Big tank for 1971 B25T

[Jeff K]

I thought that I read a long time back that they used a bigger gas tank in England for the 1971 OIF BSA and Triumph 250's. Does anyone have any information on them?
Jeff

[minetymenace]

UK bikes (not sure about the T brand) had an option of a 3 gallon tank.

If you go to "spare parts" above, then "search by illustration", "BSA B25 1971", then "Petrol Tank, Twin Seat, Controls", you will see the tank is No. 32. If you then use the drop down box to get item 32, you will see three options: 32, 32-1, 32-2. Select 32-2 and you will see the part number.

Here are a couple of pictures of my 3 gallon Fleetstar tank:

[Canberra]

From my recollection the B50MX had a 1 gallon aluminium, B50T had 2 gallon aluminium, B50SS had the 2 gallon steel and the B50H version of the B50SS had the 3 gallon steel (H = home and export). If you are looking for the latter make sure you pick up the later version with the strap under the tank (83-4320 - not the 83-2998). The early tanks didn't have the tie strap and can develop cracks in the tank or worse still crack in an accident, spilling fuel.

The B25 tanks matched the B50 models although I expect a 3 gallon on the B25 would have been a "long range" tank. The B50 can make 60-65 miles/gallon depending on how it was ridden ~ 180 miles(or ~240 km) . Not sure how much a B25 uses but expect it would have a 250 mile/tank range? Bet you can cross little old UK on a tank full!

John

[Jeff K]

Thanks for the replies. I was looking to add more range to a TR5T. I was even thinking about cutting a metal tank from the T25T and adding a section on each side.
Jeff

[minetymenace]

The bigger the tank, the smaller the seat. As the tanks get bigger it also gets longer, so the seat nose has to get shorter!

John is right, range on a B25 is 250 miles plus...

[Jeff K]

I have a couple of spare Norton Interstate gas tanks, they are +7 gallons. I should try to fit one of them. I could ride all week on a fill up.
Jeff

[beat]

range on a B25 is 250 miles plus...

there is a B50 doing 280 miles + ....

[Jeff K]

Any one have any dealings with this Ebay Seller from India. He is listing a tank for the B25T/T25T and states it is a 3 gallon model?
www.ebay.com/itm/292086514438
Jeff

[kommando]

That does not have the shape of the 3 gall, looks like a 2 gal.

[Jeff K]

Thanks Kommando, I was thinking the same thing. We bought a aluminum interstate tank a couple of years back from India for Commando project. It took a lot of work to get it to mount straight and it had one of the petcock holes tapped crooked.
I remember a old guy long, long time back actually mounted a pair of the Harley Fat Bob tanks and a solo seat on a 1969 TR25 for his wife to ride. He actually did a pretty good job of it. Now that would be a long range set.
Jeff

[Restomoto]

From my recollection the B50MX had a 1 gallon aluminium, B50T had 2 gallon aluminium, B50SS had the 2 gallon steel and the B50H version of the B50SS had the 3 gallon steel (H = home and export). If you are looking for the latter make sure you pick up the later version with the strap under the tank (83-4320 - not the 83-2998). The early tanks didn't have the tie strap and can develop cracks in the tank or worse still crack in an accident, spilling fuel.

The B25 tanks matched the B50 models although I expect a 3 gallon on the B25 would have been a "long range" tank. The B50 can make 60-65 miles/gallon depending on how it was ridden ~ 180 miles(or ~240 km) . Not sure how much a B25 uses but expect it would have a 250 mile/tank range? Bet you can cross little old UK on a tank full!

John,

Thanks John of this usefull info.
I just bought B50SS ( actually B50H) with large 3 gallon steel tank. I will have to check if there is under the tank that strap you mentioned. I will get the bike after few week, It comes from England to me.
Best regards
Erkki
Finland
A new (back coming) member

[minetymenace]

(back) to the forum.

Just re-reading this, don't think any of the oif tanks had a strap underneath....

[SteveS]

minetymenace: don't think any of the oif tanks had a strap underneath....

Hi Gerry

See post here from the late Steve m

Regards

[minetymenace]

Yes, thanks for that, still never seen one in the flesh, and not present on my late or any of the replacement tanks it has had (3 gal). The 83-4722 reveals a flat plate for later Triumph and MX machines, 2 gal tanks and John's photo is nothing like the flat plates has no part number and looks rather too well made for BSA (ready to take flack for this!). Furthermore, steve m's photo of the brackets (not threaded holes) looks like an afterthought (seems to have have been welded on after painting). I'm not saying they were never fitted, just I've never seen one,....now I'm of to consult Brads book!

[JB]

Purely from memory... I seem to recall that the main difference with the aluminium TR5T tanks compared to the similarly shaped aluminium T25T Trailblazer tanks was two extra threaded bosses for a tank strap...memories do play tricks though

[lathejack]

I bought this 3 gallon B50 tank from the Autojumble last year, it needs a respray but does appear to have original paint.

This tank also has the tank strap lugs welded on underneath, in the same position as those shown in the link to Steve m's post. The lugs on my tank measure about 9 3/16 between the centres of the hole radius.
The lugs themselves are also identical to those on Steve m's tank.

[minetymenace]

Well I'll be....

[Jeff K]

So the big tanks where only made in steel and not aluminum.
Jeff

[minetymenace]

Yep, and just for us in Blighty!

[madmac]

just spotted on well known auction site 3gall tank with brackets, with a good price
https://www.ebay.co.uk/itm/BSA-B50-petr ... SwL35coIKH

[lathejack]

I've just been looking at the tank for sale that madmac refers to, and this is it with the same lugs in the same position.

When I noticed them on the tank that I bought I thought they were a one off mod made by a previous owner, and I was all set to cut them off and smooth off the welds. Now I think I will leave them where they are.

[Jeff K]

I remember decades ago where I saw OIL 250 and the old guy had made a big tank for it. It looked like ran two aluminum tanks through a band saw and then rewelded them back together. One part was cut closer to the middle and the other farther towards the outer edge. Very crude, but he was happy. Too bad the old tanks aren't as cheap and plentiful like they used to be.
Jeff

[ghislain]

The very interesting part in fitting long ranges tanks on 250 is that you can refill and fit new shells on the same stop.... Saves time and money !!!!

[minetymenace]

Many a true word spoken in jest ghislain.

[Jeff K]

Sad, but true!
Jeff

[madmac]

As no one else has posted a photo of a OIF with a 3gal tank fitted an opportunity not to be missed my B25T
Always thought this tank was ugly, have been told the dove grey frame was a mistake? well I just love this bike! ok up hill or a strong wind leaves you struggling to reach 40mph but 200+mpg smooth running and oil tight

No strap fitted under tank was painted white with gold bsa transfers when i got it
Had to cut approx 2" off the seat to get the tank to fit,but I had extended the seat before when the small tank was fitted

[Jeff K]

Many years ago, at least 30. I knew a older gentleman (biker gang member) who naturally was a Harley man. He had a soft spot for Brit bikes and always was working on or building choppers. One Day I was picking up some T100c parts that he had and I notice a odd looking bike in the back, it looked like a mini Harley Single. He took a 1969 BSA B25 and added high bars, small head light, king queen seat etc. But what struck me was the gas tank. He had mounted the Harley 2 pc Fat Bob gas tank with the speedometer in the middle on it. It did not look too bad. He said he built it for his wife. I always wish I had a photo of it, but that was back in the days when a phone was mounted on a wall. Now that would have been a long range ride.
Jeff

[minetymenace]

Six gallons

[Canberra]

The B50SS(H) 3 gallon tank with the tank strap was a contoured wire strap with plates welded to the ends to mate with the angled screw housings welded on the tank. The contours were to ensure the strap didn't foul the top of the 500 engine as there is not a lot of room in that area.

Using the 3 gallon on a B25 would not have to worry about clearance as the top of the engine is lower. I suspect you could easily just manufacture a flat strap with a couple of curves on the end to match the angled screw housings. As the frames are identical the B50SS(H) matching seat should just drop on for a set (tank+seat).

Call me biased but I happen to like the larger tank, even though many think it is unsightly. I have yet to see a B50T rider with a standard tank who doesn't take an extra tank of fuel on longer trips such as we have in the outback trails here in Oz.

John

[skippy]

Call me biased but I happen to like the larger tank

I have had trouble with the small tank, having to find petrol on longer trips when other bikes can keep going.

[Jeff K]

Norton Interstate 7+ US gallons, 23+ to 26.5 liters depending on the year. We used a alloy one on the 850 Cafe project and I still have a Fiberglass and a what appears to be a later hard plastic one as spares. Now if i could fit that on the B25 or TR5T I could ride with out worrying about having to find a gas station for a long time

Jeff