4

I have a hybrid-style bike (Dawes Discovery 301) with a Shimano Alivio/Deore gearset.

After a recent ride I noticed that the light-coloured t-shirt I was wearing had been speckled with oil around the stomach area (and nowhere else). I later gave the bike a thorough clean, making especially sure that there were no traces of oil around the handlebars, headset and front derailleur.

However, on the next ride the same thing happened again, although to a slightly lesser extent. After cleaning the bike a couple more times the issue still occurs, so the oil appears to be squirting up from somewhere, but I don't know where.

I've had this bike a couple of years but hadn't noticed this issue before as I usually always wear a dark-coloured top when going for a ride. After inspecting the black jacket I often wear, I can see that it does have some oil stains speckled around the same area that my t-shirt was stained. So this has probably been happening for some time and I just hadn't noticed it before...

Does anyone know what might be happening here and how I can stop it?

5
  • 2
    Was it wet out? Oct 6 at 17:34
  • Can you smell the oil on the shirt? Does it smell like hydraulic fluid or chain oil?
    – Criggie
    Oct 6 at 21:47
  • Do you have a dirty filthy black chain? Does the colour of the shirt oil match the chain or is it lighter and cleaner ?
    – Criggie
    Oct 6 at 21:47
  • Do your hydraulic brakes work well? Or are they soft and spongy? If this leak has been happening for a while from the brakes, the braking performance should have dropped over time.
    – Criggie
    Oct 6 at 21:49
  • Does your bike have fenders, if not and the oil is from the road surface thrown up by the wheels there should be some on your back as well.
    – Carel
    Oct 7 at 9:18
6

The most common places where there is a chance of liquid oil getting out in bicycles are: suspension fork, rear damper, and hydraulic brakes.

The bike you mention, however, does not have suspension, but does have hydraulic brakes. Could that be brakes? Have you noticed any change in braking action recently?

Another possibility is that the contamination is actually coming from the road you ride. If your bike does not have a front fender, the road moisture and dust will be thrown by the rotating front wheel upwards towards your body.

In my opinion, it is much more likely that what you see is the result of riding (even slightly) dirty or dusty roads without a full front fender.

5

The key is to identify the source of the oil.

Some Dawes Discovery 301s have V brakes and others have hydraulic. If you have hydraulic brakes it's possible the oil could be coming from your brakes but it's unlikely to have been happening over the length of time described without noticing a reduction in braking power.

It's difficult to say with accuracy based on the description but there are two places most likely to splatter oil.

  1. The chain
    An overly oily chain can splatter oil. I can't think of a time when I've seen an oily chain splatter onto the rider's stomach so this seems unlikely. Apply lube sparingly and wipe down your chain with a rag to prevent splatter.
  2. The road
    Oil is used to treat roads and oil is dripped by cars onto the road and can be picked up by the front tire and splattered on the rider's stomach. Oil picked up by the rear tire can be splattered on the rider's back.
    The times I've ridden through oil the main area of splatter on the bike was the bottom of the down tube and the back of the seat tube.

enter image description here

If the oil is from the road the only way to keep the oil off of you is to avoid those sections of road. Every rider should be road aware - pay attention to what you are riding on so that they can avoid road hazards and pick the best path for the tires. It takes some practice to be able to safely shift your attention around your environment to watch all the things you need to keep track of.

An oily road is not only messy it's also dangerous for bicyclists. Oil can be very slippery.

3
  • Excellent idea about an environmental source. If OP has access tp a different bike, go for a ride on the same route wearing a clean white/light shirt and see what happens. Or pin a piece of scrap cloth in the same place to catch any oils.
    – Criggie
    Oct 6 at 21:51
  • Or wrap the bike tubes in white cloths to localize it to different sources.
    – Dave X
    Oct 7 at 16:29
  • My money is on spilled oil, fuel (diesel) or hydraulic fluid leaking from a roadworks machine. A chain throwing oil to the front of a T for two days is unlikely, you'd rather get it up the back, by the way the chain runs.
    – Carel
    Oct 8 at 19:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.