Twins vs. Mono

[LilTinc]

OK,

I havent even gotten into the real meat of the upgrade of my '82 1100E and I'm collecting parts for a 7/11 project. I'll never finish anything

Anyway, sort of a new-be question here. I used the search function but my search-fu seems to be weak.
Is there or what is the advantage of a mono-shock set up vs. a twin shock?

I'm getting a battle plan together. Bike will be a "mountail runner". Design concept is sort of a 1980 superbike with a Wes Cooley faring, USD forks and big (190 or maybe 200 width) rubber.

Thanks for the input.

[reddirtrider]

OK,

I havent even gotten into the real meat of the upgrade of my '82 1100E and I'm collecting parts for a 7/11 project. I'll never finish anything

Anyway, sort of a new-be question here. I used the search function but my search-fu seems to be weak.
Is there or what is the advantage of a mono-shock set up vs. a twin shock?

I'm getting a battle plan together. Bike will be a "mountail runner". Design concept is sort of a 1980 superbike with a Wes Cooley faring, USD forks and big (190 or maybe 200 width) rubber.

Thanks for the input.

Advantage? If you consider more work to be an advantage - then yes.

I've done one, and so have more than a few in here. I'm actually considring going back to dual shocks now and using the ones from my ZRX1200 after replacing them with Ohlins.

It all depends how you envision the bike to look like. I doubt there's any performance advange either way.

[80GS1000]

A mono weighs less, looks trick, and a single shock compresses and decompresses more evenly than two shocks IMO especially when cornering.

Due to frame and chain clearance considerations, you'll probably want to stick with a 5.5x17" max rear rim with a 180 radial.

[Old Colt]

The real difference is style. A real good quality twin shock setup works fine. Yes there are functional differences with a single shock such as ability to set up different rising rate geometries. But the real difference is in the look.

[reddirtrider]

A mono weighs less, looks trick, and a single shock compresses and decompresses more evenly than two shocks IMO especially when cornering.

Due to frame and chain clearance considerations, you'll probably want to stick with a 5.5x17" max rear rim with a 180 radial.

I agree it looks trick, but then again, so do a couple of ohlins.

Lighter? Not sure about that. I think once you add in the linkage and bracing the weights will be very similar.

On the ride, while a mono does feel good, so does a twin shocker with GOOD shocks. You can't really compare the stock, almost 30 year old shocks to any mono unit you're salvaging.

I agree with the tire size you suggested. Even with the 180 on back I've had frame clearance issues. I notched it a bit and went with a 520 non o-ring and there's plenty of room now.

It all boils down to what you envision the bike to look like.

[80GS1000]

Another item to consider is cost. A late model GSXR swingarm and shock can be had off eBay for around $100 and are high quality with a lot of adjustment possible. A set of ZRX shocks will be around $200-300 and a set of Ohlins is close to $800.

All modern sportbikes and roadracing bikes come with monoshocks, if there were an advantage to twinshocks then they would be so equipped. But the latest GSXR and MotoGP bikes all are monoshocked.

The late model monoshock style swingarms are also much stiffer due to their bracing.

Have to disagree with you on the weight matter reddirtrider, the last time I weighed it my bike is 450 pounds with a full tank of gas and the oil filled up (536 pounds is the listed stock wet weight) and a significant chunk of that weight savings came from the rear rim/tire/swingarm/rear brake/shock assembly.

[reddirtrider]

Another item to consider is cost. A late model GSXR swingarm and shock can be had off eBay for around $100 and are high quality with a lot of adjustment possible. A set of ZRX shocks will be around $200-300 and a set of Ohlins is close to $800.

All modern sportbikes and roadracing bikes come with monoshocks, if there were an advantage to twinshocks then they would be so equipped. But the latest GSXR and MotoGP bikes all are monoshocked.

The late model monoshock style swingarms are also much stiffer due to their bracing.

Have to disagree with you on the weight matter reddirtrider, the last time I weighed it my bike is 450 pounds with a full tank of gas and the oil filled up (536 pounds is the listed stock wet weight) and a significant chunk of that weight savings came from the rear rim/tire/swingarm/rear brake/shock assembly.

If you count rims, yes. But you can use a late model swingarm witn dual shocks to fit the newer rims and tires. If you just look at the swingarm, linkagage, and frame bracing vs. a late model swingarm with dual shocks, then I think you'll find the weight very close.

Let's not get into roadracing bikes since the frames of these GSer's are so flexible I seriously doubt a mono will give a performace boost over a good set of dual shocks. Come to think of it, I doubt if anyone short of a professional rider can take full advange of a modern sportbike either. So, IMHO, it comes down to looks.

You're right about the cost of qualify dual shocks.

[reddirtrider]

The most significant weight reduction on my sons bike came from the rims and tires. They also gave me the biggest performance increase, let alone the tire selection with radials.

Next was probably converting from a 630 to a 520. That shaved a lot of weight off.

Converting the foot pegs, both passenger and rider to modern units helped. I built plates for GSXR rearsets, which are very light compared to the originals.

Of course, the standard replacement items such as pods and header killed a bunch of stock weight.

I also put on a Hyabusa filler for the tank. No weight savings, just looks cool.

[liloaty]

I'm gonna go with PJ on this one - the monoshock if done properly will save weight. The single shock weighs a very small amount, if any, more than 1 of the dual shocks. And the linkages for the monoshock are, I believe, aluminum so they also weigh next to nothing. And the bracing will not add significant weight - it's not like you need to chunk on 20 pounds of steel.

[Old Colt]

The weight change from the swap has many factors, part of it is quite a variation in the weight of swingarms. The newest ones from The GSXRs are quite heavy, I would say heavier than the original steel arms on many bikes. Now the late 80s and early 90s alloy arms are rather light though.

[pontiacstogo]

Monoshocks are to vintage sportbikes as professional wrestling is to sports.

[LilTinc]

What I'm thinking

Here's sort of what I want to do. I will not be using this paint job (think stars and stripes)

[LilTinc]

Has anyone weighed out 2 shocks vs. a mono shock plus linkage plus frame bracing?

[reddirtrider]

The weight change from the swap has many factors, part of it is quite a variation in the weight of swingarms. The newest ones from The GSXRs are quite heavy, I would say heavier than the original steel arms on many bikes. Now the late 80s and early 90s alloy arms are rather light though.

Your are correct that the GSXR swingarms are much heavier than their aluminum GS brothers.

[reddirtrider]

Has anyone weighed out 2 shocks vs. a mono shock plus linkage plus frame bracing?

Sadly no. My past experience tells me they are too close to call. If anyone wants to disassemble their bikes ....