Wheel Slip

[The Jogger]

Hi
I want to get my brommie back out on the roads, the trouble is (or not really) I now live in a mountain village in Spain and when I cycle up the steep roads, the back wheel slips. What would the problem be and how can I correct it? Thanks
Jogger

 

[wafter]

What do you mean "slips" - the wheel slips on the road or, the chain jumps on the cassette..?

 

[rafiki]

The chain is likely stretched/sprocket worn. Use a chain wear tool to check the chain stretch. Inspect the sprocket for wear. Less likely but check the number of links on your chain against the Brompton chain size table.

Also make sure the chain is clean and lubricated and if it has been stored for a while there are no seized links.

 

[Sharky]

Are you getting out of the saddle to climb steep hills?
Transfer of weight to over the front wheel could cause the rear wheel to slip.

I get that with one particular steep hill and when it is a bit damp on the road.

If this is the problem, try using your lowest gear and remain seated for as long as possible.

 

[The Jogger]

What do you mean "slips" - the wheel slips on the road or, the chain jumps on the cassette..?

Sorry, the tyre on the road is what's slipping. It has plenty of tread on it.

 

[The Jogger]

Are you getting out of the saddle to climb steep hills?
Transfer of weight to over the front wheel could cause the rear wheel to slip.

I get that with one particular steep hill and when it is a bit damp on the road.

If this is the problem, try using your lowest gear and remain seated for as long as possible.

Yes, I have to get out because of the steepness.

 

[wafter]

Sorry, the tyre on the road is what's slipping. It has plenty of tread on it.

In that case, this:

Are you getting out of the saddle to climb steep hills?
Transfer of weight to over the front wheel could cause the rear wheel to slip.

I get that with one particular steep hill and when it is a bit damp on the road.

If this is the problem, try using your lowest gear and remain seated for as long as possible.

Sounds like you might need a lower gear if you can't maintain a steady pace seated. Of small value might be to try to keep your pedal strokes as smooth as possible if having to climb out of the saddle, but really you want to be seated if possible to keep some mass over the rear wheel. Can confirm from experiences on my local 13% gravel hill with moderate load in the panniers (which actually might help a bit ).

 

[sevenfourate]

If at a standstill you Rev the engine to approx 7’000 rpm and literally dump the clutch - you can get the wheels ‘slipping’ and sometimes smoking: at every junction. It’s great fun 🚗

***Sorry: completely wrong forum 😉

 

[Sharky]

One minor tweak. How firm is the rear tyre. Lowering pressure could give you more grip.

 

[presta]

If you're having difficulty putting enough force on the pedal without getting out of the saddle, try lifting your bum off the saddle without changing position and moving your centre of gravity forward too much.

I lowered my bottom gear from 25.7" to 17.8", and it was a bit of a mixed blessing. Yes, it's easier to get enough torque on the pedals whilst you're moving, but if you stall on the hill it's harder to restart. The problem is that during the initial pedal stroke you have less time to get your other foot on the pedal, less speed to balance with, and any temptation to lunge at it to obtain some momentum just pulls a wheelie.

 

[u_i]

Is your Brompton a 6sp one? For steep hills even 6 gears are not sufficient. Conversions to more speeds require either significant financial investments or serious mechanical skills.

 

[wafter]

You could potentially look to reduce the overall gearing by fitting a smaller chainring..

 

[T4tomo]

This isnt a brompton issue, if you are out of the saddle on very steep hill on most bikes, you unweight the backend so much the rear tyre loses traction.

lower gearing and seated climbing is the answer.

 

[ExBrit]

This isnt a brompton issue, if you are out of the saddle on very steep hill on most bikes, you unweight the backend so much the rear tyre loses traction.

lower gearing and seated climbing is the answer.

I live in mountains and had the same problem. My solution was a 44 tooth chainring (have to replace the guard too). Also clip-in pedals (I use SPD) to allow you to deliver smoother power.