| Author | Message | ||
| Skorpio (Skorpio) (24.92.193.195)
Rating: |
A lot of the new buses (mostly the 45 footers) are coming with steerable tag axles now. A little research shows that a lot of tag/pusher axles on dump trucks and such are also steerable these days and are usually an after the fact add on on these trucks. How do these systems work? Looking at the kits for trucks, they don't look much different that a standard front axle, just installed in the back. Do they physically steer or do they just track? I know some of the dumper versions lock when going forward and release in reverse, but I haven't seen any info as to how the steering actually works. | ||
| RJ Long (24.127.74.29) Rating: N/A |
Most steerable tag axles simply track, and most found on buses lock into the straight ahead position at around 10-15 mph, or when the transmission is placed in reverse. From what I understand, they are not something that can be retrofitted to an older coach, w/o spending a ton of cash, in some cases, more than the shell itself. Setra was the first, btw, with the steerable tags. A 45' Setra has a turning radius of only 39'9", and no, that's NOT a typo - it's right off their published specs. That's almost 15' tighter than their competition. HTH, RJ PD4106-2784 Fresno CA | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
My 40' Neoplan has a steerable tag. From a suspension standpoint, all the parts are essentially the same as the front -- double A-arm independent suspension. The tag has smaller air bags, though. The tag just tracks, there is no active steering. However, it "locks" in the straight-ahead position by means of air cylinders when moving forward above 35MPH, or in reverse, or in response to driver command. Gives me a very tight turning radius -- I can U-turn tighter than some 35's. -Sean | ||
| Skorpio (Skorpio) (24.92.193.195)
Rating: N/A |
Just curious, I have an RTS fascination, and basically the RTS's biggest draw back seems to be its V-drive 3 speed. Cutting out a front axle module from another RTS and welding it between the tail and the rear axle would give you a tag axle to support the weight and add the space needed for just about any engine/trans combo you wanted. And you even get a choice of IFS axles or drop axles since there are RTS's with either. How feasible is it? I dunno, I haven't seen good pictures of an RTS stripped down that far. If you were going to do this and already had a steerable axle, seems like it would be desirable to leave it steerable and figure out how to lock it when needed. Knowing what is possible allows you to make the decision as to what's practical. If your not familiar the RTS is made up of 5' modules. How long an RTS is, is simply a matter of how many modules there are, the modules containing the axles seem to be the same theory in the sense that they are welded front and rear to other modules, so it would seem like this is doable in an academic sense at least. Assuming that removing one module (most likely the rear door module) and adding a front steering module between the rear cap module and the rear axle module would result in a turning radius equal to a 35' RTS (if the new tag axle just followed), this means you could have a 40' RTS with a turning radius of about 32'. Given that an RTS without an engine and trans is basically a "if you can get it out of here its yours" proposition and the only rustable chassis parts are replaceable (bulkbeads) it would seen that putting the base structure together is not financially ridiculous. Building an engine cradle is another thing altogether.... | ||
| jmaxwell (66.42.92.26) Rating: N/A |
Skorpio: Seems like a lot of work just to have a conversion. GM's were always arguably the best engineered buses on the road and RTS was considered (again arguably) the best of the major transits. Why would u want to build a bus when your objective is to build a conversion out of a bus. U could certainly say it was different, but not necessarily better. I wonder if just a five foot section on the back would give enough room for an in-line arrangement. There certainly would be no problem with 'loading' the tags and just maybe u could eliminate the power steering while u were at it. When I was shopping buses last year, I tried several Setra's, 4 of them to be exact. 40' w/steering tags. None worked properly of the 4. All failed to turn in proper proportion and 2 would not rtn. to straight ahead.The only mechanic I could find familiar with them told me they relied on alignment for the proportional turning and rtn. to center, with air locking for the straight ahead. I could find no air assist cylinders on any of them. The 1 Neoplan Cityliner I looked at also would not rtn to straight center. The Neoplan I finally bought had steering tags, but the system components had been removed and locked in the straight ahead position. Don't know why. Steering tag was a customer option on the highway Neoplans and the components are as Sean notes, the same as the front except for the air bags. MCI has an integrated w/front, computer controlled system starting with the DL102 models and I have heard from several sources and drivers, that they were the most failure prone part of the bus. Many charter operators with DL and E Models disconnected the tag steering and locked them. But, the advantages are obvious if they work. | ||
| Jim Stacy (32.101.44.33)
Rating: N/A |
Locking the MCI tags to straight ahead was at the request of the factory. Definately trouble prone. One of the big "features" of the new, improved J model was that it didn't have steerable tags! | ||
| Skorpio (24.92.193.195)
Rating: N/A |
I greatly appreciate the info on implementations on other buses, and the short comings of the systems. Maybe steerable tags are not practical, that is what I was trying to find out. The steerable tag is interesting from a technological stand point and I'm curious about it from the stand point of mechanics. It's actually more like 8-9 feet, you're *adding* 5 feet to the original tail section. Plus the universal is at least a foot recessed into the section forward of that new 5 feet, hell you ought to be able to fit a 12v92 in there or an L8 in 9 or 10 feet. And yes I understand that you will probably loose at least 2 or 3 feet off floor space, but you'll gain a flat rear wall, and a place to put air tanks, generator, and batteries along side and above the engine. RTSs are cheap, its your chance to explore the possibilities of a unique piece of engineering. This is a half million dollar piece of hardware that you can buy for less than the cost of a nice piece of consumer electronics. To look at it as just a tube to put some furniture in is a sin. This bus is an erector set waiting to be played with. It was designed 20 some years ago and still looks current. If you look at one that has been converted and dolled up with paint and graphics it just makes you cringe to think that that sleek stylish vessel will be struggling to hit 35 at the first big hill. The RTS was made to be cut apart and modules replaced, it was a selling feature of it. So why not play with it, or at least be open minded enough to explore the idea. I am constantly amazed that a group of people that would even consider a project like turning a bus into an RV, persistently throw out the "factory knows best" line as often as I see. The "factory", in the case of buses has very few chances to get it right, buses are low quantity high investment products, that are expected to enter revenue service on day one, not make a few thousand mile trip, and return to the garage to be re-prepped for another such trip months later. The RTS has one of the highest production numbers of any bus ever made and sold fewer units in its 20 year production run than the Volkwagen Beetle did in its first 6 months. Buses never really make it out of beta testing. It's actually more like 8-9 feet your *adding* 5 feet to the original tail section. Plus the universal is at least a foot recessed into the section forward of that new 5 feet, hell you ought to be able to fit a 12v92 in there or an L8. The steerable tag is interesting from a tehnological stand point and I'm curious about it from the stand point of mechanics. | ||
| Buslady (198.81.26.174) Rating: N/A |
I drive a 102DL3 at work and I LOVE my steering tag, helps me get out of TIGHT spots. Too bad they're not making turning tags anymore. | ||
| RJ Long (24.127.74.29)
Rating: N/A |
Hey Buslady - Aren't you the one who's friends w/ Trina, the Crown Bus Kid? If so, drop me a note off the bbs, I have some Crown stuff I want to share with her. . . just click on my name above to send an email. Thanks, RJ PD4106-2784 Fresno CA |
