29 replies to this topic

[Monty_Jon]

I’ve got some cub hubs for my bantam project, but I’ve seen a few bike advertised with widened hubs?

What is the advantage & how is it done?

[Andy M]

Monty_Jon, on 30 December 2010 - 01:04 PM, said:

I’ve got some cub hubs for my bantam project, but I’ve seen a few bike advertised with widened hubs?

What is the advantage & how is it done?

I have just been looking at a sorted Bantam trials to get some ideas for mine. The rear hub is widened to help splay the spokes, which is (some say) needed to run the 4.00 tyre on a wider rim. Though having said that the bike I looked at didn't have wider hubs and ran the 4.00 tyre fine. ?? I believe it is widened by cutting and welding the centre tube.

Also I believe if you do widen the hub you need to move the engine over in the frame slightly. I am sure somone will add to this or put me right if I am wrong...

Edited by bo drinker, 30 December 2010 - 01:47 PM.

[B40RT]

Monty_Jon, on 30 December 2010 - 01:04 PM, said:

I’ve got some cub hubs for my bantam project, but I’ve seen a few bike advertised with widened hubs?

What is the advantage & how is it done?

You can buy replica widened cub hubs from Alan Whitton.

[alan]

Monty_Jon, on 30 December 2010 - 01:04 PM, said:

I’ve got some cub hubs for my bantam project, but I’ve seen a few bike advertised with widened hubs?

What is the advantage & how is it done?

To clear the chain the wheel rim is offset to the right, this makes the spokes on the right hand side near vertical and therefore less able to withstand side loads.

Less offset can be needed if the engine is moved over to the left, or a dished engine sprocket is used.

The whitton hubs also have the advantage that they have 36 spokes rather than 40, making it much easier to get hold of a rim.

(could it be that 32 spoke versions are also available making it easy to get hold of a tubless rim ?????????)

[totalshell]

pre 65 bikes with tubeless rims> it'll never happen.

[Monty_Jon]

Thanks for your help, I’m trying to build the bantam on a tight budget

So I think the offset sprocket is for me

Just out of interest what sort of price would the replica hubs be???

Edited by Monty_Jon, 30 December 2010 - 07:48 PM.

[Old trials fanatic]

Monty_Jon, on 30 December 2010 - 07:37 PM, said:

Thanks for your help, I’m trying to build the bantam on a tight budget

So I think the offset sprocket is for me

Just out of interest what sort of price would the replica hubs be???

Need to allow iro £500 for a pair depending on if you use the alloy brake plates s/s cams arms etc or not.

[B40RT]

Old trials fanatic, on 30 December 2010 - 08:23 PM, said:

Need to allow iro £500 for a pair depending on if you use the alloy brake plates s/s cams arms etc or not.

+ another £500 by the time they're on the bike.

Edited by B40RT, 30 December 2010 - 09:35 PM.

[broony]

Monty_Jon,having recently built my first D7 trials bike,I used the standard rear
sprocket as a spacer and then fitted a trials alloy sprocket and longer bolts(I
made a small spacer for the brake plate to miss the rear sprocket) cheap and cheer-
ful.Now building Evo 2.-chopped frame/subframe and a few other mods.all done on a
budget in the shed.
cheers the noo Brian

[Andy M]

The Bantam I looked at today had the std rear hub with a very thin sprocket spacer, the engine had not been moved the s/arm had the usual indent so as the tyre cleared. No need for the 500 quid here and 500 there nonsense. And the bike in question does very well in the BMCA events.

[B40RT]

bo drinker, on 30 December 2010 - 09:46 PM, said:

No need for the 500 quid here and 500 there nonsense.

Sorry to have wasted your time.

[alan]

Surely a lot of this is down to personal preference, engineering ability, facilities to hand, and whether you are cash rich or time rich.
you can get almost the same results by either spending a lot of time in the shed working on a budget, or go out and buy parts that someone else has engineered.
the choice is yours.........

[Andy M]

alan, on 31 December 2010 - 10:47 AM, said:

Surely a lot of this is down to personal preference, engineering ability, facilities to hand, and whether you are cash rich or time rich.
you can get almost the same results by either spending a lot of time in the shed working on a budget, or go out and buy parts that someone else has engineered.
the choice is yours.........

[Monty_Jon]

I would like to build a bike that is a genuine pre 65 without all the trickery & expense

(except for a good ignition, for reliability)

[B40RT]

Monty_Jon, on 31 December 2010 - 01:44 PM, said:

I would like to build a bike that is a genuine pre 65 without all the trickery & expense

(except for a good ignition, for reliability)

(& alloy handle bars, modern tyres, modern shocks, repositioned foot rests, altered steering angle)

but apart from the above, genuine pre - 65.

Not mocking but how do you define "genuine" ?