I did an unsupported century last year on my 30 pound "shop" mountain bike. The first 55 miles were easy but the last 45 or so were pretty horrible.

This year, I want to try it again but with more hills. I really don't want to lug my 30 pound mountain bike up the hills, but I don't have the money for a decent road bike.

If I follow a reasonable training plan on my 30 pound mountain bike this year, will I be "safe" moving into high-dollar 15 pound rental road bike 24 hours before an unsupported century?

WARNING: This question was edited from its original version. It originally used the term "homemade" century to denote an unsupported century. Also, the question originally asked if it would be okay to switch to a road bike the day of the mentioned century. Now, the question asks if it is safe to switch 24 hours before the mentioned century.

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    Your butt and the new bike seat will not be friends. Jan 31, 2016 at 14:27
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    You could consider some other help appart from slick tyres, like stiff saddle and good bibs and handlebar extensions (if you dont have) to have other positions. Or train on a vintage road bike (not much more expensive than a modern road rental) then switch to modern, if it is more about fitting in the ride atmosphere
    – gaurwraith
    Jan 31, 2016 at 18:58
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    Have you thought about picking up a used road bike? I had an 80s Trek 400 that was pretty great and lightweight, and rode a lot better than those heavy gas-pipe hybrid bikes. Plus it was very easy to keep in shape myself. It was very inexpensive and set me on the path to a newer road bike.
    – jfa
    Feb 1, 2016 at 1:23
  • JFA & gaurwraith - I'm considering buying a cheap vintage road bike to lower my risk. Originally, I was thinking about taking the high-end rental on a 50 mile test the weak before the century. Unfortunately, by the time I paid for both rentals, I might have forked out nearly $100.
    – Shawn Eary
    Feb 1, 2016 at 4:33
  • What makes a century homemade?
    – Holloway
    Feb 1, 2016 at 11:51

4 Answers 4


I've done pretty much exactly what you describe: training on a (really terrible old beat up MTB) and then using a rented road bike (totally different configuration, weight, etc.) for a century (RideLondon-Surrey 100) with no problems. I can't see how I wold have survived riding that distance (on those hills!) in my MTB. So I strongly recommend switching!

The answers so far sound like good general advice, but it's not clear that any of those answering have actually tried what they are advising against.

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    I've been around plenty of 'rode the MTB and now I have a new road bike' switchers. They are usually fine for 20 miles or so... then their back hurts, arms ache, and then then start trying to stand all the time because their rear is in agony. I'm glad you had a good experience, but that is the exception.
    – david1024
    Jan 31, 2016 at 15:48
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    I picked up a rental road bike around 5:00 PM last night and did about 110 unsupported miles today @ 14.6 Moving Avg & 13.4 Overall Avg. I lived through the event, but as everyone said, my rear end was in serious discomfort even with padded cycling shorts. If I had been in better shape and pedaled faster, then maybe my rear wouldn't have hurt so bad. So it seems as if it is possible to switch from an MTB to a Road Bike less than 24 hours before the start of an unsupported century.
    – Shawn Eary
    Mar 20, 2016 at 2:05
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    Disclaimer: I did look at the road bike a few days before the century to get a fitting at the rental shop, but I didn't ride it. Also, I did a very brief familiarization ride for 30 minutes the night before the century. Finally, I did have some limited road bike experience prior to this event but that was over 16 years ago on a vintage road bike. BTW: I feel that it was by the lord Jesus' grace and mercy that I completed the unsupported century today. Even though my stats may not impress the veterans here, the century was still tough for me.
    – Shawn Eary
    Mar 20, 2016 at 2:10

I would strongly advise against that. Your legs are not going to be the problem, and neither is your overall conditioning/strength.

If you are going to be around other riders, you need to be able to stop and start and steer safely. Road bikes steer with your butt while MTB steer with handlebars. This is a big deal when you are tired and running on instincts. You don't want to crash or cause a crash.

Your core and arms are probably not going to be strong enough to hold you up for a century on a road bike unless you've trained on one. A spin bike could help if you can get a road-bike-position. Also doing lots and lots of planks. Think of riding a road bike in a century like a 4-5hr plank. If you can't hold it that long, you'll start to sit which causes pain in your rump and arms/hands.

Short story:

Ride what you trained to ride, in this case the MTB. I often feel 'whiny' at the 45 mile point and again around 60 miles and again at around 90 or so. Usually eating something fixes it (power bar in my case). Almost like someone lubed my knees or something and I'm raring to go again. I usually only stop long enough to refill water bottles and carry all my food on the bike.

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    Yep, novelty is fun when you have energy to spare, familiarity is priceless when you're exhausted. Jan 31, 2016 at 7:18
  • I don't think it is impossible, it is just 100 miles after all... I tried to give some tips to help if he really wants to do it... those are issues that I've seen with a lot of MTB to road switchers..... Also, if his overall weight is low (say <150lbs), he can probably do whatever he wants as it won't require much strength to holdup the weight. Skinny guys always have it easier on bikes.
    – david1024
    Jan 31, 2016 at 15:51
  • @david1024 - Thanks for pointing out planks. I do 225 pushups a week but have never done planks. I'm 66 inches and weigh 145 but still consider myself a little "heavy" for a cyclist.
    – Shawn Eary
    Feb 4, 2016 at 2:47
  • Shawn, you probably fit in the can do just about whatever you want category. Generally, MTB is all about the short bursts of intensity and road is more of a sustained effort thing. The way I see this play out on the road for the (new-to-road-but-experienced-MTB) rider is that the first 20 miles are easy... but then they wither on the road as their arms tire, form sags, and cadence drops. Lighter guys though, tend to do a lot better. After a very-few weeks, they can hang with the group just fine. (the strength was there, just the form/pacing needed correction)
    – david1024
    Feb 5, 2016 at 14:47

No - that'd be like putting a Toyota rally driver into a F1 car, on race day. You'll be able to ride, but you won't be used to the nuances, as david1024 says, BUMSTEER.

Road bikes need at least a week to get used to, and I went 500 km of riding in a month, before becoming comfortable on a road bike after being on MTBs for years. And I still go downhills faster on the MTB than on the road bike.

You can prep your existing ride by removing non-essential weight like mudguards and lights. Go for new tyres with mostly slick tread rather than knobblies, and go for the higher end of the safe working pressure in the tubes. Lock out any suspension if you can do so.

Or if you're liking road riding, do consider buying a road bike. I know they're stupid prices new, but riding is still cheaper than other addictions like smoking and drinking :)

A good used road bike could be more within your reach. Consider several months practice if you're moving to cleats or changing cleat systems too.

Finally, remember cyclists want to own N+1 bikes....


Are you sure the weight is the real issue? Remember the weight you haul up a hill is the combined weight of the rider and bike, so cutting 15lbs off the bike will probably only be a change of around 7.5% in system weight - and you'll have a smaller choice of gears. Putting good road tyres on the MTB will make a bigger difference in energy used on the day. Where good = low hysteresis rubber, NOT racing bike narrow - look at the speed ratings on Schwalbe's site. Use a rigid fork, use the correct gear for climbing, have comfortable grips on the bars.

Qualifications for posting: ex-San Francisco bike messenger - I KNOW about riding hills!

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