furse Posted October 22, 2015 Report Share Posted October 22, 2015 Hi, I am looking for some information/ advice on a B25, what gearing? What oil?, what carb, recommended mods if any Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted October 22, 2015 Report Share Posted October 22, 2015 Hi Guy's, Hi Furse. First question before we go any further, What frame are you using? or what frame do you expect to use? Then we can go from there. it does make a vast difference. except for the oil, any oil used needs changing quite regularly and I would add an outside paper filter. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
furse Posted October 23, 2015 Author Report Share Posted October 23, 2015 Hi Charlie, It's been fitted into a RE crusader frame Quote Link to comment Share on other sites More sharing options...
bashplate Posted October 23, 2015 Report Share Posted October 23, 2015 sounds interrrrresting, keep us up to speed with the build.....pictures would be great. Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted October 24, 2015 Report Share Posted October 24, 2015 Hi Guy's. Hi Furse. Thats a good choice! Means you have room for a good carburettor line because they are tricky with any frame with a single seat post. and you have room for that all important filter. What Swinging -arm are you using? you will need the one from the sports version to get enough clearance for the tyre. What forks are you using? you may have to try a couple of different sets to find ones that suits you. I agree with Bashplate pictures would be great, Could be a really interesting machine. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
furse Posted October 24, 2015 Author Report Share Posted October 24, 2015 It has the standard swing arm I think as it is very close on one side and would need altering or as you say the 'sports version' Forks are supposed to be Betor 35mm but I dont know what from as the Rickman brake plate fits to the lug on the leg fine, I will take some photos but its been tucked away as Ive got the last round of the KIA twinshock tomorrow and been sorting the Fantic. Quote Link to comment Share on other sites More sharing options...
furse Posted October 31, 2015 Author Report Share Posted October 31, 2015 Looking at it again I think it has the sports swingarm 1 Quote Link to comment Share on other sites More sharing options...
bashplate Posted November 2, 2015 Report Share Posted November 2, 2015 that's one HUUUUUUGE sprocket Quote Link to comment Share on other sites More sharing options...
furse Posted November 2, 2015 Author Report Share Posted November 2, 2015 70t ! Hence the question on the gearing, it may act as a stabiliser Quote Link to comment Share on other sites More sharing options...
bashplate Posted November 3, 2015 Report Share Posted November 3, 2015 Hi Furse, looking good and can see where your coming from regards the gearing .The only other thing (s) I would be looking at is the swing arm.....a little longer, and ya bashplate looks a bit wide at the front....may be just camera angle. Motor sits in there real nice though..well done. Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted November 3, 2015 Report Share Posted November 3, 2015 Hi Guy's. Hi Furse. Looking at that picture, and the sprocket. Looks like you need to go down on the engine sprocket, Not that difficult, shorter primary chain,and you will have to reduce the engine oil seal in width and machine of the surrounding alloy to suit. Check what gearbox sprocket you are running too. Hope this helps? You know where to look for further information, on one of my pages. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
laird387 Posted November 3, 2015 Report Share Posted November 3, 2015 Hi, There was a lot of discussion at one stage that the larger the diameter of the rear sprocket, the easier it was to lose traction under slippery section conditions, the argument resting on the point of the diameter of the rear wheel at which the tractive effort of the chain pull was exerted. To settle the argument two machines were chosen one with a larger gearbox sprocket and huge rear sprocket, the other with a minute gearbox sprocket and a smaller rear sprocket - but both with exactly the same overall gearing. Then a multitude of riders compared the two bikes in an afternoon of various sections. Realising it wasn't a genuine comparison, one of the rear tyres might have had better grip - one of the footrest positions could be affecting the result, etc., etc., but the overall view at the end of the day was universal, every single rider was convinced the bike with the smaller sprocket gave far better grip. It was universally agreed that the minute gearbox sprockets would wear quickly - but ever one of the riders involved gradually modified their own bikes over the following season to get the smallest diameter rear sprocket that they could. Proof - several riders went down a chain size because that gave them an even smaller sprocket............... 2 Quote Link to comment Share on other sites More sharing options...
furse Posted November 3, 2015 Author Report Share Posted November 3, 2015 The engine sprocket is 18t, 13t on the g,box I had a 50 for the rear wheel so will try that, Charlie why do I need to machine seal etc? Thanks for replies, what is preference on oils? Quote Link to comment Share on other sites More sharing options...
b40rt Posted November 4, 2015 Report Share Posted November 4, 2015 http://www.trialsbits.co.uk/product_info.php?cPath=85_182_257&products_id=689 2 Quote Link to comment Share on other sites More sharing options...
davetom Posted November 4, 2015 Report Share Posted November 4, 2015 Interesting comments by Deryk re sprocket size affecting grip . Squat will increase with smaller sprockets but there's more to it than that as swingarm length, shock length, Spring strength and ride height are all factors too. A certain amount of squat is useful, but too much isn't good either so I'd be interested if anyone's done any recent comparisons, especially as bikes are lighter, softer sprung and have more travel than they did back in the day ? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.