Cycling UK Forum

I'm choosing between two bikes, not too far apart in geometry or at least the important measurements I think. Effective top tube is 5mm apart standover is higher with one but think it's down to slope of top tube I think. Reach, seat tube height, etc close. One is up to user height 6'4" the other 6'6" which is significant difference.

Now the only thing I can do is compare against my ancient steel road bike which I've been comfortable with. The effective top tube is a little less than both potential new bikes, perhaps 10mm. A standover is a lot higher, over 10mm I think. Basically it all looks to me that bike fit due to fame geometry is very rough and can be fine tuned if not quite right. Is this true?

Should I bother looking at these measurements or just trust that if I fit in the user height range that it'll be possible to make it fit with say stem changes, bar width, seat tilt angle or position of seat on seatpost (move it on rails)?

The trouble is I can't get to shop to try out the bike I really want (better spec lower price).

One thing about my ancient road bike I found when on the hoods it had pressure on the inside of the hand between thumb and hand. I'm guessing I could have been reaching too far putting my weight more on hand. Is this likely? Can you easily adjust fit for this?

Basically how to find out if bike fits based on geometry before buying and does out really matter that much?

You seem to be viewing 'fit' more in terms of reach, and that is exactly right. You can these days get two foot of adjustment out of a seatpost, but maybe only a couple of centimetres either way of stem adjustment.

Note 1/ If your the frames have stack and reach data that can simplify things.

Note 2/ A steeper seat angle can significantly push the bars forward irrespective of effective top tube length.

Why not paste up the numbers so we can look at them?
Unless you are used to looking at the numbers, they can hide more than they reveal. For example......
ETT is little influenced by how high up you measure it (ie how tall the head tube/forks are) as the head and seat tubes are roughly parallel, but ETT is influenced by seat tube angle.
Reach is unaffected by seat tube angle, but is changed by head height, as its measured vertically above the BB, but in the plane of the head tube.
If you have too much weight on your hands, then you need to move the saddle back, so seat tube angle might be important, although long layback posts are available.
ETT/standover difference of 10mm is of no consequence unless you are sat on the top tube or using an extreme stem already.

don't forget that different bar shapes can affect actual reach too.

Hopefully this link takes you to the geometry of one bike. http://www.planetx.co.uk/i/q/CBPXLDNRIV/planet-x-london-road-sram-rival-22-road-bike

Here is the other http://images.evanscycles.com/product_document/file/8b2/708/c1d/2359/pinnacle-arkose-2012-2013-geometry-chart.pdf

I have checked my old road bike which I have used on and off for 25 years and was a nice ride. Typical the light in the shed failed mid measure but I think the old bike could be comparable to these two bikes except the top bar is completely horizontal which makes it a lot higher up, the standover height). Those big old Reynolds steel framesets back in the day look a lot bigger than modern ones, no sloping top tube and smaller triangles in those days. None of this wishbone stays and curved top tubes neither. My road bike actually looks like it is a bigger size than a 60 or 61cm modern frame I've looked at but most of the dims seem the same. I've not accurately measured it TBH just approximated it against what i had seen online for these two bikes.

BTW I am looking at the largest size being 6'5" tall. The bar width 440, stem a standard 100 and chainset cranks at 175 (although measuring my old road bike it actually looked about 180 or even 185 which I doubt somehow). The Pinnacle has a top user height of 6'4" but the LR has 6'6" (although the guy I spoke to at PX seemed to think it was 6'4" until he read his own geometry data).

This fit thing is my last question on new bikes since I am almost certain it will be the LR from Planet X bikes. The reason is to my untrained eye the two bikes seem almost the same except for the better brakes and gears on the Tiagra drop bar version of the LR which i am getting (the geometry link for this was not there so used the link for the higher spec SRAM version but assume the same bike frameset). Also, with PX I have to buy it with the only crank option of 172.5 but take the order number and call PX to change it to 175 later. They have a lot of them in stock but the "Argento" version does not give the option to choose it but they will put it on if requested. Or at least i hope they do after telling me that I should do it that way. BTW just wish the PX bike was avsilable in another colour option. Silver is not my style, prefer black or blue or at a push one of those bright green colours. At least silver might be less interesting to bike thieves i hope.

I just want to pick the collective brains of the very helpful people on here one last time to stop any potential mistake I am making. My ultimate goal is to buy this bike as a stopgap bike until I can save a lot more to get a proper tourer in the future if that is the way my riding takes me. This is a commuter / mixed terrain commuter with drop bars for now. I think both Evans and PX give about 10 day lead time now.

I appreciate all your help in my threads on bike choosing ove the last few weeks, sorry if it has all been asked before (not good with search functions).

foxyrider wrote:don't forget that different bar shapes can affect actual reach too.

In what way?

These bikes are a relaxed, gravel road or endurance type of bike I think. The pinnacle has smaller diameter tubing and seems all straight tubes. The London Road has a top tube with a curved lower edge making it a smalller diameter in the middle. It has an oversized downtube which I wonder about. The tubes are all a varied diameter with a bigger variation, like each tube is specifically tuned for some reason beyond me. Not like my old Steel 501 road bike with most of the main triangle the same tube diameter with the seat stays being fragile looking they are so thin. Even the chainstays are thin compared to modern bikes.

I think the LR has a less sloping top tube and longer seat tube but guessing. The chainstays are longer on the LR than the Arkose. I seriously hope there is no clipping of the toes on the front wheel. I haven;t thought of that, a few years back I tried a ridley crossbow (IIRC) CXer bike and it was awful ride due to that. A smaller sized Cannondale I tried was similar but the larger one was ok. I got told Cannondale tend to give lower measurements for the same fitting bike, i.e. their bikes tend to be bigger than the number indicates. I think I tried a 56 and 58 or was it 58 and 60? Think the former because I remember both sizes were 2cm smaller than other bikes I looked at.

Tangled Metal wrote:

foxyrider wrote:don't forget that different bar shapes can affect actual reach too.

In what way?.........

eg. putting the hoods closer/further away
putting the drops lower/higher/closer/further away.
edit.....relative to where the bars bolt to the stem....(!)

Sorry, handlebars. That makes sense I was thinking meant the frame shape, e.g. curved top tube or something. A dumb moment I guess.

The bars I;m getting are 440cm which are the larger ones and match exactly the bars on my old road bike in terms of width. As far as hood location and angle of the drops I will be taking what PX set it up as. I reckon things like fine tuning seat height, the stem and bars can be something I could do.

BTW if for some reason I decide to later change (upgrade) my handlebars to perhaps one of those newer shape ones where the drops flare out the side more, is it an easy job to just cut the bar tape off, take the levers off the old bar, the bar out of the stem and replace with the new bars and replace the levers and bar tape??? I know more steps but you get the idea I am thinking. You can get all sorts of shapes of drop bars aftermarket from those flared out drops to ones with flat sections at popular grip locations (ergo ones I think). These are all nice things later on to treat yourself with but are they easy changes?

Same with the stem swap out for a different one, I've heard about flipping the stem for more relaxed and upright position for example.

Basically my view is at my height I am limited to the largest sizes in any range, some do not go to a rider my height too. This means I think I have to tweak what I get anyway so as long as the frameset is basically close enough it is all going to work out with a little fiddling. If it involves serious adjustment of cables, brakes and gears to replace parts for fit then beyond me but simple bolts and allen keys are not.

To me these two bikes offer good value and seem to fit my frame. just got to go and decide to take the plunge with PX london road I think. Then buy the guards (SKS trekking or bluemels I think would silver be best looking with a silver frame??), Topeak super tourist DX disc compatible rack (comes in black which I hope fits in with the silver frame) and light brackets and Shimano A530 single sided touring pedals (£29 from Wiggle right now).

Just a couple of thoughts.

1) as both of the bikes you are considering have the rear discs brake callipers mounted within the rear triangle, you may not be restricted to a disc "compatible" rear rack. IIRC most such racks are designed for use where the disc calliper is effectively above the rear axle. It is worth having a look at other racks as from the pictures on the Planet X and Evans web sites the callipers do not seem to be in the way of mounting a "normal" rack.

2) Flipping a stem is very straight forward and can normally be done without disturbing the cables etc. If swapping a stem it is worth checking the length of the clamp onto the steerer as this can differ between stems and you may need to add or remove spacers to compensate for any difference. If you are getting a new stem it may be simplest to just get a range of suitable spacers which would also allow you to play with different stem heights as well as compensate for any difference in clamp length.

I agree these disc brakes do not interfere with racks, Evans guy told me this about the arkose. The thing is this rack is the cheapest, quality rack with a second, lower set of rails to lower the pannier attachment point. It moves the Ortlieb panniers away from the top plate which prevents interference with a rack bag I use, which can easily be removed to take stuff with you. It's just a design i like. The next cheapest at Evans with this appears to be a tubus frame at twice the price. A better rack but not needed for my needs.

OK, as soon as I take a look at the geometry tables, it all degenerates into a pile of [inappropriate word removed].
According to Planet X their bike has 590ETT and 592 Reach. Well, that's completely impossible, reach is measured from vertically above the BB and ETT is actually measured in the plane of the seat tube, not as they have drawn it see here.....http://forum.ctc.org.uk/viewtopic.php?f=1&t=90079&start=30
Even in the biggest size, the Evans bike has a 74 deg seat tube.....that's really steep. and 585 ETT
Planet X has 73 deg (still steep) and 590 ETT
By the time you put the saddle back on the Evans to counteract the steep seat angle, the Evans bike is actually longer than the X
Head tube is 20mm longer in the Evans, but stack is 27mm higher in the X......so the fork in the X is 47mm longer than the Evans? If the Evans fork is 47mm shorter than the fork in the X picture, you won't get a 700c wheel in it.
Evans quote their fork length as 395, head tube of 200, BB drop of 65 add those to 660, the stack is quoted as 616 ....that hangs together with a 71.5 deg head.
Only Evans quote front centre at 643, should be OK for toe clearance.
The biggest Evans bike has a shorter reach than the smallest X.....really?....when the ETT of the 2 big bikes is comparable?

Either I'm getting it all gloriously wrong, or there is no basis here to do much of a comparison between these 2 bikes.

So as someone who knows about bike geometry you think they've got it confused. As someone without your knowledge I'm totally confused.

Guess I'll only know which works by trying them. It'll cost £50 to get Evans to bring in the arkose in my size to try. I can't get to the Planetx shop to try the London Road. Basically I'm taking a chance on fit either way. If you can't trust supplied geometry then it's a case of blind faith. Now if I was a more normal size I'd at least be able too try the Evans bike out.

Any ideas? I need to sort a new bike out and these seem good, the Planetx bike is better with gears & brakes.

On the Evans bike, I can check that the "stack" makes sense relative to fork and head tube length, and BB drop.
X don't give me the measurements to check their stack, but its wrong against Evans.
X have also got "reach" wrong, it can't possibly be the same as ETT.
X's diagram has ETT illustrated wrong.....I conclude that X don't do proof-reading.
seat tube angle is too steep for anything other than racing on both bikes (Evans is a degree worse) but a layback seatpost will fix that for about £40 if its 27.2mm http://practicalcycles.com/products/241887--velo-orange-grand-cru-layback-alloy-seatpost.aspx
I'm going to ignore "stack" because I don't trust one of the numbers, so I'm left with head tube length to gauge bar height, then Evans bike has 20mm longer head tube...from the pictures I have seen both bikes have the steerer cut short so you may need to mess about with stems and stem raisers on either bike, although a useful thing is the big bikes tend to come with fashionable long stems....when you flip them, you get a decent bar rise.
As previously, when you put the saddles in the same place, the Evans bike is probably a shade longer than the X....I doubt it matters for a tall man, and if it does a shorter stem will fix it.
Chainstays on both are short for panniers/comfort, Evans is 10mm worse.
It doesn't look like toe overlap should be a problem on either bike......on the Evans I can't see front mudguard eyes, on the X you could fit them to the low-rider mounts.....mudguards and disc brakes need a bit of work anyway. I'm only looking at pictures, but neither bike has massive clearance for guards at the front.
Can Evans really charge you £50 just to get a bike in?
If you buy it, they will deduct your £50 from the price....if you don't buy, they trouser the £50?
Best I can do, good luck in your search.
EDIT
both have alloy frame, carbon fork, one has a tapered steerer. Both have oversize downtubes and top tube flattened a bit. I expect both will bump like hell.
On the pictures I looked at, both seatposts seemed to have the front edge of the saddle clamp about the middle of the post, so nothing to choose in terms of layback.

You get the £50 back whether you buy or not, it's just a deposit to make sure you're serious and will turn up to try the bike. Not unreasonable as it costs to bring in a bike from somewhere else - possibly many miles away.

I think I'd prefer to spend £50 on a trip to a bike supplier who had a much better range of bikes that I could actually try. I'd suggest Spa at Harrogate or any similar shop that would make an effort to get me a bike in my size. Banbury Cycles in Banbury, Oxfordshire got my order for a Surly Disc Trucker because they allowed me to borrow 2 of their employees bikes in my size. For no charge. I left my credit card details with them while I went for a ride.