Brompton 3 or 6 gears
- Thread starter Rebelsurfer
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Kell
Veteran
- Location
- High Wycombe/London
It is pretty steep.
Last edited:
berlinonaut
Veteran
- Location
- Berlin Germany
Just klick on the links in my last post.
My top speed with a Brommi on a descent was somewhat north of 70kph (the person behind my had a speedometer and stopped keeping up with me at 68kph as he considered it to be too frightening while I was accelerating further). I did not feel unsafe in any way and neither did the bike. Obviously if anything unforeseen happens at that speed you are probably doomed. But this would be the same with any other bike. Downside at this speed is that the downhill part of the journey is gone quickly, especially compared to uphill part.
Kell
Veteran
- Location
- High Wycombe/London
I only meant it felt unsafe to pedal beyond around 25 mph as your legs are moving so quickly it upsets the balance of the bike.
And as Bromptons are fairly twitchy anyway, it feels more stable to coast and let gravity do the hard work.
Obviously after that speed, I keep on accelerating.
There’s a guy I see on my train that was pedalling furiously down the same hill on a hybrid bike with 27 gears and couldn’t believe it when I coasted past him on my Brompton.
But then I did point out to him that gravity was definitely pulling down harder on me than him given i’m nearly 16 stone and he’s about 12.
Funnily enough, he always beats me back up the hill.
And as Bromptons are fairly twitchy anyway, it feels more stable to coast and let gravity do the hard work.
Obviously after that speed, I keep on accelerating.
There’s a guy I see on my train that was pedalling furiously down the same hill on a hybrid bike with 27 gears and couldn’t believe it when I coasted past him on my Brompton.
But then I did point out to him that gravity was definitely pulling down harder on me than him given i’m nearly 16 stone and he’s about 12.
Funnily enough, he always beats me back up the hill.
Handlebar Moustache
Well-Known Member
- Location
- Scotlandia
Just klick on the links in my last post.
My top speed with a Brommi on a descent was somewhat north of 70kph (the person behind my had a speedometer and stopped keeping up with me at 68kph as he considered it to be too frightening while I was accelerating further). I did not feel unsafe in any way and neither did the bike. Obviously if anything unforeseen happens at that speed you are probably doomed. But this would be the same with any other bike. Downside at this speed is that the downhill part of the journey is gone quickly, especially compared to uphill part.
They do say that you have to be careful braking a Brompton on long downhill stretches as you can heat up the brakes (and more importantly the rims) to dangerous temps. But in your case you weren’t braking so it’s fine
berlinonaut
Veteran
- Location
- Berlin Germany
They do say that you have to be careful braking a Brompton on long downhill stretches as you can heat up the brakes (and more importantly the rims) to dangerous temps. But in your case you weren’t braking so it’s fine
Oh I was, as there were a couple of turns in the descent, some of them massive ones. I think the danger is overrated - it is mainly a question of braking technique. If you stand on the brakes on a longer descent the rim will heat up and in the worst case the tube may blow. If you let it roll and push the brakes only from time to time but push them hard then nothing will happen as the the rim will not heat up as much plus the heat can go in between the break intervals. In that sense on a Brommi a quick descent is safer than a slow one.
Kell
Veteran
- Location
- High Wycombe/London
I must admit, in all my years of cycling I’d never heard of that until I had a blow out coming down the same hill at about 30mph. (But then I came from an MTB background so long stretches of braking were more likely to lock your wheels than overheat anything.)
Luckily, the Marathon Plusses are quite rigid so I was able to stay on.
Other people suggested it could have been a build up of heat. In actual fact it turned out to be a badly adjusted front brake.
From a visual check, the pads hit the rims exactly where I wanted them to, but one of the callipers was loose, so under extreme braking it would swing forward and rub the tyre.
Luckily, the Marathon Plusses are quite rigid so I was able to stay on.
Other people suggested it could have been a build up of heat. In actual fact it turned out to be a badly adjusted front brake.
From a visual check, the pads hit the rims exactly where I wanted them to, but one of the callipers was loose, so under extreme braking it would swing forward and rub the tyre.
mitchibob
Über Member
- Location
- Treorchy, Wales
Super firm suspension. No issues spinning at 130+ rpm.
