Cycling UK Forum

Hi, I have Campag Mirage 9 speed on my audax-style bike. I swapped from a 53,39 double to a 50,34 compact double, then to a Stronglight Speedlight Triple (48, 38, 26). TBH the 53 chainring was practically dusty for all the use it got. I liked the compact double for a while, but the big jump between the rings is a bit of a pain.

The Speedlight Triple is also ISO standard, and kept the chainline when used with the 111mm Campag BB that came with the Campag double. The BCD is 130 for the middle ring, which limits the smallest middle to 38 teeth. I don't know what the Campag Triple BCD is, but it might be worth knowing to find out your middle ring limitations. I did consider a Campag Triple chainset, but I was swayed by the range in chainring choice offered by Spa Cycles.

The chap I brought my bike from had fitted a medium cage Mirage rear derailleur. It works as normal with the triple and 13-26 or 14-29 on the back.

I also have a Stronglight Impact Triple (44,34,24) on my Long Haul Trucker. I tried it with the Speedlight Triple but the 38 teeth of the middle ring were too high for my needs. Note that Stronglight recommend a JIS bottom bracket for the Impact Triple. I've got a UN54 I think, but can't remember the axle length unfortunately. The BCD is 110 for the middle ring.

Another difference is that the Speedlight Triple feels like it has a narrower 'Q' factor than the Impact Triple, in case this is an issue for you.

Regards,

Luke

Bicycle Quarterly mag have tested the effect that tyre size and construction has on rolling resistance. From memory the author tested various tyres by riding on a rumble strips on the road side, trying to maintain a set speed. They used power meter cranks to measure the power output required. The main variable was the tyres, as the bike, rider, rumblestrips, speed and time remain the same. The tests found that wider tyres with supple casings and thin sidewalls at lower pressures had less rolling resistance, were faster and subjectively more comfortable. I think they recommend 30-32mm tyres for 700c, ~38-42mm for 650b and ~1.75" tyres for 26" MTB wheels (sorry, I don't have the article on me, am going from memory).

In 28mm width I've tried Conti 4 seasons, Panasonic Paselas, and Grand bois Cerf tyres (see below) on my audax style bike (Van Nicholas Yukon). Paselas were good but a tighter fit with 57mm drop brakes and SKS guards. The Grand bois tyres look a little smaller. I've found them to be the best of the bunch. They feel fast and light and extremely comfortable. I run them at 50-70psi from memory. They're faster and more comfortable than the pair of 25mm Conti GP 4000s that preceded them. However, I accept there is a width difference that confounds a comparison. Their suppleness should in theory make them more vulnerable to punctures. I've yet to puncture on them, but I only brought them last summer and haven't ridden my best bike over the winter, so I haven't tested their reliability.

http://www.planet-x-bikes.co.uk/i/q/TYG ... _cerf_tyre

I have a 650b 1970s Peugeot that I've had cold set to accept 130mm 650b wheels. They wear 42mm Grand bois tyres at ~30-40psi. The ride is super-comfy, but the trade off is it doesn't feel as quick to accelerate.

Great idea for a thread Chuck Glider. I'm too late though, most of the controversial topics have gone. Best I can do is:

Carbon Fibre vs Steel.
Horizontal top tubes vs compact frames.
The number of bikes I think is reasonable to own, vs the number my missus does.

There's plenty of religious disagreement between cyclists and non-cyclists on:
The right of cyclists to use the roads.
Paying 'road tax'.
The safety of cycling.
The perceived threat posed by cyclists to pedestrians (The real, greater threat posed by traffic is of course ignored).

Hi, a pal and I once discussed this. He thought coloured tyres would perform worse than black ones, as the addition of the paint / dye / colourant would displace some of the tyre rubber. However, I'm not sure, as surely the rubber is not black in it's natural state?

I had a pair of Panaracer Pasela 700 x 28s in white. They worked as well as my 700 x 28 black/tan coloured ones, but they didn't look very nice and I passed them on. I partly brought them for the increased visibility they bring, and without mudguards they did stand out.

This one of any use? I think someone might have recommended this on Bruce Lee's thread?

http://www.ebay.co.uk/itm/Stem-ATB-Hybr ... 43aba61528

Hi Steve, I gave away my Vega light to a colleague when I upgraded to a dynamo. I've still got the old charger, shame I missed your first post requesting one. You're welcome to it for postage costs if you want a spare charger? Or if anyone else wants it just PM me.

Hi Gaz, Hi Colin, thanks for the good intel re front mechs. Duly noted.
Re chainline, apparently it's JIS taper 116mm for a double, 130mm OLN hubs; & JIS 121mm for a double with 135mm OLN hubs:
http://www.compasscycle.com/SKFbbcrank.html

Colin, thanks also for your warnings on obsolescence / stock. Good to know!

CREPELLO wrote:

531colin wrote:Also, there is no consensus that low "Q" is good for everybody....search the forum for "kneesavers", a device designed to increase "Q" !

I was thinking along those lines too. Assessing bike fit for a woman must be quite different than for a man. So I would caution against believing everything that you read in qualified journals, unless the authors are women or informed by women. Consider the difference in hips width for example. How this is reconciled with pedals and q-factor I don't know, but the optimum q-factor could go either way.

Hi Crepello, you and Colin make a good point about the lack of consensus. Like in other areas of cycling it seems there's a lack of published research and objective data. ~4-5yrs ago I read an article about female athletes having a higher incidence of Anterior Cruciate Ligament (ACL) knee injuries. The article explained their wider, child-bearing hips (High q-factor hips!) increases the strain on the knee joint. However, how this translates to cycling and crank q-factors I don't know either. Any Physios, Doctors or Physiologists out there? My gut feeling is that the low-q crank hypothesis makes sense, but I don't know for sure.

Thanks to all for top notch help. Am gonna mull over this one some more. An expensive run in to Xmas has scuppered my plans for now anyway... Bah humbug!

Hi folks, thanks all for your replies, lots of great ideas and advice as per usual.

Malaconotus wrote:Is the inner ring going to clear the frame OK?

Hi Malconotus, Good question! I think Velo Orange (VO) recommend a 118mm BB spindle for a compact double. On other forums (fora?) I've read ~121-122mm is required for fat chainstays. I'd have to take into account the different chainline on triple too.
Thanks for the Middleburn crank idea. I think the crank q-factor is a tad high, somewhere in the 160s. I've been getting into Bicycle Quarterly magazine lately, whose editors report a preference for narrow Q-cranks, citing more comfort and reduced risk of knee pain. Searching around online there seems to be some anecdotal evidence that this can be the case. I hold Bicycle Quarterly's opinions in quite high regard; of all the bike press they seem to have higher journalistic standards and more of a scientific, critical style (Along with Chris Juden's reviews in "Cycle" too).

Valbrona wrote:I would have a think ... 5'3" is not tall and after reading up on crank length you might both kind of work out that you ideally need a crank with shorter arms.

Hi Valbrona, any suggestions on crank length? "the Duchess" has an inseam length of ~73cm. I went for 165s using the bike fitting advice in "Zinn & the Art of Road Bike Maintenance". Zinn advises 165mm cranks if frame size is <45cm, or 167.5mm for 46-49cm frames. Zinn writes there's no consensus on crank sizes however, so I'd consider 160s.

Phil_Lee wrote:Why not use a single chainwheel, and fit an SRAM Dualdrive rear hub?
I recently bought both hub and changer (3x9) for a total of £54.62 plus postage on ebay.

In my case, it was to get the extremely wide ratios that I need due to disability, so I'm having a triple chainwheel as well (and yes, I'm well aware that I will get lots of duplication, but gears low enough for me to climb hills would have left me spinning out with the lightest tailwind otherwise.
I can get over 1000% gear range with those 81 gears, and the ratios can still be reasonably close

Hi Phil, have never heard of that one, thanks for the intel. (1000%! Wow!) I've got some shifters and a front mech already, and fancy an LX hubbed wheelset from Spa, so will probably pass on the hub option.

gaz wrote:

LuckyLuke wrote:...I've thought about buying and converting a Velo Orange compact double (Grand Cru 50.4 bcd crankset) into a triple ...

Why but a double to convert to a trriple? Surely it's easier to but a triple in the first place, like the Spa XD2, available in 160mm crank length.

Hi Gaz, a 110/74bcd triple would be perfect, great price too. I've got the similar Stronglight Impact triple cranks on my commuter. But I think the q-factor is quite high, ~160s. I'd really like a pair of Ritchey Logic MTB triple cranks, with a mid 150s q-factor, but they are no longer made & I couldn't find any on ebay.

reohn2 wrote:LuckyLuke
Most women pedal with the knees inward (I'm deliberately not mentioning the words knock kneed ,as theres too many women on here )
Is she comfortable? ie no knee pain when riding.
Is her saddle and riding position set up right for her?

Hi Reohn2, no offense meant! She's pain-free at present, though cycles negligibly at present. Saddle height is set based on a slight bend in the knee with the crank at 6'O Clock. From memory she has a square taper MTB triple, 42,32,22 on her current halfords bike. I think they're 170s or 175s in length. Q-factor is ~165mm.

pete75 wrote:You could try for these and then get rings and stuff from velo orange.
http://www.ebay.co.uk/itm/Specialites-T ... _675wt_932

Hi Pete, good spot! Nice one. I shall watch those with interest. Spa sell the TA chainrings, bolts etc too.

Does anyone know the bottom bracket length required for a triple MTB chainline with these TA cranks? The thought just occurs to me that narrow q cranks might require too wide a bottom bracket in order to clear the chainstays. Is it feasible or am I flogging a dead horse?

Thanks all for your help, best wishes, Luke

Hi folks,
I hope all's well. Here's the X-factor style backstory to my post:

I'm building up a flat bar road bike for the missus, based on an old steel, rigid, GT MTB frame and 26" wheels. We're looking to steadily increase her mileage in the new year and do the London to Paris in June. Her current bike is a cheap halfords MTB and she only cycles ~1-2x per month, 3-5miles each time. Watching her cycle from behind her knees are rather inward of the pedals, almost 'knock-kneed', and I worry about the potential strain on her knee joints. I thought changing her pedals and cranks to reduce her "Q-factor" or "tread" might help, and to try shorter cranks (she's 5ft 3in).

I've thought about buying and converting a Velo Orange compact double (Grand Cru 50.4 bcd crankset) into a triple using TA rings, like the TA Pro Vis 5 'Cyclotouriste' which the VO crank mimics. I emailed Velo Orange to check it would work, they think so but with longer chainring bolts (see email below). Can anyone advise as to the length of the chainring bolts that would be required? Are they readily obtainable?
Thanks in advance for your help, Best wishes, Luke

----- Forwarded Message -----
From: Velo Orange <info@velo-orange.com>
Sent: Thursday, 8 December 2011, 16:41
Subject: Re: Grand Cru 50.4bcd crankset

Dear Luke,

It should work, but we can't guarantee it. The thickness of our spider at the base of the rings is a bit thicker then the TA crank, so the bolts may be too short (by perhaps a mm), so slightly longer bolts may be required.

Cheers,

Scott Gater

Hi, another +1 for Marathon Winters. I ran them on my Long Haul Trucker last winter. They worked well on snowy roads and I kept them on even when it wasn't snowy, but still freezing, in case of black ice. Initially I rode really carefully in anticipation of a fall but they grip a treat and the fall never came. They're well worth the piece of mind and will keep you on the road this winter. I'm an NHS worker and need my bike to commute and conduct patient visits. I couldn't have done the job without these tyres.

The negatives: As others have said they are heavy and lifeless relative to normal tyres, and greater clearance is required than their 700 x 35mm size suggests. I've lost a couple of carbide studs per tyre and the central studs seem about half worn out. One other possible drawback is that car drivers nearby might think the road conditions are safer than they actually are...But overall big thumbs up and I'll use them again this winter. And +1 for a hub dynamo too!

Hi, re theft / attempted theft of dynamo lights, I thought you might be interested in this pitlock skewer:

http://www.pitlock.com/to-the-shop/furt ... /index.php

It securely attaches the light to the bracket, and the bracket to the forks. I'm a tad OCD so I've got these pitlocks on my dynamo light, plus a pitlock aheadset skewer, pitlock wheels skewers and seatclamp.

Best wishes,

Luke

Hi folks, thanks all for your help. Top notch advice as per usual. I chickened out of doing it myself though. I took it to my LBS and they removed and refitted it for a fiver. The mechanic said he used a razor blade initially, then the Park Tool. I fitted the new forks and went for a lovely spin on Sunday. All is well with the world.

Regards,

Luke

Hi, another plus one for the Topeak Road Morph with Gauge. I brought one ~5ish years ago. It works really well by the roadside. Mine did develop a problem. At the time I didn't have a track pump so was using it weekly. In time the rubber gromit that forms the seal around the valve wore, and would no longer form a good seal. Topeak customer services sent me a replacement and it worked fine again. It hasn't worn again, but I now have a track pump so it gets much less use. I also have a Zefal HPX but prefer the Road Morph.

Hi Aek, hope the build's going well. I like Deda bar tape, I usually buy it from Ribble. It's comfy, seems to wear ok, good range of colours, and cheapish too!

Belated Update: I managed to work a solution. I had snapped the earth terminal. Fortunately The live terminal was intact. I was able to connect the B&M rear light using a Schmidt Coaxial cable.

http://www.sjscycles.co.uk/schmidt-coax ... prod15905/

Both lights work great, no probs so far (touches wood).

Regards,

Luke