Search found 495 matches

by bobc
29 May 2017, 11:23am
Forum: Bikes & Bits – Technical section
Topic: Disc brake fitting
Replies: 13
Views: 2266

Re: Disc brake fitting

Be very thankful you found this in safe circumstances. Potentially lethal manufacturing error by the sound of it.
Hopping mad is well understated....
by bobc
26 May 2017, 12:17pm
Forum: Bikes & Bits – Technical section
Topic: Raleigh strada 4 belt drive problems
Replies: 6
Views: 1553

Re: Raleigh strada 4 belt drive problems

My "belt drive" experience has been overwhelmingly positive, but not much help seeing as I made all the parts except the belt myself. I have a colleague at work who has run a gates "centretrack" where the belt has failed after about 1000miles, my "flanged" homebrew one ...
by bobc
26 May 2017, 12:09pm
Forum: Bikes & Bits – Technical section
Topic: What's the term for an e-bike drive from the rack?
Replies: 10
Views: 2078

Re: What's the term for an e-bike drive from the rack?

I don't think you'll find it.
I've made a few of these but all homebrews.
Maybe you could look for "friction drive" - sounds awful but actually works OK and should be cheapest possible solution. Knobbly tyres are a nono though.
by bobc
18 May 2017, 3:15pm
Forum: Bikes & Bits – Technical section
Topic: Supercommuter?
Replies: 103
Views: 18588

Re: Supercommuter?

Seems a slightly odd attitude to the ebikes if the electrics fail - it's still a bike; pedal on dude :) the big hub issue: a legal power ebike will have a hub only slightly larger (if at all) than an IGH or a dynohub. The old nuvinci IGH weighed in at over 4kg for the hub alone & might well be h...
by bobc
16 May 2017, 9:03pm
Forum: Bikes & Bits – Technical section
Topic: Tyre width on a road bike
Replies: 22
Views: 5772

Re: Tyre width on a road bike

My bike of the last 6 years was on 28mm tyres, which are about as big as will go through long drop dual pivot rim brakes. The bike I use now has hub brakes (drum and disc) so I went for as big tyres as I could get through the frame, 35mm. It is SO nice to ride - rolls great & I no longer even no...
by bobc
9 May 2017, 11:59am
Forum: Non-standard, Human Powered Vehicles
Topic: KMX X Class 16" Replacement Front Wheel/s
Replies: 10
Views: 6960

Re: KMX X Class 16" Replacement Front Wheel/s

I have a couple of rims/tyres/tubes for this, maybe some spokes but not the hubs - any use?
by bobc
15 Apr 2017, 11:10am
Forum: Bikes & Bits – Technical section
Topic: Bullbars.....(Show us yours?)
Replies: 81
Views: 19402

Re: Bullbars.....(Show us yours?)

Lots to like there colin, & always nice to see someone going beyond chequebook engineering. Particularly liking the use of housebricks as jigs for brazing :) My brother also uses bullbars on his singlespeed. He somehow got his brake levers backwards on the bar ends - I'll give it a closer look n...
by bobc
2 Apr 2017, 11:49pm
Forum: Bikes & Bits – Technical section
Topic: Pedelec modification to enable hill start
Replies: 12
Views: 660

Re: Pedelec modification to enable hill start

I've not used a modern commercial ebike solution, so anything I say is not gospel, just observations based on the limited constructions and experiments I've made over the years... Setting off uphill is not easy. The cheapest motor controls, the radio controlled plane ESCs are all "sensorless&qu...
by bobc
27 Mar 2017, 10:48pm
Forum: Bikes & Bits – Technical section
Topic: Brakes: Rim vs Disc vs Drum - how heavy?
Replies: 96
Views: 3152

Re: Brakes: Rim vs Disc vs Drum - how heavy?

That's why PM mounts are widely used. If (if) there is any rubbing, undo the bolts, squeeze the lever & tighten the bolts. Job done. Ah - I wish I lived in that world..... We used bike cable discs on the greenpower race cars for many many years. It was never ever ever that simple. The last 2 ca...
by bobc
26 Mar 2017, 7:26pm
Forum: Bikes & Bits – Technical section
Topic: My new bike has a rohloff speedhub & belt drive
Replies: 27
Views: 1348

Re: My new bike has a rohloff speedhub & belt drive

Yeah there will be a disc setup soon enough. I'm old enough and daft enough to remember my childhood experience using feet as emergency back up brakes. :) Not recent experience..... But what does the letter of the law say? - is it illegal to use a bike with only a single brake, or just illegal to se...
by bobc
26 Mar 2017, 2:27pm
Forum: Bikes & Bits – Technical section
Topic: My new bike has a rohloff speedhub & belt drive
Replies: 27
Views: 1348

Re: My new bike has a rohloff speedhub & belt drive

Frame is 18.23 on the sticker, I measure a 23" top tube No the chainring isn't round, I couldn't resist putting a slight "osymmetry" on there. It reduces the belt tension in a couple of spots, but in theory that shouldn't be when there is most torque going through, should be top and b...
by bobc
26 Mar 2017, 12:55am
Forum: Bikes & Bits – Technical section
Topic: My new bike has a rohloff speedhub & belt drive
Replies: 27
Views: 1348

Re: My new bike has a rohloff speedhub & belt drive

I actually bought it a few years ago for £20. It's (clearly) quite a big frame I'll get or measure the size :)
by bobc
25 Mar 2017, 2:58pm
Forum: Bikes & Bits – Technical section
Topic: My new bike has a rohloff speedhub & belt drive
Replies: 27
Views: 1348

Re: My new bike has a rohloff speedhub & belt drive

I promised pictures - here are all the home made bits. Gear changer (& cables)and back brake will be sorted out in the fullness of time...
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by bobc
23 Mar 2017, 10:30am
Forum: Bikes & Bits – Technical section
Topic: Brakes: Rim vs Disc vs Drum - how heavy?
Replies: 96
Views: 3152

Re: Brakes: Rim vs Disc vs Drum - how heavy?

Thanks Brucey - very interesting! Do you know offhand what the weight penalty of going up to 90mm drums is? (I suspect it's quite significant). Note also with drum brakes, all the spokes can be a bit shorter..... discs v drums I see 2 big drum plus points - 1) no drag when brake off (very difficult ...