Page 1 of 1

Taller suspension for a trials MGB

Posted: Tue Dec 17, 2019 12:12 pm
by Hazza1190
Hi Guys,

My father and I want to do some trials events and would love to do it in a B GT. We would start with a rubber bumper car as its taller in the first place, but does anyone know how we could heighten it some more? Is there anywhere that we can purchase springs that increase the ride height? Or do you think the rubber bumper ride height should be sufficient?


Re: Taller suspension for a trials MGB

Posted: Wed Dec 18, 2019 11:57 am
by Peter Cresswell
I assume you are thinking about competing in Production Car Trials - grassy banks and mostly near standard cars?
The MGB has one disadvantage over the Midget in the longer wheelbase and the ground clearance under the centre silencer. You are right in thinking that raising the car can help, but the problem is spring availability and here you will encounter a major problem. The springs are quoted by their poundage per inch and their free length. I have found some front springs that might do the job mentioned in the notes of Gerry Browns presentation to the MGB Register 'Modifying MGBs for fast road or track days' in 2006. The longest spring I can find he listed is an early chrome bumper roadster (Part No AHH6451) at 348lb/in and 9.965 in free length. However when fitted to the heavier GT they will compress more than the rubber bumper GT spring (BHH1077) quoted as 480lb/in and 9.32in free length. There is also listed the V8 front spring (BHH1225) at 372lb/in and 10.2in free length. As with all mods for any motorsport, It is like to be a case of try and see, but fortunately they are not too expensive to experiment a bit but a chat with Malcolm Gammons at B&G might help you to narrow the choice.
Rear springs are much more of a problem, and you might have to resort to having the rubber bumper GT springs modified to have a different bow. Incidentally, if the GT you are thinking of using is a earlier rubber bumper car, then raising the suspension will make a poor handling car even worse! So take this into account driving to and from your chosen trials.

Even though the late GT rode about 2in higher some underbody protection might be desirable, and B&G list a Dural sump guard and fitting kit (STN1027K) which are not too expensive and also a Kevlar tank guard which is expensive! You might choose to remove the centre silencer and replace it with a straight pipe, but you would need to check the MotorsportUK regs for trials to see if there is a noise check. The Maniflow exhaust system is heavy duty and has skids on the front and rear edges of the rear silencer to prevent it being knocked off. It is also very quiet being designed for Rallies. Wheels have to be one of the sizes fitted to the car during its life - so steel wheels from an early roadster will I suspect be the choice as the narrower the wheel the better the grip and tyres have to come from the MotorsportUK tyre list 1a. There is a minimum pressure for tyres which I think is 12psi, but see The MotorsportUK Yearbook (known universally as the Blue Book) which is online.

If you are an MG Car Club member the Treasurer for the Midland Centre trials an MGB and you should be able get his contact details via the website. He might be worth having a chat with, although I think his passion is Classic Endurance Trials.

Hope this helps and enjoy your trials!

Re: Taller suspension for a trials MGB

Posted: Thu Dec 19, 2019 4:37 pm
by Hazza1190
Hi Peter,
Yeah that's the one! We will be competing in events such as the Exeter Trial. I helped marshal at the VSCC Exmoor Fringe Trial and have been looking for an Austin 7 since then. Unfortunately, the ulster style ones and specials that i like are a bit over my budget. I trialed an austin 7 top hat (as a passenger as was too young to drive) when i was younger which was very fun!
I have been looking into the midgets but being over 6'2 I cant see myself doing 100's of miles and lots of bouncing in any kind of comfort!
Thanks for the information regarding springs, I will have a chat with the people that you suggested to see what they think. To be honest, I think we may be fine with stock RB height, as-long as we protect the sump and fuel tank as per your suggestions.
Yeah i am a member of the MGCC so i will ping an email to see whether i can find some information from him. :)

Again, thanks for the info!


Re: Taller suspension for a trials MGB

Posted: Fri Dec 20, 2019 11:32 am
by Peter Cresswell
The Exeter Trial is one of the Classic Endurance Trials, and some of these are quite rough. The cars are also quite specialised as I'm sure you will have realised from marshalling on the Exmoor Trial. See this video from Blue Hills Mine on the Lands End Trial. The cars start at about 13 mins into the video.
A uprated clutch would be a good idea too!

Re: Taller suspension for a trials MGB

Posted: Sat Dec 21, 2019 11:39 am
by Paul Hollingworth
As Peter says the best person to talk to is Brian Osborn, he has been competing in Trials for about 30 years in his MGB. He wont mind me telling you that he's 80 now but still entering in the likes of the Lands End, Exeter and Edenborough trials. His car has become more and more specialised over the years with his fuel tank moved to the boot and the exhaust re-routed as well as the suspension being raised. The car has taken quite a beating over the years and is know affectionately at our club as the red wreck. It still has a current MOT however although it doesn't need one. Having bounced for him on a couple of occasions I have to admit its not particularly competitive. Midgets are much better. I'm also 6'1" and I was always comfortable in a Midget but that was in the late 70's and I have a bit of trouble getting in and out of one now. Rob Cull trialled a Midget reasonably successfully for many years. Although he doesn't have it anymore, I know where it is and it might be available but requiring some work. Likewise John Fry, another Midland Centre committee member, has a MGB which has been trialled by himself, Brian and Vic Lockley over the years. The problem there is that although its mechanically sound it requires two new sills. Its deemed to be uneconomical to repair and will just rot away if someone doesn't save it. I'd say its not as tatty as Brian's car but is still known as the yellow peril.

Re: Taller suspension for a trials MGB

Posted: Mon Apr 26, 2021 9:41 pm
by CurryB
The Ex John Fry/Brian Osbourne B Trials roadster lives on. My son and I rescued it in September, have put a lot of sill back in, and fettled it all over a bit. It came out competitively again for the first time yesterday on the NDMC Exmoor trial. An epic day out, and home in one piece too. A lot of fun. We now definitely need to source some higher rear springs......and maybe some fronts too......and some seats.....Pat bounced through the passengers one! I'll try and post a picture.....Winston