have pretty much addressed the other issues. But I would suggest that if you lower the bike, you should also consider fitting stiffer springs. A stock Commando, as several have already pointed out, will already grind the rubber off the footpegs and drag the pipes and sidestand in vigorous cornering. Lowering it can only make that worse, but stiffer springs will help a little. It will also ride a bit harsher, but that's part of the tradeoff in lowering it. In theory, you would also need to increase the rebound damping to compensate, but unless you plan to use adjustable shocks and experiment with heavier fork oil in front, that's probably not an option. If you're lowering it for styling reasons, the tradeoff will be cornering more conservatively and not overloading it. If you're doing it for shorter leg reasons, lowering the seat height by an inch or so seems like a good option. If you are looking for more than an inch, you will probably want to do both shorter suspension and lower seat height. Good luck with it, and please post pictures when finished.

Ken

There is a difference between 'ride height' and 'suspension travel'. If you use longer rear shocks and lay them over, you effectively soften the springs and get more travel, but the ride height can end up being lower.

In terms of comfort, the stock seats are lousy anyway, so maybe get one made that's lowered an inch or so and is narrower.

I'm a big guy so my '73 is lifted, front and rear, stiffer springs too. I hang off a little, slightly, just some "English" and that helps but over uneven ground I still drag stuff.

I went down the 18" wheel route years ago because it was the thing do, Ground clearance was ok and handling ok too until you got to 80mph on a straight road then the weave set in. I went back to 19" wheels, it still weaves a bit but that is probably due to me loosing weight. It's fine when loaded up with some ballast (not the wife) I would go down the better designed seat with a gel insert route to allow me to reach the floor if I was a shortarse.