steve Posted February 10, 2005 Report Share Posted February 10, 2005 Hi, I am looking for 2 x C15 gears to put in my Distributer type engine. Well actually I would like a complete wide ratio box for the bike but hens teeth are easier (and cheaper) to find!! I am looking for a 20T part No 40-3101 & 30T Part No 40-3100 These were fitted as 2nd gear in the wide ratio box. I have tried all the shops who advertise in Classic bike and Old bike mart hoping to find some NOS but no luck. Can anyone help? stephen.bird1@ntlworld.com Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted February 10, 2005 Report Share Posted February 10, 2005 Dont know if they can be of any help but have you tried Gagg and Sons on Alfreton road in Nottingham? they do mail order and you can find the number on Yell.com. theyve been in business for 100 years and have an alladins cave of unit BSA bits. Alan is your man. He gets a bit stressed but can be very knowledgeable and helpful. Quote Link to comment Share on other sites More sharing options...
steve Posted February 10, 2005 Author Report Share Posted February 10, 2005 I have tried Gagg and son's thanks. Someone must have a box of gears sitting in the shed just waiting for me !!! Quote Link to comment Share on other sites More sharing options...
steve Posted February 16, 2005 Author Report Share Posted February 16, 2005 Why would you want a SS motor? Ok so more power is good but it has to be in the right areas. My engine is the SS but it has a std cylinder head fitted. It also has a close ratio gearbox in it which is no good for Trials unless you want a top speed of aboout 25mph!! The SS has a higher compression, bigger valves in the head with larger Dia inlet. plus a hotter cam. It ran a larger carb to match the increased inlet dia. Much of those mods can easily be done to a std engine. Trials bikes always seem to run better on smaller carbs I remember my dad's old CCM 350T used to spit back and stall until we fitted a smaller dia carb, so why open up the inlet and then restrict it with a smaller carb? Quote Link to comment Share on other sites More sharing options...
steve Posted February 18, 2005 Author Report Share Posted February 18, 2005 I don't have a side points engine, neither do I have the money to buy one so I will try to make the best out of what I have. If in good condition the mains bush is well up to the job. A trials engine will not be reved hard for any long period of time like a road bike or scrambles bike may. Plus it will only get occasional use so a good bush will last many years. Anyway a roller conversion kit is available from Alpha if the bush ever fails. As for the gearbox a WDB40 box will not fit in an early engine. I have seen people asking silly money for these anyway. I can get a gear made way cheaper than I can buy a WD wide ratio box. I have made a spreadsheet which helps work out all the gear ratio's. Simply input the sprocket and gear sizes and it'll tell you the final drive ratio. I am happy to send it to anyone who wants it. If I had the money I would love to build a ultra trick bike with PVL and all the other off the shelf goodies based on a sidepoint engine. Unfortunately I don't have any money - this is why I have fitted my own ignition which runs directly from the crank and didn't cost a penny. One other point - all the talk on here of rules, and what is and isn't allowed. Sidepoints were not fitted until 1965. Quote Link to comment Share on other sites More sharing options...
steve Posted February 19, 2005 Author Report Share Posted February 19, 2005 I can get a gear made way cheaper than I can buy a WD wide ratio box. I didn't say I could get a new set made, I am not looking for a whole set of gears. I am only looking for 1 pair. One of those I have found so that leaves 1 gear to make. Apple rochester gears in Wellingborough will make any gears but the first one is quite expensive. I have dealt with them through work and one of the guys will do a 'dinner time rate' for me!!!. I know there is only a slim chance of finding some to buy but isn't that what these forums are for? If I never ask anyone I definitely won't find any. Quote Link to comment Share on other sites More sharing options...
steve Posted February 19, 2005 Author Report Share Posted February 19, 2005 Ok - You can change the final gear ratio's in many ways. I will use an 18t engine sprocket to keep the rear sprocket as small as possible. The aim is to get the gearbox sprocket as large as possible to keep a good chain run over the swinging arm, whilst at the same time keeping the rear sprocket as small as possible. Send me your email and I will send a copy of the spreadsheet - you will see I have looked into this in great detail. With a Std box I will have a final drive ratio of 28.44 in bottom, however 2nd will be 18.78. A big jump and probably unusable in a section. With my new 2nd gear I'll have a bottom gear of 28.76 and a 2nd of 24.27. A very usable gear for sections. The only thing better about a pukka wide ratio gearbox is that top gear will give a faster speed on the road. Quote Link to comment Share on other sites More sharing options...
steve Posted February 20, 2005 Author Report Share Posted February 20, 2005 The Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted February 23, 2005 Report Share Posted February 23, 2005 Interesting comments from Steve & HondaRS regarding fork trail (draw a line through the steering stem to the floor then a vertical line from the wheel wheel spindle centre to the floor & the distance between the two marks is the trail) this gives the steering a self centring effect That much I understand but when building a bike choosing forks/yokes etc what measurements should we be trying to acheive & would leading spindle be better than in line I am thinking about a Cub project & the merits or otherwise of Armac/Otter or modded std frames Quote Link to comment Share on other sites More sharing options...
steve Posted February 23, 2005 Author Report Share Posted February 23, 2005 You already know more than most about trail if you know how to measure it. Leading axle etc.. makes little or no difference so long as you get the trail correct. The first thing to set up though is steering head angle, this actually has no bearing on trail as such - even a bike with a vertical steering head can have as much trail as you like. Perhaps someone could tell us what angle the otter frames are running. Once you have the correct steering head angle the trail can be altered by modifying the yokes, or indeed moving the axle forward or backwards. Niether of which are easy jobs so try to choose your forks / yokes carefully to give that measurement with no alteration. Many people alter the trail by modifying the steering head angle but too steep and the bike will 'tuck under' on corners and feel very nervous on descents. This is why many of the modified road bikes just don't steer right. I hope I haven't given any duff information as I am by no means an expert on frame geometry. If there are any frame builders reading this it would be nice to hear from you. It's a very interesting subject and even the big factorys don't always get it right, anyone remember the Montesa cota 311? Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted February 24, 2005 Report Share Posted February 24, 2005 What is considered to be the best head angle when choosing a frame, with yokes some Bultaco/Montesa for example have the steering stem at a slight angle to the fork legs while Ceriani or some Marzocchi have a parrallel setting. Ceriani yokes carry the fork legs well forward whilst others bring them back much nearer the headstock I suppose this moves the weight backwards but is it important. The more you look at this the more interesting/confusing it becomes? Quote Link to comment Share on other sites More sharing options...
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