Hi!

Really really tickled by a Hello Dave, but the ones in stock are stuck with a 160mm rotor (I think anything bigger and the calliper fouls the frame).

Riding is ‘Scotland’ +, so plenty big hills and long steep descents, I am huge and fat and of marginal skill so brake ‘a lot’.

I know most is with the front, and that’ll be 200mm, and I’ve hurtled round the alps for years with a 180mm rear and the brake grip of death, with no issues.

I’m trying to think to when I ride stuff where hauling on the anchors is required, and it really is all through the front, back is only to modulate/skid as needed.

I think.

I have a gravel bike with 160mm front and back, and that manages fine even on some fire road descents from hell (e.g. round the back of Dumyat down to Menstrie for anyone that knows the Stirling area).

Or am I trying to convince myself?

…

If you want the longer story, you may know I have a glorious LLS custom ti frame, for full fat or 29+, but I am getting really tired of wheels/tires breaking/failing and the subsequent lack of availability of parts, lack of choice and the high cost.

It’s my only mountain bike, so gets ridden a lot.

The last few months have been a constant stream of hubs, free hubs, axles, spokes, rims and tires going, and it’s really putting a downer on riding. Either the bike is off the road for weeks waiting for a ‘bit’, the chances of a fix away from home if something goes are zero due to niche nature of components, or when I do go out something does break and ends the ride (or in my head I think it’s going to so I really hold back.

Long boring sob story, but I think a huge tall guy, esp with my Pppppooowweer! just puts too much strain through 150mm or 197mm hubs on 29+ rims.

The list of wheel related mechanicals is getting silly, was much less when I rode a ‘normal’ 29” bike (even full sus).

Hence desire to have a nice LLS everyday bike, with normal components, suitable for a tall chap and minimal expense.

160mm is more than enough. I’m over 6′ and the wrong side of 90kg and I’ve been riding for the last 15 years: Dumyat, Scottish Highlands stuff, Lake District, Peak District, various trail centres, Canary Islands, etc. and never had anything bigger than 160mm on the rear.

I’m 125 kg, 160 is plenty on the back.
I use 180 rear on my ebike, but only 160 rear on my bikepacking surly. Both bikes have 203 on the front though.

Stop worrying and get on with it.

Its just physics, less diameter will just mean slightly more stopping distance is needed. Assuming grip, weight and speed remain the same.

Might improve your skills as it will force you to look ahead, use the front more, weight up the front more. You could also experiment with tyre pressures and different tyres to find the best grip.

Or lose weight.
Or ride slower 🙂

My hardtail is 160/140mm, never bothered me. Big brakes are probably worth it if you need the heat dissipation of a larger rotor.

Its just physics, less diameter will just mean slightly more stopping distance is needed. Assuming grip, weight and speed remain the same.

It won’t make any difference to stopping distance if you can lock up the wheel – the stopping distance comes down to your ability to modulate the brake in that case. I run 200 mm front and 160 mm rear on all my bikes. Locking up the rear tyre is no problem. A bigger rotor would just mean skidding with less pressure on the lever, but less modulation.

The last few months have been a constant stream of hubs, free hubs, axles, spokes, rims and tires going

(IANAE but) I don’t buy the relation between those and simple axle length as you seem to imply

tyres – NO chance
hubs – how do they fail and what brand are you using?
Axles – Again how, and what provenance?
freehubs – unless the chainline on yr frame is VERY weird I don’t see how this can be related and even if it is weird, I still doubt it
Spokes – are the wheels well-built and sensible spoke count & lacing ? Straight-pull or j bend? I don’t imagine that the angle at flange or eyelet on a 29er with 197 axle or a 26er with 135 and even if the angle was greater it ought to be possible to build appropriately
Rim – same as spokes

If all the above is of good quality, I do wonder how much frame flex might have to do with axles failing and after that, maybe hubs, freehubs might have secondary problems ?

I’ve 160mm on my #downcountry and its perfect – no need for 180mm unless you’re lobbing yourself down something that gets you to the top on a chairlift.

My larger trail bike came with 180mm on the back, but I have no doubt it’d be fine with 160mm in the UK.

Just get on and ride the thing, you’ll be fine.

If anything, with a 180mm/160mm setup, put a four pot caliper up front, and if you’re really worried, one on the back – but it just means you’ll find it easier to lock up – no bad thing, but not neccessarily needed.

Just chuck some Codes /
Zees / MT7’s etc on there with a 200mm front rotor and you’ll likely be fine.

I’m not as tall / heavy as you and prob less sustained steep stuff but my Vitus Sentier with 200 front / 160mm rear (just what I had) and Code R’s had amazing braking. The same is going on my custom Marino (if it ever turns up).

I think you will be fine. The worst that will happen is the disc will go a shade of black if you are dragging it alot. As said the limiting factor to stopping is usually grip rather than braking power.

Marvellous, cheers all.

Not the responses I expected though. Bugger! 😆

scaredy – tyres I agree with you are nothing to do with the big wheels, but I have had terrible luck with ride ending failures (rips, tears, big punctures, sidewall failure and bead failure) and the chance of a quick replace and tubeless remount of a full fat tire is zero, and pretty much zero with 29+.

The constant hub/wheel failures do need its own thread however.

You’re no relation to @midlandtrailquestsgraham by any chance?

You might well just not like it, even if it works. Try it on a bike you already have first? Also, I’d have my doubts about the bike tbh, if they’re stupid enough to have it only work with 160mm rotors, that’s just such a basic screwup can you trust the rest of it?

My main bikes are all 160 rear (and mostly 203mm front, don’t know why I like it like that but I do). Works for me, for pretty much everything- I upgrade to 180 for the alps just because of longer descents but in the UK, I’ve still found nothing fierce enough to challenge the 160, that isn’t also short enough for it to not be a problem. Obviously different brakes handle heat better than others, but if you’re not a) massive, b) a chronic dragger or c) encumbered with shit brakes, I wouldn’t be too worried.

I damn nearly set the bike on fire the first time I did fort william dh, but that’s because I had the back brake on essentially the entire time as I tiptoed down it like an absolute coward on a trailbike with openface 🙂 Subsequent visits have gone better.

Probably fine in the UK, but in the Alps I’ve cooked both front and back discs to the point where the brakes just stop working and you have to stop mid descent to let it all cool down.

I think the Hello Dave frames can take a 200mm rotor anyway. Because of the way the 200mm adaptor pushes the caliper forward and upwards it clears the seatstay part of the frame. The 180mm adaptor just pushes the caliper upwards(into the seatstay). It may be worth dropping On-One an email to confirm but I saw a post on Instagram from a Hello Dave owner who had done this.

lewis75 – interesting, I did wonder if that might be the case. Would help alleviate the issue footflaps raises.

I remember midlandtrailquestsgraham used to be a regular, is he still around? no relation, that I know of!

Northwind- re on-one: yeah, it might be a bit of a risk but its a good price, ready to ride and a relatively easy way to get the geometry I’d like without investing a ton of cash.

It’s me playing to see if I like riding ‘normal’ bikes again 🙂

However if Pole ever reply to my emails I might skip straight to full-sus, lets see

He was a regular, don’t know if he ever posts now but someone was saying they’d seen him about not long ago. He had a reputation for… stress testing kit, notably including Gates carbon belts.

I’ve got a 160mm disc on the back of my hardtail, and have no problems here on any ochils descents, as long as it’s a quality 160mm disc.
I cooked a set of 203mm “aztec” discs over a short period of time, they got very scored & marked & wouldn’t stop squealing.

If your fed up with broken bikes I’d stay well clear of Pole. Give Geometron a call instead.