Search found 43 matches

by asinus
20 Apr 2019, 6:59pm
Forum: Electric bikes
Topic: Trike Conversion
Replies: 3
Views: 319

Re: Trike Conversion

Has anyone converted a Mission Tribrid? I ask because the unassisted version looks good - only 25 kg, 700C wheels, disc brakes, 21 gears (though a bit high), differential even - but Mission advise against. Alternative might be ready made up e.g. Jorvik Odin which has a differential and seemingly goo...
by asinus
14 Oct 2018, 6:55pm
Forum: Bikes & Bits – Technical section
Topic: hi, Nexus seven hub changing the rear sprocket from 21t to 16t
Replies: 13
Views: 570

Re: hi, Nexus seven hub changing the rear sprocket from 21t to 16t

Changing to a 16T sprocket will take the direct drive ratio to 2.6, above the manufacturer's recommendation, but it doesn't matter really if it's too high: it's too low a ratio that makes it more likely that the teeth on the sun pinions in the gear hub will strip. I guess the question of the bottom ...
by asinus
5 May 2018, 4:05pm
Forum: Bikes & Bits – Technical section
Topic: How does a rack like this fit a bike?
Replies: 24
Views: 1599

Re: How does a rack like this fit a bike?

The Tubus is a goood solution for some, but I wonder whether a solution that would fit more bikes, including those with rear suspension, would be a seatpost-clamped rack held in position by a brace clamped onto the top tube: it should Not rotate be able to carry more (e.g. up to 25 kg) be easy to pu...
by asinus
2 May 2018, 8:42pm
Forum: Bikes & Bits – Technical section
Topic: How does a rack like this fit a bike?
Replies: 24
Views: 1599

Re: How does a rack like this fit a bike?

To be fair, how high they are depends on frame size: on a small MTB frame the may have to be mounted up the seatpost to clear the rear wheel. There are some with a crank in the beam to make it lower than the mount, and Axiom make an invertible beam to vary the height. Some are also length-adjustable.
by asinus
1 May 2018, 9:23pm
Forum: Bikes & Bits – Technical section
Topic: How does a rack like this fit a bike?
Replies: 24
Views: 1599

Re: How does a rack like this fit a bike?

The British Standard (BS EN ISO 11243:2016) limits beam racks that aren't attached to the frame as well to 10 kg (it's 27 kg for rear racks that are attached to the frame, but only 10 again for racks above the front wheel). Interestingly, it doesn't go into the relation of the load to the position o...
by asinus
27 Apr 2018, 12:32pm
Forum: Bikes & Bits – Technical section
Topic: Raleigh Pioneer seatpost
Replies: 9
Views: 646

Re: Raleigh Pioneer seatpost

Should have added that mine is a microadjustable alloy one.
Edmund
by asinus
26 Apr 2018, 11:47pm
Forum: Bikes & Bits – Technical section
Topic: Raleigh Pioneer seatpost
Replies: 9
Views: 646

Re: Raleigh Pioneer seatpost

I have a 1998 Pioneer and the seatpost is stated to be 26 mm. Hope this helps.
Edmund
by asinus
12 Feb 2018, 10:39am
Forum: Bikes & Bits – Technical section
Topic: Beam racks
Replies: 8
Views: 415

Re: Beam racks

Thanks again all. The Arkel soves the problem of rotation, but only has a maximum load of 6 kg, consistent with its light weight, and like other beam racks increases the backwards bending moment on the seatpost, which may be a limiting factor on all such designs. For maximum utility, something that ...
by asinus
11 Feb 2018, 9:32pm
Forum: Bikes & Bits – Technical section
Topic: Beam racks
Replies: 8
Views: 415

Re: Beam racks

Thanks both. The impetus is actually an Open University project, but I guess that what I'd like to achieve is the ability to carry something like a touring load on bikes that can't take a regular rack, or where a rack needs to be demounted easily e.g. for packing for flight (or Eurostar - or even No...
by asinus
11 Feb 2018, 3:38pm
Forum: Bikes & Bits – Technical section
Topic: Beam racks
Replies: 8
Views: 415

Beam racks

Looking at previous posts, I see the problems of weight. limited load, damage to seat-posts and there's obviously the potential for rotating around the seat post. I've also had problems with vibration - due to a rubber insert to fit it to the seat-post possibly. Anyone come across any ways to mitiga...
by asinus
22 Nov 2017, 5:07pm
Forum: Electric bikes
Topic: What's best for a hilly area?
Replies: 10
Views: 1065

Re: What's best for a hilly area?

Another question, about crank drives: may have tiny chainwheels, so what are they like to pedal if either (heaven forbid) you run out of battery, or turn it off to conserve it e.g. on a long run? Are you left turning a ludicrously low gear, or does the drive go through and internal gear train with c...
by asinus
18 Nov 2017, 8:54pm
Forum: Electric bikes
Topic: What's best for a hilly area?
Replies: 10
Views: 1065

Re: What's best for a hilly area?

Quite - it's a big worry. My wife has a long Abus Sold Secure chain that's so heavy that needs a pedelec to transport it, and would hope to put that round a fence-post or tree.
by asinus
17 Nov 2017, 4:14pm
Forum: Electric bikes
Topic: What's best for a hilly area?
Replies: 10
Views: 1065

Re: What's best for a hilly area?

Thanks - but the problem is more about keeping going at maybe 6 mph up a long 1in 7 (or steeper) hill.
by asinus
12 Nov 2017, 11:21pm
Forum: Electric bikes
Topic: What's best for a hilly area?
Replies: 10
Views: 1065

What's best for a hilly area?

Living in North Lancashire, a pedelec that climbs steep and long hills well would be useful - for instance, for getting up to the start of a hill walk. Is there any decent information about what type might be best? Crank or hub drive? Presumably torque rather than cadence sensor. Any advice on geari...
by asinus
11 Nov 2016, 9:27pm
Forum: Bikes & Bits – Technical section
Topic: Alternate ways of mounting front lights
Replies: 21
Views: 1877

Re: Alternate ways of mounting front lights

There's a simple low-cost way of doing this - bolt a piece of old handlebar to the reflector bracket as in the picture. Much better than spacebar IMO, as it doesn't get in the way of turning the bike upside down.