Front wheel offset

Previously richard_norris wrote:

The front rim on my 1963 frame is offset to the right, I only noticed it recently after some years wondering why the bike didn't steer as perfectly as I expected. I fitted a TLS brake c/w hub some years ago from Norvil (works well). The rim needs to be about 1/4 in to the left. I see from an earlier thread that there should be an offset - can an expert help here? I am reluctant to fit a spacer and wonder whether the rim should be dished to centralise it?

Thanks, Richard

The front wheel needs to be aligned to the steering head axis. One method of doing this is to remove the front tyre and accurately mark the centre of the rim. If the steering column is hollow, then a straight, pointed bar, of suitable dia. to give a sliding fit, can be passed through the stem. The point of the bar is the datum to align the rim to, either by use of spacers to move the wheel or, if the difference is in the region of 0.10", then by adjustment of the spokes.I should add, this is assuming the rim has the holes drilled at the correct angle to suit the hub and that the spokes are of the correct length. If in doubt contact http://www.devonwheelbuilding.com/.

I can recommend Doug, he's done a number of my wheels and is a member of Devon TRF.

dan

Previously simon_ratcliff wrote:

Previously richard_norris wrote:

The front rim on my 1963 frame is offset to the right, I only noticed it recently after some years wondering why the bike didn't steer as perfectly as I expected. I fitted a TLS brake c/w hub some years ago from Norvil (works well). The rim needs to be about 1/4 in to the left. I see from an earlier thread that there should be an offset - can an expert help here? I am reluctant to fit a spacer and wonder whether the rim should be dished to centralise it?

Thanks, Richard

The front wheel needs to be aligned to the steering head axis. One method of doing this is to remove the front tyre and accurately mark the centre of the rim. If the steering column is hollow, then a straight, pointed bar, of suitable dia. to give a sliding fit, can be passed through the stem. The point of the bar is the datum to align the rim to, either by use of spacers to move the wheel or, if the difference is in the region of 0.10", then by adjustment of the spokes.I should add, this is assuming the rim has the holes drilled at the correct angle to suit the hub and that the spokes are of the correct length. If in doubt contact http://www.devonwheelbuilding.com/.

Hi Simon,

Would a suitable alternative be to measure the gap between the edge of the rim and the inside of the fork slider ? Or is the diameter of the fork legs potentially different between the two ?

Tony

Previously Tony Ripley wrote:

Hi Simon,

Would a suitable alternative be to measure the gap between the edge of the rim and the inside of the fork slider ? Or is the diameter of the fork legs potentially different between the two ?

Tony

Hi Tony,

You'd be better off using the stanchions as a reference point as they are more accurately machined than the sliders. That said, I've never measured the fork yoke dimensions, so I don't know the accuracy to which they are made. The frame centre line goes through the steering head axis, so a bar with a pointer turned on the end and going through the steering stem tube is going to be very close to the frame centre line,

Regards,

Simon.

You can move the rim over to be central to the stanchions by loosening all the nipples on the low side 2 flats and then tightening all on the high side 2 flats, repeat until the wheel is central which on the last one I did on a B44 took 3 goes to move it 1/4". No need to send it to a rebuilder unless its not running true.

John is quite right. Truing a wheel is fairly simple - just requires patience. One thing to remember is that when you tighten spoke nipples, the end of the spoke can protrude into the wheel well and can cause a puncture if not filed flush.

a commando slider might make up the difference fitted to the brake side.

Hi...here is a way to measure it. For the front wheel: With the old rim removed....Fit the wheel hubassembly with its spacersand tighten as if fitting a complete wheel. Cut a 2" wide strip of thick cardboard that fit exactly between the forks andmeasure the distance...Now,.. say you are fitting a WM2 rim with 69mm width; Mark the centre of the cardbord strip and measure 69/2mm from this centre mark each side of it and once again mark the strip at these positions. The two marks will represent the rim edges ...(they should be equi-distant from the ends of the strip). This will be where you want the rim to sit. Hold the cardboard between the forks and flush with the rim of the the hub. Now using a chosen reference on the hub measure where in relation one of the rim position marks is. This will be the offset you require when building the rim. Usually the face of the brake drum is used by the wheel builder, so if you have used say the spoke flange to measure from the cardboard, when you remove the hub assembly you will simply re position the cardboard strip where it tallied up before and then re measure and adjust your offset measurement to correspond to the brake drum face...This will be the rim offset to the brake drum face.For the rear wheel, this is not so easy as often swing arms are not always equal distance from the bikes centre line, although some are!.So, as before fit the rear wheel hub axle assembly pushing it all the way forward in the slots and make sure hub is directly facing forwards and not skewed to the side. Tape a bar or piece of wood across the frame directly above the rear hub. I would then use a laser line and shine this down the bikes top frame tube or use a straight edge then mark the wood cross piece's centre. Make sure the bike is level and drop a plumb-line down from this centre mark to the hub and mark with a felt tip pen this position on the hub...Remove wheel assembly. The mark will represent the centre of the bike on the rear hub position. Then using the cardboard measure used previously you can line up the centre of the 69mm cardboard marks to find where the edge of the new rim should be. Use a convenient flat edge on the hub and measure to the cardboard mark on any side you choose. Note the distance ...This will be the rear wheels offset for your wheel builder....Les