Search found 666 matches

by rfryer
26 Apr 2013, 1:00pm
Forum: Bikes & Bits – Technical section
Topic: eliptical chainring - want to try one?
Replies: 61
Views: 8462

Re: eliptical chainring - want to try one?

Surely some mistake - you don't get the ball of your foot underneath the pedal, do you? :shock:
by rfryer
25 Apr 2013, 12:29pm
Forum: Bikes & Bits – Technical section
Topic: slowing down on hills - some 'O' level physics
Replies: 70
Views: 2796

Re: slowing down on hills - some 'O' level physics

To ride up a cone, and freewheel down the other side, requires the same energy as riding round half its base circumference, if the angle is 4%. Less steep, more efficient to ride up and over. More steep, more efficient to ride round. :wink: Interesting. Though it's presumably speed-dependent - if y...
by rfryer
25 Apr 2013, 11:44am
Forum: Bikes & Bits – Technical section
Topic: eliptical chainring - want to try one?
Replies: 61
Views: 8462

Re: eliptical chainring - want to try one?

To me, "nice circles" mean that you are spinning with (what feels like) a continual forward pressure on each crank, and with smooth variations in that pressure. I've been using Rotor Q-rings on my road bike for the last year or so. I found the most noticeable difference to the pedalling ac...
by rfryer
24 Apr 2013, 11:42am
Forum: Bikes & Bits – Technical section
Topic: Shimano Alfine 11 - Longer term reliability
Replies: 754
Views: 156234

Re: Shimano Alfine 11 - Longer term reliability

There's been a lot of talk about deviation from Shimano's suggested input ratio of 1.9 having the potential to cause problems, presumably because running a lower ratio allows the rider to put more torque through the hub. But then manufacturers are freely building bikes with lower ratios than that, o...
by rfryer
22 Apr 2013, 7:49am
Forum: Bikes & Bits – Technical section
Topic: Tyre pressures.....
Replies: 39
Views: 1879

Re: Tyre pressures.....

Thanks to Reohn2 for starting this thread, and posting the link to Cycling Quarterly. As a consequence, I increased my tyre width (from 23 to 25) and dropped the pressures (from 110 to 70/95) on my road bike. I rode a sportive on this setup yesterday, and the ride was significantly smoother, and I f...
by rfryer
20 Apr 2013, 9:01am
Forum: Bikes & Bits – Technical section
Topic: bike positioning help please
Replies: 93
Views: 175044

Re: bike positioning help please

If you're pushing back onto the saddle, you might consider lifting the nose at the same time as moving the saddle back?
by rfryer
17 Apr 2013, 8:11am
Forum: Bikes & Bits – Technical section
Topic: Shimano Alfine 11 - Longer term reliability
Replies: 754
Views: 156234

Re: Shimano Alfine 11 - Longer term reliability

@rfryer: looks like the genesis cable end bolt is from an alfine 8. the 8 shifts to a higher gear as the cable tightens, and the cable wraps clockwise around the cassette joint. The 11 shifts to a lower gear as the cable tightens and wraps anticlockwise around the cassette joint. Hence the bolts ar...
by rfryer
16 Apr 2013, 10:24am
Forum: Bikes & Bits – Technical section
Topic: Double Chainring & low Gearing
Replies: 36
Views: 3366

Re: Double Chainring & low Gearing

I'm very happy that you (reohn2) get on with triples so well. My experience with Ultegra has been less rosy. It worked OK initially, but then I replaced the inner and middle chainrings to lower the gearing, and thereafter the shifting was much less clean, to the extent that I was adjusting the cabl...
by rfryer
16 Apr 2013, 8:02am
Forum: Bikes & Bits – Technical section
Topic: Double Chainring & low Gearing
Replies: 36
Views: 3366

Re: Double Chainring & low Gearing

No, I've not ridden the classic French cols on a double. I have ridden classic UK climbs, up to 1 in 3 gradient, on both a triple and a compact double with WiFli. Maybe there's a disconnect, in that by "double" you think I mean a traditional road racing double, which is invariably geared v...
by rfryer
15 Apr 2013, 11:57pm
Forum: Bikes & Bits – Technical section
Topic: Double Chainring & low Gearing
Replies: 36
Views: 3366

Re: Double Chainring & low Gearing

Without wishing to flog a dead horse... :D I'm very happy that you (reohn2) get on with triples so well. My experience with Ultegra has been less rosy. It worked OK initially, but then I replaced the inner and middle chainrings to lower the gearing, and thereafter the shifting was much less clean, t...
by rfryer
15 Apr 2013, 11:28am
Forum: Bikes & Bits – Technical section
Topic: Double Chainring & low Gearing
Replies: 36
Views: 3366

Re: Double Chainring & low Gearing

There must be something wrong with you're set up. I've been riding triples on solos and tandems for 20years,6,7,8 and 9sp with d/tube,b/ends/kelly's/MTB and road STI's without any issues.yes I've had the odd problem,mainly overshooting the granny ring,which has been cured with an N-gear Jumpstop. T...
by rfryer
15 Apr 2013, 10:11am
Forum: Bikes & Bits – Technical section
Topic: Double Chainring & low Gearing
Replies: 36
Views: 3366

Re: Double Chainring & low Gearing

I've nowhere near the touring experience of Gearoidmuar, but I've cycled a lot of hills and passes, mainly in the UK but some abroad too. My experience of triple chainsets has been sketchy - I've found them a pain to get shifting smoothly and reliably. I'm hoping to be convinced otherwise when Shima...
by rfryer
12 Apr 2013, 3:23pm
Forum: Bikes & Bits – Technical section
Topic: Shimano Alfine 11 - Longer term reliability
Replies: 754
Views: 156234

Re: Shimano Alfine 11 - Longer term reliability

The "top hat" cable stop doesn't provide any waterproofing - it's in no way a tight fit. The Shimano part is soft rubber, and seals tightly against the ferrule. The main exposure to leakage seems to be the hole where the cable exits the bellows, and my hope is that it's a pretty small expo...
by rfryer
12 Apr 2013, 11:40am
Forum: Bikes & Bits – Technical section
Topic: Chainset for mountain-climbing
Replies: 12
Views: 878

Re: Chainset for mountain-climbing

And there aren't any mountain roads in the UK. Just hills. I did try not to bite, honest I did! It all depends on how you define mountain roads, I suppose. True you won't find any sustained 1000m climbs in the UK . But you'll find some decent sustained ascents (such as the Bealach na Ba at 626m) an...
by rfryer
12 Apr 2013, 11:27am
Forum: Bikes & Bits – Technical section
Topic: Double Chainring & low Gearing
Replies: 36
Views: 3366

Re: Double Chainring & low Gearing

I once bodged a road bike for a particularly hilly sportive. It has an Ultegra compact double setup on it. I just replaced the double chainset with a road triple. I couldn't get hold of any spacer washers, so I just slapped a second middle chainring on the outside, and had a 26-tooth granny ring. I ...