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I bought a street hybrid 2010 Giant Seek 0 a decade ago. It has maybe 30 miles on it. The bike has a 700c 25mm tires and solid Aluxx frame.

I want to ride again but I'm 300 lbs. (136 kg) I'm guessing I'm either going to injure myself, or, break the frame trying to ride it in the burbs.

I'm thinking my best bet is to replace the solid front fork with a suspension fork but I don't even know what questions to ask. Can I get some advice?

I've heard compressed air shock, 29 and 80mm travel. I haven't seen any that are 80mm travel and I don't know what 29 is.

This is the same model, from https://www.pinkbike.com/buysell/2535329/

enter image description here

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    I don't think the tires are 25mm. They look wider, and 25mm would be a terrible choice for a hybrid bike.
    – Weiwen Ng
    Sep 16, 2023 at 9:52
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    @WeiwenNg that's not the OP's photo. And while I didn't go to 25s I did run 28s on my hybrid (sold with 35s) when I started doing longer rides (up to 70km). The existence of hybrids that are basically road bikes with flat bars suggests that manufacturers think there's a use case too. So unconventional, but not terrible.
    – Chris H
    Sep 16, 2023 at 14:52
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    Can you confirm the width of your current tyres please ? 25mm is possible, but according to your link it was specced with wider tyres when new. Possibly someone's changed them.
    – Criggie
    Sep 17, 2023 at 11:09
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    I have stock rims, and I changed the tires to armadillos. So if the stock rim was 28 thats likely whats on it. Would an oversized tire work and if it did, on a 28mm wheel how much good I go up?
    – Zarxs
    Sep 18, 2023 at 6:27
  • This looks like an aluminum bike frame, in which case: congrats that should be more or less safe. Carbon tends to not break at all for a long time and then fail all at once, but with alu frames you usuallly see cracks or weakening welds long before major failure (assuming regular biking and not downhill with jumps). So if you're scared just check the welds / weak spots before riding and you should be good.
    – Hobbamok
    Sep 18, 2023 at 13:35

6 Answers 6

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Personally I wouldn't replace the fork, but I'd make smaller changes and start riding.

The back wheel takes more impact than the front, because a greater proportion of your weight is over it. So far better than suspension is taking the weight off the saddle over bumps so your legs absorb the shock (assuming that's an option for you). If you can't unweight the saddle, a suspension seat post would be of some use here, either on its own or with suspension forks if you go down that route.

Fork replacement can end up being rather tricky and more expensive than it should be, especially as you'd want a good quality suspension fork that can be set for your weight. It's probably more than the bike is worth.

That looks like a sturdily built hybrid with plenty of spokes in the wheels. I'd fit the widest tyres that will fit in the frame and fork, and start riding. Run the tyres as hard as necessary but no harder. You probably need new tyres by now anyway if it's been in storage. New brake pads might be a good idea too as they harden with age.

I had a similar hybrid (a GT) and while I'm a bit lighter than you, I had a child seat on the back, plus luggage for a similar total. I cracked a rear rim at some point which meant a new wheel, but that wasn't dangerous. Eventually a weld failed, a few years after taking the child seat off, and after using the bike for 12 years and over 25000 miles (I recorded 40Mm,and know I didn't record everything).

The "29" is probably 29" wheel diameter. That's mountain bike terminology; the same size is also known as 700C. You also need to match the axle type. That's probably quick release on a decent hybrid of that age, or a solid axle with nuts - they fit the same forks, but thru axles are different.

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  • I already put in shocked seat post and when to a larger mor comfortable seat, but the first time i attempted to deal with a curb told me and shocked fork would be important.
    – Zarxs
    Sep 18, 2023 at 6:29
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    @Zarxs riding hybrids up kerbs is always to be avoided, even suspension hybrids. Riding down them can be done with care, standing on the pedals and shifting your weight over the back then the front wheel. Even on my mountain bike to ride up a kerb I'd stand and use my weight and arms to lift the front wheel
    – Chris H
    Sep 18, 2023 at 6:44
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Congrats on wanting to ride again.

If I were in your position, I'd inflate the 25mm tyres to around 80-90 PSI (or if you have the 32mm stock tyres go for perhaps 60 PSI) and then do a basic M check to make sure nothing's loose and that the brakes work as expected.

Then go for a slow gentle ride from your home up and down your street, perhaps a hundred feet, or a hundred metres. You'll probably notice something that needs tweaking, so do that, and put the bike away. This is probably 5 minutes riding total.

NEXT DAY, do it again. Go ride down to the corner, the nearest intersection or a feature like a park or a particular tree or something. There's no rush, ride at walking speed if that's comfortable. Then return home. You could follow a different route home, if feasible. 10 minutes riding or so total.

By this stage, you should have some confidence that the bike isn't going to collapse under you.

THIRD DAY, Pick a place you want to go, that is 10 minutes each way. Go there, do the thing, come home. This is the start of a habit, taking the bike to do something instead of driving.

Make this habit stick - ride every day for a week and it starts to become normalised.

Don't worry about speed, that comes later. Don't care about fancy bike clothes or shoes or whatever, your normal daily `round-home wear is going to be fine to get started. And remember your bike route doens't have to be the same route as you'd drive in a car - it's fine to take a quieter and more scenic route.


I was 120 kg in 2013 when I got back into riding. Too many pies at the office job, and too much desk/screen time. I was riding a steel MTB and it coped fine for years, until I bent the seatpost by having it up too high.

Your bike will be fine for any normal street riding. Just remember to not ride it off kerbs/curbs like a 10 year old on a BMX, and for comfort try and not put all your weight on the saddle (its not a seat, its a saddle) Some small amount can be on your arms, but your weight should be taken by your legs as much as your butt.

The existing solid fork should be fine for your initial return to riding - suspension is generally not needed on streets. If you can walk a path normally without looking at the ground, you can ride that same path with no suspension.


Once you have a couple months riding under your belt, then decide if you want to keep riding road and what about this bike annoys you or detracts from your ride.

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    I believe the stock tires are 32mm, not 25mm. 25mm would be a strange choice for a hybrid, and this article seems to confirm that they're 32mm. Does that change the pressure recommendation?
    – Weiwen Ng
    Sep 16, 2023 at 9:53
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    @WeiwenNg yes it would - good spotting. The example photo shows tyres that look wider than 25mm, but its possible OP has narrower ones fitted.
    – Criggie
    Sep 16, 2023 at 10:26
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    +1 but I'd add testing the brakes when you start riding - before brakes not working could be dangerous.
    – Pere
    Sep 16, 2023 at 16:56
  • 25mm and 80-90 PSI for someone who weighs 136 kg? That's a recipe for pinch flats!
    – juhist
    Sep 17, 2023 at 10:11
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    I would also note that various bikes have a legal disclaimer that they are designed for 130 kg maximum but at 136 kg I would not worry about that at all. Do the tests as described in your answer and OP should be fine.
    – quarague
    Sep 18, 2023 at 8:31
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Personally, I'd suggest leaving the fork as-is for now. Maybe later you'll want to change it, but save that for later.

Regarding your weight, I don't know what this specific bike is designed to be able to handle, and I seem unable to find it. That said, their generic instructions suggest that most of their bikes are rated to around 300 lbs, so I'd call that close enough. Looking at your picture, it looks like a pretty rugged bike, so I'd not be too worried about it.

Your weight is high enough that I'd suggest inflating your tires to the maximum pressure given on the side of the tire.

In any event, given that your weight is likely to be near the upper limit of what the bike is meant to be able to handle if not above it, just try to take it easy -- don't take it off any sweet jumps, don't hop curbs, avoid potholes if possible, don't take it on bumpy trails (smooth crushed granite is fine), etc. If you do find yourself in these situations, that's fine, but try to keep it to a minimum. Don't push the bike too hard, and it should be fine.

Once you've got a few hundred miles on it, then maybe you can think about a new fork, but give what you've got a chance. Personally, when it comes to a hybrid bike like this, I'd rather have a rigid fork.

As for riding again, I wouldn't worry too much about hurting yourself (unless you're in poor health or really out of shape, in which case maybe talk to a doctor first?) -- just take it slow at first -- ride short distances, and don't worry about going far or fast until you're ready. Keep it fun -- if you make it unpleasant, you won't want to do it.

Good luck!

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  • Thanks I'll do what I can to avoid curb hopping. Instincts are still there, ability is not. I was hoping a fork to reduce the risk to the bike. It's my dream bike so I would willing to pay extra (8 speed internal hub). Advice appreciated. I'll try the tires first and work my way up slowly while I carefully research forks.
    – Zarxs
    Sep 18, 2023 at 19:14
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Here are a few more general remarks from my experience (I agree with the others to keep the fork).

It's good to ride. But take it easy! I loved Criggie's approach. Specifically:

  • Protect your knees. The knees are suffering from your weight already. This involves riding at the proper saddle height, especially not too low. (This is probably the single most important adjustment.) Prefer faster pedaling at lower gears over more power at higher gears. Do not overdo it (not too long, not too steep). When the knees start to hurt, check the sitting geometry and ride gentler and less. Cycling done right is one of the best things to do for your knees (better than running in the city) but still be careful. No exercise is the worst thing though.

  • Protect your back.

    • You say in a comment that you put in a shocked seat post: Essential to have in my opinion.
    • I love to combine that with a saddle with spring (not elastomer, which is not springy enough!) suspension. They tend to be cheap. If possible, a gel saddle. These saddles tend to be ugly and bulky and seem out of place on a "sporty" bike. Bike stores often don't carry them. But they serve me well.
    • Lift your behind off the saddle when going over bumps.
    • Do not ride too upright (the back should probably be around 45°).

    All these measures and components together absorb shocks and vibrations at different frequencies which would otherwise be absorbed by your intervertebral disks.

  • I'm 220 lbs; frames started to break down under me every few years when I exceeded 80 kg (180 lbs) and was riding a lot (100 km a week?). Spokes on the back wheel can be an issue. Pay attention that all spokes are under proper tension. If you ride up curbs, make sure to be slow and take the weight off the respective wheel going up, no matter the bike.

In my experience it is best if bicycling is an integrated part of everyday life. For example:

  • One can get a surprising amount of food home from the supermarket with two large panniers, a box on the bike rack (which you have!) and a large backpack. I secure the box with an old inner tube that I attach to the saddle post and hook behind the back of the bike rack. (For sake of your back, the light items should go into the backpack and the beer in the panniers or box.) When I went to Costco by bike in Portland and had huge bags of toilet paper on the bike rack I got some nice reactions by SUV drivers in the parking lot — "that's what I call commitment!" :-). I sometimes abuse our child trailer, too.
  • Sometimes work is within bicycle range.
  • Sometimes the gym is.
  • Sometimes the bar is. I love riding home in the fresh air after a few drinks. The city at night is a much better place to ride your bike, it is a great opportunity to wind down, and it clears the head nicely. Plus you can (moderately) drink and ride but not drive.
  • Sometimes your kids's school is (they can ride their own bikes with you).
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  • Thank you yes, inaddition to a shocked seat post I got a spring seat with gell. So I hope that is covered. I will look at bigger tires based on clearance, that seems to be a common suggestion. That should be more forgiving.
    – Zarxs
    Sep 18, 2023 at 19:09
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    »Plus you can (moderately) drink and ride but not drive.« – this depends on the jurisdiction, so check the laws in your country about this. (In Germany, you can lose your (car's) drivers licence when caught biking drunk, though I'm not sure whether the threshold is the same as for cars.) Sep 18, 2023 at 23:44
  • @PaŭloEbermann that's a good point, but so is Peter's. I'm not rare among my friends in having a personal rule of "not even one drink" when driving but being willing to ride after one or two - probably within the legal limit for driving but only just.
    – Chris H
    Sep 28, 2023 at 5:34
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I agree that the fork is probably not cost effective to replace, and that it won't add much benefit - you would also need to remember that suspension forks need maintenance, which is costly.

In addition to the other advice, I'd focus on the wheels. The stock tire that came with the bike is probably 32mm. 25mm is what you put on a racing bike, and it would have been a bad choice for an original spec. Rigid bikes get their suspension from the tires - they don't need other suspension mechanisms. As a heavier rider, you definitely want 32mm tires. In fact, you should consider getting a wider tire if your bike has space for it. This answer shows how you can stick an allen wrench between the tire and the frame or fork to see how much clearance you have. If you're not comfortable doing this, you can ask the bike shop what tires you can fit.

How much pressure? Criggie said around 60 PSI, which is probably correct. In more detail, less pressure means more comfortable, which is good, but you also don't want so little pressure that you hit a crack in the road and damage the rim or cause a pinch flat. I don't have personal experience with your situation. I frequently use the Silca tire pressure calculator, but it is configured for cyclists on performance bikes and it shows the pressure to minimize rolling resistance. I entered some likely parameters for your bike, and it says 62 PSI front and 64 rear. You should consider these as maximum pressures for 32mm tires. I would go a bit lower. I will guess that 58 PSI front and 60 rear should be more comfortable. This will increase your rolling resistance, but not by much. If you don't believe me, no problem, just follow what Criggie said.

Back to the wheels themselves, OEM wheels are not going to be designed for very heavy riders, for better or worse. They are not always well built. If you experience repeated issues with yours coming out of true, consider having a good shop build you a set of stout ones. You would be talking 36 spokes or more, depending on the rim. Hopefully, big tires can help you avoid this upgrade.

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  • Silca can come in lower than manufacturers recommend, so you have to choose whether to follow it that low. I tend to use a mix of surfaces and tube types in their calculator, and go for not the lowest in the spread - but my rides often include varying surfaces
    – Chris H
    Sep 16, 2023 at 14:48
  • I tend to aim for the larger tick marks on the pressure gauge, which are often Tens.
    – Criggie
    Sep 16, 2023 at 21:49
  • You are right, it turns out the standard tire on it was 32mm and after reading more I could go to a 47mm if I have the right clearances. The dealer, after switching my tires out 10 years ago suggested I go 5 ibs over rated for my weight. I put good quality tires on it so I don't know if that makes that accommodates the advice they gave.
    – Zarxs
    Sep 18, 2023 at 19:07
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I hope my answer can help, i'll write it pretty simple and short

  1. If you wonder wether your bike can handle your weight you can check with the manufacturer (website) or at the bike shop with experienced mechanic.
  2. If possible, opt for wider tires (up to 40-50mm) buy also check if your rim width is compatible with it. It should increase comfort if pressurized right, use tire pressure calculator and insert your spesifications (tire, terrain, weight). It should give you rough estimation/starting points to your tire pressure. Wider tire also prevents flat tire and broken wheels/frame as it absorb more shock, and provide more traction.
  3. Replacing the fork with shock can alter the bike geometry, weight and force distribution through the frame, so it can cause frame to crack or even fails entirely on the joint/welding.
  4. Another option for comfort is the saddle. You can experiment and finds what saddle is right for you. Typically, saddle manufacturer stated the purpose of the saddle on the cardboard the saddle come with it. Rule of thumb: wider saddle used for more upright (70-90° to the ground) riding while narrower for more aggressive position (45-70°). You can also buy seatpost suspension although it's more expensive. Seatpost suspension is safer than changing the fork as it doesn't alter the geometry.

In the end it is safe to ride your bike as long as you don't hit a hole/curb to hard and if you ride regularly i can guarantee you'll lose weight (i have a friend who weighted 140kg, now he's 70 all from riding a bike) and the problem you dealwith/corcern with is no longer relevant then. Hope you enjoy riding!!!

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