Puncture Repair on a Full Plastic Chaincase Dutch Bike
Try to carry out a rear wheel puncture repair with wheel still on the bike if possible. Getting the rear wheel off one of these hub gear Dutch bikes is fiddly and takes time.
This was done on a Puch Brilliant with an 8 speed Shimano Nexus and a plastic chaincase, but I guess the operation will be similar for many modern designs.
It was a new technique and I knew I needed to learn how to do this, because I can venture far from home with no means of getting me and the bike back again if I get a flat tyre. There were a few internet posts on how to do it but nothing that was totally comparable from beginning to end. I was procrastinating and didn’t fancy “fixing what’s not broken” by taking the wheel off for the sake of it. But my “learning opportunity” came this weekend with a slow puncture! As the cause couldn’t be seen, the only way was to get the tube out altogether. So it was going to be a question of getting stuck in and learning as I went along.
The job was not as difficult as I’d feared but it was time consuming first time round. It’s not rocket science at all, but it does need commonsense and patience.
You really wouldn’t want to try this first time at the roadside, but it was OK in a dry, well lit, safe garage. And I figured this was the time and place to learn, particularly as there was no rush.
Tools you need for the wheel removal / refitting : a 10mm ring spanner, a 15mm ring spanner, a spike, about 3” of wire from a steel coathanger, a cross head and a flat head screwdriver.
Tools you need for the puncture repair itself : some chalk, tyre levers, some tweezers, a patch and glue, sandpaper, crayon, a small woodworking clamp, a decent pump.
Assuming you can’t find the cause of the puncture, you’ll have to get the wheel off…
If you’re not confident, at each step take photos so you can see how things were at any stage.
OK, let’s start…
See my pictures onhttps://picasaweb.google.com/110055669501444994025/RearWheelRemovalWithAModernDutchBike which are organised by name, not by sequence. They are really intended to show the parts in detail, not to be a pictorial step by step guide.
Select 4th gear.
Put some cloths or cardboard down so the saddle and handlebars don’t get scratched, then turn the bike upside down.
Make a chalk mark on only one side of tyre and rim at the valve (so you can line up again later to find the projection once you’ve found the leak, and so you can refit the tyre and tube as they were).
Deflate the tyre.
Remove the chaincase – mine came in 4 sections. First, a rear section that slides out and also holds the top and bottom sections. The top and bottom sections unclip from each other at the front. The final section is attached to the frame and can remain on the bike.
Almost certainly you’ll have drum brakes. Release the brake cable – undo the 10mm nut holding it onto the cable, open the circlip on the other side, now the nut assembly can be moved into the larger hole and released. Loosen the screw on the frame mounting (you need 10mm spanner and a cross head screwdriver) and the adjustment nut can be jiggled out.
Release the gear cable – take 3” of coathanger wire, place it into the small round hole and move it round anticlockwise. Use a spike to pop the gear nut out of the housing.
Undo the chain tensioners with a 10mm spanner.
Loosen the wheelnuts. It’s 15mm, and you need to use a ring spanner not a socket spanner – the nuts are tall and shaped in a way that stops a socket spanner from fitting.
Take the chain off (it’s easier to get it off the large ring at front first)
The wheel should be able to be manoeuvred out backwards. The grey non turn washer is on the gear side (g=g!), the black non turn washer is on the brake side (b=b!).
Remove the tyre and the tube, fix the puncture, test your fix, remove any projections from tyre (this was why you marked it with chalk, so that you’ll know where to find the problem). If you have a spare tube, you could just put that in instead, and repair the original tube when you get home.
Refit the tyre and tube onto the wheel using the chalk marks. Use the tyre levers as little as possible to avoid pinching the tube. Reseat the tube and pump it up to test it.
Deflate the tyre again to get the wheel back into its dropouts, and be sure the tensioners are fitted to the inside. (You won’t get the tyre in place if it’s inflated because it will be slightly too large).
Refit the non turn washers and reinflate the tyre fully.
Tension the chain, aiming for around ¼ inch play at the loosest part.
Finally refit the wheel nuts and tighten them (do not do this before tensioning the chain, as tight wheel nuts will make it impossible to adjust the tensioners properly)
Refit the gear cable and the brake mount and cable (which is pretty much the reverse of getting them off).
Refit the chaincase
Test the rear brake
Trim the gear adjustment (so the yellow dots line up in 4th gear)
Road test the bike.
Have a well deserved cup of tea.
And that’s it. I feel much more confident about doing this again. I’ve posted this partly so I’ve got something to remind myself what to do, partly so others can see what to do, and partly to give people who know more than me an opportunity to explain why they disagree with my method.