Search found 65 matches
- 26 Jan 2021, 6:41pm
- Forum: Bikes & Bits – Technical section
- Topic: Hub gear, front derailleur
- Replies: 55
- Views: 2084
Re: Hub gear, front derailleur
Shimano recommend that the ratio of chainwheel teeth to sprocket teeth should be about 2 or more. The smallest chainring is likely to give you a ratio much lower than this, which runs a risk of stripping sun pinions in the hub from the extra torque applied.
- 5 Jan 2021, 3:40pm
- Forum: Bikes & Bits – Technical section
- Topic: Converting a deraileur bike to use a Rohloff hub
- Replies: 31
- Views: 1323
Re: Converting a deraileur bike to use a Rohloff hub
Thanks. Actually, I doubt whether many of the light-fingered community would want to nick a Rohloff as they wouldn't recognize it if it hit them on the head - unless they thought something so bulky was an electric motor . . . but I'd hate to lose it.
- 5 Jan 2021, 10:29am
- Forum: Bikes & Bits – Technical section
- Topic: Converting a deraileur bike to use a Rohloff hub
- Replies: 31
- Views: 1323
Re: Converting a deraileur bike to use a Rohloff hub
The advice I'd give is download the manual to find out what you need for your frame to take a Rohloff - and go for it. I had a second-hand hub with a disc, which needed a bit of work to fit into the frame (a late 80s Super Galaxy - see pic). IMG_20190113_135827.jpg It's a bit nervy if you have to wo...
- 29 Dec 2020, 12:10pm
- Forum: Bikes & Bits – Technical section
- Topic: Steel handalbars
- Replies: 10
- Views: 699
Re: Steel handalbars
Alloy bars are much more likely to break from fatigue at highly stressed points e.g. abrupt changes of diameter close to the stem - and you may get little warning becuase the crack only grows quickly just before fracture. Steel is unlikely to fatigue at the stress on a handlebar - but if the corrosi...
- 29 Dec 2020, 12:04pm
- Forum: Bikes & Bits – Technical section
- Topic: Rear derailleur for 6-speed freewheel
- Replies: 5
- Views: 326
Re: Rear derailleur for 6-speed freewheel
Old flat bar-mounted Shimano thumb shifters had a lever that enabled a switch to friction mode, which can be useful if your block hasn't Shimano-compatible spacing.
- 29 Dec 2020, 11:58am
- Forum: Bikes & Bits – Technical section
- Topic: Pashley rear wheel
- Replies: 15
- Views: 590
Re: Pashley rear wheel
For replacing the spoke, the tool you need is the Spocalc spreadsheet on the Sheldon Brown site, if you can measure the hub and rim, to get the right length.
- 12 Nov 2020, 9:34pm
- Forum: Electric bikes
- Topic: Panniers that fit onto battery racks?
- Replies: 4
- Views: 285
Re: Panniers that fit onto battery racks?
My wife had this problem, but sorted it out with an extra rack that fitted on top of the battery rack, bought from Wisper (Wisperbikes.com) - it's Dutch, not purely for e-bikes - a bit of a faff to fit, and extra weight, but it does the job.
- 14 Sep 2020, 9:52pm
- Forum: Does anyone know … ?
- Topic: SAMEBIKE L026 (folding e-bike 500 watt)
- Replies: 4
- Views: 363
Re: SAMEBIKE L026 (folding e-bike 500 watt)
A 500W motor will take twice as much juice as the 250W road-legal maximum, and so if ridden on full power a small battery might run out after not very far - how many Ah is the battery, and what is the voltage (multiplied, they give the total energy stored in Watt-hours)? On the principle that you ge...
- 14 Sep 2020, 9:44pm
- Forum: Does anyone know … ?
- Topic: Northern rail folding bike options?
- Replies: 18
- Views: 608
Re: Northern rail folding bike options?
I'm 6'5" or so, and have a 26" folder - an ancient Phillips (Dahon rebadged), which does just about fit in the new Northern rolling stock without obstructing the gangway too much on a train that isn't crowded. The seatpost is at the max and the reach shortish, and so I'm not sure that you'...
- 24 Jan 2020, 8:28pm
- Forum: Bikes & Bits – Technical section
- Topic: Swarf from rim
- Replies: 9
- Views: 547
Re: Swarf from rim
Thanks all. Fortunately things are nowhere near bad enough to worry about rim thickness - that's what I'm trying to avoid before it's too late. I've ordered some Koolstop blocks, and have done the other things advised. The rims were indeed machined, which I guess could initiate the problem (though t...
- 23 Jan 2020, 11:26pm
- Forum: Bikes & Bits – Technical section
- Topic: Swarf from rim
- Replies: 9
- Views: 547
Swarf from rim
One side of my front rim (Ryde Sputnik, a year old) is continually shedding swarf into the brake block. The other side did so when new, but I've had little further trouble since I changed the blocks for ones I thought were softer, and rubbed the rim gently with fine abrasive paper. I've dug the meta...
- 12 Jan 2020, 7:52pm
- Forum: Electric bikes
- Topic: Couple of newbie questions.
- Replies: 11
- Views: 764
Re: Couple of newbie questions.
P.S. Should have said that what matters about the motor, if putting force through your foot is the problem, is the Torque it delivers, i.e. the turning force it develops - the more, the better. Since power = torque x speed of rotation, you'd just be losing top speed (but then, the motor has by law t...
- 11 Jan 2020, 6:23pm
- Forum: Bikes & Bits – Technical section
- Topic: Sachs Super 7/Sram Spectro S7 hub; No Future?
- Replies: 15
- Views: 1895
Re: Sachs Super 7/Sram Spectro S7 hub; No Future?
I rode one for about five years till I wrecked it by forgetting to fasten the reaction arm for the back-pedal brake after a tyre change (doh). I was very happy with it - only once mis-behaved - on a Saturday afternoon in rural Northumberland - but soon sorted itself out. Changing the cable at the cl...
- 11 Jan 2020, 5:55pm
- Forum: Electric bikes
- Topic: Couple of newbie questions.
- Replies: 11
- Views: 764
Re: Couple of newbie questions.
Important to distinguish power from force : I guess your foot hurts if you put too much force/weight on it: power is the rate of doing work, which is different, and only partly relevant to your problem. You could minimize the force you put through your painful foot by (a) using a cadence-sensor bike...
- 26 Nov 2019, 4:28pm
- Forum: Bikes & Bits – Technical section
- Topic: How do I tighten this bottom bracket?
- Replies: 15
- Views: 1115
Re: How do I tighten this bottom bracket?
Update: I took the chainring off, and it seems that it also engaged with more splines co-axial with the BB axle, which presumably connects it to the torque sensor inside. The play presumably comes from there, so I doubt if it matters - the chainring itself doesn't show signs of wear where it engages...