Viewing 37 posts - 81 through 117 (of 117 total)
  • Time trialling on a MTB. Does anyone do it ?
  • Premier Icon njee20
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    Herne Hill?

    Premier Icon Talkemada
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    There was, at Eastway, but it's a ruddy great building site now. 🙁

    I near killed myself on that ride. I was having to push 27+mph most of the way, just to make up for all the time lost. Parliament Square was the worst; about 6 sets of lights in 500m or so, losing loads of time at each.

    Herne Hill? Wash your mouth out; that's in South London (spits)!

    Premier Icon Speshpaul
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    our local TT is a 9 shape-ish, with plenty of left turns.

    Convert, sounds like you need to "beat yourself" if that doesn't sound to rude. Take your road to a TT and just set a time, then set out to beat it next week.
    Sometimes if you've got all the gear you need to beat all the guys with all the gear. If you're not on your game, it will set up back. But just take a step back and focus on one goal – to be faster than last week.

    Premier Icon oldgit
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    I'm half tempted to try one again myself, certainly wouldn't mind doing another 2 up.
    There was a guy that did some silly times on a mountainbike when I did them in the 80s but I think it was an Olympic standard rider being naughty. Possibly Mathew Stephens?

    Premier Icon walleater
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    I won the Mid Shropshire Wheelers road hill climb up the Burway on my mountain bike with slicks one year, much to the annoyance of certain roadies, with cries of cheating due to having lower gears (well, A. I didn't use all of them, and B. it's not my problem amateur roadies push such retarded gears uphill!).

    I also got the 'Most Improved Rider' in the Club 10's, but that was more to do with starting the season on my mountain bike, and finishing on a road bike 😀

    Premier Icon ballsofcottonwool
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    Don't turn your riser bars upside down to get a lower more aerodynamic position I did and 60 miles later my wrists were in agony.

    Premier Icon fu_manchu
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    You should definitely give it a go if you want. I am actually more a TT'er than a mountain biker and we have seen the occasional mountain bike at a time trial. With regards to being "allowed" to ride in one:

    Most clubs will support you being a provisional member, so sign up for membership (no initial membership fee) pay for the TT and you are good to go, if you don't like it that's the end of it

    CTT has designated "come and try it events", which bypass the need to be a member of the club but still ensures you are insured against third party claims. I imagine your local club, if it has designated any as such, will indicate on their list of events, mine does.

    As others say, unless you end up in some sort of rivalry you can only aim to beat yourself, once you are on the course it doesn't really matter what you ride. Just remember, ride until you can't go any harder, then keep going! 🙂

    Premier Icon trail_rat
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    tting is **** ace – love it

    been TTing on a road bike with tri bars(these make a huge difference) for years but finally bit the bullet on a tt bike this year – nothing too flash – a second hand planet x stealth – ultegra. First race tonight

    what a difference the Position makes ! barely felt the headwind – despite it blowing a full on hoolie tonight. took the win by 30 seconds instead of my normal 2nd by a 10 seconds in this event !

    140psi in the tires and no tread made for interesting in the wet though – coulda done with an mtb for the cornering !

    biggest limitation i can see in MTB is lack of gearing …. i have 53:11 and on the flat can wind that up to 130rpm – now if your on your mtb you aint got a hope in hell of keeping up on 44:11 youll have to be doing near 200rpm ….

    failing that – get a big chainring on there (most courses are flat or near enough flat so you will only need the outer) get some clip on tri bars and slicks at 100 or so psi and youll be able to get up there if you got the legs !

    Premier Icon karnali
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    anyone t on a cross bike as i think the slightly shorter tt would bea better postion for clip ons than a standard road bike, been mulling htis a week or 2 may go out and try the clip ons on both and see if there is an noticable difference.

    Premier Icon molgrips
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    Yeah but trail rat, you'll not be able to travel fast enough to need 53:11 on an mtb 🙂 You have to be pretty damn fit to spin out 44:11 on the flat but on a slight down you are right – spin tastic.

    Another point re TT bikes – it's not necessarily just the aerodynamics. They have really steep seat angles which actually helps quite a lot in getting the power down. You can help your times on any bike by moving the saddle forward as far as you can.

    EDIT: Karnali – cross bikes have slack seat angles, do they not? You might struggle to get power down as well on one – my mate got rid of his for this very reason, and he wasn't even TTing. If you are using clip ons you might also want to try tilting the saddle down to save your balls.

    Premier Icon trail_rat
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    dunno karnali – was looking at this on the weekend there – i reckon the long TT with the seat forward on the road bike would be better than a cross bike – my next purchase for the TT bike is a long adjustable stem ( i do short and long distance and so would like to change position dependant)

    borrowed bike – bit too small – ie short TT and you can see im all bunched up and rounded … my new TT bike is alot further forward saddle relation to pedals and the stem is 110 – im going for a 130 next ….but still im alot more flat backed and i can tuck comfortably down without restricting my lungs like i did in that position above

    Premier Icon karnali
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    ahh i see some of the potential downsides int he arguement, another option i'm considering is reversing the seatpost to get the seat alittle further forward on the road bike when on the clip ons

    Premier Icon trail_rat
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    just thought id post that for a laugh – saddle gets alot of strange looks and comments 😉

    Premier Icon convert
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    i have 53:11 and on the flat can wind that up to 130rpm –

    Now that would be impressive – You thought of calling Lance, he might have a spot at Radioshack 😉

    53X11 @ 130rpm = 49mph

    44:11 @ 100rpm = 32mph which if he could keep that up would be more than impressive!

    The top end gearing would not be a problem unless there were some big rolling downs to pedal, but you might find the jumps between gears more of a problem. A road cassette would sort that out though.

    Premier Icon trail_rat
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    i said on the flat … i didnt say without a tail wind 😉 it was on the return leg of a TT where the outward leg was a stiff headwind. – still relevant as you wouldnt be keeping up on your mtb 😉

    i wasnt the only one pushing that – had one guy saying he was doing 79kph according to his GPS along the same section which would suggest similar cadence …. i only ride with a cadence monitor (no speed) and a HR … i dont need the computer to tell me im going slow !

    Premier Icon aracer
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    Well I've done a TT on a mountain bike. That's despite owning and regularly using (at the time) a full on TT bike – I was curious how fast I could go. Went round our local 10 course on my full-sus (no lockouts) with proper off-road tyres – semi-slicks, but they probably rolled about the same as the Racing Ralphs I use off-road year-round nowadays (then again I did actually run semi-slicks through the winter one year – did wonders for my bike handling skills!) IIRC I was about 3 minutes (~13%) slower than I'd have been on the same course on my TT bike, and also beat several other people riding proper TT bikes. Now admittedly I did do the pretend tri-bar thing with my forearms resting on the handlebars, so was reasonably aero – but then I have an extremely radical low aero position on my TT bike. I'm sure a lot of the difference would be made up using slick tyres and proper tri bars on the MTB.

    Then again, apart from at the come and try it events where anything goes (I rode round on my TT bike pulling mini a-racer in a trailer a couple of years ago – there was also somebody riding an ordinary), I don't think I've ever seen anybody else on an MTB at one of our local events. Not that you'd be laughed at – our local club at least is very welcoming. Just get yourself some slicks and have a go.

    Actually come to think of it the fastest 10 I've ever done was on a converted MTB – that's what our tandem is!

    BTW 44/11 isn't really that low a gear – 100rpm in that with typical 26×1.25 slick tyres is 29mph, which is more than anybody who doesn't own a road bike is likely to be able to push on the flat, and not even that limiting on the downhills.

    Premier Icon convert
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    Sorry, but on the flat no tail wind in the world would have a normal solo human @ best part of 50mph unless they were sprinting. Cavendish & co can only hold that sort of speed (and then normally less than that) for a matter of a few seconds after being towed there by a lead out train – and they ain't normal!

    Premier Icon aracer
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    i said on the flat … i didnt say without a tail wind it was on the return leg of a TT where the outward leg was a stiff headwind. – still relevant as you wouldnt be keeping up on your mtb

    Relevant if you do lots of events in strong winds maybe. Not really a good argument for not using an MTB to have a go at TTs – I've done plenty of TTs and have never gone anywhere near that fast on the flat, nor span out my top gear trying.

    Premier Icon trail_rat
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    just checked it- you are right it was downhill ..it dropped 100m over 3 miles – sure as **** feels flat when you ride it in either direction – my local stomping ground n all

    got to 50 odd ave on rollapuluza over 22seconds think thats only an 84inch gear – no wind resistance obviously – but no tail wind either.

    i have been overtaken by a guy on an mtb in a TT – i was just starting out and he was on an xc race machine with knobblys on …. and he flew – beat guys on TT bikes. He was ranked up at something like 7th in the world for marathon XC when it was on the go so it was a given he was going to be fast !

    Premier Icon aracer
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    Sorry, but on the flat no tail wind in the world would have a normal solo human @ best part of 50mph unless they were sprinting.

    Oh I don't know. A 20mph tailwind would only require the same power output (and superman position) as Mr Boardman had for his hour record to manage 49mph. I presume trail-rat has a power output like that and was out TTing in a force 5.

    Of course for a mere mortal who usually does ~26mph (ie can break the hour for a 25) you'd need a 30mph wind, or the bottom end of a force 7.

    Premier Icon trail_rat
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    so your confusing speed over short distance with speed over whole event now ?

    Premier Icon trail_rat
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    even if i only max out for 30 seconds in an event ill still have traveled further than someone who maxed out for the same 30 seconds on an MTB .. thats my point /….. im not saying you CANT tt on an mtb – im all for it … all im saying is it wont be as fast on standard gearing … chaps got a rohloff so it wont be hard for him to bung on a bigger ring

    doing a fast course 10 tomorrow night – ill see what i can come up with just for you guys – and lance of course

    Premier Icon aracer
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    so your confusing speed over short distance with speed over whole event now ?

    Well I'm assuming that when doing a TT which involves continuous effort over 20 minutes+ that you don't put on a 30s sprint for the part of the course where sprinting makes the least difference to your overall time. Not sure what else is wrong with my calcs.

    Premier Icon trail_rat
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    what like the finish ? – im quite sure i saw the look of a major sprintage on a few of the otehr guys faces as they came across the line too – perhaps a sign that either we didnt put in enough effort early on in the course or that pain tollerances at the end are higher. was still pleased with my overall time as someone who doesnt TT "all that often" and trains for endurance events yes with more TT specific training i could put in a more consistant time over the whole course but im not out to win so the scores on the doors at the end is all that matter to me just now

    Premier Icon aracer
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    what like the finish ? – im quite sure i saw the look of a major sprintage on a few of the otehr guys faces as they came across the line too – perhaps a sign that either we didnt put in enough effort early on in the course or that pain tollerances at the end are higher.

    Or possibly that it hurts more to put in the same power after 20 minutes than it does when you're fresh. If you really can put significantly more power down at the end of a TT then you definitely haven't been trying hard enough earlier on – you should go across the line feeling like you've just sprinted even if you haven't done so.

    If the sprint finish is with such a huge tailwind that you're doing 49mph then it really is wasted effort, effort that you should have use earlier in the course. Doing some calcs, if you're doing a sprint which might net you 30mph in the still on the flat to manage your 49mph then you'd still manage 45.2mph if you stuck to your normal "26mph" power output. Over 30s of effort that would gain you ~2.5s. If you did a similar sprint into the same wind as a headwind then you'd increase your speed from 12.3mph to 15.8mph (given power outputs to give you 26mph and 30mph on the flat). Over 30s that gains you 8.6s!

    Premier Icon trail_rat
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    fair enough – perhaps ill try more consistant effort tomorrow night – no winding up max speeds on the return leg and go for consistant burn.

    its an uphill finish (thus a downhill start) rest of the course is pretty flat but its open so if there is wind its horrible

    only 12 folk broke the 25min barrier (on a 10) on it last week – last time i did the course people were breaking the 20 barrier

    Premier Icon aracer
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    its an uphill finish

    Worth saving a little for that (assuming you don't have a stonking tailwind blowing you up it).

    Premier Icon trail_rat
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    ill do 50mph up it no bother – only a 30 second climb 😉

    Premier Icon convert
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    It was amazing how much my tt and tri strategy and perceptions changed after I started racing with a power meter. The reality for many is that whilst you feel like you are trying so much harder at the end of the race, you are actually putting out so much less. My old methods of sticking to around the same heart rate throughout the event were proven to be a massive error. It's not as simple as just sticking to an average power output either as previously demonstrated. Reigning back or pushing hard on hills and into headwinds is strategic too.

    Premier Icon aracer
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    Reigning back or pushing hard on hills and into headwinds is strategic too.

    Though not too much. Due to the non-linearity of the human body response and the decreasing returns of putting in extra effort as you go faster it's easy to lose more than you gain. I remember reading something by Chris Boardman once commenting that he tended to crawl up hills and sprint down them compared to lots of other riders and went faster overall this way. We really need a comment from iDave on this one, as I'm sure he knows a lot more about this than anybody else on here.

    Premier Icon molgrips
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    TT strategy should be constant power – like the Chris Boardman approach cited above. I've TTed (and ridden a lot) with a power meter, and when you set off your 340W or whatever it is will feel really easy at the start, but raelly hard at the end. But yes, the non-linear response of legs means that sprinting up a hill you will take more out of your legs (even with the recovery on the down) than if you keep it constant.

    By non linear, I mean a little more power takes a load more effort. For instance, on my good season I could ride at 330W for 25 minutes, but 270W for almost two hours, and 200W all day.

    Premier Icon njee20
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    How much do you weigh? That's a pretty impressive power output!

    I can do about 320w for 6 minutes, couldn't do 200w 'all day' either!

    Premier Icon ooOOoo
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    uh oh, we're getting into power/weight ratios…

    Premier Icon trail_rat
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    nick seems to depend on the measuring equipment ….only time ive ever seen power figures was on a mates ergonmo or something power bb. Lets just say if i was putting out the power it said i wouldbe riding for lance !

    Premier Icon njee20
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    Hmmm, probably a reason they stopped selling them!

    I've found having a Power Tap really interesting, planning to do my first TT with it in the next few weeks, only be a club 10, but will be interesting to see what I can push myself to do in a race situation! I sincerely doubt I'll hit 300!

    Premier Icon trail_rat
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    Yep i was removing it from the bike after my shot and we stuck it on ebay – 800 quid – they stopped selling them and iirc wound up a couple weeks later

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