http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: Folding dilemas... en Thu, 02 Jul 2026 02:21:44 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77463 Mon, 09 Jul 2012 20:06:55 +0000 Smudge 77463@http://citycyclingedinburgh.info/bbpress/ <p>"<em>74" is quite low!</em>"</p> <p>I feel I should qualify that statement(!), low for top gear on a multi-gear bike, pretty blooming tall to be pushing uphill imo :-o</p> <p>Great link for the gear calculator thanks :) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77454 Mon, 09 Jul 2012 18:57:23 +0000 wee folding bike 77454@http://citycyclingedinburgh.info/bbpress/ <p>My old Claud Butler has a 74" fixed gear. It's had that since the '80s. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77453 Mon, 09 Jul 2012 18:52:32 +0000 Uberuce 77453@http://citycyclingedinburgh.info/bbpress/ <p>74" is what wee blue floofy's set to these days, by wacky coincidence. </p> <p>It was at 63" up until last weekend, and like chdot noticed upon getting a lighter bike, I just ride everywhere quicker now - it's apparently easier to ride at my natural cadence and shove the extra friction than it is to grind. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77452 Mon, 09 Jul 2012 18:26:10 +0000 wee folding bike 77452@http://citycyclingedinburgh.info/bbpress/ <p>There is a Brompton calculator here:</p> <p><a href="http://xldev.co.uk/bgc.html" rel="nofollow">http://xldev.co.uk/bgc.html</a></p> <p>If you want to do it by hand the ratios are 75%, 100% and 133%. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77435 Mon, 09 Jul 2012 16:12:50 +0000 cb 77435@http://citycyclingedinburgh.info/bbpress/ <p>I think my seven speed Birdy is 36" to 92". Can only really pedal it up to about 25mph downhill and it can be a bit hard work up steep hills but it's nippy away from the lights, certainly a fast bike about town and fairly easy to accelerate past people.<br /> Apart from all the times when other people accelerate past me. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77434 Mon, 09 Jul 2012 16:03:11 +0000 Smudge 77434@http://citycyclingedinburgh.info/bbpress/ <p><em>"Limitation wasn't legs but lungs - got puffed out quickly! "</em></p> <p>I think 'cause I'm a bit lazy and tend to spin rather than power up hills (the Surly's lowest gear will see you doing approx 5mph at 80-90rpm!) my heart/lungs do ok on climbs, but if I try to "power" up hills my legs give out long before I run out of puff. I guess pushing a taller gear will do me good on the whole :-) (I hope!)</p> <p>Not sure how I'd check the gear ratios on a hub gear bike, I suppose bits of chalk and a tape measure! Much easier to work out with a pair of cogs to count teeth on! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77431 Mon, 09 Jul 2012 15:55:49 +0000 wee folding bike 77431@http://citycyclingedinburgh.info/bbpress/ <p>Yes, at least some of the S2L-X advantage is in the mind of the rider. It invites you to go faster so you turn the effort up to 11. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77428 Mon, 09 Jul 2012 14:52:44 +0000 chdot 77428@http://citycyclingedinburgh.info/bbpress/ <p>"and don't realise that buying a carbon bike wont make your legs any stronger"</p> <p>My first impression with my first light/fast bike was that it 'made' me go faster. </p> <p>Limitation wasn't legs but lungs - got puffed out quickly! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77426 Mon, 09 Jul 2012 14:49:34 +0000 fimm 77426@http://citycyclingedinburgh.info/bbpress/ <p>I have a 3-speed Brompton. I can pass people on mountain bikes but proper fast people fly past me.<br /> I can "honk" it up Dundas Street or Market Street. I have no idea what the gear ratios or whatever are. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77425 Mon, 09 Jul 2012 14:45:28 +0000 Smudge 77425@http://citycyclingedinburgh.info/bbpress/ <p>74" is quite low! The paperwork with this three speed quotes the gears as 46", 62", 82"<br /> Can't remember what the Dahon's gear range is, but at about 7 1/2 kilos on Schwalbe GP tyres it's really quick when you start to spin, as you say, it plays with peoples minds when a folder passes them and they can't catch it* :-))</p> <p>*not that I'm fast, I'm not! It's just that some people are slower than they think (and don't realise that buying a carbon bike wont make your legs any stronger)! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77416 Mon, 09 Jul 2012 13:53:08 +0000 wee folding bike 77416@http://citycyclingedinburgh.info/bbpress/ <p>Brompton S2L-X is a nice Q bike. </p> <p>Anyone watching carefully would spot that I'm spinning like crazy with no higher gears because the top is only 74" but apparently being passed by a folder upsets a person's critical faculties. Flying start is great because of the wee wheels, standing start less so because of the 56" other gear. </p> <p>Expect to wear out chains at an accelerated rate. There is a Yahoo group called Bromptontalk which can answer lots of questions. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77413 Mon, 09 Jul 2012 13:44:50 +0000 Smudge 77413@http://citycyclingedinburgh.info/bbpress/ <p>Thanks all, decision made, the Brommie stays and the Dahon sadly must find a new home (sniff, I shall miss upsetting the faux roadies on it!).<br /> First batch of refurb parts ordered for the Brompton, time for a cuppa and a think about the gearing options now :-) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77382 Mon, 09 Jul 2012 08:59:47 +0000 wee folding bike 77382@http://citycyclingedinburgh.info/bbpress/ <p>There is indeed some folder witchcraft. Big sprockets will start to grind the inside of the RHS chain stay. </p> <p>There is a 15t sprocket available for the SRAM 6 speed which has the Sturmey Archer 3 tit spline pattern but I don't know if the 3 speed transmission works OK with that. I've never used it on a 3 speed set up but I do have it on a couple of 6 speed wheels. The spacing might be different. OTOH it might work just fine.</p> <p><a href="http://www.sjscycles.co.uk/brompton-sprocket-15t-r-2-mm-sram-6-spd-for-3-32-inch-chain-iso-qrspr15dr-prod22346/" rel="nofollow">http://www.sjscycles.co.uk/brompton-sprocket-15t-r-2-mm-sram-6-spd-for-3-32-inch-chain-iso-qrspr15dr-prod22346/</a></p> <p>You can get a 44t chainring for about £33 which will drop your current gearing by 12%. That's a fairly simple way round the issue. You can run a 1/8" chain on a 3/32" chainring. I don't think they make any 1/8" chainrings anymore.</p> <p><a href="http://www.sjscycles.co.uk/brompton-44t-chainwheel-only-3-32-qcw44-prod4825/" rel="nofollow">http://www.sjscycles.co.uk/brompton-44t-chainwheel-only-3-32-qcw44-prod4825/</a></p> <p>A cheaper option is to build up some muscle… </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77380 Mon, 09 Jul 2012 08:23:57 +0000 Uberuce 77380@http://citycyclingedinburgh.info/bbpress/ <p>I'd look into a bigger rear sprocket. Unless there's some folder witchcraft going on, the hub'll take any standard S-A cog, which go up to 20t. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77379 Mon, 09 Jul 2012 08:20:59 +0000 splitshift 77379@http://citycyclingedinburgh.info/bbpress/ <p>"smudge minor !" good to hear alls well mate,cant really help with your folding dilemas, last folder i had was a raleigh stowaway !I still owe you a tube ! see you out there !<br /> Scott </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77364 Sun, 08 Jul 2012 23:41:50 +0000 Smudge 77364@http://citycyclingedinburgh.info/bbpress/ <p>Ok finally got Smudge minor to calm down and go to sleep(!)<br /> Thanks for the replies.<br /> The sprockets are 50t front 14t rear with a Sturmey-Archer 3 speed "AW" hub on the back. It's a 1998 model so a 1/2" x 1/8" chain.</p> <p>I guess I either need to learn to push instead of spinning or fit a new chain and sprockets with the newer (1/2" x 3/32") size. :-/ </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77355 Sun, 08 Jul 2012 20:30:46 +0000 BikeFan 77355@http://citycyclingedinburgh.info/bbpress/ <p>Contact this guy <a href="http://www.tillercycles.co.uk/page6.html" rel="nofollow">http://www.tillercycles.co.uk/page6.html</a> about re-gearing Bromptons. Scroll down to "Lower gearing for all Bromptons (1,2,3,6, 8 and 11 speed)" for more information.</p> <p>Not that I know anything about Bromptons, he featured in an article in a magazine earlier this year. He has the only bike repair shop on a barge that I know of - maybe one needs to start on the Union Canal and berth alongside Zazou? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77351 Sun, 08 Jul 2012 19:42:20 +0000 wee folding bike 77351@http://citycyclingedinburgh.info/bbpress/ <p>You might be able to lower the gearing on the Brompton. </p> <p>Do you know how many teeth are on the chainring and sprocket?</p> <p>Smaller tyres can drop the effective gearing too. </p> <p>If it was made after early 2001 you can probably convert it to a 6 speed. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=7532#post-77341 Sun, 08 Jul 2012 16:07:24 +0000 Smudge 77341@http://citycyclingedinburgh.info/bbpress/ <p>Well, as some of the twitterati know already, I now have an old Brompton T3 sat in the front room B-)<br /> The good news is that whilst it is a little scruffy and well used, it is basically sound (and arrived at the right price!)<br /> The bad news is that either my current folder (lovely Dahon Helios SL) or the Brompton will have to be sold soon to restore "S-1".</p> <p>I've tried the Brommie today on the <em>big</em> hill back from the station and tbh it's a bit brutal. Max effort still resulted in having to walk the last 20m or so.<br /> I can stand up and power on the Brommie which I can't on the Dahon, but then the Dahon is lighter, faster and has a much larger spread of gears. Otoh the Brommie has pretty much unlimited spares availability and is infinitely customisable...</p> <p>Hmmmm tough choices!! :-/ </p>