Bayliss axle and chainline

[Uncle Monty]

Late last year I bought a 1954 Hetchins. I am trying to sort out the drivetrain and need some help. It came with duprat cranks fitted with double Simplex rings, 70s Simplex shifter and rear mech and a 12-28 five speed block. The chainring bolts were kissing the chainstay and the axle was loose. Adjusting the cups worsened the fouling and the axle would alternate between loose and tight when rotated. I removed a very worn #23 125mm hollow axle and fitted a nos #14 129mm. Classic lightweights list both as being for single rings, but I supposed the extra 4mm would cure the clearance issue without affecting chainline too much. Couldn't find a # 23 at the time either.
Reassembled, the chain when on the smaller ring is only aligned on the third cog. Large ring to third cog looks awful. Is this normal? The misalignment looks more exagerated than I would have thougt a four mm increase in axle length would have caused. BB stills feels awful so I think the cups are shot.
The rear mech is on a dropout bracket, the original Simplex hanger having been cut off the frame. I am assuming the cranks, chainrings, axle and hub are all original. Could it originally have been single ring and three or four speed? Are four speed blocks evenly spaced in the gap between hub flange and dropout face or biased towards the flange?

Any ideas? Chris.

 

[lewisfoto]

Yes it is possible that it was meant for 3 or 4 speed drivetrain, although if the rear spacing is 120 then a five speed should fit fine. Maybe your issue doess lie in the bottom bracket itself? The clearance issues with the old set up could have been created by the worn out parts and so when you went with the longer spindle then the chain line was thrown off?

Just a guess.

Steen

 

[Uncle Monty]

Re:

It is possible. I think I might put the worn axle back in and check everything again. I had to straighten the three arms on the cranks once fitted. Wheels next. Hub centres are rusty, so I could split them and have them rechromed. Spokes are rusted to hell. Rims are Dunlop lightweight. Not a box rim, so again they could be stripped and chromed, but they do have some nasty dings in the sides. You have to ask yourself is it worth it. Trouble is it is very easy to start just throwing stuff away which was not my intention at the outset. I am toying with fitting the original type Simplex deralieur and shifter, returning the bike virtually to its possible original spec. I have given up on the idea of this being 100% practical and accepted that it requires more in the way of a restoration than a clean up.

 

[keithglos]

Re:

The first chainset I fitted that didn't need truing was campagnolo in 1958.
The Duprat cranks I remember were French size, 9mm cotters and a bit loose on a british axle. If yours are french then a continental axle might do. Surely you should replace the bracket cups.

I doubt if rechroming old Dunlop steel rims is likely to be successful, apart from dents there will be wear on the brake surfaces.
Keith