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MG MGB Technical - 2nd opinion re rear tube shocks
|I owned a 74 RB in college a decade or more ago and recently bought another to restore. In doing research I'd all but concluded that rear tube shocks were a no brainer particularly based on Roger Williams' book "How to improve MGB, C etc". while browsing BBS i found a thread that was prety much all negative re rear tube shocks. I'm was very surprised by this so i'm throwing it out there again for some more thoughts and a 2nd or 3rd opinion. Rear tube shocks, yeah or nah???|
|The standard shocks are more than adequate. They last forever and the tube shocks put loads on bady parts that they were not designed for. A waste of time and money in my opinion.|
A bit depends on what you want to do with the car. Standard engine and regular driving, stay stock.
Racing or other modifications, tube may be better.
Others with that experience should be able to advise.
|They harshen the ride, but weigh less. Unless you're runnign a very soft spring (racing) you won't like the ride.|
|Stay stock. The tube shocks are stiff and the car dances around bumpy corners.|
|I have them on my '69 roadster. Hate them to death. Car rides funky as well and the squeeks and rattles! Can't wait to go back the the OE type levers. This time I'll try the uprated valves.|
|I have tube shocks gas filled Dodge Colt ones and since I do a lot of back road driving on the twisties I like them.They are stiffer on the freeway but I don't drive there unless I have to But I think the car handles better with them.If you will drive your car with spirit I would go with them If you just putt down to the IHOP on sunday mornings or drive the freeway stay with the stock ones and hope they don't leak or you will be topping them up all the time.|
Pat in Tehachapi
|Opinion here pretty much in accord with what has already been said - My son and I both have adjustables screwed down to soft on the back of our cars - the ride can be jittery on country roads but at least they keep the rubber on the road in testing circumstances. I would have changed back to the Armstrong levers if I did not occasionally tow a ton - when they come into their element and help reduce the grounding.|
If you are changing to Nyloc bushes - you may not notice the stiffer shocks anyway.
Up front it's a different story and one has to remember that the replacement lever arms are not up to factory quality.
Enjoy her !
|Despite the good advice from the BBS, I’ve taken the plunge and ordered the SPAX conversion from Moss. After looking at an RV8 set-up and reading my old MG magazine articles, I have concluded that it is the damping factor that most individuals get wrong with the adjustable dampers. The rear spring rate does not change, so the set-up must be over damped! I can’t find the Damping Value (C) in kN sec / m or lb.sec /inch for the original Lever Arms, (anyone know this?) but the Gas SPAX dampers can be ‘dialled’ to a low Damping Factor (approx C=0.30). Added to this the simpler design, improved reliability (IMHO) I’m giving it a try…Well my lever arms need replacing anyway!|
|MG Mike at work|
|I am very curious to know (and I do have a financial interest, admittedly) what are the principal objections to using lever shocks. We are trying very hard to come up with solutions to problems, and enhancements to the product. (If this post is viewed as too commercial, I apologize.) Thanks Peter C.|
Give the service you do for those of us that like to have the lever shocks. I think it is a very appropriate question. You need to know if something can be improved so we get the best units possible.
|Peter, in my opinion, the lever arm shocks weigh a ton. They also allow less travel than the tube-type shocks, not that that comes in to play frequently. Lately, reliability has also been a big issue.|
|Jeff. Thanks for responding. The rears are a little under 7lbs. without link. Arm swing is 8", again without link, which I think would add. Reliabilty has been solved. Peter|
|The Spax & Koni conversions mount at an angle & tend to swivel as well as compressing. I changed from Spax to Monro shocks but with a vertical mounting method. This turned out to be a great improvement & the rubber bushes last a whole olt longer. Barrie E|
|I post, once again, the number for the Monroe SensaTrack gas shocks I used for my rear shock conversion (otherwise Typical cheap Moss setup) ~ #5893. Seems to have proper travel and reasonably duplicates comfort of Armstrong lever shox with perhaps a bit better handling of rear end. Never been sure the whole rear tube shox thing was really worth the effort on a daily driver. Spax units might be worthwhile with proper rearend locating gear and some other mods, such as Steve S, Va, suggested some time ago. You'll have to look up his info in the Archives, tho.|
My Monroes mount on the angle, but at a steeper one than used in the kit. FWIW
|Gentlemen, many thanks for your input. Collectively it paints a clearer picture. |
Peter i think your question was completely appropraite. what better feedback could you ask for than from the "die hard"?
Bob Muenchausen,what was your point about the Monroe sensa track? You mention this and other solutions and i just want to make sure i'm clear on your recommendations.
again thanks guys - this was my first post and not only is this helpful, relevant and insightful...it's also fun. can't beat that.
|When I bought my 74.5 MGB last year I was experiencing very bad wheel hop over bumps on curves due to the worn out lever arms. I replaced them with the cheap Moss set up as described by Bob Muenchausen. Because they were new and actually offering some ride control the handling was greatly improved. I could not comment on how a new or refurbished set of lever arms would work in comparison but I am happy with the ride and handling as it is now. I am not completly happy with the way they are installed to the body however and I believe they will put a bit of strain at the upper mounting point. It was an easy installation for a neophyte MGB home mechanic. I do plan to replace the existing front lever arms with refurbished units with the uprated spring. I probably will revert to the lever arms in the rear when the teloscopic units need replacing.|
|Neison, I have two MGBs, a GT and a Roadster |
, both '72 and both restored to virtually as new condition. The GT has rebuilt standard lever arms, they are fine and I haven't considered replacing them. The roadster has a Spax tube conversion all round and is far from fine. The rear is the main problem and even at the softest setting the car is over damped and hops about on corners. Coupled to this the dampers are noisy and the adjuster seizes and becomes u/s. I replaced these with uprated lever arms and the difference to comfort and handling was significant. Now I still have the Spax conversion on the front and it seems to be OK, perhaps a little hard but acceptable. However the design is bad as it creats a twisting action on the front wishbones. The only way to overcome this is to have the shocker on the king pin vertical centre line and this would be a coil over type similar to the RV8 which is expensive. I will replace these before too long with uprated lever arms which will not impose twisting on the wishbone and also provide a good compromise between comfort and handling. Tubes are several times the price of lever arms, don't provide the same neutral characteristics and IMHO are waste of cash. Aftermarket suppliers identify gaps in the market and try to plug these sometimes successfully but not so on the B. They still however have to sell their products.
|The recommendation is that there is, in my opinion only marginal improvement over the lever shocks, if any at all. What I believe to be true may be founded on little more than a subjective impression that there is little difference except in some minor control of the choppiness of the rear suspension over rough or rocky surfaces. |
I mention the Monroe's model # because there has been more than one model tried/used by folks over time, and I only make claims for the ones that I used. I think it is a decent choice because it is used well within its range of motion and there is no possibility of the shock hitting either end of its travel in this application. Not necessarily the most significant reasons to use this model, but at least one can be sure it is safe for both the suspension and the shock.
|When I rebuilt my 69 B about 10 years ago the levers were shot. I wasn't aware of Peter's excellent rebuild service at that time ( he did a great job on my TF's) so I threw a wad of money to Moss and put the Spax on the rear and the gas coil over kit on the front. I did a lot of experimenting with tire preasures and shock settings to get the ride I wanted. I had a 72 GT at that time also that had good stock shocks to use as a comparison. I love what the coil over did for the ride of the front end. The rear end is ok but I didn't notice any big transformation. I also put in nylatron bushings and new springs at the same time. Worth the price? I don't think so. Fun to tinker with? Sure. Do it again ? Not since I discovered Peter's no leak rebuild services.|
| I have Spax on my '70 roadster, fore and aft. Some years ago, my lever shocks were shot and my guru suggested the Spax. I don't notice any special difference in the kind of driving I do --- perhaps it corners a bit flatter on one curvy hill I drive rather fast on. My setting still is on the middle position that I began with.|
It didn't seem worth the cost at the time. Other than my pockets, I have no complaints.
This thread was discussed between 28/09/2005 and 30/09/2005
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