Old mtb to gravel conversions – the problems.

Prior to the introduction of “gravel” bikes I did a number of conversions of mtb frames to dropbar to get a bike suitable for riding long distances to get to tracks. Although probably I was aiming for mild monster cross because I want large volume tyres.

It’s an attractive idea to take an old quality 26″ frame and repurpose it. Many of the old mtbs have what is now basically “gravel” geometry at the front end, and a comfortable wheelbase. There’s plenty clearance for 2′ tyres on 700c rims in this particular case. (Obviously a 29er will present no tyre size problems.)

There are a few gotchas though.

One is a higher BB, which I’d regard as a feature rather than a bug, but the other is more of a problem, and it’s the reach.

If you take a 26″ mtb frame that fitted you and put dropbars on it, then the reach will be much longer.

As shown here. Using a very short stem, and Brian dropbars from On-One (which have a short forward extension), the hand position is much further forward than the original. The straight bars are those I used to use on this bike.

The bike is still quite rideable and feels ok, but I’m not used to a stretched out position. It doesn’t bother me when the bike is in single speed mode because your position is more fluid, but I notice it much more when I have gears on it because more time is spent in the saddle.

Probably the answer for recycling is to find a frame a size down so the reach is more suitable.

Your reach is also affected by bar width. Typically, MTB bars will be wider. Your hands being further apart shifts your shoulders forward (isosceles triangles) so the difference in top tube length will be less than at first apparent.

One of the old bokor’s – lovely frame – I’ve still got mine running on 26″

As an aside, people have tried running this frame with 27.5″ with some success (moveable dropouts helping here)

How do you measure reach? I have an old charge duster frame thats setup as a 9 speed / single speed rigid bodge but I think would work quite well for this? Its a medium frame and I ride a large new style BFe now so its a bit small for me (might be a good thing?)

Yeah you need to size the frame down a couple and have a loooong seatpost.

Fit the shortest stem you can find.

How about reversing the stem? Will look “edgy” but put the hoods and drops in a similar position to the flats.

I just bought £21 of narrow tyres , luckily they set up tubeless fine, lowered the bars as much as I could and bought the biggest front ring I could find at the time that fitted .
All seems to work well,gave an old bike that I nearly gave away a new lease of life/more value.I rode in loads heading out of winter.

I’ve stuck 27.5″wheels/47mm gravel kings on my Soda and the rolling diameter has barely changed from the previous 26″+ Maxxis 2.3s. I can see a low BB being beneficial if all you’re doing is fireroads, but as soon as there’s anything approaching “easy MTB”, a sensible height is beneficial for being able to pedal up stuff.

As for the drop bar thing, I’ve still yet to understand why drop bars are good for gravel, and if you’re repurposing an old MTB, why not just stick flats on it and have a bike that will still cope with the odd bit of mild technicality or singletrack? There’s plenty of ways to achieve more hand position options on flats, or indeed use weirdy bars like Jones ones. I’ve tried both, but prefer the flats with inboard bar-end options.

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I’d be looking at flats and bar-ends, however you could easily lose a load off the stem on that drop bar pic up there.

scotroutes
Your reach is also affected by bar width. Typically, MTB bars will be wider. Your hands being further apart shifts your shoulders forward (isosceles triangles) so the difference in top tube length will be less than at first apparent.

Good point, especially for a modern mtb, but the old ones used narrower bars. The flat bars I have in the picture place the centre of my hands at the same distance apart as the drops.

JonEdwards
As for the drop bar thing, I’ve still yet to understand why drop bars are good for gravel,

I don’t think they’re any better for gravel particularly, but they’re not a disadvantage, and they’re much better for long road rides to offroad tracks – especially when you live up our end of the country where headwinds are guaranteed. They’re also ok on mild technical stuff, e.g. the descent on the StrathPuffer track if you’re not prone to heroics.

For local stuff, there’s no reason not to use flat bars.

wzzzz
How about reversing the stem? Will look “edgy” but put the hoods and drops in a similar position to the flats.

I’ve thought of that. :)
It may work quite well with a really short stem.

No problems here. Only bike I’ve ridden since early March; got 1000km on it now, pretty much entirely out of the front door. Canal track at dawn this morning to an old quarry for picnic breakfast, then back along minor lanes.

Stopped at the shop on the home leg and filled the pannier for tonight’s barbecue…faster than my mountain bike was, more comfortable and versatile than the road bike.

I have done something similar with my old 26″ soul. Put on some carbon forks, 700c wheels with cheap gravel tyres and resurrected an old longer stem but still using flat bars which gives a riding position between the op’s extremes. I find it ideal for these times of’ no car no gnarr’ , the only problem being that the cheap tyres are a bit limiting if I start getting carried away.

#everybasecovered

Just needs aero bars, and every base is covered.

It won’t be the first Thorn I’ve seen with a similar setup, do Thorn know something we don’t?

do Thorn know something we don’t?

A dealer with a good stock of mind altering drugs?

I did this for Mrs Blackflag to make her a bike she can use for gravel / touring while im on my arkose. Slick tyres, rigid forks, very short stem. Everything else is over thinking it.

Personally I don’t have an issue with reach, but then I like my MTBs on the short side and my curly-bar bikes long.

Stack is more of an issue for me, especially (since the title mentions them) old MTBs which are often uncorrected.

The big one for me, though, is head angle. I find drop bars and “slack” head angles (and in this context I’m talking less than about 71 degrees) just feel like a square peg in a round hole: the whole cornering technique and body language is completely different for each. Find for plodding around but awkward for anything more engaging. YMMV and probably will ;)

Everything’s a compromise.  Decide which is more important, getting on the drops to get out of the wind on the road, or reach issues with bendy bars.

Personally I’ve never found that drop bars make that much difference. (especially with fat tyres on anyway)

Bez
…The big one for me, though, is head angle. I find drop bars and “slack” head angles (and in this context I’m talking less than about 71 degrees) just feel like a square peg in a round hole: the whole cornering technique and body language is completely different for each…

A lot of the older mobs do have steep enough HAs.

Personally I’ve never found that drop bars make that much difference.

Nor me. Very little difference in speed on a 10 mile loop I have done a lot of times over the year and the time difference between drops and flats is negligible. All really down to if you like ether multiple hand positions of drops or the better handling/more fun hand position of flat bars. I use the latter as I don’t ride for 5 hours at a time so don’t need multiple hand positions.

kerley
Nor me. Very little difference in speed on a 10 mile loop I have done a lot of times over the year and the time difference between drops and flats is negligible.

But 10 miles isn’t very far, is it?

As I said previously I see the advantage of a dropbar when there’s a lot of road miles between home and the trail, doing your stuff, and then riding home. I’m not greatly concerned about maximum speed as such, but I don’t want my body pushing more air than necessary.

However flats are quite unpleasant if you have a persistent headwind and have a long way home. Eg, when I do the Alladale loop, I have 30+km road, 50 km dirt track, and about 35km road back. There’s plenty rides like that up here, RSF paradise.

Currently in similar situ except with my 29er, because like it or not can’t deny that I miss the multi-position ride on the wide drops that I had on the predecessor (Vagabond monstercross) which I was using for an all-rounder.

Similarly to OP I would probably need a very short (and steep?) stem to fit drop bars suitable for my reach.

Currently dithering between 1. a loop bar or 2. a flat with stubby bar-ends.

Wish I could easily say in totality what it was about the drops that felt so right. Being mostly an MTBr all of my adult life I hadn’t ridden drop-bars since about 30 years earlier. Maybe it was a combination of the Vagabond geo and the bars that did it. It was at least partly down to the many grip-positions (at least 5) as I enjoyed changing posture regularly. The padded bar-tape felt great too. It just felt right For purpose, especially longer rides. Complete. Without trying drops out on a different bike I’ll not know for sure which way to stay.

Here’s a pic of a similar conversion to yours, epicyclo. Stem is pretty short. Looks fine.

https://theradavist.com/2017/12/kyle-from-outer-shells-mikkelsen-drop-bar-mtb/

ARRRHHHHHHH! Pass the eye bleach, Please! One of the most expensive Headset bearings known to man (Chris King) and he’s installed it UPSIDE DOWN!!!!!!!

Has he NO respect?

@Malvern Rider – some nice touches on your bike. I like it.

ARRRHHHHHHH! Pass the eye bleach, Please! One of the most expensive Headset bearings known to man (Chris King) and he’s installed it UPSIDE DOWN!!!!!!!

Has he NO respect?

its a hipster niche bike thing, they all do it.

That and builds dripping in paul component kit.

get with the times

@Malvern Rider – some nice touches on your bike. I like it.

Not mine honest guv, just googled a pic of drop bars on mtb

I do remember Pauls components though, was the bling of the day. Afraid that I’m a Deore bore.

@Simon_Semtex

You neglected to mention the Hite Rite! As a hipster-spotter you’ll know that anything that was manufactured before 2k is unfit for any purpose (excepting ill-considered fashion/posing).

Watch the underscore BTW, I read that it’s approaching hipsterish in a meta-ironic boomerish-stylee (along with the word ‘stylee’)

Modern life eh? 😎

*doubleedit- wow, it appears to be true! https://chrisking.com/products/t-shirt-upsidedown-king-indigo-lg

Learn something new-sless every day!

But 10 miles isn’t very far, is it?

It certainly isn’t but the point of my comment was that I have done the 10 mile loop 100’s of times over the years (all recorded) so have a very good set of data. Drops don’t make a lot of difference to speed when riding an undulating loop (for me). I also have quite big saddle to bar drop so my flat bars are pretty low and in a headwind I can crouch down further for short stints.

Whatever oddball stuff we might try, Rivendell have probably done before..
The actual bar to front hub relationship is quite roadster, probably could ride OK with the right bar flare, a bit elbows-out. Looks too short to me though. At this point I fail to see the point in drops but each to their own : )

Aren’t the drops meant to be further forward anyway?
I would thought some stumpy aero bars clamped on to the flats would be better. At least then you have the flat bars for the off road stuff.

jameso
At this point I fail to see the point in drops but each to their own

I’m pretty agnostic about bar shapes, it’s really about having suitable hand positions for each of the bike’s purposes, road, offroad etc. For the purposes I mentioned being able to get out of the wind on long hauls on the road is useful (if not in the tropical south, at least up here in the northern Highlands). A dropbar does all that in one go.

In many ways a set of North Road bars may be better. With a long quill stem and with a quick adjustment it provides the same utility as a set of deep drops and has the advantage of being able to be reversed for more upright cruising. Problem is you can’t use quill stems on modern forks.

Whatever shape works for you is best.

Maybe it was a combination of the Vagabond geo and the bars that did it.

I shifted all the parts off my Vagabond onto a rigid Cannondale Flash & it works great & saves a boat anchor of weight. Conversely I’ve put flat bars on my Awol that replaced the Vagabond because the reach on it is too the moon and back. I think we get too het up about what type of bars a bike was planned to be fitted with rather than looking at the actual numbers and working with our own body shape & riding preference.