Pre-65 Bikes

So, where do I start. We built an Ariel a few years ago and I just cannot get it to run when hot without making hideous noises. My initial thoughts were that the top end was getting starved of oil, I have a frame with the oil filler under the seat and the return pipe has a hole in it before it pushes the oil up to the rocker. The hole is about 5mm diameter so the oil does not bother to carry on past it. I put an additional pipe in before it entered the return pipe, issue was the same, I then removed this and restricted the return hole by putting an inner clutch cable down the pipe along with a nipple that closed up the hole whilst oil returned, issue was the same. So I…

Hi guys (and gals?),does any one know what size amal concentric carb works best on a marcelle barrel (for trials).In the box of bits which it came with was a 930,with a 928/ 2 1/2 slide,is this in the right ball park? Thanks.

Just bought a BSA B25 and stripped it down for a service, on inspection I found quite a lot of sludge/carbon in the oil tank strainer, is this normal? Don't think its dirt as the bike's never been offroad When I collected the bike it ran fine, All the bikes I’ve previously owned have always been clean

If anyone knows of any Ariel engine building specialists, can they please send me a message with their contact details? Thanks

As per pictures below, I have fitted engine (which is offset to give clearance) - and have widened swinging arm. Ive got the rear hub in what I think is the correct alignment measuring as best I can, I can then measure to get correct spacers manufactured. Is there an easy way to check front to back sprocket alignment ? cheers John

When reading about the BSA Sunbeam (good luck in the P65 Stu) and following the story on these engines elsewhere I noticed a link to Villiers engined trials bikes. Two are of particular interest to me. Firstly the Firefly I have seen one of these ridden in local trials and thought it to be a good bike, the other is the Kyffin Saphire trials which I have heard of but never seen though I have seen a number of th Triumph engined scrambles bikes as wll as a BSA A65 powered version. The frame on the Red Rose trials appears to be a virtual copy? of the Bultaco of the same period but were any sold, has anyone seen one/got one or remember them being ridden.

Hi All, i am in the process of building myself a unit construction BSA either C15G or WD B40 for trials, my question is simply this. how essential is the Wide ratio box. I have a C15G, which has the standard road box in it, unfortunately the B40 GB motor i bought has had the Wide ratio gears robbed and a stub tooth B25, B44 road box in it, i was assured on buying the motor it was a standard B40GB with the wide ratio box, unfortunately the owner got his facts wrong, he has offered to have it back but for what I paid I would sooner keep it. unfortunately a Wide Ratio box is going to cost in the region of £300, which is alot of money to me. I am an average club level…

Looking to either service or replace the MK 1 Concentric fitted to my G3C. It is currently fitted with a MK1 Concentric 626 model. Its a 1960 G3C 350cc engine, wader MAG, fitted with a pancake filter. If I go for a new carb, should I stick with the same model? Any suggestions on jet sizes, if I get another 626?

Lots of interest in my friends Sunbeam today at the Vmcc trial, thought I'd post a pic, for anyone interested it will be competing in the 2016 Scottish.

Hi Ive covered rim size on a previous post, but thought I would ask the remaing (at the moment) questions in one go 1 - Sprocket size Its a 4 speed engine - unsure of any internal gearing changes. What the best combination of sprocket sizes ? Also- chain, 428 ? 2 - Wheel offet Im about to get new rims built onto bantam hubs Rear (using a widened swinging arm and engine offset 8mm) - I think needs no offset ? Front - I think 6mm offset to brake side ? 3 - Chain tensioner Any advice on best type ? may think of more ! cheers John

Just fitted an Amal stay up float kit to the concentric carb on my bike but now it floods as soon as the fuel is switched on, have tried to lower the float level as well as checking the viton tipped float needles operation but without effecting a cure. Any ideas please.

Quick question buikding a bantam at the moment, whats suitable rim size (building new wheels) cheers John

What type of wheel spindle arrangement is best when using a Cub type hub in AJS, Matchless fork legs?

Greetings All I have just fitted a Mk1 concentric on my 53 Matchless in place of the old worn Mono block just wondering what jetting / slide other people were using as I cant get it to run spot on , I have to flood it to start even when hot and a flat spot on acceleration. Any input welcomed Regards Geoff

The bash plate i built for my heavyweight Enfield is cracking and dented. It as made of 3/16 inch aluminum with welded "wings". I need something heavier duty. what is the recommended aluminum? Should I switch to steel? Dave

Hi, I am resurrecting a rigid Bantam, now 185cc with a modified frame at the rear end and loop under the engine. Two problems have come to light, where the rear of the frame was widened for the tyre it seems to be lop-sided, i.e. tyre clears on chain side, but is very close on the other. Main prob though, is the steering head angle, having fitted honda forks with parallel steering stem, it looks like a chopper! Can anyone tell me what the steering head angle should be, as other people I have heard from say that other forks have been fitted yet the bike looks normal. I am judging this against tlr 200 honda and my 4rt, the 4rt isn't really comparable of course, just using…

All the talk about period correct Pre 65 trias motorcycles and I havent seen any mention of modern tires. My guess is if a specification tire such as a Chang Shin C186 was mandated then the sport would be much closer to the magic pre 65 than by limiting any other modification? Maybe this has been discussed already?

Hi can anyone tell me where i could get my bike insured for fire and theft, its not road registered i have a bike already insured with carole nash but there is a upper value limit then theyre not interested many thanks

Can anyone tell me where this washer should be? Took the sump filter off today and it was lying in the bottom, it's about 22mm diameter

Trying to identify this Royal Enfield so i can suggest a value to it's owner.I'm not selling it and won't make a penny out of it.The owner has lost his storage due to circumstances beyond his control,his friend contacted me as he knows little about older bikes and asked for advice.I've explained that dating Royal Enfields can be a bit hit and miss.He found an old buff logbook for a 1948 350 Royal Enfield which shows Frame number and Engine number as 19499 and reg as what looks like JFJ210 ,next time he goes he'll look to see if the numbers are on either the bike or the frame and engine next to it.As i understand it this would be a very early "Bullet" type.What i need to k…