rusty ken Posted January 16, 2017 Report Share Posted January 16, 2017 I'm looking for some advice on what is suitable gearing for a 350cc Matchless G3L (I expect a 350 Ariel would be very similar). I've been using the bike in my local trials, none of which involve a particularly long lap or any road work, and she is currently quite low geared. With aspirations of entering a NBBC round, or a two day event in GB or Ireland, I am looking for some guidance on what is the normal set-up for a pre-unit 350 being used in todays events? The bike is fitted with a GB Burman box, with Mick Ash gears and a standard clutch. The current gearing uses a 16t engine sprocket and 14t gearbox sprocket fitted. The rear drum allows the rear sprocket to be changed, and there is a 50t sprocket fitted. This means the 350 is pretty low geared, which is good in the tight sections set in my local events, but crossing fields between sections she is happily pulling top gear, and any road work would be painfull. I've looked at the recommended trials gearing in the original handbooks, but am concerned this might be too high for the type of section that is being used in many events today. As a relative novice I'm cautious of reverting to this only to find I'm having to continually slip the clutch to control the speed in tight sections, but I obviously need to up at least the gearbox sprocket to make her more bearable between sections. All advice welcome. Quote Link to comment Share on other sites More sharing options...
collyolly Posted January 16, 2017 Report Share Posted January 16, 2017 Be interested to know when you last rode a bike in a trial, they are set out so tight these days that the modern way of riding the clutch gives the best result. 24 or 26 to 1 rings a bell for the 1st gear ratio ( crank to rear wheel rotation ratio) a starting point for your guidance anyway, I have progressively geared mine up as the use of the clutch permits control in turns and still gives a long gear for the rest of the section. I also have the Mick Ash gear set and my top gear is perfect for the road, maybe a little high for 'through the woods' Quote Link to comment Share on other sites More sharing options...
jon v8 Posted January 16, 2017 Report Share Posted January 16, 2017 I think my Ariel had an overall ratio of just over 25:1 in first gear, using Mick Ash gears in a Burman GB box. The spread of ratio's gave three perfect gears for sections ,but still quite a low top gear for roadwork. As Collyolly says,even with these ratio's at times you are forced to use the clutch for some of the tight turns,be interesting to see how the Talmag is marked out this year... I have no idea what my AJS box contains,its an AMC box and gives a perfect set of three section gears and the big jump to top gear.From a riders view pretty much identical to my HT. For roadwork in all the Miller rounds last year we were cruising at a steady 22-24mph according to my GPS bicycle speedo,so no speed limits were broken, above about 28mph the vibration blurs vision too much to ride safely on either bike. For your info,the GB box ratios with Mick Ash gears are as follows; 1st gear, Main 17,Lay 29.(Standard road gears) 2nd gear, M 22, L 24. (Mick's gears, same as the original trials cluster) 3rd gear, M 25, L 21. (Standard road gears) Sleeve Gears, M 31, L 15 (Micks gears, original trials cluster was M30, L16) Hope this may help. 1 Quote Link to comment Share on other sites More sharing options...
trickymicky Posted January 17, 2017 Report Share Posted January 17, 2017 (edited) That's standard road 2nd gear quoted there Jon, you should have 20 / 26 (same as original wide ratio) Edited January 17, 2017 by trickymicky 2 Quote Link to comment Share on other sites More sharing options...
jon v8 Posted January 17, 2017 Report Share Posted January 17, 2017 3 hours ago, trickymicky said: That's standard road 2nd gear quoted there Jon, you should have 20 / 26 (same as original wide ratio) Oops ! Spot on Mick, you are dead right - I miss read my own Email I sent to a mate just before Christmas who was asking what the original road/trials and your ratio's are. Can't blame the wine,not had a drink since Boxing day,must be old age... 1 Quote Link to comment Share on other sites More sharing options...
brian0304 Posted January 18, 2017 Report Share Posted January 18, 2017 (edited) Times change, things move on, using the clutch now and again doesn't spoil a day out riding a nice bike. Just be happy that 50 years from 1965 that anyone wants to ride anything from that era, as it has less and less relevance to younger riders . The Talmag is a one off like the Banbury Run, when often rarely used bikes get an annual airing. Nostalgia ain't like it used to be Edited January 18, 2017 by Brian0304 3 Quote Link to comment Share on other sites More sharing options...
jon v8 Posted January 18, 2017 Report Share Posted January 18, 2017 Time has moved on Deryk, I've just looked through the entry list of 200 and I know at least 51 of the entries - and their bikes, at least 25 of them are on electronic ignition for a start and few of them are anything like original,many are virtually new bikes. Last time I rode the hard route there the clutch was needed... The Arbuthnot is really a better example,no clutch needed there. To me it doesn't matter, pre unit four strokes are what I like to see,original or modified. 2 Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 18, 2017 Report Share Posted January 18, 2017 Originality is an issue in every sort of old-vehicle motorsport. Cars and bikes. Racing, rallying and trials. Even karts. It's especially a problem when (at the time the class was contemporary) the bikes or cars were modified versions of something more mundane. The best you can really say is that modifications must be "in period". Even then, tyres are bound to be somewhat different because you can't get the original construction or compound. Quote Link to comment Share on other sites More sharing options...
rusty ken Posted January 19, 2017 Author Report Share Posted January 19, 2017 Laird; thanks for your offer of advice on people to talk to and events to ride, but I am fairly up to speed with the events organised in Ireland, and I do my best to follow the GB calendar and events through the wonders of the web and social media. Hopefully I'll get to an event over there in the not to distant future, which is what prompted my original question. I do appreciate the rule of thumb of 25:1 will be a good starting point to set 1st gear (thanks Collyolly and Jon V8), and I appreciate your openness and willingness to provide information (which can also be applied wider than just to my original question). I also appreciate the info on your speed between subs, maybe my gearing isn't as far out as I thought! I'd understood that Mick's gear modifications were now pretty much 'best practice' for anyone starting out with a B53 Burman with a road cluster (they are excellent, thanks trickymicky), so hadn't expected to need to go back to first principles to finalise the gearing. To answer Laird's earlier comment, in posting on Trials Central I thought that I was "asking someone using a similar machine these days for advice", but as an interim step I'm intending to fit a larger gearbox sprocket and see how it works. When I posted my original question I had no intention of restarting the discussion on how current sections set for Pre '65 trials have changed from set-out back in the day, or how much development and modification has gone into today's Pre 65 bikes. So apologies to everyone for prompting the reopening this can of worms. Without getting into the rights and wrongs of Pre '65, I'm pragmatic enough to accept that If I want to ride my Matchless in events then I have to make the best of the events that I can get to, and the sections that have been set. There are very few pre 65 bikes being used in my area, but my local club does cater well for novices and a number of twin-shocks usually appear. It invariably gives me a challenging and enjoyable day on the bike and, while I'm happy to admit that this isn't ideal for a pre '65 bike, unless we get more appropriate events organised, it's better than parking my Matchless in the shed. 3 Quote Link to comment Share on other sites More sharing options...
metisse Posted January 19, 2017 Report Share Posted January 19, 2017 Not getting into the rights or wrongs of Pre 65, the irony here across the channel, is that first model Bultacos are now classed as ...yep you guessed.. I blame brexit.. 1 Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted January 21, 2017 Report Share Posted January 21, 2017 On 1/19/2017 at 10:01 PM, metisse said: Not getting into the rights or wrongs of Pre 65, the irony here across the channel, is that first model Bultacos are now classed as ...yep you guessed.. I blame brexit.. But if they were manufactured before December 31st 1964 then surely thats correct. They did exist ive seen photos to prove it although i think they were converted road or trail bikes but then again so were the British bikes werent they ? 1 Quote Link to comment Share on other sites More sharing options...
stickinthemud Posted February 8, 2017 Report Share Posted February 8, 2017 I have a spreadsheet that tells me with your MA gears (assuming a 40t clutch) you have the following ratios (standard ratios in brackets). 1st 31.48 (23.69) ; 2nd 23.99 (15.15); 3rd 15.50 (11.67) ; top 8.93 (8.93). On these ratios you should do about 8.7mph per 1,000rpm in top gear so 30mph at 3,500 revs. That's better than most P65 machines in road trials can do these days. Hope this helps. Other options are avialable Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted February 9, 2017 Report Share Posted February 9, 2017 Hi Guy's. Hi Deryk, Don't forget my connection to the Bultaco story. You can read it all on my website. Rickman Bros became distributors in late 1964 guy's. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
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