USD Forks Worth the Effort?

[Guest]

question Upside Down Fork conversion on a 1985 gs 1150s the modification worth it in regards to handling/ Just wonder if it really makes any difference on these old Bikes Thanx Guys

[gsrick]

question Upside Down Fork conversion on a 1985 gs 1150s the modification worth it in regards to handling/ Just wonder if it really makes any difference on these old Bikes Thanx Guys

Are you looking to go with wider wheels and tires? You will need to if you use late model GSXR, R6.......... They use different sizes of axles and brake rotors. I think All Balls has bearing conversions for a lot of combinations, so you'll need to pick what you think will look the best. The rake is different, so the front wheel will be closer to the exhaust, which will definitely change the handling characteristics, unless you get aftermarket offset triples or rake the neck. You'll also need to do a rear swing arm swap with either welded on shock mounts or convert to a mono shock mount on the frame if you want matching wheels.

If you just want better forks, I think I've seen members use Bandit forks for that.

[bwringer]

The big thing that's tough to engineer around is ride height, which impacts cornering clearance. Most modern forks are a good bit shorter, and of course they're designed around a 17" front wheel with a low profile tire instead of a 19" with a taller tire.

Zooty USD forks don't really do a damn bit of good if the front end is so low you can't lean the thing without dragging the engine case, or if you're banging the oil pan on speed bumps.

[Agemax]

Also, apart from the problem with the ride height, USD forks weigh a great deal more than the conventional GS forks.

[posplayr]

USD Absolutely worth it on an 1150






You need early 1990's GSXR 1100 of Later Bandit USD forks for the required length. 4:2:1 exhaust provides the best ground clearance.

[mmattockx]

question Upside Down Fork conversion on a 1985 gs 1150s the modification worth it in regards to handling/ Just wonder if it really makes any difference on these old Bikes Thanx Guys

USD or conventional doesn't really make much difference compared to going to cartridge damping over the original damper rod system.

You need early 1990's GSXR 1100 of Later Bandit USD forks for the required length.

I wasn't aware that any year of Bandit came with USD forks.


Mark

[posplayr]

I wasn't aware that any year of Bandit came with USD forks.


Mark

Yea, you are correct; the Bandits fit well but they are RSU

[Nessism]

You would have to ride the bike pretty damn hard to over tax the stock parts enough to justify the effort. I'm not sure how many 1150's were road raced but unless you ride on that level I'd leave well enough alone.

Mind you, USD forks look very cool and all and if that figures into your equation that's a different matter entirely. Just my opinion of course...

[bwringer]

Not to be all curmudgeonly about it, but if you're after better performance, cartridge emulators, straight-weight springs, fresh slider bushings, fork oil, maybe a fork brace, and a thorough cleaning will go a long way. The forks won't be a factor limiting handling.

If you just like the look, the grab a tape measure and calipers and start prowling the boneyards.

[Chancho196]

Also, apart from the problem with the ride height, USD forks weigh a great deal more than the conventional GS forks.

Really? 43mm USD's are generally much lighter than, for instance, the 37mm conventional forks in my GSX750ES. What are we comparing with?

[Agemax]

Really? 43mm USD's are generally much lighter than, for instance, the 37mm conventional forks in my GSX750ES. What are we comparing with?

Have you actually weighed them?

[gsrick]

I haven't weighed them, but having done many fork seal on both styles, I think USD forks are lighter. The outer tube on a USD fork is almost weightless. The fork caps are lighter, they usually use shorter fork springs since they have a thin steel or plastic spacers. Also factor in that clipons are lighter than handle bars, the triples are lighter, the fenders are lighter, wheels and rotors are lighter. It all ads up. I wish I had a scale, I have an '07 GSXR 750 and an '81 1100E forks around, but I can tell you by lifting them both there is a difference.

https://www.motorcyclenews.com/news/2002/february/the-reason-behind-upside-down-forks/

The final advantage of inverted forks is their weight. It’s often assumed inverted forks are heavier because of the carriers, but that’s not the case. The steel stanchion is the heaviest part of the fork assembly and inverted forks have shorter and thinner walled ones. This means less steering inertia and a more responsive feel.

[TxGSrider]

I don't know how many people ride their bikes hard enough to notice any difference in performance, but I do think that with the right fender and rims that the USD forks give the old GS's a really "muscular" stance and for some, that's enough reason to change them. I swapped to the last of the regular style forks (87 GSXR1100) because they were the simplest way to use my GS1150/GSXR750 rims and tires. If were to do it over I probably would have went the late model rims and USD fork route.

[posplayr]

I don't know how many people ride their bikes hard enough to notice any difference in performance, but I do think that with the right fender and rims that the USD forks give the old GS's a really "muscular" stance and for some, that's enough reason to change them. I swapped to the last of the regular style forks (87 GSXR1100) because they were the simplest way to use my GS1150/GSXR750 rims and tires. If were to do it over I probably would have went the late model rims and USD fork route.

Agree, if you can tell the difference on the street in handling, then you are riding way too fast. The 18" v.s 17" wheels and tires will make much more difference without having to invite a felony ticket.

[garyS-NJ]

I have a '95 katana 750 with low miles and the front end is a dream compared to my old bikes. The kat750 is not USD and I don't think catridges.. I have a '97 Kat 600 front end and wheels in the basement planned for my '79 gs1000 death machine but at present I'm installing racetec straight springs. Cheaper out on the cartridge emulators bc I planned on swapping the front end and wheels...what kind of fork brace could I buy for the stock front?