Cycling UK Forum

pherron wrote:cycling sandals - never a comfortable option before clipless

Ah - SPD sandals - fair enough.

What exactly are the functional, quantified, benefits of clipless pedals, over toe-straps, or strapless toe-clips ?

How much more power can one expect from "clipless" pedals compared to toe-straps, for the same effort ?

It's clear that "proper cyclists" now are "clipless" - almost by social definition.

But my (anecdotal) understanding is that clipless pedals can (and frequently do) cause injuries that would not happen with less rigid toe-straps, and that knee injuries for cyclists were rare or non-existant before "clipless" pedals.

I have the impression that most of the benefit of any kind of device that stops our feet flying off flat pedals mostly comes from two things:
- We can unload the pedals on the upstroke more, while still being in the right place to push for the next downstroke (more torque).
- We can spin faster - so our feet haven't flown off the pedals (more rpm).

Is that right ?

[XAP]Bob wrote:

SPARK76 wrote:the stopping power was fine should be better still if I upgrade the padds i guess, although my first time on full slicks - a bit slippery when breaking hard!

On a bike slicks won't make it slippery - no risk of aquaplaning, which is why car tyres have tread

Pads - it's not just about the braking. We didn't have a problem with braking, but I noticed chunks of swarf from the rims stuck in the pads. Shimano pads are particularly bad, AFAICT. The pads turn into cutting tools. Usual recomendation is salmon koolstop pads. More expensive, but they wear well, and have minimal swarf pickup. There's a few threads about this.

Slicks in the wet - on a clean (not muddy) surface, I'd expect better grip, other things being equal. But the tyre pressure, tyre compound and carcass construction are going to make a difference.

SPARK76 wrote:http://www.evanscycles.com/products/kon ... w%20deluxe
http://www.evanscycles.com/products/can ... 5#features
Shayne

The Kona, like ?all? off-the shelf big-wheeled hybrids has a ludicrously high top gear, too high for many professionals. The badboy still has a higher top gear than a typical modern roadbike.

They're both 8-speed, and off-the shelf 8-speed gives jumpy gears. Folks round here tinker to get closer 8-speed gears by ditching the silly high gears. And put smaller cogs on the front to get proper low gears for hills.

Rim brakes are fine (for us), but almost no-one sells rim-braked bikes with decent brake pads. Problems are excessive rim wear due to swarf pickup, and poor wet braking. So you should change the pads. Search forum.

SPARK76 wrote:I do wonder if I ought to consider a MTB and fit road tyres

Depends how fast & how rough, maybe. Could get a second set of wheels, with different tyres & gears - which is less expensive/fiddly with rim brakes.

How about:
http://www.edinburghbicycle.com/ebwPNLq ... ctID=12409
?
That has less jumpy gears & lower low gear.

Dafne123 wrote:First of all, do you think it is worth spending a little bit more on shifters?
I am not looking for fancy performance here, but essentially for solid, reliable gear levers, then if they are even faster/smoother, all the better.

No - actually I'd suggest spending less:

http://www.parkersofbolton.co.uk/p-1222 ... evers.aspx

That's down 3 (thumb push) / up 1 (first finger pull). I think they work better than the Alivio (or other) shift pods, becauese you don't have to put your first finger behind the brake levers to shift down at the front or up at the back.

I'd guess you don't use big front / small rear. This might be a good time to consider whether you would prefer slightly different gearing.
If you don't need the low gears, you can sacrifice them for closer gearing in the middle of the range, and get a road cassette: 12-26, 13-26, 13-23...
If you do need the low gears, 13-30 or 13-32 at the back will get rid of the jumps in the middle of the range - but this needs more tinkering - need to take half of a 13-26 and half of an 11-30 or 11-32, and assemble them together.

Boomeister wrote:I own a Specialised Sirrus. (3 x 8 speed shimano low quality mostly mountain bike transmission but with a road 11-25 rear cassette). I commute daily (20 miles in all weathers). I want to convert it to dropped handlebars because I no longer want to ride with my arms spread out wide (the bars are 590mm) or my hands at 90 degrees to the natural position. Plus I would like to change gear and brake without having to move my hands. It would also help to be able to duck under the wind a bit more.

I did consider selling the bike and getting a road bike that accepts panniers and mudguards (Trek 1.1). The problem is I like my bike and it is practically worthless (£130 on Ebay) and I don't see what something like the Trek would give me that putting dropped bars on my Sirrus wouldn't.

Dunno why you think your transmission is low quality. 48-11 top gear seems a bit mental to me unless you're a fell runner or a rower or a weight lifter. But that's not your question.

Our Giant CRS hybrids take anything up to 47mm knobblies with mudguards. That's a bit more flexibility than a road bike.


There's a continuum of ergonomically valid and useful riding positions between high riser bars on a dutch bike, and Tri bars. ~ But not all of them are valid from a marketing point of view.

You seem to have worked out some of this.

The first thing is the grip width:

Boomeister wrote:I no longer want to ride with my arms spread out wide (the bars are 590mm)

Well, get some BBB foam grips (designed for butterfly bars, you get two 40cm lengths), remove your existing bar end grips, move the controls inwards to roughly shoulder width - or just try with the controls as far in as they will go on your bars. Cut the foam grips long (by a cm or two) to start with - you can always cut more off later.
Other foam grips will work too, but the pairs of butterfly bar grips give you two sets of grips for the price of one.
If you find a position you like, but you don't like the foam, you could use gel bar tape. I think a pack of drop-bar bar tape would do two flat bars. But foam grips are easier to tinker with.

Bar end extensions are USELESS because they are too wide.


Then there's the wrist angle:

Boomeister wrote:or my hands at 90 degrees to the natural position.)

Well, I have been on runs with folks on road bikes with completely straight sawn off bars - so their grip width was roughly their shoulder width. But *I* think that would be rather uncomfortable for *my* wrists. - Well I think completely straight bars are ergonomically INSANE on a road bike. But their visual simplicity makes them a marketing hit.

So you want more swept back bars, to reduce wrist strain.

I think the reliable answer is Raleigh RNH361 "trekking bars", a stem about 4-6cm longer than you have now, and the BBB foam grips. These bars have about 40 degree sweepback . The point of these bars is that the outer bends are quite close, so it's easy to achieve a shoulder-width grip position (assuming you're happy to abandon bar-end based grips). Use the bars upside-down.

If you're lucky, you might find a weird bar in an an LBS that has the outer bends close together, more than 40 degrees sweepback, and not too much rise/drop. I have found such things.

Photos later.


If you're a right tinkerer you want:
- Thorn 220mm (sic) adjustable stem
- Thorn 35mm 0 degree stem ( needed for above )
- 22.2 - 25.4 quill stem shim (you'll need to saw this in half)
- Raask Jota Bars (Busters may be cheap)
- Foam Grips

This funky option will give you riding positions from the hoods to sit-up-and-beg.

More later.

Boomeister wrote:It would also help to be able to duck under the wind a bit more.

Yes, thats's what we're talking about.

Boomeister wrote:Plus I would like to change gear and brake without having to move my hands..

What seems to be the problem ? You have Shimanano EF50 ? Or Similar ?

Personally I rather like Shimano Ez-fire - they're better than the MTB shift pods because you don't have to put your finger between the bar and the lever to shift with the spring.
And I think they're better than Campy/Shimano brifters, because shifting doesn't Interfere with braking.
.

This got more complicated, but it seems OK now.

We got a 115mm BB. After tightening up the retaining bolts to 40Nm, chainline is 43.9mm (averaging over several measurements of inner & outer rings).

So the chainline should have changed by 2.5mm, but it's only changed by 1.4mm - as if the BB was 113mm instead of 115mm.

Unhelpfully, the BB is marked "D-H", rather than with the width. Not sure how to measure the nominal width of a JIS taper.

Further confusing things, the BB package is marked "E-type" - that might roughly explain the discrepancy.

Take BB back to LBS. All their new BBs from Madison are in boxes marked "E-type". But a 107mm E-type is impossible.

Comparing with other BBs, it does appear to be a normal 115mm. LBS has a spare 1mm spacer from an external bearing
chainset that we can have.

Re-assemble Chainset & BB, with spacer. Spacer measures 0.97mm. 40Nm for retaining bolt. Chainline has moved out by 0.63mm, to ~44.51mm.

Well, that's OK for a chainline, & it shifts fine with Tiagra 4503 & Tiagra brifters, losing 1 gear (of 9) on the middle & granny rings.

But every time the thing goes on, something is getting squished. The chainset is now ~1.5mm further in than I'd expect.

I'm not sure how that much could come from the BB/frame without stripping the BB threads.

Tapers, BB/frame, and retaining bolt threads all greased before assembly.

Frame is a Ribble 7005 alloy road frame.

Not using a torque wrench on the BB because I can't get a torque wrench on the BB tool, and I believe the rated torque is 70Nm - quite a lot.


I think if I'd known it would behave like this I'd have got an external bearing chainset, and swapped the rings.

meic wrote:That fits in with what I think to be the case.

Great. Thanks. I'm not going mad- well not as far as this goes...

meic wrote:When I bought my first Impact Triple they were all sold to be used with 110mm BBs.
When I bought one of the new ones a year ago, the website said 115mm BBs and popular consensus said this was correct for the new version (with 5 separate chainring arms as well as the crank).

If the website that you were getting your data from was the Chain Reaction Cycle one, then it could say ANTHING it is riddled with errors.

- No, the stronglight website.
I guess I should have tried searching harder: "The "new" Stronglight Impact Triple".

CREPELLO wrote:Can you confirm which Impact CH/S you want the BB to fit? And triple or double?
I use a 107mm UN54 BB with the XD2 triple version. This on a steel frame with a 28.6mm mech clamp.

JEJV wrote:Stronglight Impact Triple

- the new one.

Your setup agrees with my measurements - I'd guess you have a perfectly good 45.4mm-ish road chainline.

What BB length for Stronglight Impact ?

- I rather answer my own question further on, but perhaps someone else has made their own measurements.

It seems there are now two Stronglight Impact triple chainsets:
- The old one, with the bolt behind the crankarm, marked XD-2 (Sugino design)
- The new one, with a "normal" bolt pattern.

The two chainsets have very obviously different (square taper) BB mounts, with the new one starting further out from the centreline.

The box (new & old) says 110mm JIS bottom bracket for a 46mm chainline.
The website says 115mm JIS, with no chainline mentioned (shows picture of old design).
The vendor says 110mm JIS for 45mm chainline, for old & new.

The website also says it's made of 6061, rather than the XD-2 2014

Measurements on UN54 110mm; 40Nm torque :
New: 42.58mm 42.40mm - say 42.50mm
Old: 46.88mm
M442 on UN54 107mm; 40Nm torque: 48.04mm (averaging multiple measurements on both sides of chainset).

The M442 is nominally 50mm chainline at 113mm BB.

By "chainline" I mean the centreline of the chainset, not the location of the middle ring.

So, from this, it looks like:
- Old Impact triple (XD-2) wants a 107mm BB for a 45.4mm chainline
- New Impact triple wants 115mm BB for a 45.0mm chainline.

The point that I started measuring this stuff was when I realised that the new chainset couldn't work with the recommended 110mm BB - small front/large rear was rubbing, even with the front mech in contact with the frame...

reohn2 wrote:Either method may take a few goes so be patient with it.

Thankyou. Yes. Small steps & re-measure.

But I think 0.5mm is roughly the tolerance that I'd adjust a front mech to, so, really, I think the rings should be somewhat flatter than that.

Does anyone make tough, reliably flat, rings in odd sizes ? Say 46-34-24 110/74mm ?

Shimano do 46-34-24 hybrid/trekking, but 4-arm, and I don't think it would go down to a 45mm road chainline.

I was trying to set up a Tiagra front mech with a Stronglight "Impact" chainset when we noticed that chain rubbing on (the outside of) front mech happened once per rpm, always behind the crank. I hadn't come across this before, so I tried to measure the wobble, on the bike, with vernier callipers. I get 0.8-1.0mm peak-peak wobble. Looking a the thing going round, it appears that the wobble is only on the big ring.
I measured a Shimano M442 MTB chainset on another bike, and found 0.5mm wobble.

What's a reasonable ammount to expect ?
I think 0.8-0.9mm is too much - that's starting to make a difference to the range of gears. Can I make the alloy ring flatter by bending it ?

We use Kool-stop salmon or salmon/black V-brake pads (On CR520s and V-brakes). They work fine for us.

I think the only problem would be if the fork clearances were very tight, so the tail of the v-pads wouldn't fit in the forks. I guess (I don't know) that would be what the "low profile" canti pads were for.

http://www.cyclesportsuk.co.uk/product_ ... ts_id=8081

They are available as inserts/holders as well, and we have one bike with them, but I didn't bother with the other bikes, as the pads wore much less than the pads we had before.


I'm not sure which is the best location for the spacers - the side the big spacer goes on will make a small difference to the mechanical advantage, and the progressiveness.

dnr wrote:I ride a Specialized Tricross as a winter commuter with guards. Drop bars are essential. I have had issues with fork shudder and dispite Chris Judens advice Tektro 520/720s have not really been that great. I have decided the way to go is with disc brakes with my STI levers. Any advice or experience re fork, wheels and brake advice would be much valued.

Perhaps discs are the way to go, but...

What brake pads do you have now ?

Perhaps (if you haven't alredy tried this) kool-stop salmon or swiss-stop ?

Tektro & Shimano pads can be poor.

If you have wide cantis, I think that you want to arrange the pad bolt spacers to make the cantis as far out/down as possible.

PH wrote:You could also look at the KF uphanger, I only know it from the frequent recommendations on this forum;
http://Touring Tips/index.php?ap ... wv3917h7hg

Not sure that kind of thing goes up enough for wide cyclocross cantis like CR520/CR720 ?