Just a thought, but which side should he front brake be on. (or would have been on originally)

Hi Guy's

Hi B40rt.

Well the front on Scott's bike and most of the others using Bantam hubs at the time would have been on the right as you sat on the bike.

It Is only over the past few years that, shall we say engineers, have worked out that you get a better cable run when the brake is on the other side. Some works riders did swop from side to side to get even brake ware, and seemed to think some trials suited the brake on one side or the other. Also BSA works riders did try other available brakes. I.E. 7inch BSA as on Pat's bike and the Ariel Leader alloy brake Etc.

One other little hint on the new Alloy replica Cub/Bantam hubs is, be carefull which way you fit them because the good ones are designed to be fitted only on the side you spec , and some of the copies of these the braking surface comes away from the alloy hub, because there design is not quite right..

Regards Charlie.

One other little hint on the new Alloy replica Cub/Bantam hubs is, be carefull which way you fit them because the good ones are designed to be fitted only on the side you spec , and some of the copies of these the braking surface comes away from the alloy hub, because there design is not quite right..

Regards Charlie.

uhhhhhmmm

i can only imagine that you are referring to hubs with threaded braking surface inserts ???

even then wouldn't there be a risk of the insert un-screwing as you roll backwards down the hill with the brake on.

aren't the more expensive hubs metal sprayed so you can fit them either way (i note they use a circlip as a bearing retainer for the same reason, when you fit a cub hub backwards there is a possiblity of unscrewing the lefthanded bearing retaining ring.)

as a side note... i understand that apart from a better cable run, the brake plate is orientated so that the leading edge of the shoe acts on the weight bearing side of the drum for a more positive action..

Edited December 21, 200916 yr by Andy
Fix borked quote

Hi Guy's

Hi B40rt.

Well the front on Scott's bike and most of the others using Bantam hubs at the time would have been on the right as you sat on the bike.

It Is only over the past few years that, shall we say engineers, have worked out that you get a better cable run when the brake is on the other side. Some works riders did swop from side to side to get even brake ware, and seemed to think some trials suited the brake on one side or the other. Also BSA works riders did try other available brakes. I.E. 7inch BSA as on Pat's bike and the Ariel Leader alloy brake Etc.

One other little hint on the new Alloy replica Cub/Bantam hubs is, be carefull which way you fit them because the good ones are designed to be fitted only on the side you spec , and some of the copies of these the braking surface comes away from the alloy hub, because there design is not quite right..

Regards Charlie.

Hi Charlie

That makes sense regarding the cable run.

I was told that some of the replica hubs had a groove to encourage water to exit the hub, and that would be specific to which side the brake plate was on.

I thought that the steel/iron insert was shrunk into the hub, and therefore not effected by direction ?

Ross

Hi Guy's

Hi B40rt.

Alans said it all realy. but you can see you need to check out which hubs you use and it is not a matter of just fitting them. Locktite stops the bearing retainer from moving !!!

Regards Charlie.

Hi Charlie,

Did you ever find out where BOK 228C is?.

Happy christmas to everybody.

Pat Slinn.

Hi Charlie,

Did you ever find out where BOK 228C is?.

Happy christmas to everybody.

Pat Slinn.

Of course, Colin Dommett has it!

Big John

Hi Guy's.

Hi Pat.

Happy Christmas, mate, and every one on here.

Well I think Colin still has the log book , but I don't know about the bike, I think the frame has been scraped? I would like to know?

Regards Charlie.

Hi Charlie,

Yes it would be nice to know what happened to that frame.

I hope everybody has a really good Christmas, and all the best to everybody who is trials riding on Boxing day.

Pat.

Hi Charlie,

Yes it would be nice to know what happened to that frame.

I hope everybody has a really good Christmas, and all the best to everybody who is trials riding on Boxing day.

Pat.

Hi Pat,

I've just sent you an e-mail with the details you requested!

Best wishes,

Big John

HI

I

Hi Guy's

Hi TBoy.

OK I will make it simple ?.

Now the proper way to cast a steel liner into alloy is to sit it in the casting sand in the right position then cast the alloy around it. but because this is complicated, it makes the hubs expensive to produce. So you can either shrink a liner into the machined cast alloy hub, and hope it does not get to hot while you are using it, or you can machine the liner and hub with a fast screw thread, so when you apply the brake the force applied tends to screw the liner further into the hub, so it does not come loose. this is why the hubs need to be fitted the correct way, otherwise when the brake was applied it would tend to loosen the liner, just think of it as a nut and bolt? The other way is to have the machined hub chrome plated onto the braking surface, has were some Bultaco hubs I seem to remember, and these soon went oval and the chrome peeled off. Fascinating brakes you know.

Regards Charlie.

Hi Guy's

Hi TBoy.

OK I will make it simple ?.

Now the proper way to cast a steel liner into alloy is to sit it in the casting sand in the right position then cast the alloy around it. but because this is complicated, it makes the hubs expensive to produce. So you can either shrink a liner into the machined cast alloy hub, and hope it does not get to hot while you are using it, or you can machine the liner and hub with a fast screw thread, so when you apply the brake the force applied tends to screw the liner further into the hub, so it does not come loose. this is why the hubs need to be fitted the correct way, otherwise when the brake was applied it would tend to loosen the liner, just think of it as a nut and bolt? The other way is to have the machined hub chrome plated onto the braking surface, has were some Bultaco hubs I seem to remember, and these soon went oval and the chrome peeled off. Fascinating brakes you know.

Regards Charlie.

I take it that the aluminium of the hub expand faster than the liner. If they expand at the same rate, or the steel faster, presumabley not a problem, or can that make the hubs oval.

Genuinly interested.

Do Grimeca hubs have a thread or are they shrunk. Anybody know ?

Edited December 29, 200916 yr by B40RT

Ross

Alloy will expand much faster than steel/iron.

With shrunk in liners it's about getting the fit correct. I must of relined over 100 Bultaco hubs throughout the 90's as far as I know none of the liners slipped or came loose and that was a thin insert (1.5mm Wall). The interference fit I used was severe though.

Wayne.....

quite agree, the heat rise on a trials bike will not cause significant expansion,

However, being further away from the heat source ,exposed to the air and a good conductor, the aluminium hub will be cooler than the steel liner so the differential expansion will have little impact if the correct fit was used to start with.

Edited December 31, 200916 yr by alan